Merge branch 'master' into feature_target_filtering_supports_overdue

Conflicts:
	hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/JpaTargetManagement.java

README.md

@@ -1,11 +1,12 @@
-Build: [![Circle CI](https://circleci.com/gh/eclipse/hawkbit.svg?style=svg)](https://circleci.com/gh/eclipse/hawkbit)
-
 <img src=hawkbit_logo.png width=533 height=246 />
 
 # Eclipse.IoT hawkBit - Update Server
 
 [hawkBit](https://projects.eclipse.org/projects/iot.hawkbit) is an domain independent back end solution for rolling out software updates to constrained edge devices as well as more powerful controllers and gateways connected to IP based networking infrastructure.
 
+Build: [![Circle CI](https://circleci.com/gh/eclipse/hawkbit.svg?style=shield)](https://circleci.com/gh/eclipse/hawkbit) 
+[![SonarQuality](https://sonar.eu-gb.mybluemix.net/api/badges/gate?key=org.eclipse.hawkbit:hawkbit-parent)](https://sonar.eu-gb.mybluemix.net)
+
 # Documentation
 
 see [hawkBit Wiki](https://github.com/eclipse/hawkbit/wiki)

examples/hawkbit-custom-theme-example/src/main/java/org/eclipse/hawkbit/app/MyUI.java

@@ -8,6 +8,8 @@ package org.eclipse.hawkbit.app;
  * http://www.eclipse.org/legal/epl-v10.html
  */
 
+import java.util.concurrent.ScheduledExecutorService;
+
 import org.eclipse.hawkbit.ui.HawkbitUI;
 import org.eclipse.hawkbit.ui.UIEventProvider;
 import org.eclipse.hawkbit.ui.push.DelayedEventBusPushStrategy;
@@ -38,8 +40,8 @@ public class MyUI extends HawkbitUI {
     private static final long serialVersionUID = 1L;
 
     @Autowired
-    public MyUI(final EventBus systemEventBus, final org.vaadin.spring.events.EventBus.SessionEventBus eventBus,
+    public MyUI(final ScheduledExecutorService executorService, final EventBus systemEventBus,
-            final UIEventProvider provider) {
+            final org.vaadin.spring.events.EventBus.SessionEventBus eventBus, final UIEventProvider provider) {
-        super(new DelayedEventBusPushStrategy(eventBus, systemEventBus, provider));
+        super(new DelayedEventBusPushStrategy(executorService, eventBus, systemEventBus, provider));
     }
 }

examples/hawkbit-device-simulator/src/main/java/org/eclipse/hawkbit/simulator/amqp/AmqpConfiguration.java

@@ -11,7 +11,6 @@ package org.eclipse.hawkbit.simulator.amqp;
 import static org.eclipse.hawkbit.simulator.amqp.AmqpProperties.CONFIGURATION_PREFIX;
 
 import java.time.Duration;
-import java.util.HashMap;
 import java.util.Map;
 
 import org.slf4j.Logger;
@@ -36,6 +35,8 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.retry.backoff.ExponentialBackOffPolicy;
 import org.springframework.retry.support.RetryTemplate;
 
+import com.google.common.collect.Maps;
+
 /**
  * The spring AMQP configuration to use a AMQP for communication with SP update
  * server.
@@ -200,13 +201,13 @@ public class AmqpConfiguration {
     }
 
     private Map<String, Object> getDeadLetterExchangeArgs() {
-        final Map<String, Object> args = new HashMap<>();
+        final Map<String, Object> args = Maps.newHashMapWithExpectedSize(1);
         args.put("x-dead-letter-exchange", amqpProperties.getDeadLetterExchange());
         return args;
     }
 
     private static Map<String, Object> getTTLMaxArgs() {
-        final Map<String, Object> args = new HashMap<>();
+        final Map<String, Object> args = Maps.newHashMapWithExpectedSize(2);
         args.put("x-message-ttl", Duration.ofDays(1).toMillis());
         args.put("x-max-length", 100_000);
         return args;

examples/hawkbit-example-app/src/main/java/org/eclipse/hawkbit/app/MyUI.java

@@ -8,6 +8,8 @@
  */
 package org.eclipse.hawkbit.app;
 
+import java.util.concurrent.ScheduledExecutorService;
+
 import org.eclipse.hawkbit.ui.HawkbitUI;
 import org.eclipse.hawkbit.ui.UIEventProvider;
 import org.eclipse.hawkbit.ui.push.DelayedEventBusPushStrategy;
@@ -37,8 +39,8 @@ public class MyUI extends HawkbitUI {
     private static final long serialVersionUID = 1L;
 
     @Autowired
-    public MyUI(final EventBus systemEventBus, final org.vaadin.spring.events.EventBus.SessionEventBus eventBus,
+    public MyUI(final ScheduledExecutorService scheduledExecutorService, final EventBus systemEventBus,
-            final UIEventProvider provider) {
+            final org.vaadin.spring.events.EventBus.SessionEventBus eventBus, final UIEventProvider provider) {
-        super(new DelayedEventBusPushStrategy(eventBus, systemEventBus, provider));
+        super(new DelayedEventBusPushStrategy(scheduledExecutorService, eventBus, systemEventBus, provider));
     }
 }

hawkbit-autoconfigure/src/main/java/org/eclipse/hawkbit/autoconfigure/url/PropertyHostnameResolverAutoConfiguration.java

@@ -41,14 +41,11 @@ public class PropertyHostnameResolverAutoConfiguration {
     @Bean
     @ConditionalOnMissingBean(value = HostnameResolver.class)
     public HostnameResolver hostnameResolver() {
-        return new HostnameResolver() {
+        return () -> {
-            @Override
+            try {
-            public URL resolveHostname() {
+                return new URL(serverProperties.getUrl());
-                try {
+            } catch (final MalformedURLException e) {
-                    return new URL(serverProperties.getUrl());
+                throw Throwables.propagate(e);
-                } catch (final MalformedURLException e) {
-                    throw Throwables.propagate(e);
-                }
             }
         };
     }

hawkbit-ddi-api/src/main/java/org/eclipse/hawkbit/ddi/rest/api/DdiRootControllerRestApi.java

@@ -37,7 +37,9 @@ public interface DdiRootControllerRestApi {
 
     /**
      * Returns all artifacts of a given software module and target.
-     *
+     * 
+     * @param tenant
+     *            of the request
      * @param targetid
      *            of the target that matches to controller id
      * @param softwareModuleId
@@ -53,6 +55,8 @@ public interface DdiRootControllerRestApi {
     /**
      * Root resource for an individual {@link Target}.
      *
+     * @param tenant
+     *            of the request
      * @param targetid
      *            of the target that matches to controller id
      * @param request
@@ -68,6 +72,8 @@ public interface DdiRootControllerRestApi {
      * Handles GET {@link DdiArtifact} download request. This could be full or
      * partial (as specified by RFC7233 (Range Requests)) download request.
      *
+     * @param tenant
+     *            of the request
      * @param targetid
      *            of the related target
      * @param softwareModuleId
@@ -92,6 +98,8 @@ public interface DdiRootControllerRestApi {
     /**
      * Handles GET {@link DdiArtifact} MD5 checksum file download request.
      *
+     * @param tenant
+     *            of the request
      * @param targetid
      *            of the related target
      * @param softwareModuleId
@@ -116,6 +124,8 @@ public interface DdiRootControllerRestApi {
     /**
      * Resource for software module.
      *
+     * @param tenant
+     *            of the request
      * @param targetid
      *            of the target that matches to controller id
      * @param actionId
@@ -139,6 +149,8 @@ public interface DdiRootControllerRestApi {
     /**
      * This is the feedback channel for the {@link DdiDeploymentBase} action.
      *
+     * @param tenant
+     *            of the request
      * @param feedback
      *            to provide
      * @param targetid
@@ -159,6 +171,8 @@ public interface DdiRootControllerRestApi {
     /**
      * This is the feedback channel for the config data action.
      *
+     * @param tenant
+     *            of the request
      * @param configData
      *            as body
      * @param targetid
@@ -176,6 +190,8 @@ public interface DdiRootControllerRestApi {
     /**
      * RequestMethod.GET method for the {@link DdiCancel} action.
      *
+     * @param tenant
+     *            of the request
      * @param targetid
      *            ID of the calling target
      * @param actionId
@@ -195,6 +211,8 @@ public interface DdiRootControllerRestApi {
      * RequestMethod.POST method receiving the {@link DdiActionFeedback} from
      * the target.
      *
+     * @param tenant
+     *            of the request
      * @param feedback
      *            the {@link DdiActionFeedback} from the target.
      * @param targetid

hawkbit-ddi-resource/src/main/java/org/eclipse/hawkbit/ddi/rest/resource/DataConversionHelper.java

@@ -12,7 +12,6 @@ import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;
 
 import java.io.IOException;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
 import java.util.stream.Collectors;
@@ -73,16 +72,16 @@ public final class DataConversionHelper {
      *            of the target
      * @param module
      *            the software module
+     * @param artifactUrlHandler
+     *            for creating download URLs
      * @return a list of artifacts or a empty list. Cannot be <null>.
      */
     public static List<DdiArtifact> createArtifacts(final String targetid,
             final org.eclipse.hawkbit.repository.model.SoftwareModule module,
             final ArtifactUrlHandler artifactUrlHandler) {
-        final List<DdiArtifact> files = new ArrayList<>();
 
-        module.getLocalArtifacts()
+        return module.getLocalArtifacts().stream()
-                .forEach(artifact -> files.add(createArtifact(targetid, artifactUrlHandler, artifact)));
+                .map(artifact -> createArtifact(targetid, artifactUrlHandler, artifact)).collect(Collectors.toList());
-        return files;
     }
 
     private static DdiArtifact createArtifact(final String targetid, final ArtifactUrlHandler artifactUrlHandler,

hawkbit-ddi-resource/src/main/java/org/eclipse/hawkbit/ddi/rest/resource/DdiArtifactStoreController.java

@@ -35,7 +35,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Scope;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
-import org.springframework.security.web.bind.annotation.AuthenticationPrincipal;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.context.WebApplicationContext;

hawkbit-ddi-resource/src/main/java/org/eclipse/hawkbit/ddi/rest/resource/DdiRootController.java

@@ -151,7 +151,12 @@ public class DdiRootController implements DdiRootControllerRestApi {
             LOG.warn("Softare module with id {} could not be found.", softwareModuleId);
             result = new ResponseEntity<>(HttpStatus.NOT_FOUND);
         } else {
+
+            // Exception squid:S3655 - Optional access is checked in checkModule
+            // subroutine
+            @SuppressWarnings("squid:S3655")
             final LocalArtifact artifact = module.getLocalArtifactByFilename(fileName).get();
+
             final DbArtifact file = artifactManagement.loadLocalArtifactBinary(artifact);
 
             final String ifMatch = requestResponseContextHolder.getHttpServletRequest().getHeader("If-Match");
@@ -196,6 +201,9 @@ public class DdiRootController implements DdiRootControllerRestApi {
     }
 
     @Override
+    // Exception squid:S3655 - Optional access is checked in checkModule
+    // subroutine
+    @SuppressWarnings("squid:S3655")
     public ResponseEntity<Void> downloadArtifactMd5(@PathVariable("tenant") final String tenant,
             @PathVariable("targetid") final String targetid,
             @PathVariable("softwareModuleId") final Long softwareModuleId,

hawkbit-dmf-amqp/src/main/java/org/eclipse/hawkbit/amqp/AmqpConfiguration.java

@@ -9,7 +9,6 @@
 package org.eclipse.hawkbit.amqp;
 
 import java.time.Duration;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.Executor;
 import java.util.concurrent.ScheduledExecutorService;
@@ -47,6 +46,8 @@ import org.springframework.retry.backoff.ExponentialBackOffPolicy;
 import org.springframework.retry.support.RetryTemplate;
 import org.springframework.util.ErrorHandler;
 
+import com.google.common.collect.Maps;
+
 /**
  * Spring configuration for AMQP 0.9 based DMF communication for indirect device
  * integration.
@@ -306,7 +307,7 @@ public class AmqpConfiguration {
     }
 
     private static Map<String, Object> getTTLMaxArgsAuthenticationQueue() {
-        final Map<String, Object> args = new HashMap<>();
+        final Map<String, Object> args = Maps.newHashMapWithExpectedSize(2);
         args.put("x-message-ttl", Duration.ofSeconds(30).toMillis());
         args.put("x-max-length", 1_000);
         return args;

hawkbit-dmf-amqp/src/main/java/org/eclipse/hawkbit/amqp/AmqpDeadletterProperties.java

@@ -9,24 +9,26 @@
 package org.eclipse.hawkbit.amqp;
 
 import java.time.Duration;
-import java.util.HashMap;
 import java.util.Map;
 
 import org.springframework.amqp.core.Queue;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
+import com.google.common.collect.Maps;
+
 /**
  * Bean which holds the necessary properties for configuring the AMQP deadletter
  * queue.
  */
 @ConfigurationProperties("hawkbit.dmf.rabbitmq.deadLetter")
 public class AmqpDeadletterProperties {
+    private static final int THREE_WEEKS = 21;
 
     /**
      * Message time to live (ttl) for the deadletter queue. Default ttl is 3
      * weeks.
      */
-    private long ttl = Duration.ofDays(21).toMillis();
+    private long ttl = Duration.ofDays(THREE_WEEKS).toMillis();
 
     /**
      * Return the deadletter arguments.
@@ -36,7 +38,7 @@ public class AmqpDeadletterProperties {
      * @return map which holds the properties
      */
     public Map<String, Object> getDeadLetterExchangeArgs(final String exchange) {
-        final Map<String, Object> args = new HashMap<>();
+        final Map<String, Object> args = Maps.newHashMapWithExpectedSize(1);
         args.put("x-dead-letter-exchange", exchange);
         return args;
     }
@@ -53,7 +55,7 @@ public class AmqpDeadletterProperties {
     }
 
     private Map<String, Object> getTTLArgs() {
-        final Map<String, Object> args = new HashMap<>();
+        final Map<String, Object> args = Maps.newHashMapWithExpectedSize(1);
         args.put("x-message-ttl", getTtl());
         return args;
     }

hawkbit-dmf-amqp/src/main/java/org/eclipse/hawkbit/amqp/AmqpProperties.java

@@ -20,6 +20,16 @@ import org.springframework.boot.context.properties.ConfigurationProperties;
 @ConfigurationProperties("hawkbit.dmf.rabbitmq")
 public class AmqpProperties {
 
+    private static final int ONE_MINUTE = 60;
+
+    private static final int DEFAULT_QUEUE_DECLARATION_RETRIES = 50;
+
+    private static final int DEFAULT_INITIAL_CONSUMERS = 3;
+
+    private static final int DEFAULT_PREFETCH_COUNT = 10;
+
+    private static final int DEFAULT_MAX_CONSUMERS = 10;
+
     /**
      * Enable DMF API based on AMQP 0.9
      */
@@ -54,24 +64,24 @@ public class AmqpProperties {
     /**
      * Requested heartbeat interval from broker in {@link TimeUnit#SECONDS}.
      */
-    private int requestedHeartBeat = (int) TimeUnit.SECONDS.toSeconds(60);
+    private int requestedHeartBeat = (int) TimeUnit.SECONDS.toSeconds(ONE_MINUTE);
 
     /**
      * Sets an upper limit to the number of consumers.
      */
-    private int maxConcurrentConsumers = 10;
+    private int maxConcurrentConsumers = DEFAULT_MAX_CONSUMERS;
 
     /**
      * Tells the broker how many messages to send to each consumer in a single
      * request. Often this can be set quite high to improve throughput.
      */
-    private int prefetchCount = 10;
+    private int prefetchCount = DEFAULT_PREFETCH_COUNT;
 
     /**
      * Initial number of consumers. Is scaled up if necessary up to
      * {@link #maxConcurrentConsumers}.
      */
-    private int initialConcurrentConsumers = 3;
+    private int initialConcurrentConsumers = DEFAULT_INITIAL_CONSUMERS;
 
     /**
      * The number of retry attempts when passive queue declaration fails.
@@ -79,7 +89,7 @@ public class AmqpProperties {
      * consuming from multiple queues, when not all queues were available during
      * initialization.
      */
-    private int declarationRetries = 50;
+    private int declarationRetries = DEFAULT_QUEUE_DECLARATION_RETRIES;
 
     public int getDeclarationRetries() {
         return declarationRetries;

hawkbit-mgmt-resource/src/main/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtDistributionSetMapper.java

@@ -12,7 +12,10 @@ import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;
 
 import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.eclipse.hawkbit.mgmt.json.model.MgmtMetadata;
 import org.eclipse.hawkbit.mgmt.json.model.distributionset.MgmtDistributionSet;
@@ -34,10 +37,6 @@ import org.eclipse.hawkbit.repository.model.SoftwareModule;
 /**
  * A mapper which maps repository model to RESTful model representation and
  * back.
- *
- *
- *
- *
  */
 public final class MgmtDistributionSetMapper {
     private MgmtDistributionSetMapper() {
@@ -75,15 +74,13 @@ public final class MgmtDistributionSetMapper {
      *            to use for conversion
      * @return converted list of {@link DistributionSet}s
      */
-    static List<DistributionSet> dsFromRequest(final Iterable<MgmtDistributionSetRequestBodyPost> sets,
+    static List<DistributionSet> dsFromRequest(final Collection<MgmtDistributionSetRequestBodyPost> sets,
             final SoftwareManagement softwareManagement, final DistributionSetManagement distributionSetManagement,
             final EntityFactory entityFactory) {
 
-        final List<DistributionSet> mappedList = new ArrayList<>();
+        return sets.stream()
-        for (final MgmtDistributionSetRequestBodyPost dsRest : sets) {
+                .map(dsRest -> fromRequest(dsRest, softwareManagement, distributionSetManagement, entityFactory))
-            mappedList.add(fromRequest(dsRest, softwareManagement, distributionSetManagement, entityFactory));
+                .collect(Collectors.toList());
-        }
-        return mappedList;
 
     }
 
@@ -139,15 +136,12 @@ public final class MgmtDistributionSetMapper {
      */
     static List<DistributionSetMetadata> fromRequestDsMetadata(final DistributionSet ds,
             final List<MgmtMetadata> metadata, final EntityFactory entityFactory) {
-        final List<DistributionSetMetadata> mappedList = new ArrayList<>(metadata.size());
+        if (metadata == null) {
-        for (final MgmtMetadata metadataRest : metadata) {
+            return Collections.emptyList();
-            if (metadataRest.getKey() == null) {
-                throw new IllegalArgumentException("the key of the metadata must be present");
-            }
-            mappedList.add(
-                    entityFactory.generateDistributionSetMetadata(ds, metadataRest.getKey(), metadataRest.getValue()));
         }
-        return mappedList;
+
+        return metadata.stream().map(metadataRest -> entityFactory.generateDistributionSetMetadata(ds,
+                metadataRest.getKey(), metadataRest.getValue())).collect(Collectors.toList());
     }
 
     /**
@@ -196,15 +190,12 @@ public final class MgmtDistributionSetMapper {
         return result;
     }
 
-    static List<MgmtDistributionSet> toResponseDistributionSets(final Iterable<DistributionSet> sets) {
+    static List<MgmtDistributionSet> toResponseDistributionSets(final Collection<DistributionSet> sets) {
-        final List<MgmtDistributionSet> response = new ArrayList<>();
+        if (sets == null) {
-        if (sets != null) {
+            return Collections.emptyList();
-
-            for (final DistributionSet set : sets) {
-                response.add(toResponse(set));
-            }
         }
-        return response;
+
+        return sets.stream().map(MgmtDistributionSetMapper::toResponse).collect(Collectors.toList());
     }
 
     static MgmtMetadata toResponseDsMetadata(final DistributionSetMetadata metadata) {
@@ -224,14 +215,10 @@ public final class MgmtDistributionSetMapper {
     }
 
     static List<MgmtDistributionSet> toResponseFromDsList(final List<DistributionSet> sets) {
-        final List<MgmtDistributionSet> mappedList = new ArrayList<>();
+        if (sets == null) {
-        if (sets != null) {
+            return Collections.emptyList();
-            for (final DistributionSet set : sets) {
-                final MgmtDistributionSet response = toResponse(set);
-
-                mappedList.add(response);
-            }
         }
-        return mappedList;
+
+        return sets.stream().map(MgmtDistributionSetMapper::toResponse).collect(Collectors.toList());
     }
 }

hawkbit-mgmt-resource/src/main/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtDistributionSetResource.java

@@ -8,6 +8,7 @@
  */
 package org.eclipse.hawkbit.mgmt.rest.resource;
 
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -123,7 +124,7 @@ public class MgmtDistributionSetResource implements MgmtDistributionSetRestApi {
                 .runAsSystem(() -> this.systemManagement.getTenantMetadata().getDefaultDsType().getKey());
         sets.stream().filter(ds -> ds.getType() == null).forEach(ds -> ds.setType(defaultDsKey));
 
-        final Iterable<DistributionSet> createdDSets = this.distributionSetManagement
+        final Collection<DistributionSet> createdDSets = this.distributionSetManagement
                 .createDistributionSets(MgmtDistributionSetMapper.dsFromRequest(sets, this.softwareManagement,
                         this.distributionSetManagement, entityFactory));
 

hawkbit-mgmt-resource/src/main/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtDistributionSetTypeMapper.java

@@ -11,8 +11,10 @@ package org.eclipse.hawkbit.mgmt.rest.resource;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;
 
-import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.eclipse.hawkbit.mgmt.json.model.distributionsettype.MgmtDistributionSetType;
 import org.eclipse.hawkbit.mgmt.json.model.distributionsettype.MgmtDistributionSetTypeRequestBodyPost;
@@ -39,13 +41,13 @@ final class MgmtDistributionSetTypeMapper {
 
     static List<DistributionSetType> smFromRequest(final EntityFactory entityFactory,
             final SoftwareManagement softwareManagement,
-            final Iterable<MgmtDistributionSetTypeRequestBodyPost> smTypesRest) {
+            final Collection<MgmtDistributionSetTypeRequestBodyPost> smTypesRest) {
-        final List<DistributionSetType> mappedList = new ArrayList<>();
+        if (smTypesRest == null) {
-
+            return Collections.emptyList();
-        for (final MgmtDistributionSetTypeRequestBodyPost smRest : smTypesRest) {
-            mappedList.add(fromRequest(entityFactory, softwareManagement, smRest));
         }
-        return mappedList;
+
+        return smTypesRest.stream().map(smRest -> fromRequest(entityFactory, softwareManagement, smRest))
+                .collect(Collectors.toList());
     }
 
     static DistributionSetType fromRequest(final EntityFactory entityFactory,
@@ -91,19 +93,19 @@ final class MgmtDistributionSetTypeMapper {
     }
 
     static List<MgmtDistributionSetType> toTypesResponse(final List<DistributionSetType> types) {
-        final List<MgmtDistributionSetType> response = new ArrayList<>();
+        if (types == null) {
-        for (final DistributionSetType dsType : types) {
+            return Collections.emptyList();
-            response.add(toResponse(dsType));
         }
-        return response;
+
+        return types.stream().map(MgmtDistributionSetTypeMapper::toResponse).collect(Collectors.toList());
     }
 
     static List<MgmtDistributionSetType> toListResponse(final List<DistributionSetType> types) {
-        final List<MgmtDistributionSetType> response = new ArrayList<>();
+        if (types == null) {
-        for (final DistributionSetType dsType : types) {
+            return Collections.emptyList();
-            response.add(toResponse(dsType));
         }
-        return response;
+
+        return types.stream().map(MgmtDistributionSetTypeMapper::toResponse).collect(Collectors.toList());
     }
 
     static MgmtDistributionSetType toResponse(final DistributionSetType type) {

hawkbit-mgmt-resource/src/main/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtDistributionSetTypeResource.java

@@ -8,6 +8,12 @@
  */
 package org.eclipse.hawkbit.mgmt.rest.resource;
 
+import static org.eclipse.hawkbit.mgmt.rest.resource.MgmtDistributionSetTypeMapper.toResponse;
+import static org.eclipse.hawkbit.mgmt.rest.resource.MgmtDistributionSetTypeMapper.toTypesResponse;
+import static org.eclipse.hawkbit.mgmt.rest.resource.MgmtSoftwareModuleTypeMapper.toResponse;
+import static org.eclipse.hawkbit.mgmt.rest.resource.MgmtSoftwareModuleTypeMapper.toTypesResponse;
+import static org.springframework.http.HttpStatus.CREATED;
+
 import java.util.List;
 
 import org.eclipse.hawkbit.mgmt.json.model.MgmtId;
@@ -32,7 +38,6 @@ import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Slice;
 import org.springframework.data.domain.Sort;
-import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestBody;
@@ -42,8 +47,6 @@ import org.springframework.web.bind.annotation.RestController;
 /**
  * REST Resource handling for {@link SoftwareModule} and related
  * {@link Artifact} CRUD operations.
- *
- *
  */
 @RestController
 public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeRestApi {
@@ -67,7 +70,6 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
         final int sanitizedOffsetParam = PagingUtility.sanitizeOffsetParam(pagingOffsetParam);
         final int sanitizedLimitParam = PagingUtility.sanitizePageLimitParam(pagingLimitParam);
         final Sort sorting = PagingUtility.sanitizeDistributionSetTypeSortParam(sortParam);
-
         final Pageable pageable = new OffsetBasedPageRequest(sanitizedOffsetParam, sanitizedLimitParam, sorting);
 
         final Slice<DistributionSetType> findModuleTypessAll;
@@ -82,31 +84,32 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
 
         final List<MgmtDistributionSetType> rest = MgmtDistributionSetTypeMapper
                 .toListResponse(findModuleTypessAll.getContent());
-        return new ResponseEntity<>(new PagedList<>(rest, countModulesAll), HttpStatus.OK);
+        return ResponseEntity.ok(new PagedList<>(rest, countModulesAll));
     }
 
     @Override
     public ResponseEntity<MgmtDistributionSetType> getDistributionSetType(
             @PathVariable("distributionSetTypeId") final Long distributionSetTypeId) {
-        final DistributionSetType foundType = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
 
-        return new ResponseEntity<>(MgmtDistributionSetTypeMapper.toResponse(foundType), HttpStatus.OK);
+        final DistributionSetType foundType = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
+        return ResponseEntity.ok(toResponse(foundType));
     }
 
     @Override
     public ResponseEntity<Void> deleteDistributionSetType(
             @PathVariable("distributionSetTypeId") final Long distributionSetTypeId) {
-        final DistributionSetType module = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
 
+        final DistributionSetType module = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
         distributionSetManagement.deleteDistributionSetType(module);
 
-        return new ResponseEntity<>(HttpStatus.OK);
+        return ResponseEntity.ok().build();
     }
 
     @Override
     public ResponseEntity<MgmtDistributionSetType> updateDistributionSetType(
             @PathVariable("distributionSetTypeId") final Long distributionSetTypeId,
             @RequestBody final MgmtDistributionSetTypeRequestBodyPut restDistributionSetType) {
+
         final DistributionSetType type = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
 
         // only description can be modified
@@ -117,8 +120,7 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
         final DistributionSetType updatedDistributionSetType = distributionSetManagement
                 .updateDistributionSetType(type);
 
-        return new ResponseEntity<>(MgmtDistributionSetTypeMapper.toResponse(updatedDistributionSetType),
+        return ResponseEntity.ok(toResponse(updatedDistributionSetType));
-                HttpStatus.OK);
     }
 
     @Override
@@ -128,16 +130,17 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
         final List<DistributionSetType> createdSoftwareModules = distributionSetManagement.createDistributionSetTypes(
                 MgmtDistributionSetTypeMapper.smFromRequest(entityFactory, softwareManagement, distributionSetTypes));
 
-        return new ResponseEntity<>(MgmtDistributionSetTypeMapper.toTypesResponse(createdSoftwareModules),
+        return ResponseEntity.status(CREATED).body(toTypesResponse(createdSoftwareModules));
-                HttpStatus.CREATED);
     }
 
     private DistributionSetType findDistributionSetTypeWithExceptionIfNotFound(final Long distributionSetTypeId) {
+
         final DistributionSetType module = distributionSetManagement.findDistributionSetTypeById(distributionSetTypeId);
         if (module == null) {
             throw new EntityNotFoundException(
                     "DistributionSetType with Id {" + distributionSetTypeId + "} does not exist");
         }
+
         return module;
     }
 
@@ -146,8 +149,7 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
             @PathVariable("distributionSetTypeId") final Long distributionSetTypeId) {
 
         final DistributionSetType foundType = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
-        return new ResponseEntity<>(MgmtSoftwareModuleTypeMapper.toListResponse(foundType.getMandatoryModuleTypes()),
+        return ResponseEntity.ok(toTypesResponse(foundType.getMandatoryModuleTypes()));
-                HttpStatus.OK);
     }
 
     @Override
@@ -156,7 +158,6 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
             @PathVariable("softwareModuleTypeId") final Long softwareModuleTypeId) {
 
         final DistributionSetType foundType = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
-
         final SoftwareModuleType foundSmType = findSoftwareModuleTypeWithExceptionIfNotFound(softwareModuleTypeId);
 
         if (!foundType.containsMandatoryModuleType(foundSmType)) {
@@ -164,7 +165,7 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
                     "Software module with given ID is not part of this distribution set type!");
         }
 
-        return new ResponseEntity<>(MgmtSoftwareModuleTypeMapper.toResponse(foundSmType), HttpStatus.OK);
+        return ResponseEntity.ok(toResponse(foundSmType));
     }
 
     @Override
@@ -173,7 +174,6 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
             @PathVariable("softwareModuleTypeId") final Long softwareModuleTypeId) {
 
         final DistributionSetType foundType = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
-
         final SoftwareModuleType foundSmType = findSoftwareModuleTypeWithExceptionIfNotFound(softwareModuleTypeId);
 
         if (!foundType.containsOptionalModuleType(foundSmType)) {
@@ -181,7 +181,7 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
                     "Software module with given ID is not part of this distribution set type!");
         }
 
-        return new ResponseEntity<>(MgmtSoftwareModuleTypeMapper.toResponse(foundSmType), HttpStatus.OK);
+        return ResponseEntity.ok(toResponse(foundSmType));
     }
 
     @Override
@@ -189,9 +189,7 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
             @PathVariable("distributionSetTypeId") final Long distributionSetTypeId) {
 
         final DistributionSetType foundType = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
-
+        return ResponseEntity.ok(toTypesResponse(foundType.getOptionalModuleTypes()));
-        return new ResponseEntity<>(MgmtSoftwareModuleTypeMapper.toListResponse(foundType.getOptionalModuleTypes()),
-                HttpStatus.OK);
     }
 
     @Override
@@ -200,7 +198,6 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
             @PathVariable("softwareModuleTypeId") final Long softwareModuleTypeId) {
 
         final DistributionSetType foundType = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
-
         final SoftwareModuleType foundSmType = findSoftwareModuleTypeWithExceptionIfNotFound(softwareModuleTypeId);
 
         if (!foundType.containsMandatoryModuleType(foundSmType)) {
@@ -209,18 +206,17 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
         }
 
         foundType.removeModuleType(softwareModuleTypeId);
-
         distributionSetManagement.updateDistributionSetType(foundType);
 
-        return new ResponseEntity<>(HttpStatus.OK);
+        return ResponseEntity.ok().build();
     }
 
     @Override
     public ResponseEntity<Void> removeOptionalModule(
             @PathVariable("distributionSetTypeId") final Long distributionSetTypeId,
             @PathVariable("softwareModuleTypeId") final Long softwareModuleTypeId) {
-        final DistributionSetType foundType = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
 
+        final DistributionSetType foundType = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
         final SoftwareModuleType foundSmType = findSoftwareModuleTypeWithExceptionIfNotFound(softwareModuleTypeId);
 
         if (!foundType.containsOptionalModuleType(foundSmType)) {
@@ -229,10 +225,9 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
         }
 
         foundType.removeModuleType(softwareModuleTypeId);
-
         distributionSetManagement.updateDistributionSetType(foundType);
 
-        return new ResponseEntity<>(HttpStatus.OK);
+        return ResponseEntity.ok().build();
     }
 
     @Override
@@ -240,14 +235,11 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
             @PathVariable("distributionSetTypeId") final Long distributionSetTypeId, @RequestBody final MgmtId smtId) {
 
         final DistributionSetType foundType = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
-
         final SoftwareModuleType smType = findSoftwareModuleTypeWithExceptionIfNotFound(smtId.getId());
-
         foundType.addMandatoryModuleType(smType);
-
         distributionSetManagement.updateDistributionSetType(foundType);
 
-        return new ResponseEntity<>(HttpStatus.OK);
+        return ResponseEntity.ok().build();
     }
 
     @Override
@@ -255,23 +247,22 @@ public class MgmtDistributionSetTypeResource implements MgmtDistributionSetTypeR
             @PathVariable("distributionSetTypeId") final Long distributionSetTypeId, @RequestBody final MgmtId smtId) {
 
         final DistributionSetType foundType = findDistributionSetTypeWithExceptionIfNotFound(distributionSetTypeId);
-
         final SoftwareModuleType smType = findSoftwareModuleTypeWithExceptionIfNotFound(smtId.getId());
-
         foundType.addOptionalModuleType(smType);
 
         distributionSetManagement.updateDistributionSetType(foundType);
 
-        return new ResponseEntity<>(HttpStatus.OK);
+        return ResponseEntity.ok().build();
-
     }
 
     private SoftwareModuleType findSoftwareModuleTypeWithExceptionIfNotFound(final Long softwareModuleTypeId) {
+
         final SoftwareModuleType module = softwareManagement.findSoftwareModuleTypeById(softwareModuleTypeId);
         if (module == null) {
             throw new EntityNotFoundException(
                     "SoftwareModuleType with Id {" + softwareModuleTypeId + "} does not exist");
         }
+
         return module;
     }
 }

hawkbit-mgmt-resource/src/main/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtRolloutMapper.java

@@ -11,8 +11,9 @@ package org.eclipse.hawkbit.mgmt.rest.resource;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;
 
-import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.eclipse.hawkbit.mgmt.json.model.rollout.MgmtRolloutCondition.Condition;
 import org.eclipse.hawkbit.mgmt.json.model.rollout.MgmtRolloutErrorAction.ErrorAction;
@@ -48,9 +49,11 @@ final class MgmtRolloutMapper {
     }
 
     static List<MgmtRolloutResponseBody> toResponseRollout(final List<Rollout> rollouts) {
-        final List<MgmtRolloutResponseBody> result = new ArrayList<>(rollouts.size());
+        if (rollouts == null) {
-        rollouts.forEach(r -> result.add(toResponseRollout(r)));
+            return Collections.emptyList();
-        return result;
+        }
+
+        return rollouts.stream().map(MgmtRolloutMapper::toResponseRollout).collect(Collectors.toList());
     }
 
     static MgmtRolloutResponseBody toResponseRollout(final Rollout rollout) {
@@ -103,9 +106,11 @@ final class MgmtRolloutMapper {
     }
 
     static List<MgmtRolloutGroupResponseBody> toResponseRolloutGroup(final List<RolloutGroup> rollouts) {
-        final List<MgmtRolloutGroupResponseBody> result = new ArrayList<>(rollouts.size());
+        if (rollouts == null) {
-        rollouts.forEach(r -> result.add(toResponseRolloutGroup(r)));
+            return Collections.emptyList();
-        return result;
+        }
+
+        return rollouts.stream().map(MgmtRolloutMapper::toResponseRolloutGroup).collect(Collectors.toList());
     }
 
     static MgmtRolloutGroupResponseBody toResponseRolloutGroup(final RolloutGroup rolloutGroup) {

hawkbit-mgmt-resource/src/main/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtSoftwareModuleMapper.java

@@ -11,8 +11,10 @@ package org.eclipse.hawkbit.mgmt.rest.resource;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;
 
-import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.eclipse.hawkbit.mgmt.json.model.MgmtMetadata;
 import org.eclipse.hawkbit.mgmt.json.model.artifact.MgmtArtifact;
@@ -65,60 +67,46 @@ public final class MgmtSoftwareModuleMapper {
     }
 
     static List<SoftwareModuleMetadata> fromRequestSwMetadata(final EntityFactory entityFactory,
-            final SoftwareModule sw, final List<MgmtMetadata> metadata) {
+            final SoftwareModule sw, final Collection<MgmtMetadata> metadata) {
-        final List<SoftwareModuleMetadata> mappedList = new ArrayList<>(metadata.size());
+        if (metadata == null) {
-        for (final MgmtMetadata metadataRest : metadata) {
+            return Collections.emptyList();
-            if (metadataRest.getKey() == null) {
-                throw new IllegalArgumentException("the key of the metadata must be present");
-            }
-            mappedList.add(
-                    entityFactory.generateSoftwareModuleMetadata(sw, metadataRest.getKey(), metadataRest.getValue()));
         }
-        return mappedList;
+
+        return metadata.stream().map(metadataRest -> entityFactory.generateSoftwareModuleMetadata(sw,
+                metadataRest.getKey(), metadataRest.getValue())).collect(Collectors.toList());
     }
 
     static List<SoftwareModule> smFromRequest(final EntityFactory entityFactory,
-            final Iterable<MgmtSoftwareModuleRequestBodyPost> smsRest, final SoftwareManagement softwareManagement) {
+            final Collection<MgmtSoftwareModuleRequestBodyPost> smsRest, final SoftwareManagement softwareManagement) {
-        final List<SoftwareModule> mappedList = new ArrayList<>();
+        if (smsRest == null) {
-        for (final MgmtSoftwareModuleRequestBodyPost smRest : smsRest) {
+            return Collections.emptyList();
-            mappedList.add(fromRequest(entityFactory, smRest, softwareManagement));
         }
-        return mappedList;
+
+        return smsRest.stream().map(smRest -> fromRequest(entityFactory, smRest, softwareManagement))
+                .collect(Collectors.toList());
     }
 
     /**
      * Create response for sw modules.
      * 
-     * @param baseSoftareModules
+     * @param softwareModules
      *            the modules
      * @return the response
      */
-    public static List<MgmtSoftwareModule> toResponse(final List<SoftwareModule> baseSoftareModules) {
+    public static List<MgmtSoftwareModule> toResponse(final Collection<SoftwareModule> softwareModules) {
-        final List<MgmtSoftwareModule> mappedList = new ArrayList<>();
+        if (softwareModules == null) {
-        if (baseSoftareModules != null) {
+            return Collections.emptyList();
-            for (final SoftwareModule target : baseSoftareModules) {
-                final MgmtSoftwareModule response = toResponse(target);
-
-                mappedList.add(response);
-            }
         }
-        return mappedList;
+
+        return softwareModules.stream().map(MgmtSoftwareModuleMapper::toResponse).collect(Collectors.toList());
     }
 
-    static List<MgmtSoftwareModule> toResponseSoftwareModules(final Iterable<SoftwareModule> softwareModules) {
+    static List<MgmtMetadata> toResponseSwMetadata(final Collection<SoftwareModuleMetadata> metadata) {
-        final List<MgmtSoftwareModule> response = new ArrayList<>();
+        if (metadata == null) {
-        for (final SoftwareModule softwareModule : softwareModules) {
+            return Collections.emptyList();
-            response.add(toResponse(softwareModule));
         }
-        return response;
-    }
 
-    static List<MgmtMetadata> toResponseSwMetadata(final List<SoftwareModuleMetadata> metadata) {
+        return metadata.stream().map(MgmtSoftwareModuleMapper::toResponseSwMetadata).collect(Collectors.toList());
-        final List<MgmtMetadata> mappedList = new ArrayList<>(metadata.size());
-        for (final SoftwareModuleMetadata distributionSetMetadata : metadata) {
-            mappedList.add(toResponseSwMetadata(distributionSetMetadata));
-        }
-        return mappedList;
     }
 
     static MgmtMetadata toResponseSwMetadata(final SoftwareModuleMetadata metadata) {
@@ -194,15 +182,11 @@ public final class MgmtSoftwareModuleMapper {
         return artifactRest;
     }
 
-    static List<MgmtArtifact> artifactsToResponse(final List<Artifact> artifacts) {
+    static List<MgmtArtifact> artifactsToResponse(final Collection<Artifact> artifacts) {
-        final List<MgmtArtifact> mappedList = new ArrayList<>();
+        if (artifacts == null) {
-
+            return Collections.emptyList();
-        if (artifacts != null) {
-            for (final Artifact artifact : artifacts) {
-                final MgmtArtifact response = toResponse(artifact);
-                mappedList.add(response);
-            }
         }
-        return mappedList;
+
+        return artifacts.stream().map(MgmtSoftwareModuleMapper::toResponse).collect(Collectors.toList());
     }
 }

hawkbit-mgmt-resource/src/main/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtSoftwareModuleResource.java

@@ -8,7 +8,15 @@
  */
 package org.eclipse.hawkbit.mgmt.rest.resource;
 
+import static org.eclipse.hawkbit.mgmt.rest.resource.MgmtSoftwareModuleMapper.artifactsToResponse;
+import static org.eclipse.hawkbit.mgmt.rest.resource.MgmtSoftwareModuleMapper.toResponse;
+import static org.eclipse.hawkbit.mgmt.rest.resource.MgmtSoftwareModuleMapper.toResponseSwMetadata;
+import static org.springframework.http.HttpStatus.BAD_REQUEST;
+import static org.springframework.http.HttpStatus.CREATED;
+import static org.springframework.http.HttpStatus.INTERNAL_SERVER_ERROR;
+
 import java.io.IOException;
+import java.util.Collection;
 import java.util.List;
 
 import org.eclipse.hawkbit.mgmt.json.model.MgmtMetadata;
@@ -46,10 +54,10 @@ import org.springframework.web.multipart.MultipartFile;
 /**
  * REST Resource handling for {@link SoftwareModule} and related
  * {@link Artifact} CRUD operations.
- *
  */
 @RestController
 public class MgmtSoftwareModuleResource implements MgmtSoftwareModuleRestApi {
+
     private static final Logger LOG = LoggerFactory.getLogger(MgmtSoftwareModuleResource.class);
 
     @Autowired
@@ -69,7 +77,7 @@ public class MgmtSoftwareModuleResource implements MgmtSoftwareModuleRestApi {
             @RequestParam(value = "sha1sum", required = false) final String sha1Sum) {
 
         if (file.isEmpty()) {
-            return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
+            return new ResponseEntity<>(BAD_REQUEST);
         }
         String fileName = optionalFileName;
 
@@ -81,10 +89,10 @@ public class MgmtSoftwareModuleResource implements MgmtSoftwareModuleRestApi {
             final Artifact result = artifactManagement.createLocalArtifact(file.getInputStream(), softwareModuleId,
                     fileName, md5Sum == null ? null : md5Sum.toLowerCase(),
                     sha1Sum == null ? null : sha1Sum.toLowerCase(), false, file.getContentType());
-            return new ResponseEntity<>(MgmtSoftwareModuleMapper.toResponse(result), HttpStatus.CREATED);
+            return ResponseEntity.status(CREATED).body(toResponse(result));
         } catch (final IOException e) {
             LOG.error("Failed to store artifact", e);
-            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
+            return new ResponseEntity<>(INTERNAL_SERVER_ERROR);
         }
     }
 
@@ -92,31 +100,34 @@ public class MgmtSoftwareModuleResource implements MgmtSoftwareModuleRestApi {
     @ResponseBody
     public ResponseEntity<List<MgmtArtifact>> getArtifacts(
             @PathVariable("softwareModuleId") final Long softwareModuleId) {
-        final SoftwareModule module = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
 
-        return new ResponseEntity<>(MgmtSoftwareModuleMapper.artifactsToResponse(module.getArtifacts()), HttpStatus.OK);
+        final SoftwareModule module = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
+        return ResponseEntity.ok(artifactsToResponse(module.getArtifacts()));
     }
 
     @Override
     @ResponseBody
+    // Exception squid:S3655 - Optional access is checked in
+    // findSoftwareModuleWithExceptionIfNotFound
+    // subroutine
+    @SuppressWarnings("squid:S3655")
     public ResponseEntity<MgmtArtifact> getArtifact(@PathVariable("softwareModuleId") final Long softwareModuleId,
             @PathVariable("artifactId") final Long artifactId) {
+
         final SoftwareModule module = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, artifactId);
 
-        return new ResponseEntity<>(MgmtSoftwareModuleMapper.toResponse(module.getLocalArtifact(artifactId).get()),
+        return ResponseEntity.ok(toResponse(module.getLocalArtifact(artifactId).get()));
-                HttpStatus.OK);
     }
 
     @Override
     @ResponseBody
     public ResponseEntity<Void> deleteArtifact(@PathVariable("softwareModuleId") final Long softwareModuleId,
             @PathVariable("artifactId") final Long artifactId) {
-        findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, artifactId);
 
+        findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, artifactId);
         artifactManagement.deleteLocalArtifact(artifactId);
 
-        return new ResponseEntity<>(HttpStatus.OK);
+        return ResponseEntity.ok().build();
-
     }
 
     @Override
@@ -143,33 +154,34 @@ public class MgmtSoftwareModuleResource implements MgmtSoftwareModuleRestApi {
         }
 
         final List<MgmtSoftwareModule> rest = MgmtSoftwareModuleMapper.toResponse(findModulesAll.getContent());
-        return new ResponseEntity<>(new PagedList<>(rest, countModulesAll), HttpStatus.OK);
+        return ResponseEntity.ok(new PagedList<>(rest, countModulesAll));
     }
 
     @Override
     public ResponseEntity<MgmtSoftwareModule> getSoftwareModule(
             @PathVariable("softwareModuleId") final Long softwareModuleId) {
-        final SoftwareModule findBaseSoftareModule = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
 
-        return new ResponseEntity<>(MgmtSoftwareModuleMapper.toResponse(findBaseSoftareModule), HttpStatus.OK);
+        final SoftwareModule findBaseSoftareModule = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
+        return ResponseEntity.ok(toResponse(findBaseSoftareModule));
     }
 
     @Override
     public ResponseEntity<List<MgmtSoftwareModule>> createSoftwareModules(
             @RequestBody final List<MgmtSoftwareModuleRequestBodyPost> softwareModules) {
+
         LOG.debug("creating {} softwareModules", softwareModules.size());
-        final Iterable<SoftwareModule> createdSoftwareModules = softwareManagement.createSoftwareModule(
+        final Collection<SoftwareModule> createdSoftwareModules = softwareManagement.createSoftwareModule(
                 MgmtSoftwareModuleMapper.smFromRequest(entityFactory, softwareModules, softwareManagement));
         LOG.debug("{} softwareModules created, return status {}", softwareModules.size(), HttpStatus.CREATED);
 
-        return new ResponseEntity<>(MgmtSoftwareModuleMapper.toResponseSoftwareModules(createdSoftwareModules),
+        return ResponseEntity.status(CREATED).body(toResponse(createdSoftwareModules));
-                HttpStatus.CREATED);
     }
 
     @Override
     public ResponseEntity<MgmtSoftwareModule> updateSoftwareModule(
             @PathVariable("softwareModuleId") final Long softwareModuleId,
             @RequestBody final MgmtSoftwareModuleRequestBodyPut restSoftwareModule) {
+
         final SoftwareModule module = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
 
         // only description and vendor can be modified
@@ -181,16 +193,16 @@ public class MgmtSoftwareModuleResource implements MgmtSoftwareModuleRestApi {
         }
 
         final SoftwareModule updateSoftwareModule = softwareManagement.updateSoftwareModule(module);
-        return new ResponseEntity<>(MgmtSoftwareModuleMapper.toResponse(updateSoftwareModule), HttpStatus.OK);
+        return ResponseEntity.ok(toResponse(updateSoftwareModule));
     }
 
     @Override
     public ResponseEntity<Void> deleteSoftwareModule(@PathVariable("softwareModuleId") final Long softwareModuleId) {
-        final SoftwareModule module = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
 
+        final SoftwareModule module = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
         softwareManagement.deleteSoftwareModule(module);
 
-        return new ResponseEntity<>(HttpStatus.OK);
+        return ResponseEntity.ok().build();
     }
 
     @Override
@@ -218,34 +230,38 @@ public class MgmtSoftwareModuleResource implements MgmtSoftwareModuleRestApi {
             metaDataPage = softwareManagement.findSoftwareModuleMetadataBySoftwareModuleId(softwareModuleId, pageable);
         }
 
-        return new ResponseEntity<>(
+        return ResponseEntity
-                new PagedList<>(MgmtSoftwareModuleMapper.toResponseSwMetadata(metaDataPage.getContent()),
+                .ok(new PagedList<>(toResponseSwMetadata(metaDataPage.getContent()), metaDataPage.getTotalElements()));
-                        metaDataPage.getTotalElements()),
-                HttpStatus.OK);
     }
 
     @Override
     public ResponseEntity<MgmtMetadata> getMetadataValue(@PathVariable("softwareModuleId") final Long softwareModuleId,
             @PathVariable("metadataKey") final String metadataKey) {
+
         final SoftwareModule sw = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
         final SoftwareModuleMetadata findOne = softwareManagement.findSoftwareModuleMetadata(sw, metadataKey);
-        return ResponseEntity.<MgmtMetadata> ok(MgmtSoftwareModuleMapper.toResponseSwMetadata(findOne));
+
+        return ResponseEntity.ok(toResponseSwMetadata(findOne));
     }
 
     @Override
     public ResponseEntity<MgmtMetadata> updateMetadata(@PathVariable("softwareModuleId") final Long softwareModuleId,
             @PathVariable("metadataKey") final String metadataKey, @RequestBody final MgmtMetadata metadata) {
+
         final SoftwareModule sw = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
         final SoftwareModuleMetadata updated = softwareManagement.updateSoftwareModuleMetadata(
                 entityFactory.generateSoftwareModuleMetadata(sw, metadataKey, metadata.getValue()));
-        return ResponseEntity.ok(MgmtSoftwareModuleMapper.toResponseSwMetadata(updated));
+
+        return ResponseEntity.ok(toResponseSwMetadata(updated));
     }
 
     @Override
     public ResponseEntity<Void> deleteMetadata(@PathVariable("softwareModuleId") final Long softwareModuleId,
             @PathVariable("metadataKey") final String metadataKey) {
+
         final SoftwareModule sw = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
         softwareManagement.deleteSoftwareModuleMetadata(sw, metadataKey);
+
         return ResponseEntity.ok().build();
     }
 
@@ -253,24 +269,25 @@ public class MgmtSoftwareModuleResource implements MgmtSoftwareModuleRestApi {
     public ResponseEntity<List<MgmtMetadata>> createMetadata(
             @PathVariable("softwareModuleId") final Long softwareModuleId,
             @RequestBody final List<MgmtMetadata> metadataRest) {
-        final SoftwareModule sw = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
 
+        final SoftwareModule sw = findSoftwareModuleWithExceptionIfNotFound(softwareModuleId, null);
         final List<SoftwareModuleMetadata> created = softwareManagement.createSoftwareModuleMetadata(
                 MgmtSoftwareModuleMapper.fromRequestSwMetadata(entityFactory, sw, metadataRest));
 
-        return new ResponseEntity<>(MgmtSoftwareModuleMapper.toResponseSwMetadata(created), HttpStatus.CREATED);
+        return ResponseEntity.status(CREATED).body(toResponseSwMetadata(created));
-
     }
 
     private SoftwareModule findSoftwareModuleWithExceptionIfNotFound(final Long softwareModuleId,
             final Long artifactId) {
+
         final SoftwareModule module = softwareManagement.findSoftwareModuleById(softwareModuleId);
         if (module == null) {
             throw new EntityNotFoundException("SoftwareModule with Id {" + softwareModuleId + "} does not exist");
-        } else if (artifactId != null && !module.getLocalArtifact(artifactId).isPresent()) {
+        }
+        if (artifactId != null && !module.getLocalArtifact(artifactId).isPresent()) {
             throw new EntityNotFoundException("Artifact with Id {" + artifactId + "} does not exist");
         }
+
         return module;
     }
-
 }

hawkbit-mgmt-resource/src/main/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtSoftwareModuleTypeMapper.java

@@ -11,9 +11,10 @@ package org.eclipse.hawkbit.mgmt.rest.resource;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;
 
-import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.eclipse.hawkbit.mgmt.json.model.softwaremoduletype.MgmtSoftwareModuleType;
 import org.eclipse.hawkbit.mgmt.json.model.softwaremoduletype.MgmtSoftwareModuleTypeRequestBodyPost;
@@ -25,9 +26,6 @@ import org.eclipse.hawkbit.repository.model.SoftwareModuleType;
  * A mapper which maps repository model to RESTful model representation and
  * back.
  *
- *
- *
- *
  */
 final class MgmtSoftwareModuleTypeMapper {
 
@@ -37,13 +35,12 @@ final class MgmtSoftwareModuleTypeMapper {
     }
 
     static List<SoftwareModuleType> smFromRequest(final EntityFactory entityFactory,
-            final Iterable<MgmtSoftwareModuleTypeRequestBodyPost> smTypesRest) {
+            final Collection<MgmtSoftwareModuleTypeRequestBodyPost> smTypesRest) {
-        final List<SoftwareModuleType> mappedList = new ArrayList<>();
+        if (smTypesRest == null) {
-
+            return Collections.emptyList();
-        for (final MgmtSoftwareModuleTypeRequestBodyPost smRest : smTypesRest) {
-            mappedList.add(fromRequest(entityFactory, smRest));
         }
-        return mappedList;
+
+        return smTypesRest.stream().map(smRest -> fromRequest(entityFactory, smRest)).collect(Collectors.toList());
     }
 
     static SoftwareModuleType fromRequest(final EntityFactory entityFactory,
@@ -57,20 +54,12 @@ final class MgmtSoftwareModuleTypeMapper {
         return result;
     }
 
-    static List<MgmtSoftwareModuleType> toTypesResponse(final List<SoftwareModuleType> types) {
+    static List<MgmtSoftwareModuleType> toTypesResponse(final Collection<SoftwareModuleType> types) {
-        final List<MgmtSoftwareModuleType> response = new ArrayList<>();
+        if (types == null) {
-        for (final SoftwareModuleType softwareModule : types) {
+            return Collections.emptyList();
-            response.add(toResponse(softwareModule));
         }
-        return response;
-    }
 
-    static List<MgmtSoftwareModuleType> toListResponse(final Collection<SoftwareModuleType> types) {
+        return types.stream().map(MgmtSoftwareModuleTypeMapper::toResponse).collect(Collectors.toList());
-        final List<MgmtSoftwareModuleType> response = new ArrayList<>();
-        for (final SoftwareModuleType softwareModule : types) {
-            response.add(toResponse(softwareModule));
-        }
-        return response;
     }
 
     static MgmtSoftwareModuleType toResponse(final SoftwareModuleType type) {

hawkbit-mgmt-resource/src/main/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtSoftwareModuleTypeResource.java

@@ -72,7 +72,7 @@ public class MgmtSoftwareModuleTypeResource implements MgmtSoftwareModuleTypeRes
         }
 
         final List<MgmtSoftwareModuleType> rest = MgmtSoftwareModuleTypeMapper
-                .toListResponse(findModuleTypessAll.getContent());
+                .toTypesResponse(findModuleTypessAll.getContent());
         return new ResponseEntity<>(new PagedList<>(rest, countModulesAll), HttpStatus.OK);
     }
 

hawkbit-mgmt-resource/src/main/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtTargetMapper.java

@@ -13,9 +13,11 @@ import static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;
 
 import java.net.URI;
 import java.time.ZoneId;
-import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.Date;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.eclipse.hawkbit.mgmt.json.model.MgmtPollStatus;
 import org.eclipse.hawkbit.mgmt.json.model.action.MgmtAction;
@@ -92,17 +94,17 @@ public final class MgmtTargetMapper {
      *            the targets
      * @return the response
      */
-    public static List<MgmtTarget> toResponseWithLinksAndPollStatus(final Iterable<Target> targets) {
+    public static List<MgmtTarget> toResponseWithLinksAndPollStatus(final Collection<Target> targets) {
-        final List<MgmtTarget> mappedList = new ArrayList<>();
+        if (targets == null) {
-        if (targets != null) {
+            return Collections.emptyList();
-            for (final Target target : targets) {
-                final MgmtTarget response = toResponse(target);
-                addPollStatus(target, response);
-                addTargetLinks(response);
-                mappedList.add(response);
-            }
         }
-        return mappedList;
+
+        return targets.stream().map(target -> {
+            final MgmtTarget response = toResponse(target);
+            addPollStatus(target, response);
+            addTargetLinks(response);
+            return response;
+        }).collect(Collectors.toList());
     }
 
     /**
@@ -112,15 +114,12 @@ public final class MgmtTargetMapper {
      *            list of targets
      * @return the response
      */
-    public static List<MgmtTarget> toResponse(final Iterable<Target> targets) {
+    public static List<MgmtTarget> toResponse(final Collection<Target> targets) {
-        final List<MgmtTarget> mappedList = new ArrayList<>();
+        if (targets == null) {
-        if (targets != null) {
+            return Collections.emptyList();
-            for (final Target target : targets) {
-                final MgmtTarget response = toResponse(target);
-                mappedList.add(response);
-            }
         }
-        return mappedList;
+
+        return targets.stream().map(MgmtTargetMapper::toResponse).collect(Collectors.toList());
     }
 
     /**
@@ -173,12 +172,13 @@ public final class MgmtTargetMapper {
     }
 
     static List<Target> fromRequest(final EntityFactory entityFactory,
-            final Iterable<MgmtTargetRequestBody> targetsRest) {
+            final Collection<MgmtTargetRequestBody> targetsRest) {
-        final List<Target> mappedList = new ArrayList<>();
+        if (targetsRest == null) {
-        for (final MgmtTargetRequestBody targetRest : targetsRest) {
+            return Collections.emptyList();
-            mappedList.add(fromRequest(entityFactory, targetRest));
         }
-        return mappedList;
+
+        return targetsRest.stream().map(targetRest -> fromRequest(entityFactory, targetRest))
+                .collect(Collectors.toList());
     }
 
     static Target fromRequest(final EntityFactory entityFactory, final MgmtTargetRequestBody targetRest) {
@@ -190,17 +190,12 @@ public final class MgmtTargetMapper {
         return target;
     }
 
-    static List<MgmtActionStatus> toActionStatusRestResponse(final List<ActionStatus> actionStatus) {
+    static List<MgmtActionStatus> toActionStatusRestResponse(final Collection<ActionStatus> actionStatus) {
-        final List<MgmtActionStatus> mappedList = new ArrayList<>();
+        if (actionStatus == null) {
-
+            return Collections.emptyList();
-        if (actionStatus != null) {
-            for (final ActionStatus status : actionStatus) {
-                final MgmtActionStatus response = toResponse(status);
-                mappedList.add(response);
-            }
         }
 
-        return mappedList;
+        return actionStatus.stream().map(MgmtTargetMapper::toResponse).collect(Collectors.toList());
     }
 
     static MgmtAction toResponse(final String targetId, final Action action, final boolean isActive) {
@@ -222,14 +217,13 @@ public final class MgmtTargetMapper {
         return result;
     }
 
-    static List<MgmtAction> toResponse(final String targetId, final List<Action> actions) {
+    static List<MgmtAction> toResponse(final String targetId, final Collection<Action> actions) {
-        final List<MgmtAction> mappedList = new ArrayList<>();
+        if (actions == null) {
-
+            return Collections.emptyList();
-        for (final Action action : actions) {
-            final MgmtAction response = toResponse(targetId, action, action.isActive());
-            mappedList.add(response);
         }
-        return mappedList;
+
+        return actions.stream().map(action -> toResponse(targetId, action, action.isActive()))
+                .collect(Collectors.toList());
     }
 
     private static String getNameOfActionStatusType(final Action.Status type) {

hawkbit-mgmt-resource/src/main/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtTargetResource.java

@@ -11,6 +11,7 @@ package org.eclipse.hawkbit.mgmt.rest.resource;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;
 import static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;
 
+import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -108,7 +109,7 @@ public class MgmtTargetResource implements MgmtTargetRestApi {
     @Override
     public ResponseEntity<List<MgmtTarget>> createTargets(@RequestBody final List<MgmtTargetRequestBody> targets) {
         LOG.debug("creating {} targets", targets.size());
-        final Iterable<Target> createdTargets = this.targetManagement
+        final Collection<Target> createdTargets = this.targetManagement
                 .createTargets(MgmtTargetMapper.fromRequest(entityFactory, targets));
         LOG.debug("{} targets created, return status {}", targets.size(), HttpStatus.CREATED);
         return new ResponseEntity<>(MgmtTargetMapper.toResponse(createdTargets), HttpStatus.CREATED);

hawkbit-mgmt-resource/src/test/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtDistributionSetTypeResourceTest.java

@@ -494,9 +494,6 @@ public class MgmtDistributionSetTypeResourceTest extends AbstractRestIntegration
         final SoftwareModuleType testSmType = softwareManagement.createSoftwareModuleType(
                 entityFactory.generateSoftwareModuleType("test123", "TestName123", "Desc123", 5));
 
-        final List<DistributionSetType> types = new ArrayList<>();
-        types.add(testType);
-
         // DST does not exist
         mvc.perform(get("/rest/v1/distributionsettypes/12345678")).andDo(MockMvcResultPrinter.print())
                 .andExpect(status().isNotFound());
@@ -554,9 +551,8 @@ public class MgmtDistributionSetTypeResourceTest extends AbstractRestIntegration
                 .contentType(MediaType.APPLICATION_JSON)).andDo(MockMvcResultPrinter.print())
                 .andExpect(status().isBadRequest());
 
-        final DistributionSetType missingName = entityFactory.generateDistributionSetType("test123", null, "Desc123");
+        // Missing mandatory field name
-        mvc.perform(post("/rest/v1/distributionsettypes")
+        mvc.perform(post("/rest/v1/distributionsettypes").content("[{\"description\":\"Desc123\",\"key\":\"test123\"}]")
-                .content(JsonBuilder.distributionSetTypes(Lists.newArrayList(missingName)))
                 .contentType(MediaType.APPLICATION_JSON)).andDo(MockMvcResultPrinter.print())
                 .andExpect(status().isBadRequest());
 

hawkbit-mgmt-resource/src/test/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtSoftwareModuleResourceTest.java

@@ -438,8 +438,7 @@ public class MgmtSoftwareModuleResourceTest extends AbstractRestIntegrationTestW
         SoftwareModule sm = entityFactory.generateSoftwareModule(osType, "name 1", "version 1", null, null);
         sm = softwareManagement.createSoftwareModule(sm);
 
-        final List<SoftwareModule> modules = new ArrayList<>();
+        final List<SoftwareModule> modules = Lists.newArrayList(sm);
-        modules.add(sm);
 
         // SM does not exist
         mvc.perform(get("/rest/v1/softwaremodules/12345678")).andDo(MockMvcResultPrinter.print())
@@ -457,11 +456,10 @@ public class MgmtSoftwareModuleResourceTest extends AbstractRestIntegrationTestW
                 .contentType(MediaType.APPLICATION_JSON)).andDo(MockMvcResultPrinter.print())
                 .andExpect(status().isBadRequest());
 
-        final SoftwareModule missingName = entityFactory.generateSoftwareModule(osType, null, "version 1", null, null);
+        mvc.perform(post("/rest/v1/softwaremodules")
-        mvc.perform(
+                .content("[{\"description\":\"Desc123\",\"key\":\"test123\", \"type\":\"os\"}]")
-                post("/rest/v1/softwaremodules").content(JsonBuilder.softwareModules(Lists.newArrayList(missingName)))
+                .contentType(MediaType.APPLICATION_JSON)).andDo(MockMvcResultPrinter.print())
-                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isBadRequest());
-                .andDo(MockMvcResultPrinter.print()).andExpect(status().isBadRequest());
 
         final SoftwareModule toLongName = entityFactory.generateSoftwareModule(osType,
                 RandomStringUtils.randomAscii(80), "version 1", null, null);

hawkbit-mgmt-resource/src/test/java/org/eclipse/hawkbit/mgmt/rest/resource/MgmtSoftwareModuleTypeResourceTest.java

@@ -318,8 +318,7 @@ public class MgmtSoftwareModuleTypeResourceTest extends AbstractRestIntegrationT
         final SoftwareModuleType testType = softwareManagement.createSoftwareModuleType(
                 entityFactory.generateSoftwareModuleType("test123", "TestName123", "Desc123", 5));
 
-        final List<SoftwareModuleType> types = new ArrayList<>();
+        final List<SoftwareModuleType> types = Lists.newArrayList(testType);
-        types.add(testType);
 
         // SM does not exist
         mvc.perform(get("/rest/v1/softwaremoduletypes/12345678")).andDo(MockMvcResultPrinter.print())
@@ -337,9 +336,9 @@ public class MgmtSoftwareModuleTypeResourceTest extends AbstractRestIntegrationT
                 .contentType(MediaType.APPLICATION_JSON)).andDo(MockMvcResultPrinter.print())
                 .andExpect(status().isBadRequest());
 
-        final SoftwareModuleType missingName = entityFactory.generateSoftwareModuleType("test123", null, "Desc123", 5);
         mvc.perform(post("/rest/v1/softwaremoduletypes")
-                .content(JsonBuilder.softwareModuleTypes(Lists.newArrayList(missingName)))
+                .content(
+                        "[{\"description\":\"Desc123\",\"id\":9223372036854775807,\"key\":\"test123\",\"maxAssignments\":5}]")
                 .contentType(MediaType.APPLICATION_JSON)).andDo(MockMvcResultPrinter.print())
                 .andExpect(status().isBadRequest());
 

hawkbit-mgmt-resource/src/test/resources/logback-spring.xml

@@ -23,7 +23,7 @@
    <Logger name="org.apache.catalina.startup.DigesterFactory" level="ERROR" />   
    
    
-<!--    <Logger name="org.eclipse.hawkbit.rest.util.MockMvcResultPrinter" level="DEBUG" /> -->
+   <Logger name="org.eclipse.hawkbit.rest.util.MockMvcResultPrinter" level="DEBUG" />
 
    <!-- Security Log with hints on potential attacks -->
    <logger name="server-security" level="INFO" />

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/EntityFactory.java

@@ -11,6 +11,8 @@ package org.eclipse.hawkbit.repository;
 import java.util.Collection;
 import java.util.concurrent.TimeUnit;
 
+import javax.validation.constraints.NotNull;
+
 import org.eclipse.hawkbit.repository.model.Action;
 import org.eclipse.hawkbit.repository.model.Action.Status;
 import org.eclipse.hawkbit.repository.model.ActionStatus;
@@ -64,7 +66,7 @@ public interface EntityFactory {
      * 
      * @return {@link ActionStatus} object
      */
-    ActionStatus generateActionStatus(Action action, Status status, Long occurredAt);
+    ActionStatus generateActionStatus(@NotNull Action action, @NotNull Status status, Long occurredAt);
 
     /**
      * Generates an {@link ActionStatus} object without persisting it.
@@ -81,7 +83,7 @@ public interface EntityFactory {
      * 
      * @return {@link ActionStatus} object
      */
-    ActionStatus generateActionStatus(Action action, final Status status, Long occurredAt,
+    ActionStatus generateActionStatus(@NotNull Action action, @NotNull Status status, Long occurredAt,
             final Collection<String> messages);
 
     /**
@@ -99,7 +101,8 @@ public interface EntityFactory {
      * 
      * @return {@link ActionStatus} object
      */
-    ActionStatus generateActionStatus(Action action, Status status, Long occurredAt, final String message);
+    ActionStatus generateActionStatus(@NotNull Action action, @NotNull Status status, Long occurredAt,
+            final String message);
 
     /**
      * Generates an empty {@link DistributionSet} without persisting it.
@@ -124,8 +127,8 @@ public interface EntityFactory {
      * 
      * @return {@link DistributionSet} object
      */
-    DistributionSet generateDistributionSet(String name, String version, String description, DistributionSetType type,
+    DistributionSet generateDistributionSet(@NotNull String name, @NotNull String version, String description,
-            Collection<SoftwareModule> moduleList);
+            @NotNull DistributionSetType type, Collection<SoftwareModule> moduleList);
 
     /**
      * Generates an empty {@link DistributionSetMetadata} element without
@@ -148,7 +151,8 @@ public interface EntityFactory {
      * 
      * @return {@link DistributionSetMetadata} object
      */
-    DistributionSetMetadata generateDistributionSetMetadata(DistributionSet distributionSet, String key, String value);
+    DistributionSetMetadata generateDistributionSetMetadata(@NotNull DistributionSet distributionSet,
+            @NotNull String key, String value);
 
     /**
      * Generates an empty {@link DistributionSetTag} without persisting it.
@@ -164,7 +168,7 @@ public interface EntityFactory {
      *            of the tag
      * @return {@link DistributionSetTag} object
      */
-    DistributionSetTag generateDistributionSetTag(String name);
+    DistributionSetTag generateDistributionSetTag(@NotNull String name);
 
     /**
      * Generates a {@link DistributionSetTag} without persisting it.
@@ -177,7 +181,7 @@ public interface EntityFactory {
      *            of the tag
      * @return {@link DistributionSetTag} object
      */
-    DistributionSetTag generateDistributionSetTag(String name, String description, String colour);
+    DistributionSetTag generateDistributionSetTag(@NotNull String name, String description, String colour);
 
     /**
      * Generates an empty {@link DistributionSetType} without persisting it.
@@ -198,7 +202,7 @@ public interface EntityFactory {
      * 
      * @return {@link DistributionSetType} object
      */
-    DistributionSetType generateDistributionSetType(String key, String name, String description);
+    DistributionSetType generateDistributionSetType(@NotNull String key, @NotNull String name, String description);
 
     /**
      * Generates an empty {@link Rollout} without persisting it.
@@ -237,8 +241,8 @@ public interface EntityFactory {
      * 
      * @return {@link SoftwareModule} object
      */
-    SoftwareModule generateSoftwareModule(SoftwareModuleType type, String name, String version, String description,
+    SoftwareModule generateSoftwareModule(@NotNull SoftwareModuleType type, @NotNull String name,
-            String vendor);
+            @NotNull String version, String description, String vendor);
 
     /**
      * Generates an empty {@link SoftwareModuleMetadata} pair without persisting
@@ -260,7 +264,8 @@ public interface EntityFactory {
      * 
      * @return {@link SoftwareModuleMetadata} object
      */
-    SoftwareModuleMetadata generateSoftwareModuleMetadata(SoftwareModule softwareModule, String key, String value);
+    SoftwareModuleMetadata generateSoftwareModuleMetadata(@NotNull SoftwareModule softwareModule, @NotNull String key,
+            String value);
 
     /**
      * Generates an empty {@link SoftwareModuleType} without persisting it.
@@ -283,7 +288,8 @@ public interface EntityFactory {
      * 
      * @return {@link SoftwareModuleType} object
      */
-    SoftwareModuleType generateSoftwareModuleType(String key, String name, String description, int maxAssignments);
+    SoftwareModuleType generateSoftwareModuleType(@NotNull String key, @NotNull String name, String description,
+            int maxAssignments);
 
     /**
      * Generates an empty {@link Target} without persisting it.
@@ -307,7 +313,7 @@ public interface EntityFactory {
      * 
      * @return {@link Target} object
      */
-    Target generateTarget(@NotEmpty String controllerID, @NotEmpty String securityToken);
+    Target generateTarget(@NotEmpty String controllerID, String securityToken);
 
     /**
      * Generates an empty {@link TargetFilterQuery} without persisting it.
@@ -330,7 +336,7 @@ public interface EntityFactory {
      *            of the tag
      * @return {@link TargetTag} object
      */
-    TargetTag generateTargetTag(String name);
+    TargetTag generateTargetTag(@NotNull String name);
 
     /**
      * Generates a {@link TargetTag} without persisting it.
@@ -343,7 +349,7 @@ public interface EntityFactory {
      *            of the tag
      * @return {@link TargetTag} object
      */
-    TargetTag generateTargetTag(String name, String description, String colour);
+    TargetTag generateTargetTag(@NotNull String name, String description, String colour);
 
     /**
      * Generates an empty {@link LocalArtifact} without persisting it.

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/ActionStatus.java

@@ -47,10 +47,10 @@ public interface ActionStatus extends TenantAwareBaseEntity {
      * @return current {@link Status#DOWNLOAD} progress if known by the update
      *         server.
      */
-    int getDownloadProgressPercent();
+    short getDownloadProgressPercent();
 
     /**
-     * @return list of message entries that can be added to the
+     * @return immutable list of message entries that in the
      *         {@link ActionStatus}.
      */
     List<String> getMessages();

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/Artifact.java

@@ -37,6 +37,6 @@ public interface Artifact extends TenantAwareBaseEntity {
     /**
      * @return size of the artifact in bytes.
      */
-    Long getSize();
+    long getSize();
 
 }

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/BaseEntity.java

@@ -44,6 +44,6 @@ public interface BaseEntity extends Serializable, Identifiable<Long> {
     /**
      * @return version of the {@link BaseEntity}.
      */
-    long getOptLockRevision();
+    int getOptLockRevision();
 
 }

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/DistributionSet.java

@@ -26,10 +26,25 @@ import org.eclipse.hawkbit.repository.DistributionSetManagement;
 public interface DistributionSet extends NamedVersionedEntity {
 
     /**
-     * @return {@link Set} of assigned {@link DistributionSetTag}s.
+     * @return immutable {@link Set} of assigned {@link DistributionSetTag}s.
      */
     Set<DistributionSetTag> getTags();
 
+    /**
+     * @param tag
+     *            to add
+     * @return <code>true</code> if tag could be added sucessfully (i.e. was not
+     *         already in the list).
+     */
+    boolean addTag(final DistributionSetTag tag);
+
+    /**
+     * @param tag
+     *            to remove
+     * @return <code>true</code> if tag was in the list and removed
+     */
+    boolean removeTag(final DistributionSetTag tag);
+
     /**
      * @return <code>true</code> if the set is deleted and only kept for history
      *         purposes.

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/DistributionSetTag.java

@@ -17,8 +17,8 @@ import java.util.List;
 public interface DistributionSetTag extends Tag {
 
     /**
-     * @return {@link List} of {@link DistributionSet}s this {@link Tag} is
+     * @return immutable {@link List} of {@link DistributionSet}s this
-     *         assigned to.
+     *         {@link Tag} is assigned to.
      */
     List<DistributionSet> getAssignedToDistributionSet();
 

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/DistributionSetType.java

@@ -27,15 +27,15 @@ public interface DistributionSetType extends NamedEntity {
     boolean isDeleted();
 
     /**
-     * @return set of {@link SoftwareModuleType}s that need to be in a
+     * @return immutable set of {@link SoftwareModuleType}s that need to be in a
      *         {@link DistributionSet} of this type to be
      *         {@link DistributionSet#isComplete()}.
      */
     Set<SoftwareModuleType> getMandatoryModuleTypes();
 
     /**
-     * @return set of optional {@link SoftwareModuleType}s that can be in a
+     * @return immutable set of optional {@link SoftwareModuleType}s that can be
-     *         {@link DistributionSet} of this type.
+     *         in a {@link DistributionSet} of this type.
      */
     Set<SoftwareModuleType> getOptionalModuleTypes();
 

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/Rollout.java

@@ -38,7 +38,7 @@ public interface Rollout extends NamedEntity {
     void setDistributionSet(DistributionSet distributionSet);
 
     /**
-     * @return list of deployment groups of the rollout.
+     * @return immutable list of deployment groups of the rollout.
      */
     List<RolloutGroup> getRolloutGroups();
 

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/RolloutGroup.java

@@ -155,7 +155,7 @@ public interface RolloutGroup extends NamedEntity {
     /**
      * @return the total amount of targets containing in this group
      */
-    long getTotalTargets();
+    int getTotalTargets();
 
     /**
      * @return the totalTargetCountStatus

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/SoftwareModule.java

@@ -11,6 +11,10 @@ package org.eclipse.hawkbit.repository.model;
 import java.util.List;
 import java.util.Optional;
 
+/**
+ * Software package as sub element of a {@link DistributionSet}.
+ *
+ */
 public interface SoftwareModule extends NamedVersionedEntity {
 
     /**
@@ -40,12 +44,12 @@ public interface SoftwareModule extends NamedVersionedEntity {
     Optional<LocalArtifact> getLocalArtifactByFilename(String fileName);
 
     /**
-     * @return the artifacts
+     * @return immutable list of all artifacts
      */
     List<Artifact> getArtifacts();
 
     /**
-     * @return local artifacts only
+     * @return immutable list of local artifacts only
      */
     List<LocalArtifact> getLocalArtifacts();
 
@@ -104,7 +108,8 @@ public interface SoftwareModule extends NamedVersionedEntity {
     List<SoftwareModuleMetadata> getMetadata();
 
     /**
-     * @return the assignedTo
+     * @return immutable list of {@link DistributionSet}s the module is assigned
+     *         to
      */
     List<DistributionSet> getAssignedTo();
 

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/Target.java

@@ -32,12 +32,12 @@ public interface Target extends NamedEntity {
     String getControllerId();
 
     /**
-     * @return assigned {@link TargetTag}s.
+     * @return immutable set of assigned {@link TargetTag}s.
      */
     Set<TargetTag> getTags();
 
     /**
-     * @return {@link Action} history of the {@link Target}.
+     * @return immutable {@link Action} history of the {@link Target}.
      */
     List<Action> getActions();
 
@@ -64,4 +64,19 @@ public interface Target extends NamedEntity {
      */
     void setSecurityToken(String token);
 
+    /**
+     * @param tag
+     *            to add
+     * @return <code>true</code> if tag could be added sucessfully (i.e. was not
+     *         already in the list).
+     */
+    public boolean addTag(TargetTag tag);
+
+    /**
+     * @param tag
+     *            to remove
+     * @return <code>true</code> if tag was in the list and removed
+     */
+    public boolean removeTag(TargetTag tag);
+
 }

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/TargetInfo.java

@@ -36,7 +36,8 @@ public interface TargetInfo extends Serializable {
 
     /**
      * @return time in {@link TimeUnit#MILLISECONDS} GMT when the {@link Target}
-     *         polled the server the last time.
+     *         polled the server the last time or <code>null</code> if target
+     *         has never queried yet.
      */
     Long getLastTargetQuery();
 

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/TargetTag.java

@@ -17,7 +17,7 @@ import java.util.List;
 public interface TargetTag extends Tag {
 
     /**
-     * @return {@link List} of targets assigned to this {@link Tag}.
+     * @return immutable {@link List} of targets assigned to this {@link Tag}.
      */
     List<Target> getAssignedToTargets();
 

hawkbit-repository/hawkbit-repository-jpa/pom.xml

@@ -89,6 +89,10 @@
          <groupId>cz.jirutka.rsql</groupId>
          <artifactId>rsql-parser</artifactId>
       </dependency>
+      <dependency>
+      	<groupId>org.apache.commons</groupId>
+      	<artifactId>commons-collections4</artifactId>
+      </dependency>
 
       <!-- Test -->
       <dependency>

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/RepositoryApplicationConfiguration.java

@@ -8,7 +8,6 @@
  */
 package org.eclipse.hawkbit;
 
-import java.util.HashMap;
 import java.util.Map;
 
 import org.eclipse.hawkbit.repository.ArtifactManagement;
@@ -73,6 +72,7 @@ import org.springframework.transaction.PlatformTransactionManager;
 import org.springframework.transaction.annotation.EnableTransactionManagement;
 import org.springframework.validation.beanvalidation.MethodValidationPostProcessor;
 
+import com.google.common.collect.Maps;
 import com.google.common.eventbus.EventBus;
 
 /**
@@ -197,7 +197,7 @@ public class RepositoryApplicationConfiguration extends JpaBaseConfiguration {
     @Override
     protected Map<String, Object> getVendorProperties() {
 
-        final Map<String, Object> properties = new HashMap<>();
+        final Map<String, Object> properties = Maps.newHashMapWithExpectedSize(5);
         // Turn off dynamic weaving to disable LTW lookup in static weaving mode
         properties.put("eclipselink.weaving", "false");
         // needed for reports

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/ActionRepository.java

@@ -30,6 +30,7 @@ import org.springframework.cache.annotation.CacheEvict;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Slice;
+import org.springframework.data.domain.Sort;
 import org.springframework.data.jpa.repository.EntityGraph;
 import org.springframework.data.jpa.repository.EntityGraph.EntityGraphType;
 import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
@@ -103,7 +104,7 @@ public interface ActionRepository extends BaseEntityRepository<JpaAction, Long>,
      * @return the found {@link Action}
      */
     @EntityGraph(value = "Action.ds", type = EntityGraphType.LOAD)
-    Optional<Action> findFirstByTargetAndActiveOrderByIdAsc(final JpaTarget target, boolean active);
+    Optional<Action> findFirstByTargetAndActive(final Sort sort, final JpaTarget target, boolean active);
 
     /**
      * Retrieves latest {@link UpdateAction} for given target and

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/JpaControllerManagement.java

@@ -9,7 +9,7 @@
 package org.eclipse.hawkbit.repository.jpa;
 
 import java.net.URI;
-import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -54,6 +54,8 @@ import org.eclipse.hawkbit.tenancy.configuration.TenantConfigurationKey;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.domain.Sort.Direction;
 import org.springframework.data.jpa.domain.Specification;
 import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.transaction.annotation.Isolation;
@@ -163,12 +165,15 @@ public class JpaControllerManagement implements ControllerManagement {
 
     @Override
     public Optional<Action> findOldestActiveActionByTarget(final Target target) {
-        return actionRepository.findFirstByTargetAndActiveOrderByIdAsc((JpaTarget) target, true);
+        // used in favorite to findFirstByTargetAndActiveOrderByIdAsc due to
+        // DATAJPA-841 issue.
+        return actionRepository.findFirstByTargetAndActive(new Sort(Direction.ASC, "id"), (JpaTarget) target, true);
     }
 
     @Override
     public List<SoftwareModule> findSoftwareModulesByDistributionSet(final DistributionSet distributionSet) {
-        return new ArrayList<>(softwareModuleRepository.findByAssignedTo((JpaDistributionSet) distributionSet));
+        return Collections
+                .unmodifiableList(softwareModuleRepository.findByAssignedTo((JpaDistributionSet) distributionSet));
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/JpaDeploymentManagement.java

@@ -597,7 +597,7 @@ public class JpaDeploymentManagement implements DeploymentManagement {
         multiselect.where(cb.equal(actionRoot.get(JpaAction_.target), target));
         multiselect.orderBy(cb.desc(actionRoot.get(JpaAction_.id)));
         multiselect.groupBy(actionRoot.get(JpaAction_.id));
-        return new ArrayList<>(entityManager.createQuery(multiselect).getResultList());
+        return Collections.unmodifiableList(entityManager.createQuery(multiselect).getResultList());
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/JpaDistributionSetManagement.java

@@ -15,7 +15,6 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -68,6 +67,7 @@ import org.springframework.transaction.annotation.Transactional;
 import org.springframework.validation.annotation.Validated;
 
 import com.google.common.base.Strings;
+import com.google.common.collect.Lists;
 import com.google.common.eventbus.EventBus;
 
 /**
@@ -130,26 +130,24 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
         final DistributionSetTag myTag = tagManagement.findDistributionSetTag(tagName);
 
         DistributionSetTagAssignmentResult result;
-        final List<JpaDistributionSet> toBeChangedDSs = new ArrayList<>();
+
-        for (final JpaDistributionSet set : sets) {
+        final List<JpaDistributionSet> toBeChangedDSs = sets.stream().filter(set -> set.addTag(myTag))
-            if (set.getTags().add(myTag)) {
+                .collect(Collectors.toList());
-                toBeChangedDSs.add(set);
-            }
-        }
 
         // un-assignment case
         if (toBeChangedDSs.isEmpty()) {
             for (final JpaDistributionSet set : sets) {
-                if (set.getTags().remove(myTag)) {
+                if (set.removeTag(myTag)) {
                     toBeChangedDSs.add(set);
                 }
             }
             result = new DistributionSetTagAssignmentResult(dsIds.size() - toBeChangedDSs.size(), 0,
                     toBeChangedDSs.size(), Collections.emptyList(),
-                    new ArrayList<>(distributionSetRepository.save(toBeChangedDSs)), myTag);
+                    Collections.unmodifiableList(distributionSetRepository.save(toBeChangedDSs)), myTag);
         } else {
             result = new DistributionSetTagAssignmentResult(dsIds.size() - toBeChangedDSs.size(), toBeChangedDSs.size(),
-                    0, new ArrayList<>(distributionSetRepository.save(toBeChangedDSs)), Collections.emptyList(), myTag);
+                    0, Collections.unmodifiableList(distributionSetRepository.save(toBeChangedDSs)),
+                    Collections.emptyList(), myTag);
         }
 
         final DistributionSetTagAssignmentResult resultAssignment = result;
@@ -178,8 +176,6 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
     @Modifying
     @Transactional(isolation = Isolation.READ_UNCOMMITTED)
     public void deleteDistributionSet(final Long... distributionSetIDs) {
-        final List<Long> toHardDelete = new ArrayList<>();
-
         final List<Long> assigned = distributionSetRepository
                 .findAssignedToTargetDistributionSetsById(distributionSetIDs);
         assigned.addAll(distributionSetRepository.findAssignedToRolloutDistributionSetsById(distributionSetIDs));
@@ -190,13 +186,10 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
         }
 
         // mark the rest as hard delete
-        for (final Long setId : distributionSetIDs) {
+        final List<Long> toHardDelete = Arrays.stream(distributionSetIDs).filter(setId -> !assigned.contains(setId))
-            if (!assigned.contains(setId)) {
+                .collect(Collectors.toList());
-                toHardDelete.add(setId);
-            }
-        }
 
-        // hard delete the rest if exixts
+        // hard delete the rest if exists
         if (!toHardDelete.isEmpty()) {
             // don't give the delete statement an empty list, JPA/Oracle cannot
             // handle the empty list
@@ -243,7 +236,7 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
         @SuppressWarnings({ "unchecked", "rawtypes" })
         final Collection<JpaDistributionSet> toSave = (Collection) distributionSets;
 
-        return new ArrayList<>(distributionSetRepository.save(toSave));
+        return Collections.unmodifiableList(distributionSetRepository.save(toSave));
     }
 
     @Override
@@ -296,7 +289,7 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
     }
 
     private static Page<DistributionSetType> convertDsTPage(final Page<JpaDistributionSetType> findAll) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()));
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()));
     }
 
     @Override
@@ -314,7 +307,7 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
 
     private static Page<DistributionSet> convertDsPage(final Page<JpaDistributionSet> findAll,
             final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, findAll.getTotalElements());
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, findAll.getTotalElements());
     }
 
     /**
@@ -337,7 +330,7 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
     @Override
     public Page<DistributionSet> findDistributionSetsByDeletedAndOrCompleted(final Pageable pageReq,
             final Boolean deleted, final Boolean complete) {
-        final List<Specification<JpaDistributionSet>> specList = new ArrayList<>();
+        final List<Specification<JpaDistributionSet>> specList = new ArrayList<>(2);
 
         if (deleted != null) {
             final Specification<JpaDistributionSet> spec = DistributionSetSpecification.isDeleted(deleted);
@@ -359,11 +352,12 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
         final Specification<JpaDistributionSet> spec = RSQLUtility.parse(rsqlParam, DistributionSetFields.class,
                 virtualPropertyLookup);
 
-        final List<Specification<JpaDistributionSet>> specList = new ArrayList<>();
+        final List<Specification<JpaDistributionSet>> specList = new ArrayList<>(2);
         if (deleted != null) {
             specList.add(DistributionSetSpecification.isDeleted(deleted));
         }
         specList.add(spec);
+
         return convertDsPage(findByCriteriaAPI(pageReq, specList), pageReq);
     }
 
@@ -388,7 +382,7 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
         final Page<DistributionSet> findDistributionSetsByFilters = findDistributionSetsByFilters(pageable,
                 dsFilterWithNoTargetLinked);
 
-        final List<DistributionSet> resultSet = new LinkedList<>(findDistributionSetsByFilters.getContent());
+        final List<DistributionSet> resultSet = new ArrayList<>(findDistributionSetsByFilters.getContent());
         int orderIndex = 0;
         if (installedDS != null) {
             final boolean remove = resultSet.remove(installedDS);
@@ -419,18 +413,15 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
 
     @Override
     public List<DistributionSet> findDistributionSetsAll(final Collection<Long> dist) {
-        return new ArrayList<>(distributionSetRepository.findAll(DistributionSetSpecification.byIds(dist)));
+        return Collections
+                .unmodifiableList(distributionSetRepository.findAll(DistributionSetSpecification.byIds(dist)));
     }
 
     @Override
     public Long countDistributionSetsAll() {
-
-        final List<Specification<JpaDistributionSet>> specList = new LinkedList<>();
-
         final Specification<JpaDistributionSet> spec = DistributionSetSpecification.isDeleted(Boolean.FALSE);
-        specList.add(spec);
 
-        return distributionSetRepository.count(SpecificationsBuilder.combineWithAnd(specList));
+        return distributionSetRepository.count(SpecificationsBuilder.combineWithAnd(Lists.newArrayList(spec)));
     }
 
     @Override
@@ -560,7 +551,7 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
 
     @Override
     public List<DistributionSetMetadata> findDistributionSetMetadataByDistributionSetId(final Long distributionSetId) {
-        return new ArrayList<>(distributionSetMetadataRepository
+        return Collections.unmodifiableList(distributionSetMetadataRepository
                 .findAll((Specification<JpaDistributionSetMetadata>) (root, query, cb) -> cb.equal(
                         root.get(JpaDistributionSetMetadata_.distributionSet).get(JpaDistributionSet_.id),
                         distributionSetId)));
@@ -584,7 +575,7 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
 
     private static Page<DistributionSetMetadata> convertMdPage(final Page<JpaDistributionSetMetadata> findAll,
             final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, findAll.getTotalElements());
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, findAll.getTotalElements());
     }
 
     @Override
@@ -609,7 +600,7 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
 
     private static List<Specification<JpaDistributionSet>> buildDistributionSetSpecifications(
             final DistributionSetFilter distributionSetFilter) {
-        final List<Specification<JpaDistributionSet>> specList = new ArrayList<>();
+        final List<Specification<JpaDistributionSet>> specList = new ArrayList<>(7);
 
         Specification<JpaDistributionSet> spec;
 
@@ -710,9 +701,9 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
     public List<DistributionSet> assignTag(final Collection<Long> dsIds, final DistributionSetTag tag) {
         final List<JpaDistributionSet> allDs = findDistributionSetListWithDetails(dsIds);
 
-        allDs.forEach(ds -> ds.getTags().add(tag));
+        allDs.forEach(ds -> ds.addTag(tag));
 
-        final List<DistributionSet> save = new ArrayList<>(distributionSetRepository.save(allDs));
+        final List<DistributionSet> save = Collections.unmodifiableList(distributionSetRepository.save(allDs));
 
         afterCommit.afterCommit(() -> {
 
@@ -732,7 +723,7 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
         @SuppressWarnings({ "unchecked", "rawtypes" })
         final Collection<JpaDistributionSet> distributionSets = (Collection) tag.getAssignedToDistributionSet();
 
-        return new ArrayList<>(unAssignTag(distributionSets, tag));
+        return Collections.unmodifiableList(unAssignTag(distributionSets, tag));
     }
 
     @Override
@@ -746,7 +737,7 @@ public class JpaDistributionSetManagement implements DistributionSetManagement {
 
     private List<JpaDistributionSet> unAssignTag(final Collection<JpaDistributionSet> distributionSets,
             final DistributionSetTag tag) {
-        distributionSets.forEach(ds -> ds.getTags().remove(tag));
+        distributionSets.forEach(ds -> ds.removeTag(tag));
         return distributionSetRepository.save(distributionSets);
     }
 

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/JpaEntityFactory.java

@@ -43,11 +43,13 @@ import org.eclipse.hawkbit.repository.model.SoftwareModuleType;
 import org.eclipse.hawkbit.repository.model.Target;
 import org.eclipse.hawkbit.repository.model.TargetFilterQuery;
 import org.eclipse.hawkbit.repository.model.TargetTag;
+import org.springframework.validation.annotation.Validated;
 
 /**
  * JPA Implementation of {@link EntityFactory}.
  *
  */
+@Validated
 public class JpaEntityFactory implements EntityFactory {
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/JpaRolloutGroupManagement.java

@@ -8,7 +8,7 @@
  */
 package org.eclipse.hawkbit.repository.jpa;
 
-import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
@@ -85,11 +85,11 @@ public class JpaRolloutGroupManagement implements RolloutGroupManagement {
     }
 
     private static Page<RolloutGroup> convertPage(final Page<JpaRolloutGroup> findAll, final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, findAll.getTotalElements());
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, findAll.getTotalElements());
     }
 
     private static Page<Target> convertTPage(final Page<JpaTarget> findAll, final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, findAll.getTotalElements());
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, findAll.getTotalElements());
     }
 
     @Override
@@ -119,7 +119,7 @@ public class JpaRolloutGroupManagement implements RolloutGroupManagement {
 
         for (final RolloutGroup rolloutGroup : rolloutGroups) {
             final TotalTargetCountStatus totalTargetCountStatus = new TotalTargetCountStatus(
-                    allStatesForRollout.get(rolloutGroup.getId()), rolloutGroup.getTotalTargets());
+                    allStatesForRollout.get(rolloutGroup.getId()), Long.valueOf(rolloutGroup.getTotalTargets()));
             rolloutGroup.setTotalTargetCountStatus(totalTargetCountStatus);
         }
 
@@ -133,7 +133,7 @@ public class JpaRolloutGroupManagement implements RolloutGroupManagement {
                 .getStatusCountByRolloutGroupId(rolloutGroupId);
 
         final TotalTargetCountStatus totalTargetCountStatus = new TotalTargetCountStatus(rolloutStatusCountItems,
-                rolloutGroup.getTotalTargets());
+                Long.valueOf(rolloutGroup.getTotalTargets()));
         rolloutGroup.setTotalTargetCountStatus(totalTargetCountStatus);
         return rolloutGroup;
 

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/JpaRolloutManagement.java

@@ -8,7 +8,7 @@
  */
 package org.eclipse.hawkbit.repository.jpa;
 
-import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -144,11 +144,11 @@ public class JpaRolloutManagement implements RolloutManagement {
     }
 
     private static Page<Rollout> convertPage(final Page<JpaRollout> findAll, final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, findAll.getTotalElements());
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, findAll.getTotalElements());
     }
 
     private static Slice<Rollout> convertPage(final Slice<JpaRollout> findAll, final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, 0);
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, 0);
     }
 
     @Override
@@ -656,7 +656,7 @@ public class JpaRolloutManagement implements RolloutManagement {
 
     @Override
     public float getFinishedPercentForRunningGroup(final Long rolloutId, final RolloutGroup rolloutGroup) {
-        final Long totalGroup = rolloutGroup.getTotalTargets();
+        final int totalGroup = rolloutGroup.getTotalTargets();
         final Long finished = actionRepository.countByRolloutIdAndRolloutGroupIdAndStatus(rolloutId,
                 rolloutGroup.getId(), Action.Status.FINISHED);
         if (totalGroup == 0) {

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/JpaSoftwareManagement.java

@@ -11,12 +11,15 @@ package org.eclipse.hawkbit.repository.jpa;
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import javax.persistence.EntityManager;
 import javax.persistence.criteria.CriteriaBuilder;
@@ -66,6 +69,7 @@ import org.springframework.transaction.annotation.Transactional;
 import org.springframework.validation.annotation.Validated;
 
 import com.google.common.base.Strings;
+import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 
 /**
@@ -170,7 +174,7 @@ public class JpaSoftwareManagement implements SoftwareManagement {
         @SuppressWarnings({ "unchecked", "rawtypes" })
         final Collection<JpaSoftwareModule> jpaCast = (Collection) swModules;
 
-        return new ArrayList<>(softwareModuleRepository.save(jpaCast));
+        return Collections.unmodifiableList(softwareModuleRepository.save(jpaCast));
     }
 
     @Override
@@ -189,22 +193,22 @@ public class JpaSoftwareManagement implements SoftwareManagement {
 
     private static Slice<SoftwareModule> convertSmPage(final Slice<JpaSoftwareModule> findAll,
             final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, 0);
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, 0);
     }
 
     private static Page<SoftwareModule> convertSmPage(final Page<JpaSoftwareModule> findAll, final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, findAll.getTotalElements());
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, findAll.getTotalElements());
     }
 
     private static Page<SoftwareModuleMetadata> convertSmMdPage(final Page<JpaSoftwareModuleMetadata> findAll,
             final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, findAll.getTotalElements());
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, findAll.getTotalElements());
     }
 
     @Override
     public Long countSoftwareModulesByType(final SoftwareModuleType type) {
 
-        final List<Specification<JpaSoftwareModule>> specList = new ArrayList<>();
+        final List<Specification<JpaSoftwareModule>> specList = new ArrayList<>(2);
 
         Specification<JpaSoftwareModule> spec = SoftwareModuleSpecification.equalType((JpaSoftwareModuleType) type);
         specList.add(spec);
@@ -281,7 +285,7 @@ public class JpaSoftwareManagement implements SoftwareManagement {
     @Override
     public Slice<SoftwareModule> findSoftwareModulesAll(final Pageable pageable) {
 
-        final List<Specification<JpaSoftwareModule>> specList = new ArrayList<>();
+        final List<Specification<JpaSoftwareModule>> specList = new ArrayList<>(2);
 
         Specification<JpaSoftwareModule> spec = SoftwareModuleSpecification.isDeletedFalse();
         specList.add(spec);
@@ -300,13 +304,9 @@ public class JpaSoftwareManagement implements SoftwareManagement {
 
     @Override
     public Long countSoftwareModulesAll() {
-
-        final List<Specification<JpaSoftwareModule>> specList = new ArrayList<>();
-
         final Specification<JpaSoftwareModule> spec = SoftwareModuleSpecification.isDeletedFalse();
-        specList.add(spec);
 
-        return countSwModuleByCriteriaAPI(specList);
+        return countSwModuleByCriteriaAPI(Lists.newArrayList(spec));
     }
 
     @Override
@@ -333,20 +333,20 @@ public class JpaSoftwareManagement implements SoftwareManagement {
 
     private static Page<SoftwareModuleType> convertSmTPage(final Page<JpaSoftwareModuleType> findAll,
             final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, findAll.getTotalElements());
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, findAll.getTotalElements());
     }
 
     @Override
     @PreAuthorize(SpringEvalExpressions.HAS_AUTH_READ_REPOSITORY)
     public List<SoftwareModule> findSoftwareModulesById(final Collection<Long> ids) {
-        return new ArrayList<>(softwareModuleRepository.findByIdIn(ids));
+        return Collections.unmodifiableList(softwareModuleRepository.findByIdIn(ids));
     }
 
     @Override
     public Slice<SoftwareModule> findSoftwareModuleByFilters(final Pageable pageable, final String searchText,
             final SoftwareModuleType type) {
 
-        final List<Specification<JpaSoftwareModule>> specList = new ArrayList<>();
+        final List<Specification<JpaSoftwareModule>> specList = new ArrayList<>(4);
 
         Specification<JpaSoftwareModule> spec = SoftwareModuleSpecification.isDeletedFalse();
         specList.add(spec);
@@ -444,7 +444,7 @@ public class JpaSoftwareManagement implements SoftwareManagement {
 
     private static List<Specification<JpaSoftwareModule>> buildSpecificationList(final String searchText,
             final JpaSoftwareModuleType type) {
-        final List<Specification<JpaSoftwareModule>> specList = new ArrayList<>();
+        final List<Specification<JpaSoftwareModule>> specList = new ArrayList<>(3);
         if (!Strings.isNullOrEmpty(searchText)) {
             specList.add(SoftwareModuleSpecification.likeNameOrVersion(searchText));
         }
@@ -458,18 +458,15 @@ public class JpaSoftwareManagement implements SoftwareManagement {
     private Predicate[] specificationsToPredicate(final List<Specification<JpaSoftwareModule>> specifications,
             final Root<JpaSoftwareModule> root, final CriteriaQuery<?> query, final CriteriaBuilder cb,
             final Predicate... additionalPredicates) {
-        final List<Predicate> predicates = new ArrayList<>();
+
-        specifications.forEach(spec -> predicates.add(spec.toPredicate(root, query, cb)));
+        return Stream.concat(specifications.stream().map(spec -> spec.toPredicate(root, query, cb)),
-        for (final Predicate predicate : additionalPredicates) {
+                Arrays.stream(additionalPredicates)).toArray(Predicate[]::new);
-            predicates.add(predicate);
-        }
-        return predicates.toArray(new Predicate[predicates.size()]);
     }
 
     @Override
     public Long countSoftwareModuleByFilters(final String searchText, final SoftwareModuleType type) {
 
-        final List<Specification<JpaSoftwareModule>> specList = new ArrayList<>();
+        final List<Specification<JpaSoftwareModule>> specList = new ArrayList<>(3);
 
         Specification<JpaSoftwareModule> spec = SoftwareModuleSpecification.isDeletedFalse();
         specList.add(spec);
@@ -579,7 +576,7 @@ public class JpaSoftwareManagement implements SoftwareManagement {
             checkAndThrowAlreadyExistsIfSoftwareModuleMetadataExists(softwareModuleMetadata.getId());
         }
         metadata.forEach(m -> entityManager.merge((JpaSoftwareModule) m.getSoftwareModule()).setLastModifiedAt(-1L));
-        return new ArrayList<>(softwareModuleMetadataRepository.save(metadata));
+        return Collections.unmodifiableList(softwareModuleMetadataRepository.save(metadata));
     }
 
     @Override
@@ -629,8 +626,8 @@ public class JpaSoftwareManagement implements SoftwareManagement {
 
     @Override
     public List<SoftwareModuleMetadata> findSoftwareModuleMetadataBySoftwareModuleId(final Long softwareModuleId) {
-        return new ArrayList<>(
+        return Collections
-                softwareModuleMetadataRepository
+                .unmodifiableList(softwareModuleMetadataRepository
                         .findAll((Specification<JpaSoftwareModuleMetadata>) (root, query,
                                 cb) -> cb.and(cb.equal(
                                         root.get(JpaSoftwareModuleMetadata_.softwareModule).get(JpaSoftwareModule_.id),

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/JpaTagManagement.java

@@ -10,8 +10,8 @@ package org.eclipse.hawkbit.repository.jpa;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
-import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 
@@ -115,7 +115,7 @@ public class JpaTagManagement implements TagManagement {
             }
         });
 
-        final List<TargetTag> save = new ArrayList<>(targetTagRepository.save(targetTags));
+        final List<TargetTag> save = Collections.unmodifiableList(targetTagRepository.save(targetTags));
         afterCommit
                 .afterCommit(() -> eventBus.post(new TargetTagCreatedBulkEvent(tenantAware.getCurrentTenant(), save)));
         return save;
@@ -145,7 +145,7 @@ public class JpaTagManagement implements TagManagement {
 
     @Override
     public List<TargetTag> findAllTargetTags() {
-        return new ArrayList<>(targetTagRepository.findAll());
+        return Collections.unmodifiableList(targetTagRepository.findAll());
     }
 
     @Override
@@ -156,12 +156,12 @@ public class JpaTagManagement implements TagManagement {
     }
 
     private static Page<TargetTag> convertTPage(final Page<JpaTargetTag> findAll, final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, findAll.getTotalElements());
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, findAll.getTotalElements());
     }
 
     private static Page<DistributionSetTag> convertDsPage(final Page<JpaDistributionSetTag> findAll,
             final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, findAll.getTotalElements());
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, findAll.getTotalElements());
     }
 
     @Override
@@ -217,7 +217,8 @@ public class JpaTagManagement implements TagManagement {
                 throw new EntityAlreadyExistsException();
             }
         }
-        final List<DistributionSetTag> save = new ArrayList<>(distributionSetTagRepository.save(distributionSetTags));
+        final List<DistributionSetTag> save = Collections
+                .unmodifiableList(distributionSetTagRepository.save(distributionSetTags));
         afterCommit.afterCommit(
                 () -> eventBus.post(new DistributionSetTagCreatedBulkEvent(tenantAware.getCurrentTenant(), save)));
 
@@ -232,7 +233,7 @@ public class JpaTagManagement implements TagManagement {
 
         final List<JpaDistributionSet> changed = new LinkedList<>();
         for (final JpaDistributionSet set : distributionSetRepository.findByTag(tag)) {
-            set.getTags().remove(tag);
+            set.removeTag(tag);
             changed.add(set);
         }
 
@@ -258,7 +259,7 @@ public class JpaTagManagement implements TagManagement {
 
     @Override
     public List<DistributionSetTag> findAllDistributionSetTags() {
-        return new ArrayList<>(distributionSetTagRepository.findAll());
+        return Collections.unmodifiableList(distributionSetTagRepository.findAll());
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/JpaTargetManagement.java

@@ -132,7 +132,7 @@ public class JpaTargetManagement implements TargetManagement {
 
     @Override
     public List<Target> findTargetByControllerID(final Collection<String> controllerIDs) {
-        return new ArrayList<>(targetRepository
+        return Collections.unmodifiableList(targetRepository
                 .findAll(TargetSpecifications.byControllerIdWithStatusAndAssignedInJoin(controllerIDs)));
     }
 
@@ -201,7 +201,7 @@ public class JpaTargetManagement implements TargetManagement {
 
         toUpdate.forEach(target -> target.setNew(false));
 
-        return new ArrayList<>(targetRepository.save(toUpdate));
+        return Collections.unmodifiableList(targetRepository.save(toUpdate));
     }
 
     @Override
@@ -245,11 +245,11 @@ public class JpaTargetManagement implements TargetManagement {
     }
 
     private static Page<Target> convertPage(final Page<JpaTarget> findAll, final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, findAll.getTotalElements());
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, findAll.getTotalElements());
     }
 
     private static Slice<Target> convertPage(final Slice<JpaTarget> findAll, final Pageable pageable) {
-        return new PageImpl<>(new ArrayList<>(findAll.getContent()), pageable, 0);
+        return new PageImpl<>(Collections.unmodifiableList(findAll.getContent()), pageable, 0);
     }
 
     @Override
@@ -291,8 +291,8 @@ public class JpaTargetManagement implements TargetManagement {
 
     @Override
     public Long countTargetByFilters(final Collection<TargetUpdateStatus> status, final Boolean overdueState,
-            final String searchText, final Long installedOrAssignedDistributionSetId,
+                                     final String searchText, final Long installedOrAssignedDistributionSetId,
-            final Boolean selectTargetWithNoTag, final String... tagNames) {
+                                     final Boolean selectTargetWithNoTag, final String... tagNames) {
         final List<Specification<JpaTarget>> specList = buildSpecificationList(
                 new FilterParams(installedOrAssignedDistributionSetId, status, overdueState, searchText,
                         selectTargetWithNoTag, tagNames),
@@ -301,7 +301,7 @@ public class JpaTargetManagement implements TargetManagement {
     }
 
     private static List<Specification<JpaTarget>> buildSpecificationList(final FilterParams filterParams,
-            final boolean fetch) {
+                                                                         final boolean fetch) {
         final List<Specification<JpaTarget>> specList = new ArrayList<>();
         if (filterParams.getFilterByStatus() != null && !filterParams.getFilterByStatus().isEmpty()) {
             specList.add(TargetSpecifications.hasTargetUpdateStatus(filterParams.getFilterByStatus(), fetch));
@@ -362,7 +362,7 @@ public class JpaTargetManagement implements TargetManagement {
 
         // all are already assigned -> unassign
         if (alreadyAssignedTargets.size() == allTargets.size()) {
-            alreadyAssignedTargets.forEach(target -> target.getTags().remove(tag));
+            alreadyAssignedTargets.forEach(target -> target.removeTag(tag));
             final TargetTagAssignmentResult result = new TargetTagAssignmentResult(0, 0, alreadyAssignedTargets.size(),
                     Collections.emptyList(), alreadyAssignedTargets, tag);
 
@@ -372,9 +372,10 @@ public class JpaTargetManagement implements TargetManagement {
 
         allTargets.removeAll(alreadyAssignedTargets);
         // some or none are assigned -> assign
-        allTargets.forEach(target -> target.getTags().add(tag));
+        allTargets.forEach(target -> target.addTag(tag));
         final TargetTagAssignmentResult result = new TargetTagAssignmentResult(alreadyAssignedTargets.size(),
-                allTargets.size(), 0, new ArrayList<>(targetRepository.save(allTargets)), Collections.emptyList(), tag);
+                allTargets.size(), 0, Collections.unmodifiableList(targetRepository.save(allTargets)),
+                Collections.emptyList(), tag);
 
         afterCommit.afterCommit(() -> eventBus.post(new TargetTagAssigmentResultEvent(result)));
 
@@ -390,8 +391,8 @@ public class JpaTargetManagement implements TargetManagement {
         final List<JpaTarget> allTargets = targetRepository
                 .findAll(TargetSpecifications.byControllerIdWithStatusAndTagsInJoin(targetIds));
 
-        allTargets.forEach(target -> target.getTags().add(tag));
+        allTargets.forEach(target -> target.addTag(tag));
-        final List<Target> save = new ArrayList<>(targetRepository.save(allTargets));
+        final List<Target> save = Collections.unmodifiableList(targetRepository.save(allTargets));
 
         afterCommit.afterCommit(() -> {
             final TargetTagAssignmentResult assigmentResult = new TargetTagAssignmentResult(0, save.size(), 0, save,
@@ -403,11 +404,12 @@ public class JpaTargetManagement implements TargetManagement {
     }
 
     private List<Target> unAssignTag(final Collection<Target> targets, final TargetTag tag) {
+        @SuppressWarnings({ "unchecked", "rawtypes" })
         final Collection<JpaTarget> toUnassign = (Collection) targets;
 
-        toUnassign.forEach(target -> target.getTags().remove(tag));
+        toUnassign.forEach(target -> target.removeTag(tag));
 
-        final List<Target> save = new ArrayList<>(targetRepository.save(toUnassign));
+        final List<Target> save = Collections.unmodifiableList(targetRepository.save(toUnassign));
         afterCommit.afterCommit(() -> {
             final TargetTagAssignmentResult assigmentResult = new TargetTagAssignmentResult(0, 0, save.size(),
                     Collections.emptyList(), save, tag);
@@ -427,7 +429,7 @@ public class JpaTargetManagement implements TargetManagement {
     @Modifying
     @Transactional(isolation = Isolation.READ_UNCOMMITTED)
     public Target unAssignTag(final String controllerID, final TargetTag targetTag) {
-        final List<Target> allTargets = new ArrayList<>(targetRepository
+        final List<Target> allTargets = Collections.unmodifiableList(targetRepository
                 .findAll(TargetSpecifications.byControllerIdWithStatusAndTagsInJoin(Arrays.asList(controllerID))));
         final List<Target> unAssignTag = unAssignTag(allTargets, targetTag);
         return unAssignTag.isEmpty() ? null : unAssignTag.get(0);
@@ -481,7 +483,7 @@ public class JpaTargetManagement implements TargetManagement {
         final List<JpaTarget> resultList = entityManager.createQuery(query).setFirstResult(pageable.getOffset())
                 .setMaxResults(pageSize + 1).getResultList();
         final boolean hasNext = resultList.size() > pageSize;
-        return new SliceImpl<>(new ArrayList<>(resultList), pageable, hasNext);
+        return new SliceImpl<>(Collections.unmodifiableList(resultList), pageable, hasNext);
     }
 
     private static Predicate[] specificationsToPredicate(final List<Specification<JpaTarget>> specifications,
@@ -564,13 +566,9 @@ public class JpaTargetManagement implements TargetManagement {
         final CriteriaQuery<Object[]> multiselect = query.multiselect(targetRoot.get(JpaTarget_.id),
                 targetRoot.get(JpaTarget_.controllerId), targetRoot.get(JpaTarget_.name), targetRoot.get(sortProperty));
 
-        final Specification<JpaTarget> spec = RSQLUtility.parse(targetFilterQuery.getQuery(), TargetFields.class,
+        final Specification<JpaTarget> spec = RSQLUtility.parse(targetFilterQuery.getQuery(), TargetFields.class, virtualPropertyLookup);
-                virtualPropertyLookup);
+        final Predicate[] specificationsForMultiSelect = specificationsToPredicate(Lists.newArrayList(spec), targetRoot,
-        final List<Specification<JpaTarget>> specList = new ArrayList<>();
+                multiselect, cb);
-        specList.add(spec);
-
-        final Predicate[] specificationsForMultiSelect = specificationsToPredicate(specList, targetRoot, multiselect,
-                cb);
 
         // if we have some predicates then add it to the where clause of the
         // multiselect
@@ -632,18 +630,16 @@ public class JpaTargetManagement implements TargetManagement {
                 targets.stream().map(target -> target.getControllerId()).collect(Collectors.toList())) > 0) {
             throw new EntityAlreadyExistsException();
         }
-        final List<Target> savedTargets = new ArrayList<>();
+
-        for (final Target t : targets) {
+        return targets.stream()
-            final Target myTarget = createTarget(t, TargetUpdateStatus.UNKNOWN, null, t.getTargetInfo().getAddress());
+                .map(t -> createTarget(t, TargetUpdateStatus.UNKNOWN, null, t.getTargetInfo().getAddress()))
-            savedTargets.add(myTarget);
+                .collect(Collectors.toList());
-        }
-        return savedTargets;
     }
 
     @Override
     public List<Target> findTargetsByTag(final String tagName) {
         final JpaTargetTag tag = targetTagRepository.findByNameEquals(tagName);
-        return new ArrayList<>(targetRepository.findByTag(tag));
+        return Collections.unmodifiableList(targetRepository.findByTag(tag));
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/aspects/ExceptionMappingAspectHandler.java

@@ -10,7 +10,6 @@ package org.eclipse.hawkbit.repository.jpa.aspects;
 
 import java.sql.SQLException;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -36,6 +35,8 @@ import org.springframework.orm.jpa.JpaVendorAdapter;
 import org.springframework.security.access.AccessDeniedException;
 import org.springframework.transaction.TransactionSystemException;
 
+import com.google.common.collect.Maps;
+
 /**
  * {@link Aspect} catches persistence exceptions and wraps them to custom
  * specific exceptions Additionally it checks and prevents access to certain
@@ -49,14 +50,14 @@ public class ExceptionMappingAspectHandler implements Ordered {
 
     private static final Logger LOG = LoggerFactory.getLogger(ExceptionMappingAspectHandler.class);
 
-    private static final Map<String, String> EXCEPTION_MAPPING = new HashMap<>();
+    private static final Map<String, String> EXCEPTION_MAPPING = Maps.newHashMapWithExpectedSize(4);
 
     /**
      * this is required to enable a certain order of exception and to select the
      * most specific mappable exception according to the type hierarchy of the
      * exception.
      */
-    private static final List<Class<?>> MAPPED_EXCEPTION_ORDER = new ArrayList<>();
+    private static final List<Class<?>> MAPPED_EXCEPTION_ORDER = new ArrayList<>(4);
 
     @Autowired
     private JpaVendorAdapter jpaVendorAdapter;

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/AbstractJpaArtifact.java

@@ -32,7 +32,7 @@ public abstract class AbstractJpaArtifact extends AbstractJpaTenantAwareBaseEnti
     private String md5Hash;
 
     @Column(name = "file_size")
-    private Long size;
+    private long size;
 
     @Override
     public abstract SoftwareModule getSoftwareModule();
@@ -56,11 +56,11 @@ public abstract class AbstractJpaArtifact extends AbstractJpaTenantAwareBaseEnti
     }
 
     @Override
-    public Long getSize() {
+    public long getSize() {
         return size;
     }
 
-    public void setSize(final Long size) {
+    public void setSize(final long size) {
         this.size = size;
     }
 }

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/AbstractJpaBaseEntity.java

@@ -48,7 +48,7 @@ public abstract class AbstractJpaBaseEntity implements BaseEntity {
 
     @Version
     @Column(name = "optlock_revision")
-    private long optLockRevision;
+    private int optLockRevision;
 
     /**
      * Default constructor needed for JPA entities.
@@ -106,11 +106,11 @@ public abstract class AbstractJpaBaseEntity implements BaseEntity {
     }
 
     @Override
-    public long getOptLockRevision() {
+    public int getOptLockRevision() {
         return optLockRevision;
     }
 
-    public void setOptLockRevision(final long optLockRevision) {
+    public void setOptLockRevision(final int optLockRevision) {
         this.optLockRevision = optLockRevision;
     }
 
@@ -142,7 +142,7 @@ public abstract class AbstractJpaBaseEntity implements BaseEntity {
         final int prime = 31;
         int result = 1;
         result = prime * result + (id == null ? 0 : id.hashCode());
-        result = prime * result + (int) (optLockRevision ^ optLockRevision >>> 32);
+        result = prime * result + optLockRevision;
         result = prime * result + this.getClass().getName().hashCode();
         return result;
     }
@@ -179,5 +179,4 @@ public abstract class AbstractJpaBaseEntity implements BaseEntity {
         return true;
     }
 
-    
 }

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/AbstractJpaMetaData.java

@@ -26,7 +26,7 @@ public abstract class AbstractJpaMetaData implements MetaData {
     private static final long serialVersionUID = 1L;
 
     @Id
-    @Column(name = "meta_key", length = 128)
+    @Column(name = "meta_key", nullable = false, length = 128)
     @Size(min = 1, max = 128)
     @NotNull
     private String key;
@@ -37,7 +37,6 @@ public abstract class AbstractJpaMetaData implements MetaData {
     private String value;
 
     public AbstractJpaMetaData(final String key, final String value) {
-        super();
         this.key = key;
         this.value = value;
     }

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/AbstractJpaNamedEntity.java

@@ -40,7 +40,7 @@ public abstract class AbstractJpaNamedEntity extends AbstractJpaTenantAwareBaseE
      * Default constructor.
      */
     public AbstractJpaNamedEntity() {
-        super();
+        // Default constructor needed for JPA entities
     }
 
     /**

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/AbstractJpaNamedVersionedEntity.java

@@ -47,7 +47,7 @@ public abstract class AbstractJpaNamedVersionedEntity extends AbstractJpaNamedEn
     }
 
     AbstractJpaNamedVersionedEntity() {
-        super();
+        // Default constructor needed for JPA entities
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/AbstractJpaTag.java

@@ -31,7 +31,7 @@ public abstract class AbstractJpaTag extends AbstractJpaNamedEntity implements T
     private String colour;
 
     protected AbstractJpaTag() {
-        super();
+        // Default constructor needed for JPA entities
     }
 
     /**

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaAction.java

@@ -8,6 +8,7 @@
  */
 package org.eclipse.hawkbit.repository.jpa.model;
 
+import java.util.Collections;
 import java.util.List;
 
 import javax.persistence.CascadeType;
@@ -134,7 +135,11 @@ public class JpaAction extends AbstractJpaTenantAwareBaseEntity implements Actio
 
     @Override
     public List<ActionStatus> getActionStatus() {
-        return actionStatus;
+        if (actionStatus == null) {
+            return Collections.emptyList();
+        }
+
+        return Collections.unmodifiableList(actionStatus);
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaActionStatus.java

@@ -9,6 +9,7 @@
 package org.eclipse.hawkbit.repository.jpa.model;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 import javax.persistence.CollectionTable;
@@ -48,6 +49,8 @@ import com.google.common.base.Splitter;
 // sub entities
 @SuppressWarnings("squid:S2160")
 public class JpaActionStatus extends AbstractJpaTenantAwareBaseEntity implements ActionStatus {
+    private static final int MESSAGE_ENTRY_LENGTH = 512;
+
     private static final long serialVersionUID = 1L;
 
     @Column(name = "target_occurred_at")
@@ -67,14 +70,14 @@ public class JpaActionStatus extends AbstractJpaTenantAwareBaseEntity implements
     @CollectionTable(name = "sp_action_status_messages", joinColumns = @JoinColumn(name = "action_status_id", foreignKey = @ForeignKey(value = ConstraintMode.CONSTRAINT, name = "fk_stat_msg_act_stat")), indexes = {
             @Index(name = "sp_idx_action_status_msgs_01", columnList = "action_status_id") })
     @Column(name = "detail_message", length = 512)
-    private final List<String> messages = new ArrayList<>();
+    private List<String> messages;
 
     /**
      * Note: filled only in {@link Status#DOWNLOAD}.
      */
     @Transient
     @CacheField(key = CacheKeys.DOWNLOAD_PROGRESS_PERCENT)
-    private int downloadProgressPercent;
+    private short downloadProgressPercent;
 
     /**
      * Creates a new {@link ActionStatus} object.
@@ -86,7 +89,7 @@ public class JpaActionStatus extends AbstractJpaTenantAwareBaseEntity implements
      * @param occurredAt
      *            the occurred timestamp
      */
-    public JpaActionStatus(final Action action, final Status status, final Long occurredAt) {
+    public JpaActionStatus(final Action action, final Status status, final long occurredAt) {
         this.action = (JpaAction) action;
         this.status = status;
         this.occurredAt = occurredAt;
@@ -119,7 +122,7 @@ public class JpaActionStatus extends AbstractJpaTenantAwareBaseEntity implements
     }
 
     @Override
-    public int getDownloadProgressPercent() {
+    public short getDownloadProgressPercent() {
         return downloadProgressPercent;
     }
 
@@ -136,13 +139,20 @@ public class JpaActionStatus extends AbstractJpaTenantAwareBaseEntity implements
     @Override
     public final void addMessage(final String message) {
         if (message != null) {
-            Splitter.fixedLength(512).split(message).forEach(messages::add);
+            if (messages == null) {
+                messages = new ArrayList<>((message.length() / MESSAGE_ENTRY_LENGTH) + 1);
+            }
+            Splitter.fixedLength(MESSAGE_ENTRY_LENGTH).split(message).forEach(messages::add);
         }
     }
 
     @Override
     public List<String> getMessages() {
-        return messages;
+        if (messages == null) {
+            messages = Collections.emptyList();
+        }
+
+        return Collections.unmodifiableList(messages);
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaActionWithStatusCount.java

@@ -59,7 +59,7 @@ public class JpaActionWithStatusCount implements ActionWithStatusCount {
     // Exception squid:S00107 - needed this way for JPA to fill the view
     @SuppressWarnings("squid:S00107")
     public JpaActionWithStatusCount(final Long actionId, final ActionType actionType, final boolean active,
-            final long forcedTime, final Status status, final Long actionCreatedAt, final Long actionLastModifiedAt,
+            final Long forcedTime, final Status status, final Long actionCreatedAt, final Long actionLastModifiedAt,
             final Long dsId, final String dsName, final String dsVersion, final Long actionStatusCount,
             final String rolloutName) {
         this.dsId = dsId;

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaDistributionSet.java

@@ -8,7 +8,6 @@
  */
 package org.eclipse.hawkbit.repository.jpa.model;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
@@ -82,13 +81,13 @@ public class JpaDistributionSet extends AbstractJpaNamedVersionedEntity implemen
     @JoinTable(name = "sp_ds_module", joinColumns = {
             @JoinColumn(name = "ds_id", foreignKey = @ForeignKey(value = ConstraintMode.CONSTRAINT, name = "fk_ds_module_ds")) }, inverseJoinColumns = {
                     @JoinColumn(name = "module_id", foreignKey = @ForeignKey(value = ConstraintMode.CONSTRAINT, name = "fk_ds_module_module")) })
-    private final Set<SoftwareModule> modules = new HashSet<>();
+    private Set<SoftwareModule> modules;
 
     @ManyToMany(targetEntity = JpaDistributionSetTag.class)
     @JoinTable(name = "sp_ds_dstag", joinColumns = {
             @JoinColumn(name = "ds", foreignKey = @ForeignKey(value = ConstraintMode.CONSTRAINT, name = "fk_ds_dstag_ds")) }, inverseJoinColumns = {
                     @JoinColumn(name = "TAG", foreignKey = @ForeignKey(value = ConstraintMode.CONSTRAINT, name = "fk_ds_dstag_tag")) })
-    private Set<DistributionSetTag> tags = new HashSet<>();
+    private Set<DistributionSetTag> tags;
 
     @Column(name = "deleted")
     private boolean deleted;
@@ -106,7 +105,7 @@ public class JpaDistributionSet extends AbstractJpaNamedVersionedEntity implemen
     @OneToMany(fetch = FetchType.LAZY, targetEntity = JpaDistributionSetMetadata.class, cascade = {
             CascadeType.REMOVE })
     @JoinColumn(name = "ds_id", insertable = false, updatable = false)
-    private final List<DistributionSetMetadata> metadata = new ArrayList<>();
+    private List<DistributionSetMetadata> metadata;
 
     @ManyToOne(fetch = FetchType.LAZY, targetEntity = JpaDistributionSetType.class)
     @JoinColumn(name = "ds_id", nullable = false, foreignKey = @ForeignKey(value = ConstraintMode.CONSTRAINT, name = "fk_ds_dstype_ds"))
@@ -120,7 +119,7 @@ public class JpaDistributionSet extends AbstractJpaNamedVersionedEntity implemen
      * Default constructor.
      */
     public JpaDistributionSet() {
-        super();
+        // Default constructor for JPA
     }
 
     /**
@@ -152,7 +151,29 @@ public class JpaDistributionSet extends AbstractJpaNamedVersionedEntity implemen
 
     @Override
     public Set<DistributionSetTag> getTags() {
-        return tags;
+        if (tags == null) {
+            return Collections.emptySet();
+        }
+
+        return Collections.unmodifiableSet(tags);
+    }
+
+    @Override
+    public boolean addTag(final DistributionSetTag tag) {
+        if (tags == null) {
+            tags = new HashSet<>();
+        }
+
+        return tags.add(tag);
+    }
+
+    @Override
+    public boolean removeTag(final DistributionSetTag tag) {
+        if (tags == null) {
+            return false;
+        }
+
+        return tags.remove(tag);
     }
 
     @Override
@@ -162,11 +183,19 @@ public class JpaDistributionSet extends AbstractJpaNamedVersionedEntity implemen
 
     @Override
     public List<DistributionSetMetadata> getMetadata() {
+        if (metadata == null) {
+            return Collections.emptyList();
+        }
+
         return Collections.unmodifiableList(metadata);
     }
 
     public List<Action> getActions() {
-        return actions;
+        if (actions == null) {
+            return Collections.emptyList();
+        }
+
+        return Collections.unmodifiableList(actions);
     }
 
     @Override
@@ -186,19 +215,22 @@ public class JpaDistributionSet extends AbstractJpaNamedVersionedEntity implemen
         return this;
     }
 
-    public DistributionSet setTags(final Set<DistributionSetTag> tags) {
-        this.tags = tags;
-        return this;
-    }
-
     @Override
     public List<Target> getAssignedTargets() {
-        return assignedToTargets;
+        if (assignedToTargets == null) {
+            return Collections.emptyList();
+        }
+
+        return Collections.unmodifiableList(assignedToTargets);
     }
 
     @Override
     public List<TargetInfo> getInstalledTargets() {
-        return installedAtTargets;
+        if (installedAtTargets == null) {
+            return Collections.emptyList();
+        }
+
+        return Collections.unmodifiableList(installedAtTargets);
     }
 
     @Override
@@ -209,21 +241,20 @@ public class JpaDistributionSet extends AbstractJpaNamedVersionedEntity implemen
 
     @Override
     public Set<SoftwareModule> getModules() {
+        if (modules == null) {
+            return Collections.emptySet();
+        }
+
         return Collections.unmodifiableSet(modules);
     }
 
     @Override
     public boolean addModule(final SoftwareModule softwareModule) {
-
+        if (modules == null) {
-        // we cannot allow that modules are added without a type defined
+            modules = new HashSet<>();
-        if (type == null) {
-            throw new DistributionSetTypeUndefinedException();
         }
 
-        // check if it is allowed to such a module to this DS type
+        checkTypeCompatability(softwareModule);
-        if (!type.containsModuleType(softwareModule.getType())) {
-            throw new UnsupportedSoftwareModuleForThisDistributionSetException();
-        }
 
         final Optional<SoftwareModule> found = modules.stream()
                 .filter(module -> module.getId().equals(softwareModule.getId())).findFirst();
@@ -249,8 +280,24 @@ public class JpaDistributionSet extends AbstractJpaNamedVersionedEntity implemen
         return false;
     }
 
+    private void checkTypeCompatability(final SoftwareModule softwareModule) {
+        // we cannot allow that modules are added without a type defined
+        if (type == null) {
+            throw new DistributionSetTypeUndefinedException();
+        }
+
+        // check if it is allowed to such a module to this DS type
+        if (!type.containsModuleType(softwareModule.getType())) {
+            throw new UnsupportedSoftwareModuleForThisDistributionSetException();
+        }
+    }
+
     @Override
     public boolean removeModule(final SoftwareModule softwareModule) {
+        if (modules == null) {
+            return false;
+        }
+
         final Optional<SoftwareModule> found = modules.stream()
                 .filter(module -> module.getId().equals(softwareModule.getId())).findFirst();
 
@@ -266,6 +313,10 @@ public class JpaDistributionSet extends AbstractJpaNamedVersionedEntity implemen
 
     @Override
     public SoftwareModule findFirstModuleByType(final SoftwareModuleType type) {
+        if (modules == null) {
+            return null;
+        }
+
         final Optional<SoftwareModule> result = modules.stream().filter(module -> module.getType().equals(type))
                 .findFirst();
 

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaDistributionSetTag.java

@@ -8,6 +8,7 @@
  */
 package org.eclipse.hawkbit.repository.jpa.model;
 
+import java.util.Collections;
 import java.util.List;
 
 import javax.persistence.Entity;
@@ -68,7 +69,11 @@ public class JpaDistributionSetTag extends AbstractJpaTag implements Distributio
 
     @Override
     public List<DistributionSet> getAssignedToDistributionSet() {
-        return assignedToDistributionSet;
+        if (assignedToDistributionSet == null) {
+            return Collections.emptyList();
+        }
+
+        return Collections.unmodifiableList(assignedToDistributionSet);
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaDistributionSetType.java

@@ -8,6 +8,7 @@
  */
 package org.eclipse.hawkbit.repository.jpa.model;
 
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.Optional;
 import java.util.Set;
@@ -24,6 +25,7 @@ import javax.persistence.Table;
 import javax.persistence.UniqueConstraint;
 import javax.validation.constraints.Size;
 
+import org.apache.commons.collections4.CollectionUtils;
 import org.eclipse.hawkbit.repository.model.DistributionSet;
 import org.eclipse.hawkbit.repository.model.DistributionSetType;
 import org.eclipse.hawkbit.repository.model.SoftwareModuleType;
@@ -48,7 +50,7 @@ public class JpaDistributionSetType extends AbstractJpaNamedEntity implements Di
     @OneToMany(targetEntity = DistributionSetTypeElement.class, cascade = {
             CascadeType.ALL }, fetch = FetchType.EAGER, orphanRemoval = true)
     @JoinColumn(name = "distribution_set_type", insertable = false, updatable = false)
-    private final Set<DistributionSetTypeElement> elements = new HashSet<>();
+    private Set<DistributionSetTypeElement> elements;
 
     @Column(name = "type_key", nullable = false, length = 64)
     @Size(max = 64)
@@ -108,23 +110,52 @@ public class JpaDistributionSetType extends AbstractJpaNamedEntity implements Di
 
     @Override
     public Set<SoftwareModuleType> getMandatoryModuleTypes() {
+        if (elements == null) {
+            return Collections.emptySet();
+        }
+
         return elements.stream().filter(element -> element.isMandatory()).map(element -> element.getSmType())
                 .collect(Collectors.toSet());
     }
 
     @Override
     public Set<SoftwareModuleType> getOptionalModuleTypes() {
+        if (elements == null) {
+            return Collections.emptySet();
+        }
+
         return elements.stream().filter(element -> !element.isMandatory()).map(element -> element.getSmType())
                 .collect(Collectors.toSet());
     }
 
     @Override
     public boolean areModuleEntriesIdentical(final DistributionSetType dsType) {
+        if (!(dsType instanceof JpaDistributionSetType) || isOneModuleListEmpty(dsType)) {
+            return false;
+        } else if (areBothModuleListsEmpty(dsType)) {
+            return true;
+        }
+
         return new HashSet<DistributionSetTypeElement>(((JpaDistributionSetType) dsType).elements).equals(elements);
     }
 
+    private boolean isOneModuleListEmpty(final DistributionSetType dsType) {
+        return (!CollectionUtils.isEmpty(((JpaDistributionSetType) dsType).elements)
+                && CollectionUtils.isEmpty(elements))
+                || (CollectionUtils.isEmpty(((JpaDistributionSetType) dsType).elements)
+                        && !CollectionUtils.isEmpty(elements));
+    }
+
+    private boolean areBothModuleListsEmpty(final DistributionSetType dsType) {
+        return CollectionUtils.isEmpty(((JpaDistributionSetType) dsType).elements) && CollectionUtils.isEmpty(elements);
+    }
+
     @Override
     public DistributionSetType addOptionalModuleType(final SoftwareModuleType smType) {
+        if (elements == null) {
+            elements = new HashSet<>();
+        }
+
         elements.add(new DistributionSetTypeElement(this, (JpaSoftwareModuleType) smType, false));
 
         return this;
@@ -132,6 +163,10 @@ public class JpaDistributionSetType extends AbstractJpaNamedEntity implements Di
 
     @Override
     public DistributionSetType addMandatoryModuleType(final SoftwareModuleType smType) {
+        if (elements == null) {
+            elements = new HashSet<>();
+        }
+
         elements.add(new DistributionSetTypeElement(this, (JpaSoftwareModuleType) smType, true));
 
         return this;
@@ -139,6 +174,10 @@ public class JpaDistributionSetType extends AbstractJpaNamedEntity implements Di
 
     @Override
     public DistributionSetType removeModuleType(final Long smTypeId) {
+        if (elements == null) {
+            return this;
+        }
+
         // we search by id (standard equals compares also revison)
         final Optional<DistributionSetTypeElement> found = elements.stream()
                 .filter(element -> element.getSmType().getId().equals(smTypeId)).findFirst();
@@ -177,7 +216,11 @@ public class JpaDistributionSetType extends AbstractJpaNamedEntity implements Di
     }
 
     public Set<DistributionSetTypeElement> getElements() {
-        return elements;
+        if (elements == null) {
+            return Collections.emptySet();
+        }
+
+        return Collections.unmodifiableSet(elements);
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaRollout.java

@@ -8,6 +8,7 @@
  */
 package org.eclipse.hawkbit.repository.jpa.model;
 
+import java.util.Collections;
 import java.util.List;
 
 import javax.persistence.Column;
@@ -108,11 +109,11 @@ public class JpaRollout extends AbstractJpaNamedEntity implements Rollout, Event
 
     @Override
     public List<RolloutGroup> getRolloutGroups() {
-        return rolloutGroups;
+        if (rolloutGroups == null) {
-    }
+            return Collections.emptyList();
+        }
 
-    public void setRolloutGroups(final List<RolloutGroup> rolloutGroups) {
+        return Collections.unmodifiableList(rolloutGroups);
-        this.rolloutGroups = rolloutGroups;
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaRolloutGroup.java

@@ -8,7 +8,7 @@
  */
 package org.eclipse.hawkbit.repository.jpa.model;
 
-import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 import javax.persistence.CascadeType;
@@ -58,7 +58,7 @@ public class JpaRolloutGroup extends AbstractJpaNamedEntity implements RolloutGr
 
     @OneToMany(fetch = FetchType.LAZY, cascade = { CascadeType.PERSIST }, targetEntity = RolloutTargetGroup.class)
     @JoinColumn(name = "rolloutGroup_Id", insertable = false, updatable = false)
-    private final List<RolloutTargetGroup> rolloutTargetGroup = new ArrayList<>();
+    private List<RolloutTargetGroup> rolloutTargetGroup;
 
     @ManyToOne(fetch = FetchType.LAZY)
     private JpaRolloutGroup parent;
@@ -92,7 +92,7 @@ public class JpaRolloutGroup extends AbstractJpaNamedEntity implements RolloutGr
     private String errorActionExp;
 
     @Column(name = "total_targets")
-    private long totalTargets;
+    private int totalTargets;
 
     @Transient
     private transient TotalTargetCountStatus totalTargetCountStatus;
@@ -118,7 +118,11 @@ public class JpaRolloutGroup extends AbstractJpaNamedEntity implements RolloutGr
     }
 
     public List<RolloutTargetGroup> getRolloutTargetGroup() {
-        return rolloutTargetGroup;
+        if (rolloutTargetGroup == null) {
+            return Collections.emptyList();
+        }
+
+        return Collections.unmodifiableList(rolloutTargetGroup);
     }
 
     @Override
@@ -201,11 +205,11 @@ public class JpaRolloutGroup extends AbstractJpaNamedEntity implements RolloutGr
     }
 
     @Override
-    public long getTotalTargets() {
+    public int getTotalTargets() {
         return totalTargets;
     }
 
-    public void setTotalTargets(final long totalTargets) {
+    public void setTotalTargets(final int totalTargets) {
         this.totalTargets = totalTargets;
     }
 
@@ -223,7 +227,7 @@ public class JpaRolloutGroup extends AbstractJpaNamedEntity implements RolloutGr
     @Override
     public TotalTargetCountStatus getTotalTargetCountStatus() {
         if (totalTargetCountStatus == null) {
-            totalTargetCountStatus = new TotalTargetCountStatus(totalTargets);
+            totalTargetCountStatus = new TotalTargetCountStatus(new Long(totalTargets));
         }
         return totalTargetCountStatus;
     }

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaSoftwareModule.java

@@ -10,6 +10,7 @@ package org.eclipse.hawkbit.repository.jpa.model;
 
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Optional;
 
@@ -40,6 +41,8 @@ import org.eclipse.hawkbit.repository.model.SoftwareModuleMetadata;
 import org.eclipse.hawkbit.repository.model.SoftwareModuleType;
 import org.eclipse.persistence.annotations.CascadeOnDelete;
 
+import com.google.common.collect.Lists;
+
 /**
  * Base Software Module that is supported by OS level provisioning mechanism on
  * the edge controller, e.g. OS, JVM, AgentHub.
@@ -64,7 +67,7 @@ public class JpaSoftwareModule extends AbstractJpaNamedVersionedEntity implement
     private JpaSoftwareModuleType type;
 
     @ManyToMany(mappedBy = "modules", targetEntity = JpaDistributionSet.class, fetch = FetchType.LAZY)
-    private final List<DistributionSet> assignedTo = new ArrayList<>();
+    private List<DistributionSet> assignedTo;
 
     @Column(name = "deleted")
     private boolean deleted;
@@ -82,13 +85,13 @@ public class JpaSoftwareModule extends AbstractJpaNamedVersionedEntity implement
     @CascadeOnDelete
     @OneToMany(fetch = FetchType.LAZY, cascade = { CascadeType.REMOVE }, targetEntity = JpaSoftwareModuleMetadata.class)
     @JoinColumn(name = "sw_id", insertable = false, updatable = false)
-    private final List<SoftwareModuleMetadata> metadata = new ArrayList<>();
+    private List<SoftwareModuleMetadata> metadata;
 
     /**
      * Default constructor.
      */
     public JpaSoftwareModule() {
-        super();
+        // Default constructor for JPA
     }
 
     /**
@@ -120,6 +123,8 @@ public class JpaSoftwareModule extends AbstractJpaNamedVersionedEntity implement
     public void addArtifact(final LocalArtifact artifact) {
         if (null == artifacts) {
             artifacts = new ArrayList<>(4);
+            artifacts.add(artifact);
+            return;
         }
 
         if (!artifacts.contains(artifact)) {
@@ -134,7 +139,9 @@ public class JpaSoftwareModule extends AbstractJpaNamedVersionedEntity implement
     @Override
     public void addArtifact(final ExternalArtifact artifact) {
         if (null == externalArtifacts) {
-            externalArtifacts = new ArrayList<>(4);
+            externalArtifacts = new LinkedList<>();
+            externalArtifacts.add(artifact);
+            return;
         }
 
         if (!externalArtifacts.contains(artifact)) {
@@ -143,28 +150,18 @@ public class JpaSoftwareModule extends AbstractJpaNamedVersionedEntity implement
 
     }
 
-    /**
-     * @param artifactId
-     *            to look for
-     * @return found {@link Artifact}
-     */
     @Override
     public Optional<LocalArtifact> getLocalArtifact(final Long artifactId) {
-        if (null == artifacts) {
+        if (artifacts == null) {
             return Optional.empty();
         }
 
         return artifacts.stream().filter(artifact -> artifact.getId().equals(artifactId)).findFirst();
     }
 
-    /**
-     * @param fileName
-     *            to look for
-     * @return found {@link Artifact}
-     */
     @Override
     public Optional<LocalArtifact> getLocalArtifactByFilename(final String fileName) {
-        if (null == artifacts) {
+        if (artifacts == null) {
             return Optional.empty();
         }
 
@@ -177,11 +174,18 @@ public class JpaSoftwareModule extends AbstractJpaNamedVersionedEntity implement
      */
     @Override
     public List<Artifact> getArtifacts() {
-        final List<Artifact> result = new ArrayList<>();
+        if (artifacts == null && externalArtifacts == null) {
-        result.addAll(artifacts);
+            return Collections.emptyList();
+        } else if (artifacts == null) {
+            return Collections.unmodifiableList(externalArtifacts);
+        } else if (externalArtifacts == null) {
+            return Collections.unmodifiableList(artifacts);
+        }
+
+        final List<Artifact> result = Lists.newLinkedList(artifacts);
         result.addAll(externalArtifacts);
 
-        return result;
+        return Collections.unmodifiableList(result);
     }
 
     /**
@@ -207,7 +211,7 @@ public class JpaSoftwareModule extends AbstractJpaNamedVersionedEntity implement
      */
     @Override
     public void removeArtifact(final LocalArtifact artifact) {
-        if (null != artifacts) {
+        if (artifacts != null) {
             artifacts.remove(artifact);
         }
     }
@@ -218,7 +222,7 @@ public class JpaSoftwareModule extends AbstractJpaNamedVersionedEntity implement
      */
     @Override
     public void removeArtifact(final ExternalArtifact artifact) {
-        if (null != externalArtifacts) {
+        if (externalArtifacts != null) {
             externalArtifacts.remove(artifact);
         }
     }
@@ -248,11 +252,12 @@ public class JpaSoftwareModule extends AbstractJpaNamedVersionedEntity implement
         this.type = (JpaSoftwareModuleType) type;
     }
 
-    /**
-     * @return immutable list of meta data elements.
-     */
     @Override
     public List<SoftwareModuleMetadata> getMetadata() {
+        if (metadata == null) {
+            return Collections.emptyList();
+        }
+
         return Collections.unmodifiableList(metadata);
     }
 
@@ -262,12 +267,13 @@ public class JpaSoftwareModule extends AbstractJpaNamedVersionedEntity implement
                 + ", revision=" + getOptLockRevision() + ", Id=" + getId() + ", type=" + getType().getName() + "]";
     }
 
-    /**
-     * @return the assignedTo
-     */
     @Override
     public List<DistributionSet> getAssignedTo() {
-        return assignedTo;
+        if (assignedTo == null) {
+            return Collections.emptyList();
+        }
+
+        return Collections.unmodifiableList(assignedTo);
     }
 
 }

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaTarget.java

@@ -9,6 +9,7 @@
 package org.eclipse.hawkbit.repository.jpa.model;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -85,13 +86,13 @@ public class JpaTarget extends AbstractJpaNamedEntity implements Persistable<Lon
     @JoinTable(name = "sp_target_target_tag", joinColumns = {
             @JoinColumn(name = "target", foreignKey = @ForeignKey(value = ConstraintMode.CONSTRAINT, name = "fk_targ_targtag_target")) }, inverseJoinColumns = {
                     @JoinColumn(name = "tag", foreignKey = @ForeignKey(value = ConstraintMode.CONSTRAINT, name = "fk_targ_targtag_tag")) })
-    private Set<TargetTag> tags = new HashSet<>();
+    private Set<TargetTag> tags;
 
     @CascadeOnDelete
     @OneToMany(fetch = FetchType.LAZY, orphanRemoval = true, cascade = {
             CascadeType.REMOVE }, targetEntity = JpaAction.class)
     @JoinColumn(name = "target", insertable = false, updatable = false, foreignKey = @ForeignKey(value = ConstraintMode.CONSTRAINT, name = "fk_targ_act_hist_targ"))
-    private final List<Action> actions = new ArrayList<>();
+    private List<Action> actions;
 
     @ManyToOne(optional = true, fetch = FetchType.LAZY, targetEntity = JpaDistributionSet.class)
     @JoinColumn(name = "assigned_distribution_set", nullable = true, foreignKey = @ForeignKey(value = ConstraintMode.CONSTRAINT, name = "fk_target_assign_ds"))
@@ -114,7 +115,7 @@ public class JpaTarget extends AbstractJpaNamedEntity implements Persistable<Lon
     @CascadeOnDelete
     @OneToMany(fetch = FetchType.LAZY, cascade = { CascadeType.REMOVE, CascadeType.PERSIST })
     @JoinColumn(name = "target_Id", insertable = false, updatable = false)
-    private final List<RolloutTargetGroup> rolloutTargetGroup = new ArrayList<>();
+    private List<RolloutTargetGroup> rolloutTargetGroup;
 
     /**
      * Constructor.
@@ -141,12 +142,8 @@ public class JpaTarget extends AbstractJpaNamedEntity implements Persistable<Lon
         targetInfo = new JpaTargetInfo(this);
     }
 
-    /**
-     * empty constructor for JPA.
-     */
     JpaTarget() {
-        controllerId = null;
+        // empty constructor for JPA.
-        securityToken = null;
     }
 
     @Override
@@ -161,9 +158,39 @@ public class JpaTarget extends AbstractJpaNamedEntity implements Persistable<Lon
 
     @Override
     public Set<TargetTag> getTags() {
+        if (tags == null) {
+            return Collections.emptySet();
+        }
+
         return tags;
     }
 
+    public List<RolloutTargetGroup> getRolloutTargetGroup() {
+        if (rolloutTargetGroup == null) {
+            return Collections.emptyList();
+        }
+
+        return Collections.unmodifiableList(rolloutTargetGroup);
+    }
+
+    @Override
+    public boolean addTag(final TargetTag tag) {
+        if (tags == null) {
+            tags = new HashSet<>();
+        }
+
+        return tags.add(tag);
+    }
+
+    @Override
+    public boolean removeTag(final TargetTag tag) {
+        if (tags == null) {
+            return false;
+        }
+
+        return tags.remove(tag);
+    }
+
     public void setAssignedDistributionSet(final DistributionSet assignedDistributionSet) {
         this.assignedDistributionSet = (JpaDistributionSet) assignedDistributionSet;
     }
@@ -172,13 +199,21 @@ public class JpaTarget extends AbstractJpaNamedEntity implements Persistable<Lon
         this.controllerId = controllerId;
     }
 
-    public void setTags(final Set<TargetTag> tags) {
-        this.tags = tags;
-    }
-
     @Override
     public List<Action> getActions() {
-        return actions;
+        if (actions == null) {
+            return Collections.emptyList();
+        }
+
+        return Collections.unmodifiableList(actions);
+    }
+
+    public boolean addAction(final Action action) {
+        if (actions == null) {
+            actions = new ArrayList<>(4);
+        }
+
+        return actions.add(action);
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaTargetInfo.java

@@ -220,7 +220,7 @@ public class JpaTargetInfo implements Persistable<Long>, TargetInfo, EventAwareE
         return lastTargetQuery;
     }
 
-    public void setLastTargetQuery(final Long lastTargetQuery) {
+    public void setLastTargetQuery(final long lastTargetQuery) {
         this.lastTargetQuery = lastTargetQuery;
     }
 

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/model/JpaTargetTag.java

@@ -8,6 +8,7 @@
  */
 package org.eclipse.hawkbit.repository.jpa.model;
 
+import java.util.Collections;
 import java.util.List;
 
 import javax.persistence.Entity;
@@ -65,7 +66,11 @@ public class JpaTargetTag extends AbstractJpaTag implements TargetTag {
 
     @Override
     public List<Target> getAssignedToTargets() {
-        return assignedToTargets;
+        if (assignedToTargets == null) {
+            return Collections.emptyList();
+        }
+
+        return Collections.unmodifiableList(assignedToTargets);
     }
 
     @Override

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/rollout/condition/ThresholdRolloutGroupSuccessCondition.java

@@ -29,8 +29,8 @@ public class ThresholdRolloutGroupSuccessCondition implements RolloutGroupCondit
 
     @Override
     public boolean eval(final Rollout rollout, final RolloutGroup rolloutGroup, final String expression) {
-        final Long totalGroup = rolloutGroup.getTotalTargets();
+        final long totalGroup = rolloutGroup.getTotalTargets();
-        final Long finished = this.actionRepository.countByRolloutIdAndRolloutGroupIdAndStatus(rollout.getId(),
+        final long finished = this.actionRepository.countByRolloutIdAndRolloutGroupIdAndStatus(rollout.getId(),
                 rolloutGroup.getId(), Action.Status.FINISHED);
         try {
             final Integer threshold = Integer.valueOf(expression);

hawkbit-repository/hawkbit-repository-jpa/src/test/java/org/eclipse/hawkbit/repository/jpa/DeploymentManagementTest.java

@@ -106,7 +106,7 @@ public class DeploymentManagementTest extends AbstractJpaIntegrationTest {
 
         assertThat(findActionsWithStatusCountByTarget).as("wrong action size").hasSize(1);
         assertThat(findActionsWithStatusCountByTarget.get(0).getActionStatusCount()).as("wrong action status size")
-                .isEqualTo(3L);
+                .isEqualTo(3);
     }
 
     @Test
@@ -842,8 +842,8 @@ public class DeploymentManagementTest extends AbstractJpaIntegrationTest {
         final DistributionSet ds = testdataFactory.createDistributionSet("a");
         // assign ds to create an action
         final DistributionSetAssignmentResult assignDistributionSet = deploymentManagement.assignDistributionSet(
-                ds.getId(), ActionType.SOFT, org.eclipse.hawkbit.repository.model.RepositoryModelConstants.NO_FORCE_TIME,
+                ds.getId(), ActionType.SOFT,
-                target.getControllerId());
+                org.eclipse.hawkbit.repository.model.RepositoryModelConstants.NO_FORCE_TIME, target.getControllerId());
         final Action action = deploymentManagement.findActionWithDetails(assignDistributionSet.getActions().get(0));
         // verify preparation
         Action findAction = deploymentManagement.findAction(action.getId());
@@ -865,8 +865,8 @@ public class DeploymentManagementTest extends AbstractJpaIntegrationTest {
         final DistributionSet ds = testdataFactory.createDistributionSet("a");
         // assign ds to create an action
         final DistributionSetAssignmentResult assignDistributionSet = deploymentManagement.assignDistributionSet(
-                ds.getId(), ActionType.FORCED, org.eclipse.hawkbit.repository.model.RepositoryModelConstants.NO_FORCE_TIME,
+                ds.getId(), ActionType.FORCED,
-                target.getControllerId());
+                org.eclipse.hawkbit.repository.model.RepositoryModelConstants.NO_FORCE_TIME, target.getControllerId());
         final Action action = deploymentManagement.findActionWithDetails(assignDistributionSet.getActions().get(0));
         // verify perparation
         Action findAction = deploymentManagement.findAction(action.getId());

hawkbit-repository/hawkbit-repository-jpa/src/test/java/org/eclipse/hawkbit/repository/jpa/DistributionSetManagementTest.java

@@ -396,14 +396,14 @@ public class DistributionSetManagementTest extends AbstractJpaIntegrationTest {
         // create a DS
         final DistributionSet ds = testdataFactory.createDistributionSet("testDs");
         // initial opt lock revision must be zero
-        assertThat(ds.getOptLockRevision()).isEqualTo(1L);
+        assertThat(ds.getOptLockRevision()).isEqualTo(1);
 
         // create an DS meta data entry
         final DistributionSetMetadata dsMetadata = distributionSetManagement
                 .createDistributionSetMetadata(new JpaDistributionSetMetadata(knownKey, ds, knownValue));
 
         DistributionSet changedLockRevisionDS = distributionSetManagement.findDistributionSetById(ds.getId());
-        assertThat(changedLockRevisionDS.getOptLockRevision()).isEqualTo(2L);
+        assertThat(changedLockRevisionDS.getOptLockRevision()).isEqualTo(2);
 
         // modifying the meta data value
         dsMetadata.setValue(knownUpdateValue);
@@ -419,7 +419,7 @@ public class DistributionSetManagementTest extends AbstractJpaIntegrationTest {
         // module so opt lock
         // revision must be three
         changedLockRevisionDS = distributionSetManagement.findDistributionSetById(ds.getId());
-        assertThat(changedLockRevisionDS.getOptLockRevision()).isEqualTo(3L);
+        assertThat(changedLockRevisionDS.getOptLockRevision()).isEqualTo(3);
         assertThat(changedLockRevisionDS.getLastModifiedAt()).isGreaterThan(0L);
 
         // verify updated meta data contains the updated value

hawkbit-repository/hawkbit-repository-jpa/src/test/java/org/eclipse/hawkbit/repository/jpa/SoftwareManagementTest.java

@@ -848,7 +848,7 @@ public class SoftwareManagementTest extends AbstractJpaIntegrationTestWithMongoD
         final SoftwareModule ah = softwareManagement
                 .createSoftwareModule(new JpaSoftwareModule(appType, "agent-hub", "1.0.1", null, ""));
 
-        assertThat(ah.getOptLockRevision()).isEqualTo(1L);
+        assertThat(ah.getOptLockRevision()).isEqualTo(1);
 
         final SoftwareModuleMetadata swMetadata1 = new JpaSoftwareModuleMetadata(knownKey1, ah, knownValue1);
 
@@ -858,7 +858,7 @@ public class SoftwareManagementTest extends AbstractJpaIntegrationTestWithMongoD
                 .createSoftwareModuleMetadata(Lists.newArrayList(swMetadata1, swMetadata2));
 
         final SoftwareModule changedLockRevisionModule = softwareManagement.findSoftwareModuleById(ah.getId());
-        assertThat(changedLockRevisionModule.getOptLockRevision()).isEqualTo(2L);
+        assertThat(changedLockRevisionModule.getOptLockRevision()).isEqualTo(2);
 
         assertThat(softwareModuleMetadata).hasSize(2);
         assertThat(softwareModuleMetadata.get(0)).isNotNull();
@@ -900,7 +900,7 @@ public class SoftwareManagementTest extends AbstractJpaIntegrationTestWithMongoD
         final SoftwareModule ah = softwareManagement
                 .createSoftwareModule(new JpaSoftwareModule(appType, "agent-hub", "1.0.1", null, ""));
         // initial opt lock revision must be 1
-        assertThat(ah.getOptLockRevision()).isEqualTo(1L);
+        assertThat(ah.getOptLockRevision()).isEqualTo(1);
 
         // create an software module meta data entry
         final List<SoftwareModuleMetadata> softwareModuleMetadata = softwareManagement.createSoftwareModuleMetadata(
@@ -910,7 +910,7 @@ public class SoftwareManagementTest extends AbstractJpaIntegrationTestWithMongoD
         // because we are modifying the
         // base software module
         SoftwareModule changedLockRevisionModule = softwareManagement.findSoftwareModuleById(ah.getId());
-        assertThat(changedLockRevisionModule.getOptLockRevision()).isEqualTo(2L);
+        assertThat(changedLockRevisionModule.getOptLockRevision()).isEqualTo(2);
 
         // modifying the meta data value
         softwareModuleMetadata.get(0).setValue(knownUpdateValue);
@@ -925,7 +925,7 @@ public class SoftwareManagementTest extends AbstractJpaIntegrationTestWithMongoD
         // module so opt lock
         // revision must be two
         changedLockRevisionModule = softwareManagement.findSoftwareModuleById(ah.getId());
-        assertThat(changedLockRevisionModule.getOptLockRevision()).isEqualTo(3L);
+        assertThat(changedLockRevisionModule.getOptLockRevision()).isEqualTo(3);
 
         // verify updated meta data contains the updated value
         assertThat(updated).isNotNull();

hawkbit-repository/hawkbit-repository-jpa/src/test/java/org/eclipse/hawkbit/repository/jpa/TargetManagementSearchTest.java

@@ -735,7 +735,8 @@ public class TargetManagementSearchTest extends AbstractJpaIntegrationTest {
 
         final DistributionSet ds = testdataFactory.createDistributionSet("a");
 
-        targAssigned = deploymentManagement.assignDistributionSet(ds, targAssigned).getAssignedEntity();
+        targAssigned = Lists
+                .newLinkedList(deploymentManagement.assignDistributionSet(ds, targAssigned).getAssignedEntity());
         targInstalled = deploymentManagement.assignDistributionSet(ds, targInstalled).getAssignedEntity();
         targInstalled = sendUpdateActionStatusToTargets(ds, targInstalled, Status.FINISHED, "installed");
 
@@ -863,7 +864,7 @@ public class TargetManagementSearchTest extends AbstractJpaIntegrationTest {
 
     private List<Target> sendUpdateActionStatusToTargets(final DistributionSet dsA, final Iterable<Target> targs,
             final Status status, final String... msgs) {
-        final List<Target> result = new ArrayList<Target>();
+        final List<Target> result = new ArrayList<>();
         for (final Target t : targs) {
             final List<Action> findByTarget = actionRepository.findByTarget((JpaTarget) t);
             for (final Action action : findByTarget) {

hawkbit-repository/hawkbit-repository-jpa/src/test/java/org/eclipse/hawkbit/repository/jpa/TargetManagementTest.java

@@ -541,28 +541,30 @@ public class TargetManagementTest extends AbstractJpaIntegrationTest {
     @Test
     @Description("Tests the assigment of tags to the a single target.")
     public void targetTagAssignment() {
-        Target t1 = testdataFactory.generateTarget("id-1", "blablub");
+        final Target t1 = testdataFactory.generateTarget("id-1", "blablub");
         final int noT2Tags = 4;
         final int noT1Tags = 3;
         final List<TargetTag> t1Tags = tagManagement
                 .createTargetTags(testdataFactory.generateTargetTags(noT1Tags, "tag1"));
-        t1.getTags().addAll(t1Tags);
-        t1 = targetManagement.createTarget(t1);
 
-        Target t2 = testdataFactory.generateTarget("id-2", "blablub");
+        t1Tags.forEach(tag -> ((JpaTarget) t1).addTag(tag));
+
+        targetManagement.createTarget(t1);
+        final Target t2 = testdataFactory.generateTarget("id-2", "blablub");
         final List<TargetTag> t2Tags = tagManagement
                 .createTargetTags(testdataFactory.generateTargetTags(noT2Tags, "tag2"));
-        t2.getTags().addAll(t2Tags);
-        t2 = targetManagement.createTarget(t2);
 
-        t1 = targetManagement.findTargetByControllerID(t1.getControllerId());
+        t2Tags.forEach(tag -> ((JpaTarget) t2).addTag(tag));
-        assertThat(t1.getTags()).as("Tag size is wrong").hasSize(noT1Tags).containsAll(t1Tags);
+        targetManagement.createTarget(t2);
-        assertThat(t1.getTags()).as("Tag size is wrong").hasSize(noT1Tags)
+
+        final Target t11 = targetManagement.findTargetByControllerID(t1.getControllerId());
+        assertThat(t11.getTags()).as("Tag size is wrong").hasSize(noT1Tags).containsAll(t1Tags);
+        assertThat(t11.getTags()).as("Tag size is wrong").hasSize(noT1Tags)
                 .doesNotContain(Iterables.toArray(t2Tags, TargetTag.class));
 
-        t2 = targetManagement.findTargetByControllerID(t2.getControllerId());
+        final Target t21 = targetManagement.findTargetByControllerID(t2.getControllerId());
-        assertThat(t2.getTags()).as("Tag size is wrong").hasSize(noT2Tags).containsAll(t2Tags);
+        assertThat(t21.getTags()).as("Tag size is wrong").hasSize(noT2Tags).containsAll(t2Tags);
-        assertThat(t2.getTags()).as("Tag size is wrong").hasSize(noT2Tags)
+        assertThat(t21.getTags()).as("Tag size is wrong").hasSize(noT2Tags)
                 .doesNotContain(Iterables.toArray(t1Tags, TargetTag.class));
     }
 

hawkbit-repository/hawkbit-repository-jpa/src/test/java/org/eclipse/hawkbit/repository/jpa/rsql/RSQLActionFieldsTest.java

@@ -18,7 +18,6 @@ import org.eclipse.hawkbit.repository.jpa.model.JpaAction;
 import org.eclipse.hawkbit.repository.jpa.model.JpaTarget;
 import org.eclipse.hawkbit.repository.model.Action;
 import org.eclipse.hawkbit.repository.model.Action.ActionType;
-import org.eclipse.hawkbit.repository.model.Target;
 import org.junit.Before;
 import org.junit.Test;
 import org.springframework.data.domain.PageRequest;
@@ -32,7 +31,7 @@ import ru.yandex.qatools.allure.annotations.Stories;
 @Stories("RSQL filter actions")
 public class RSQLActionFieldsTest extends AbstractJpaIntegrationTest {
 
-    private Target target;
+    private JpaTarget target;
     private JpaAction action;
 
     @Before
@@ -42,7 +41,7 @@ public class RSQLActionFieldsTest extends AbstractJpaIntegrationTest {
         targetManagement.createTarget(target);
         action = new JpaAction();
         action.setActionType(ActionType.SOFT);
-        target.getActions().add(action);
+        target.addAction(action);
         action.setTarget(target);
         actionRepository.save(action);
         for (int i = 0; i < 10; i++) {
@@ -51,7 +50,7 @@ public class RSQLActionFieldsTest extends AbstractJpaIntegrationTest {
             newAction.setActive(i % 2 == 0);
             newAction.setTarget(target);
             actionRepository.save(newAction);
-            target.getActions().add(newAction);
+            target.addAction(newAction);
         }
 
     }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/artifacts/details/ArtifactDetailsLayout.java

@@ -9,8 +9,8 @@
 package org.eclipse.hawkbit.ui.artifacts.details;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Date;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -46,6 +46,7 @@ import org.vaadin.spring.events.EventScope;
 import org.vaadin.spring.events.annotation.EventBusListenerMethod;
 
 import com.google.common.base.Strings;
+import com.google.common.collect.Maps;
 import com.vaadin.data.Container;
 import com.vaadin.server.FontAwesome;
 import com.vaadin.shared.ui.label.ContentMode;
@@ -207,8 +208,7 @@ public class ArtifactDetailsLayout extends VerticalLayout {
     }
 
     private Container createArtifactLazyQueryContainer() {
-        final Map<String, Object> queryConfiguration = new HashMap<>();
+        return getArtifactLazyQueryContainer(Collections.emptyMap());
-        return getArtifactLazyQueryContainer(queryConfiguration);
     }
 
     private LazyQueryContainer getArtifactLazyQueryContainer(final Map<String, Object> queryConfig) {
@@ -429,9 +429,12 @@ public class ArtifactDetailsLayout extends VerticalLayout {
                 titleOfArtifactDetails.setContentMode(ContentMode.HTML);
             }
         }
-        final Map<String, Object> queryConfiguration = new HashMap<>();
+        final Map<String, Object> queryConfiguration;
         if (baseSwModuleId != null) {
+            queryConfiguration = Maps.newHashMapWithExpectedSize(1);
             queryConfiguration.put(SPUIDefinitions.BY_BASE_SOFTWARE_MODULE, baseSwModuleId);
+        } else {
+            queryConfiguration = Collections.emptyMap();
         }
         final LazyQueryContainer artifactContainer = getArtifactLazyQueryContainer(queryConfiguration);
         artifactDetailsTable.setContainerDataSource(artifactContainer);

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/artifacts/event/UploadViewAcceptCriteria.java

@@ -9,13 +9,13 @@
 package org.eclipse.hawkbit.ui.artifacts.event;
 
 import java.util.Arrays;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
 import org.eclipse.hawkbit.ui.common.AbstractAcceptCriteria;
 import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 
+import com.google.common.collect.Maps;
 import com.vaadin.spring.annotation.SpringComponent;
 import com.vaadin.spring.annotation.ViewScope;
 import com.vaadin.ui.Component;
@@ -54,7 +54,7 @@ public class UploadViewAcceptCriteria extends AbstractAcceptCriteria {
     }
 
     private static Map<String, List<String>> createDropConfigurations() {
-        final Map<String, List<String>> config = new HashMap<>();
+        final Map<String, List<String>> config = Maps.newHashMapWithExpectedSize(1);
         // Delete drop area droppable components
         config.put(UIComponentIdProvider.DELETE_BUTTON_WRAPPER_ID, Arrays.asList(
                 UIComponentIdProvider.UPLOAD_SOFTWARE_MODULE_TABLE, UIComponentIdProvider.UPLOAD_TYPE_BUTTON_PREFIX));
@@ -63,7 +63,7 @@ public class UploadViewAcceptCriteria extends AbstractAcceptCriteria {
     }
 
     private static Map<String, Object> createDropHintConfigurations() {
-        final Map<String, Object> config = new HashMap<>();
+        final Map<String, Object> config = Maps.newHashMapWithExpectedSize(2);
         config.put(UIComponentIdProvider.UPLOAD_TYPE_BUTTON_PREFIX, UploadArtifactUIEvent.SOFTWARE_TYPE_DRAG_START);
         config.put(UIComponentIdProvider.UPLOAD_SOFTWARE_MODULE_TABLE, UploadArtifactUIEvent.SOFTWARE_DRAG_START);
         return config;

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/artifacts/footer/UploadViewConfirmationWindowLayout.java

@@ -9,7 +9,6 @@
 package org.eclipse.hawkbit.ui.artifacts.footer;
 
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -21,11 +20,12 @@ import org.eclipse.hawkbit.ui.artifacts.state.CustomFile;
 import org.eclipse.hawkbit.ui.common.confirmwindow.layout.AbstractConfirmationWindowLayout;
 import org.eclipse.hawkbit.ui.common.confirmwindow.layout.ConfirmationTab;
 import org.eclipse.hawkbit.ui.utils.HawkbitCommonUtil;
-import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.eclipse.hawkbit.ui.utils.SPUIDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUILabelDefinitions;
+import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.springframework.beans.factory.annotation.Autowired;
 
+import com.google.common.collect.Maps;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
 import com.vaadin.data.util.IndexedContainer;
@@ -64,7 +64,7 @@ public class UploadViewConfirmationWindowLayout extends AbstractConfirmationWind
 
     @Override
     protected Map<String, ConfirmationTab> getConfimrationTabs() {
-        final Map<String, ConfirmationTab> tabs = new HashMap<>();
+        final Map<String, ConfirmationTab> tabs = Maps.newHashMapWithExpectedSize(2);
         if (!artifactUploadState.getDeleteSofwareModules().isEmpty()) {
             tabs.put(i18n.get("caption.delete.swmodule.accordion.tab"), createSMDeleteConfirmationTab());
         }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/artifacts/smtable/SoftwareModuleTable.java

@@ -8,7 +8,6 @@
  */
 package org.eclipse.hawkbit.ui.artifacts.smtable;
 
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -25,11 +24,11 @@ import org.eclipse.hawkbit.ui.components.SPUIComponentProvider;
 import org.eclipse.hawkbit.ui.decorators.SPUIButtonStyleSmallNoBorder;
 import org.eclipse.hawkbit.ui.distributions.smtable.SwMetadataPopupLayout;
 import org.eclipse.hawkbit.ui.utils.HawkbitCommonUtil;
-import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.eclipse.hawkbit.ui.utils.SPUIDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUILabelDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUIStyleDefinitions;
 import org.eclipse.hawkbit.ui.utils.TableColumn;
+import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.vaadin.addons.lazyquerycontainer.BeanQueryFactory;
 import org.vaadin.addons.lazyquerycontainer.LazyQueryContainer;
@@ -37,6 +36,7 @@ import org.vaadin.addons.lazyquerycontainer.LazyQueryDefinition;
 import org.vaadin.spring.events.EventScope;
 import org.vaadin.spring.events.annotation.EventBusListenerMethod;
 
+import com.google.common.collect.Maps;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
 import com.vaadin.event.dd.DragAndDropEvent;
@@ -97,7 +97,7 @@ public class SoftwareModuleTable extends AbstractNamedVersionTable<SoftwareModul
     }
 
     private Map<String, Object> prepareQueryConfigFilters() {
-        final Map<String, Object> queryConfig = new HashMap<>();
+        final Map<String, Object> queryConfig = Maps.newHashMapWithExpectedSize(2);
         artifactUploadState.getSoftwareModuleFilters().getSearchText()
                 .ifPresent(value -> queryConfig.put(SPUIDefinitions.FILTER_BY_TEXT, value));
 

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/artifacts/upload/UploadConfirmationWindow.java

@@ -32,11 +32,11 @@ import org.eclipse.hawkbit.ui.decorators.SPUIButtonStyleSmallNoBorder;
 import org.eclipse.hawkbit.ui.decorators.SPUIButtonStyleTiny;
 import org.eclipse.hawkbit.ui.utils.HawkbitCommonUtil;
 import org.eclipse.hawkbit.ui.utils.I18N;
-import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.eclipse.hawkbit.ui.utils.SPUIDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUILabelDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUIStyleDefinitions;
 import org.eclipse.hawkbit.ui.utils.SpringContextHelper;
+import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -572,6 +572,9 @@ public class UploadConfirmationWindow implements Button.ClickListener {
 
     }
 
+    // Exception squid:S3655 - Optional access is checked in
+    // checkIfArtifactDetailsDispalyed subroutine
+    @SuppressWarnings("squid:S3655")
     private void processArtifactUpload() {
         final List<String> itemIds = (List<String>) uploadDetailsTable.getItemIds();
         if (preUploadValidation(itemIds)) {
@@ -593,6 +596,7 @@ public class UploadConfirmationWindow implements Button.ClickListener {
                 }
                 refreshArtifactDetailsLayout = checkIfArtifactDetailsDispalyed(bSoftwareModule.getId());
             }
+
             if (refreshArtifactDetailsLayout) {
                 uploadLayout.refreshArtifactDetailsLayout(artifactUploadState.getSelectedBaseSoftwareModule().get());
             }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/artifacts/upload/UploadLayout.java

@@ -34,10 +34,10 @@ import org.eclipse.hawkbit.ui.components.SPUIComponentProvider;
 import org.eclipse.hawkbit.ui.decorators.SPUIButtonStyleSmall;
 import org.eclipse.hawkbit.ui.utils.HawkbitCommonUtil;
 import org.eclipse.hawkbit.ui.utils.I18N;
-import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.eclipse.hawkbit.ui.utils.SPUIDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUILabelDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUIStyleDefinitions;
+import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.eclipse.hawkbit.ui.utils.UINotification;
 import org.eclipse.hawkbit.util.SPInfo;
 import org.slf4j.Logger;
@@ -254,6 +254,11 @@ public class UploadLayout extends VerticalLayout {
                 final Html5File[] files = ((WrapperTransferable) event.getTransferable()).getFiles();
                 // selected software module at the time of file drop is
                 // considered for upload
+
+                if (!artifactUploadState.getSelectedBaseSoftwareModule().isPresent()) {
+                    return;
+                }
+
                 final SoftwareModule selectedSw = artifactUploadState.getSelectedBaseSoftwareModule().get();
                 // reset the flag
                 hasDirectory = Boolean.FALSE;

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/CommonDialogWindow.java

@@ -12,7 +12,6 @@ import static com.google.common.base.Preconditions.checkNotNull;
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -28,11 +27,12 @@ import org.eclipse.hawkbit.ui.decorators.SPUIButtonStyleNoBorderWithIcon;
 import org.eclipse.hawkbit.ui.layouts.AbstractCreateUpdateTagLayout;
 import org.eclipse.hawkbit.ui.management.targettable.TargetAddUpdateWindowLayout;
 import org.eclipse.hawkbit.ui.utils.I18N;
-import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.eclipse.hawkbit.ui.utils.SPUIStyleDefinitions;
+import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.vaadin.hene.flexibleoptiongroup.FlexibleOptionGroupItemComponent;
 
 import com.google.common.base.Strings;
+import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 import com.vaadin.data.Container.ItemSetChangeEvent;
 import com.vaadin.data.Container.ItemSetChangeListener;
@@ -129,8 +129,8 @@ public class CommonDialogWindow extends Window {
         this.helpLink = helpLink;
         this.closeListener = closeListener;
         this.cancelButtonClickListener = cancelButtonClickListener;
-        this.orginalValues = new HashMap<>();
         this.allComponents = getAllComponents(layout);
+        this.orginalValues = Maps.newHashMapWithExpectedSize(allComponents.size());
         this.i18n = i18n;
         init();
     }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/table/AbstractTable.java

@@ -30,8 +30,8 @@ import org.eclipse.hawkbit.ui.utils.UINotification;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.vaadin.spring.events.EventBus;
 
-import com.google.gwt.thirdparty.guava.common.collect.Iterables;
+import com.google.common.collect.Iterables;
-import com.google.gwt.thirdparty.guava.common.collect.Sets;
+import com.google.common.collect.Sets;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
 import com.vaadin.event.Transferable;

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/dstable/DistributionSetDetails.java

@@ -93,7 +93,7 @@ public class DistributionSetDetails extends AbstractNamedVersionedEntityTableDet
 
     private VerticalLayout tagsLayout;
 
-    private final Map<String, StringBuilder> assignedSWModule = new HashMap<>();
+    private Map<String, StringBuilder> assignedSWModule;
 
     /**
      * softwareLayout Initialize the component.
@@ -144,6 +144,10 @@ public class DistributionSetDetails extends AbstractNamedVersionedEntityTableDet
         }
 
         if (null != softwareModuleIdNameList) {
+            if (assignedSWModule == null) {
+                assignedSWModule = new HashMap<>();
+            }
+
             for (final SoftwareModuleIdName swIdName : softwareModuleIdNameList) {
                 final SoftwareModule softwareModule = softwareManagement.findSoftwareModuleById(swIdName.getId());
                 if (assignedSWModule.containsKey(softwareModule.getType().getName())) {
@@ -169,9 +173,11 @@ public class DistributionSetDetails extends AbstractNamedVersionedEntityTableDet
     }
 
     private Button assignSoftModuleButton(final String softwareModuleName) {
-        if (getPermissionChecker().hasUpdateDistributionPermission() && distributionSetManagement
+        if (getPermissionChecker().hasUpdateDistributionPermission()
-                .findDistributionSetById(manageDistUIState.getLastSelectedDistribution().get().getId())
+                && manageDistUIState.getLastSelectedDistribution().isPresent()
-                .getAssignedTargets().isEmpty()) {
+                && distributionSetManagement
+                        .findDistributionSetById(manageDistUIState.getLastSelectedDistribution().get().getId())
+                        .getAssignedTargets().isEmpty()) {
             final Button reassignSoftModule = SPUIComponentProvider.getButton(softwareModuleName, "", "", "", true,
                     FontAwesome.TIMES, SPUIButtonStyleSmallNoBorder.class);
             reassignSoftModule.setEnabled(false);
@@ -186,6 +192,9 @@ public class DistributionSetDetails extends AbstractNamedVersionedEntityTableDet
 
     @SuppressWarnings("unchecked")
     private void updateSoftwareModule(final SoftwareModule module) {
+        if (assignedSWModule == null) {
+            assignedSWModule = new HashMap<>();
+        }
 
         softwareModuleTable.getContainerDataSource().getItemIds();
         if (assignedSWModule.containsKey(module.getType().getName())) {
@@ -363,7 +372,9 @@ public class DistributionSetDetails extends AbstractNamedVersionedEntityTableDet
         if ((saveActionWindowEvent == SaveActionWindowEvent.SAVED_ASSIGNMENTS
                 || saveActionWindowEvent == SaveActionWindowEvent.DISCARD_ALL_ASSIGNMENTS)
                 && getSelectedBaseEntity() != null) {
-            assignedSWModule.clear();
+            if (assignedSWModule != null) {
+                assignedSWModule.clear();
+            }
             setSelectedBaseEntity(
                     distributionSetManagement.findDistributionSetByIdWithDetails(getSelectedBaseEntityId()));
             UI.getCurrent().access(() -> populateModule());
@@ -375,7 +386,9 @@ public class DistributionSetDetails extends AbstractNamedVersionedEntityTableDet
         if (saveActionWindowEvent == SaveActionWindowEvent.DISCARD_ASSIGNMENT
                 || saveActionWindowEvent == SaveActionWindowEvent.DISCARD_ALL_ASSIGNMENTS
                 || saveActionWindowEvent == SaveActionWindowEvent.DELETE_ALL_SOFWARE) {
-            assignedSWModule.clear();
+            if (assignedSWModule != null) {
+                assignedSWModule.clear();
+            }
             showUnsavedAssignment();
         }
     }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/dstable/DistributionSetTable.java

@@ -57,6 +57,7 @@ import org.vaadin.addons.lazyquerycontainer.LazyQueryDefinition;
 import org.vaadin.spring.events.EventScope;
 import org.vaadin.spring.events.annotation.EventBusListenerMethod;
 
+import com.google.common.collect.Maps;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
 import com.vaadin.event.dd.DragAndDropEvent;
@@ -167,7 +168,7 @@ public class DistributionSetTable extends AbstractNamedVersionTable<Distribution
     }
 
     private Map<String, Object> prepareQueryConfigFilters() {
-        final Map<String, Object> queryConfig = new HashMap<>();
+        final Map<String, Object> queryConfig = Maps.newHashMapWithExpectedSize(2);
         manageDistUIState.getManageDistFilters().getSearchText()
                 .ifPresent(value -> queryConfig.put(SPUIDefinitions.FILTER_BY_TEXT, value));
 
@@ -530,7 +531,7 @@ public class DistributionSetTable extends AbstractNamedVersionTable<Distribution
         return manageMetadataBtn;
     }
 
-   private void showMetadataDetails(final Long itemId) {
+    private void showMetadataDetails(final Long itemId) {
         final DistributionSet ds = distributionSetManagement.findDistributionSetByIdWithDetails(itemId);
         UI.getCurrent().addWindow(dsMetadataPopupLayout.getWindow(ds, null));
     }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/event/DistributionsViewAcceptCriteria.java

@@ -9,7 +9,6 @@
 package org.eclipse.hawkbit.ui.distributions.event;
 
 import java.util.Arrays;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -17,6 +16,7 @@ import org.eclipse.hawkbit.ui.common.AbstractAcceptCriteria;
 import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.eclipse.hawkbit.ui.utils.SPUIDefinitions;
 
+import com.google.common.collect.Maps;
 import com.vaadin.spring.annotation.SpringComponent;
 import com.vaadin.spring.annotation.ViewScope;
 import com.vaadin.ui.Component;
@@ -66,7 +66,7 @@ public class DistributionsViewAcceptCriteria extends AbstractAcceptCriteria {
     }
 
     private static Map<String, List<String>> createDropConfigurations() {
-        final Map<String, List<String>> config = new HashMap<>();
+        final Map<String, List<String>> config = Maps.newHashMapWithExpectedSize(2);
 
         // Delete drop area droppable components
         config.put(UIComponentIdProvider.DELETE_BUTTON_WRAPPER_ID,
@@ -82,7 +82,7 @@ public class DistributionsViewAcceptCriteria extends AbstractAcceptCriteria {
     }
 
     private static Map<String, Object> createDropHintConfigurations() {
-        final Map<String, Object> config = new HashMap<>();
+        final Map<String, Object> config = Maps.newHashMapWithExpectedSize(4);
         config.put(SPUIDefinitions.DISTRIBUTION_TYPE_ID_PREFIXS, DragEvent.DISTRIBUTION_TYPE_DRAG);
         config.put(UIComponentIdProvider.DIST_TABLE_ID, DragEvent.DISTRIBUTION_DRAG);
         config.put(UIComponentIdProvider.UPLOAD_SOFTWARE_MODULE_TABLE, DragEvent.SOFTWAREMODULE_DRAG);

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/footer/DistributionsConfirmationWindowLayout.java

@@ -8,7 +8,6 @@
  */
 package org.eclipse.hawkbit.ui.distributions.footer;
 
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -37,6 +36,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.vaadin.spring.events.EventScope;
 import org.vaadin.spring.events.annotation.EventBusListenerMethod;
 
+import com.google.common.collect.Maps;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
 import com.vaadin.data.util.IndexedContainer;
@@ -90,7 +90,7 @@ public class DistributionsConfirmationWindowLayout extends AbstractConfirmationW
 
     @Override
     protected Map<String, ConfirmationTab> getConfimrationTabs() {
-        final Map<String, ConfirmationTab> tabs = new HashMap<>();
+        final Map<String, ConfirmationTab> tabs = Maps.newHashMapWithExpectedSize(5);
         /* Create tab for SW Modules delete */
         if (!manageDistUIState.getDeleteSofwareModulesList().isEmpty()) {
             tabs.put(i18n.get("caption.delete.swmodule.accordion.tab"), createSMDeleteConfirmationTab());
@@ -112,7 +112,6 @@ public class DistributionsConfirmationWindowLayout extends AbstractConfirmationW
         }
 
         /* Create tab for Assign Software Module */
-
         if (!manageDistUIState.getAssignedList().isEmpty()) {
             tabs.put(i18n.get("caption.assign.dist.accordion.tab"), createAssignSWModuleConfirmationTab());
         }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/smtable/SwModuleTable.java

@@ -8,7 +8,6 @@
  */
 package org.eclipse.hawkbit.ui.distributions.smtable;
 
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -40,6 +39,7 @@ import org.vaadin.addons.lazyquerycontainer.LazyQueryDefinition;
 import org.vaadin.spring.events.EventScope;
 import org.vaadin.spring.events.annotation.EventBusListenerMethod;
 
+import com.google.common.collect.Maps;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
 import com.vaadin.event.dd.DragAndDropEvent;
@@ -143,7 +143,7 @@ public class SwModuleTable extends AbstractNamedVersionTable<SoftwareModule, Lon
     }
 
     private Map<String, Object> prepareQueryConfigFilters() {
-        final Map<String, Object> queryConfig = new HashMap<>();
+        final Map<String, Object> queryConfig = Maps.newHashMapWithExpectedSize(3);
         manageDistUIState.getSoftwareModuleFilters().getSearchText()
                 .ifPresent(value -> queryConfig.put(SPUIDefinitions.FILTER_BY_TEXT, value));
 

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/smtype/DistSMTypeFilterButtons.java

@@ -13,8 +13,7 @@ import static org.eclipse.hawkbit.ui.artifacts.event.SoftwareModuleTypeEvent.Sof
 import static org.eclipse.hawkbit.ui.utils.UIComponentIdProvider.SW_MODULE_TYPE_TABLE_ID;
 import static org.eclipse.hawkbit.ui.utils.SPUILabelDefinitions.VAR_NAME;
 
-import java.util.HashMap;
+import java.util.Collections;
-import java.util.Map;
 
 import org.eclipse.hawkbit.ui.artifacts.event.SoftwareModuleTypeEvent;
 import org.eclipse.hawkbit.ui.common.SoftwareModuleTypeBeanQuery;
@@ -59,10 +58,9 @@ public class DistSMTypeFilterButtons extends AbstractFilterButtons {
 
     @Override
     protected LazyQueryContainer createButtonsLazyQueryContainer() {
-        final Map<String, Object> queryConfig = new HashMap<>();
         final BeanQueryFactory<SoftwareModuleTypeBeanQuery> typeQF = new BeanQueryFactory<>(
                 SoftwareModuleTypeBeanQuery.class);
-        typeQF.setQueryConfiguration(queryConfig);
+        typeQF.setQueryConfiguration(Collections.emptyMap());
         return new LazyQueryContainer(new LazyQueryDefinition(true, 20, VAR_NAME), typeQF);
     }
 

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/state/ManageDistUIState.java

@@ -52,7 +52,7 @@ public class ManageDistUIState implements ManagmentEntityState<DistributionSetId
 
     private Set<Long> selectedSoftwareModules = emptySet();
 
-    private Set<String> selectedDeleteDistSetTypes = new HashSet<>();
+    private final Set<String> selectedDeleteDistSetTypes = new HashSet<>();
 
     private Set<String> selectedDeleteSWModuleTypes = new HashSet<>();
 
@@ -201,10 +201,6 @@ public class ManageDistUIState implements ManagmentEntityState<DistributionSetId
         return selectedDeleteDistSetTypes;
     }
 
-    public void setSelectedDeleteDistSetTypes(final Set<String> selectedDeleteDistSetTypes) {
-        this.selectedDeleteDistSetTypes = selectedDeleteDistSetTypes;
-    }
-
     public Set<String> getSelectedDeleteSWModuleTypes() {
         return selectedDeleteSWModuleTypes;
     }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/filter/FilterExpression.java

@@ -1,27 +0,0 @@
-/**
- * Copyright (c) 2015 Bosch Software Innovations GmbH and others.
- *
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- */
-package org.eclipse.hawkbit.ui.filter;
-
-/**
- * A filter expression interface definition to implement the UI filter
- * mechanism. The filter expression can evaluate if e.g. Targets should
- * currently be added to the target list or if the current enabled filtered will
- * filter the target and not show the newly created target.
- *
- */
-@FunctionalInterface
-public interface FilterExpression {
-
-    /**
-     * @return {@code true} if the expression evaluate that it should be
-     *         filtered and not shown on the UI, otherwise {@code false}
-     */
-    boolean doFilter();
-
-}

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/filter/Filters.java

@@ -1,77 +0,0 @@
-/**
- * Copyright (c) 2015 Bosch Software Innovations GmbH and others.
- *
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- */
-package org.eclipse.hawkbit.ui.filter;
-
-import java.util.Arrays;
-import java.util.List;
-
-/**
- * {@link Filters} which provides the functionality to combine
- * {@link FilterExpression}s.
- * 
- *
- *
- * @see FilterExpression
- *
- */
-public final class Filters {
-
-    /**
-     * private.
-     */
-    private Filters() {
-
-    }
-
-    /**
-     * Combines the given filter to an or-expression and evaluate them.
-     * 
-     * @param expressions
-     *            the expressions to combine with an or-filter
-     * @return an or-combined filter expression
-     */
-    public static FilterExpression or(final List<FilterExpression> expressions) {
-        return or(expressions.toArray(new FilterExpression[expressions.size()]));
-    }
-
-    /**
-     * Combines the given filter to an or-expression and evaluate them.
-     * 
-     * @param expressions
-     *            the expressions to combine with an or-filter
-     * @return an or-combined filter expression
-     */
-    public static FilterExpression or(final FilterExpression... expressions) {
-        return new OrFilterExpression(expressions);
-    }
-
-    private static final class OrFilterExpression implements FilterExpression {
-
-        private final FilterExpression[] expresssions;
-
-        private OrFilterExpression(final FilterExpression[] expresssions) {
-            this.expresssions = Arrays.copyOf(expresssions, expresssions.length);
-        }
-
-        /*
-         * (non-Javadoc)
-         * 
-         * @see org.eclipse.hawkbit.server.ui.filter.FilterExpression#evaluate()
-         */
-        @Override
-        public boolean doFilter() {
-            for (final FilterExpression filterExpression : expresssions) {
-                if (filterExpression.doFilter()) {
-                    return true;
-                }
-            }
-            return false;
-        }
-    }
-}

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/filter/target/CustomTargetFilter.java

@@ -1,48 +0,0 @@
-/**
- * Copyright (c) 2015 Bosch Software Innovations GmbH and others.
- *
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- */
-package org.eclipse.hawkbit.ui.filter.target;
-
-import java.util.Optional;
-
-import org.eclipse.hawkbit.repository.model.TargetFilterQuery;
-import org.eclipse.hawkbit.ui.filter.FilterExpression;
-
-/**
- * Checks if custom target filter is applied.
- *
- */
-public class CustomTargetFilter implements FilterExpression {
-
-    private final Optional<TargetFilterQuery> targetFilterQuery;
-
-    /**
-     * Initialize.
-     * 
-     * @param targetFilterQuery
-     *            custom target filter applied
-     */
-    public CustomTargetFilter(final Optional<TargetFilterQuery> targetFilterQuery) {
-        this.targetFilterQuery = targetFilterQuery;
-
-    }
-
-    /*
-     * (non-Javadoc)
-     * 
-     * @see org.eclipse.hawkbit.ui.filter.FilterExpression#doFilter()
-     */
-    @Override
-    public boolean doFilter() {
-        if (!targetFilterQuery.isPresent()) {
-            return false;
-        }
-        return true;
-    }
-
-}

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/filter/target/TargetSearchTextFilter.java

@@ -1,67 +0,0 @@
-/**
- * Copyright (c) 2011-2015 Bosch Software Innovations GmbH, Germany. All rights reserved.
- */
-package org.eclipse.hawkbit.ui.filter.target;
-
-import java.net.URI;
-
-import org.eclipse.hawkbit.repository.model.Target;
-import org.eclipse.hawkbit.ui.filter.FilterExpression;
-
-/**
- *
- *
- *
- */
-public class TargetSearchTextFilter implements FilterExpression {
-
-    private final Target target;
-    private final String searchTextUpper;
-
-    /**
-     * @param target
-     *            the target to check against the search text
-     * @param searchText
-     *            the search text check against the given target
-     */
-    public TargetSearchTextFilter(final Target target, final String searchText) {
-        this.target = target;
-        this.searchTextUpper = searchText.toUpperCase();
-    }
-
-    /*
-     * (non-Javadoc)
-     * 
-     * @see org.eclipse.hawkbit.server.ui.filter.FilterExpression#evaluate()
-     */
-    @Override
-    public boolean doFilter() {
-        return !(descriptionIgnoreCase() || nameIgnoreCase() || controllerIdIgnoreCase() || ipAddressIgnoreCase());
-    }
-
-    private boolean descriptionIgnoreCase() {
-        if (target.getDescription() == null) {
-            return false;
-        }
-        return target.getDescription().toUpperCase().contains(searchTextUpper);
-    }
-
-    private boolean nameIgnoreCase() {
-        if (target.getName() == null) {
-            return false;
-        }
-        return target.getName().toUpperCase().contains(searchTextUpper);
-    }
-
-    private boolean controllerIdIgnoreCase() {
-        return target.getControllerId().toUpperCase().contains(searchTextUpper);
-    }
-
-    private boolean ipAddressIgnoreCase() {
-        final URI targetAddress = target.getTargetInfo().getAddress();
-        if (targetAddress == null || targetAddress.getHost() == null) {
-            return false;
-        }
-        return targetAddress.getHost().toUpperCase().contains(searchTextUpper);
-    }
-}

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/filter/target/TargetStatusFilter.java

@@ -1,42 +0,0 @@
-/**
- * Copyright (c) 2011-2015 Bosch Software Innovations GmbH, Germany. All rights reserved.
- */
-package org.eclipse.hawkbit.ui.filter.target;
-
-import java.util.List;
-
-import org.eclipse.hawkbit.repository.model.TargetUpdateStatus;
-import org.eclipse.hawkbit.ui.filter.FilterExpression;
-
-/**
- *
- *
- *
- */
-public class TargetStatusFilter implements FilterExpression {
-
-    private final List<TargetUpdateStatus> targetUpdateStatus;
-
-    /**
-     * @param target
-     *            the target to check the update status against
-     * @param updateStatus
-     *            the target update status to check against the given target
-     */
-    public TargetStatusFilter(final List<TargetUpdateStatus> updateStatus) {
-        this.targetUpdateStatus = updateStatus;
-    }
-
-    /*
-     * (non-Javadoc)
-     * 
-     * @see org.eclipse.hawkbit.server.ui.filter.FilterExpression#evaluate()
-     */
-    @Override
-    public boolean doFilter() {
-        if (targetUpdateStatus.isEmpty()) {
-            return false;
-        }
-        return true;
-    }
-}

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/filter/target/TargetTagFilter.java

@@ -1,54 +0,0 @@
-/**
- * Copyright (c) 2011-2015 Bosch Software Innovations GmbH, Germany. All rights reserved.
- */
-package org.eclipse.hawkbit.ui.filter.target;
-
-import java.util.Collection;
-import java.util.List;
-import java.util.stream.Collectors;
-
-import org.eclipse.hawkbit.repository.model.Target;
-import org.eclipse.hawkbit.ui.filter.FilterExpression;
-import org.springframework.util.CollectionUtils;
-
-/**
- *
- *
- *
- */
-public class TargetTagFilter implements FilterExpression {
-
-    private final Target target;
-    private final Collection<String> tags;
-    private final boolean noTag;
-
-    /**
-     * @param target
-     *            the target to check the filter against
-     * @param tags
-     *            the tags to check the target against it
-     * @param noTag
-     *            {@code true} indicates that targets which have no tags should
-     *            not be filtered, otherwise {@code false}
-     */
-    public TargetTagFilter(final Target target, final Collection<String> tags, final boolean noTag) {
-        this.target = target;
-        this.tags = tags;
-        this.noTag = noTag;
-    }
-
-    /*
-     * (non-Javadoc)
-     * 
-     * @see org.eclipse.hawkbit.server.ui.filter.FilterExpression#evaluate()
-     */
-    @Override
-    public boolean doFilter() {
-        final List<String> targetTags = target.getTags().stream().map(targetTag -> targetTag.getName())
-                .collect(Collectors.toList());
-        if (targetTags.isEmpty() || (noTag && targetTags.isEmpty())) {
-            return false;
-        }
-        return !CollectionUtils.containsAny(targetTags, tags);
-    }
-}

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/filtermanagement/CreateOrUpdateFilterHeader.java

@@ -26,9 +26,9 @@ import org.eclipse.hawkbit.ui.decorators.SPUIButtonStyleSmallNoBorder;
 import org.eclipse.hawkbit.ui.filtermanagement.event.CustomFilterUIEvent;
 import org.eclipse.hawkbit.ui.filtermanagement.state.FilterManagementUIState;
 import org.eclipse.hawkbit.ui.utils.I18N;
-import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.eclipse.hawkbit.ui.utils.SPUILabelDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUIStyleDefinitions;
+import org.eclipse.hawkbit.ui.utils.UIComponentIdProvider;
 import org.eclipse.hawkbit.ui.utils.UINotification;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
@@ -136,7 +136,7 @@ public class CreateOrUpdateFilterHeader extends VerticalLayout implements Button
 
     private LayoutClickListener nameLayoutClickListner;
 
-    private boolean validationFailed = false;
+    private boolean validationFailed;
 
     /**
      * Initialize the Campaign Status History Header.
@@ -509,6 +509,10 @@ public class CreateOrUpdateFilterHeader extends VerticalLayout implements Button
     }
 
     private void updateCustomFilter() {
+        if (!filterManagementUIState.getTfQuery().isPresent()) {
+            return;
+        }
+
         final TargetFilterQuery targetFilterQuery = filterManagementUIState.getTfQuery().get();
         targetFilterQuery.setName(nameTextField.getValue());
         targetFilterQuery.setQuery(queryTextField.getValue());