.travis.yml

 language: java
 
-sudo: false
-dist: trusty
-
 matrix:
   include:
     - os: linux
@@ -10,18 +7,19 @@ matrix:
     - os: linux
       jdk: openjdk8
     - os: linux
-      jdk: openjdk10
+      jdk: openjdk11
+    - os: linux
+      jdk: openjdk12
 
 before_install:
 # https://github.com/travis-ci/travis-ci/issues/8408
   - unset _JAVA_OPTIONS
 
-install: mvn clean dependency:go-offline -V
-
 before_script: true
+install: true
 
 script:
-  - mvn verify
+  - mvn -V -Prun-its clean verify
 
 cache:
   directories:

maven-resolver-api/pom.xml

@@ -25,7 +25,7 @@
   <parent>
     <groupId>org.apache.maven.resolver</groupId>
     <artifactId>maven-resolver</artifactId>
-    <version>1.3.1</version>
+    <version>1.4.0</version>
   </parent>
 
   <artifactId>maven-resolver-api</artifactId>

maven-resolver-api/src/main/java/org/eclipse/aether/DefaultRepositoryCache.java

@@ -30,7 +30,7 @@ public final class DefaultRepositoryCache
     implements RepositoryCache
 {
 
-    private final Map<Object, Object> cache = new ConcurrentHashMap<Object, Object>( 256 );
+    private final Map<Object, Object> cache = new ConcurrentHashMap<>( 256 );
 
     public Object get( RepositorySystemSession session, Object key )
     {

maven-resolver-api/src/main/java/org/eclipse/aether/DefaultRepositorySystemSession.java

@@ -127,11 +127,11 @@ public final class DefaultRepositorySystemSession
      */
     public DefaultRepositorySystemSession()
     {
-        systemProperties = new HashMap<String, String>();
+        systemProperties = new HashMap<>();
         systemPropertiesView = Collections.unmodifiableMap( systemProperties );
-        userProperties = new HashMap<String, String>();
+        userProperties = new HashMap<>();
         userPropertiesView = Collections.unmodifiableMap( userProperties );
-        configProperties = new HashMap<String, Object>();
+        configProperties = new HashMap<>();
         configPropertiesView = Collections.unmodifiableMap( configProperties );
         mirrorSelector = NullMirrorSelector.INSTANCE;
         proxySelector = NullProxySelector.INSTANCE;
@@ -212,7 +212,8 @@ public final class DefaultRepositorySystemSession
      *            descriptors, {@code false} to merge those with the originally specified repositories.
      * @return This session for chaining, never {@code null}.
      */
-    public DefaultRepositorySystemSession setIgnoreArtifactDescriptorRepositories( boolean ignoreArtifactDescriptorRepositories )
+    public DefaultRepositorySystemSession setIgnoreArtifactDescriptorRepositories(
+            boolean ignoreArtifactDescriptorRepositories )
     {
         failIfReadOnly();
         this.ignoreArtifactDescriptorRepositories = ignoreArtifactDescriptorRepositories;
@@ -250,7 +251,8 @@ public final class DefaultRepositorySystemSession
      *            errors should generally not be tolerated.
      * @return This session for chaining, never {@code null}.
      */
-    public DefaultRepositorySystemSession setArtifactDescriptorPolicy( ArtifactDescriptorPolicy artifactDescriptorPolicy )
+    public DefaultRepositorySystemSession setArtifactDescriptorPolicy(
+            ArtifactDescriptorPolicy artifactDescriptorPolicy )
     {
         failIfReadOnly();
         this.artifactDescriptorPolicy = artifactDescriptorPolicy;
@@ -398,16 +400,17 @@ public final class DefaultRepositorySystemSession
         return this;
     }
 
+    @SuppressWarnings( "checkstyle:magicnumber" )
     private <T> Map<String, T> copySafe( Map<?, ?> table, Class<T> valueType )
     {
         Map<String, T> map;
         if ( table == null || table.isEmpty() )
         {
-            map = new HashMap<String, T>();
+            map = new HashMap<>();
         }
         else
         {
-            map = new HashMap<String, T>( (int) ( table.size() / 0.75f ) + 1 );
+            map = new HashMap<>( (int) ( table.size() / 0.75f ) + 1 );
             for ( Map.Entry<?, ?> entry : table.entrySet() )
             {
                 Object key = entry.getKey();
@@ -738,7 +741,8 @@ public final class DefaultRepositorySystemSession
      *            {@code null}.
      * @return This session for chaining, never {@code null}.
      */
-    public DefaultRepositorySystemSession setDependencyGraphTransformer( DependencyGraphTransformer dependencyGraphTransformer )
+    public DefaultRepositorySystemSession setDependencyGraphTransformer(
+            DependencyGraphTransformer dependencyGraphTransformer )
     {
         failIfReadOnly();
         this.dependencyGraphTransformer = dependencyGraphTransformer;

maven-resolver-api/src/main/java/org/eclipse/aether/DefaultSessionData.java

@@ -35,7 +35,7 @@ public final class DefaultSessionData
 
     public DefaultSessionData()
     {
-        data = new ConcurrentHashMap<Object, Object>();
+        data = new ConcurrentHashMap<>();
     }
 
     public void set( Object key, Object value )

maven-resolver-api/src/main/java/org/eclipse/aether/RepositoryException.java

@@ -49,6 +49,9 @@ public class RepositoryException
     }
 
     /**
+     * @param  prefix The prefix.
+     * @param cause The exception that caused this one, may be {@code null}.
+     * @return The message.
      * @noreference This method is not intended to be used by clients.
      */
     protected static String getMessage( String prefix, Throwable cause )

maven-resolver-api/src/main/java/org/eclipse/aether/RepositorySystem.java

@@ -107,7 +107,8 @@ public interface RepositorySystem
      * @see RepositorySystemSession#getArtifactDescriptorPolicy()
      * @see #newResolutionRepositories(RepositorySystemSession, List)
      */
-    ArtifactDescriptorResult readArtifactDescriptor( RepositorySystemSession session, ArtifactDescriptorRequest request )
+    ArtifactDescriptorResult readArtifactDescriptor( RepositorySystemSession session,
+                                                     ArtifactDescriptorRequest request )
         throws ArtifactDescriptorException;
 
     /**
@@ -225,7 +226,8 @@ public interface RepositorySystem
      * @throws IllegalArgumentException If the specified repository type is not recognized or no base directory is
      *             given.
      */
-    LocalRepositoryManager newLocalRepositoryManager( RepositorySystemSession session, LocalRepository localRepository );
+    LocalRepositoryManager newLocalRepositoryManager( RepositorySystemSession session,
+                                                      LocalRepository localRepository );
 
     /**
      * Creates a new synchronization context.

maven-resolver-api/src/main/java/org/eclipse/aether/artifact/AbstractArtifact.java

@@ -23,6 +23,7 @@ import java.io.File;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Objects;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -115,7 +116,7 @@ public abstract class AbstractArtifact
     public Artifact setFile( File file )
     {
         File current = getFile();
-        if ( ( current == null ) ? file == null : current.equals( file ) )
+        if ( Objects.equals( current, file ) )
         {
             return this;
         }
@@ -149,7 +150,7 @@ public abstract class AbstractArtifact
     {
         if ( properties != null && !properties.isEmpty() )
         {
-            return Collections.unmodifiableMap( new HashMap<String, String>( properties ) );
+            return Collections.unmodifiableMap( new HashMap<>( properties ) );
         }
         else
         {
@@ -193,15 +194,13 @@ public abstract class AbstractArtifact
 
         Artifact that = (Artifact) obj;
 
-        return getArtifactId().equals( that.getArtifactId() ) && getGroupId().equals( that.getGroupId() )
-            && getVersion().equals( that.getVersion() ) && getExtension().equals( that.getExtension() )
-            && getClassifier().equals( that.getClassifier() ) && eq( getFile(), that.getFile() )
-            && getProperties().equals( that.getProperties() );
-    }
-
-    private static <T> boolean eq( T s1, T s2 )
-    {
-        return s1 != null ? s1.equals( s2 ) : s2 == null;
+        return Objects.equals( getArtifactId(), that.getArtifactId() )
+                && Objects.equals( getGroupId(), that.getGroupId() )
+                && Objects.equals( getVersion(), that.getVersion() )
+                && Objects.equals( getExtension(), that.getExtension() )
+                && Objects.equals( getClassifier(), that.getClassifier() )
+                && Objects.equals( getFile(), that.getFile() )
+                && Objects.equals( getProperties(), that.getProperties() );
     }
 
     /**

maven-resolver-api/src/main/java/org/eclipse/aether/artifact/DefaultArtifact.java

@@ -56,6 +56,9 @@ public final class DefaultArtifact
      * 
      * @param coords The artifact coordinates in the format
      *            {@code <groupId>:<artifactId>[:<extension>[:<classifier>]]:<version>}, must not be {@code null}.
+     *
+     * @throws IllegalArgumentException If the artifact coordinates found in {@code coords} do not match the expected
+     * format.
      */
     public DefaultArtifact( String coords )
     {
@@ -69,6 +72,9 @@ public final class DefaultArtifact
      * @param coords The artifact coordinates in the format
      *            {@code <groupId>:<artifactId>[:<extension>[:<classifier>]]:<version>}, must not be {@code null}.
      * @param properties The artifact properties, may be {@code null}.
+     *
+     * @throws IllegalArgumentException If the artifact coordinates found in {@code coords} do not match the expected
+     * format.
      */
     public DefaultArtifact( String coords, Map<String, String> properties )
     {
@@ -191,7 +197,7 @@ public final class DefaultArtifact
         }
         else
         {
-            properties = new HashMap<String, String>();
+            properties = new HashMap<>();
             if ( recessive != null )
             {
                 properties.putAll( recessive );

maven-resolver-api/src/main/java/org/eclipse/aether/artifact/DefaultArtifactType.java

@@ -91,7 +91,7 @@ public final class DefaultArtifactType
         }
         this.extension = emptify( extension );
         this.classifier = emptify( classifier );
-        Map<String, String> props = new HashMap<String, String>();
+        Map<String, String> props = new HashMap<>();
         props.put( ArtifactProperties.TYPE, id );
         props.put( ArtifactProperties.LANGUAGE, ( language != null && language.length() > 0 ) ? language : "none" );
         props.put( ArtifactProperties.INCLUDES_DEPENDENCIES, Boolean.toString( includesDependencies ) );

maven-resolver-api/src/main/java/org/eclipse/aether/collection/CollectRequest.java

@@ -24,7 +24,6 @@ import java.util.Collections;
 import java.util.List;
 
 import org.eclipse.aether.RepositorySystem;
-import org.eclipse.aether.RepositorySystemSession;
 import org.eclipse.aether.RequestTrace;
 import org.eclipse.aether.artifact.Artifact;
 import org.eclipse.aether.graph.Dependency;
@@ -37,7 +36,7 @@ import org.eclipse.aether.repository.RemoteRepository;
  * retrieved from the artifact descriptor of the root dependency. And last, only direct dependencies can be specified in
  * which case the root node of the resulting graph has no associated dependency.
  * 
- * @see RepositorySystem#collectDependencies(RepositorySystemSession, CollectRequest)
+ * @see RepositorySystem#collectDependencies(org.eclipse.aether.RepositorySystemSession, CollectRequest)
  */
 public final class CollectRequest
 {
@@ -199,7 +198,7 @@ public final class CollectRequest
         {
             if ( this.dependencies.isEmpty() )
             {
-                this.dependencies = new ArrayList<Dependency>();
+                this.dependencies = new ArrayList<>();
             }
             this.dependencies.add( dependency );
         }
@@ -248,7 +247,7 @@ public final class CollectRequest
         {
             if ( this.managedDependencies.isEmpty() )
             {
-                this.managedDependencies = new ArrayList<Dependency>();
+                this.managedDependencies = new ArrayList<>();
             }
             this.managedDependencies.add( managedDependency );
         }
@@ -296,7 +295,7 @@ public final class CollectRequest
         {
             if ( this.repositories.isEmpty() )
             {
-                this.repositories = new ArrayList<RemoteRepository>();
+                this.repositories = new ArrayList<>();
             }
             this.repositories.add( repository );
         }

maven-resolver-api/src/main/java/org/eclipse/aether/collection/CollectResult.java

@@ -25,14 +25,13 @@ import java.util.List;
 import static java.util.Objects.requireNonNull;
 
 import org.eclipse.aether.RepositorySystem;
-import org.eclipse.aether.RepositorySystemSession;
 import org.eclipse.aether.graph.DependencyCycle;
 import org.eclipse.aether.graph.DependencyNode;
 
 /**
  * The result of a dependency collection request.
  * 
- * @see RepositorySystem#collectDependencies(RepositorySystemSession, CollectRequest)
+ * @see RepositorySystem#collectDependencies(org.eclipse.aether.RepositorySystemSession, CollectRequest)
  */
 public final class CollectResult
 {
@@ -89,7 +88,7 @@ public final class CollectResult
         {
             if ( exceptions.isEmpty() )
             {
-                exceptions = new ArrayList<Exception>();
+                exceptions = new ArrayList<>();
             }
             exceptions.add( exception );
         }
@@ -118,7 +117,7 @@ public final class CollectResult
         {
             if ( cycles.isEmpty() )
             {
-                cycles = new ArrayList<DependencyCycle>();
+                cycles = new ArrayList<>();
             }
             cycles.add( cycle );
         }

maven-resolver-api/src/main/java/org/eclipse/aether/collection/DependencyManagement.java

@@ -22,13 +22,12 @@ package org.eclipse.aether.collection;
 import java.util.Collection;
 import java.util.Map;
 
-import org.eclipse.aether.graph.Dependency;
 import org.eclipse.aether.graph.Exclusion;
 
 /**
  * The management updates to apply to a dependency.
  * 
- * @see DependencyManager#manageDependency(Dependency)
+ * @see DependencyManager#manageDependency(org.eclipse.aether.graph.Dependency)
  */
 public final class DependencyManagement
 {

maven-resolver-api/src/main/java/org/eclipse/aether/collection/UnsolvableVersionConflictException.java

@@ -57,7 +57,7 @@ public class UnsolvableVersionConflictException
         else
         {
             this.paths = paths;
-            this.versions = new LinkedHashSet<String>();
+            this.versions = new LinkedHashSet<>();
             for ( List<? extends DependencyNode> path : paths )
             {
                 VersionConstraint constraint = path.get( path.size() - 1 ).getVersionConstraint();
@@ -75,7 +75,7 @@ public class UnsolvableVersionConflictException
 
         if ( paths != null )
         {
-            Collection<String> strings = new LinkedHashSet<String>();
+            Collection<String> strings = new LinkedHashSet<>();
 
             for ( List<? extends DependencyNode> path : paths )
             {

maven-resolver-api/src/main/java/org/eclipse/aether/deployment/DeployRequest.java

@@ -23,8 +23,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 
-import org.eclipse.aether.RepositorySystem;
-import org.eclipse.aether.RepositorySystemSession;
 import org.eclipse.aether.RequestTrace;
 import org.eclipse.aether.artifact.Artifact;
 import org.eclipse.aether.metadata.Metadata;
@@ -33,7 +31,7 @@ import org.eclipse.aether.repository.RemoteRepository;
 /**
  * A request to deploy artifacts and their accompanying metadata into the a remote repository.
  * 
- * @see RepositorySystem#deploy(RepositorySystemSession, DeployRequest)
+ * @see org.eclipse.aether.RepositorySystem#deploy(org.eclipse.aether.RepositorySystemSession, DeployRequest)
  */
 public final class DeployRequest
 {
@@ -94,7 +92,7 @@ public final class DeployRequest
         {
             if ( artifacts.isEmpty() )
             {
-                artifacts = new ArrayList<Artifact>();
+                artifacts = new ArrayList<>();
             }
             artifacts.add( artifact );
         }
@@ -142,7 +140,7 @@ public final class DeployRequest
         {
             if ( this.metadata.isEmpty() )
             {
-                this.metadata = new ArrayList<Metadata>();
+                this.metadata = new ArrayList<>();
             }
             this.metadata.add( metadata );
         }

maven-resolver-api/src/main/java/org/eclipse/aether/deployment/DeployResult.java

@@ -25,14 +25,13 @@ import java.util.Collections;
 import static java.util.Objects.requireNonNull;
 
 import org.eclipse.aether.RepositorySystem;
-import org.eclipse.aether.RepositorySystemSession;
 import org.eclipse.aether.artifact.Artifact;
 import org.eclipse.aether.metadata.Metadata;
 
 /**
  * The result of deploying artifacts and their accompanying metadata into the a remote repository.
  * 
- * @see RepositorySystem#deploy(RepositorySystemSession, DeployRequest)
+ * @see RepositorySystem#deploy(org.eclipse.aether.RepositorySystemSession, DeployRequest)
  */
 public final class DeployResult
 {
@@ -106,7 +105,7 @@ public final class DeployResult
         {
             if ( artifacts.isEmpty() )
             {
-                artifacts = new ArrayList<Artifact>();
+                artifacts = new ArrayList<>();
             }
             artifacts.add( artifact );
         }
@@ -155,7 +154,7 @@ public final class DeployResult
         {
             if ( this.metadata.isEmpty() )
             {
-                this.metadata = new ArrayList<Metadata>();
+                this.metadata = new ArrayList<>();
             }
             this.metadata.add( metadata );
         }

maven-resolver-api/src/main/java/org/eclipse/aether/graph/DefaultDependencyNode.java

@@ -71,7 +71,8 @@ public final class DefaultDependencyNode
         this.dependency = dependency;
         artifact = ( dependency != null ) ? dependency.getArtifact() : null;
         children = new ArrayList<DependencyNode>( 0 );
-        aliases = relocations = Collections.emptyList();
+        aliases = Collections.emptyList();
+        relocations = Collections.emptyList();
         repositories = Collections.emptyList();
         context = "";
         data = Collections.emptyMap();
@@ -88,7 +89,8 @@ public final class DefaultDependencyNode
     {
         this.artifact = artifact;
         children = new ArrayList<DependencyNode>( 0 );
-        aliases = relocations = Collections.emptyList();
+        aliases = Collections.emptyList();
+        relocations = Collections.emptyList();
         repositories = Collections.emptyList();
         context = "";
         data = Collections.emptyMap();
@@ -104,7 +106,7 @@ public final class DefaultDependencyNode
     {
         dependency = node.getDependency();
         artifact = node.getArtifact();
-        children = new ArrayList<DependencyNode>( 0 );
+        children = new ArrayList<>( 0 );
         setAliases( node.getAliases() );
         setRequestContext( node.getRequestContext() );
         setManagedBits( node.getManagedBits() );
@@ -113,7 +115,7 @@ public final class DefaultDependencyNode
         setVersion( node.getVersion() );
         setVersionConstraint( node.getVersionConstraint() );
         Map<?, ?> data = node.getData();
-        setData( data.isEmpty() ? null : new HashMap<Object, Object>( data ) );
+        setData( data.isEmpty() ? null : new HashMap<>( data ) );
     }
 
     public List<DependencyNode> getChildren()
@@ -125,7 +127,7 @@ public final class DefaultDependencyNode
     {
         if ( children == null )
         {
-            this.children = new ArrayList<DependencyNode>( 0 );
+            this.children = new ArrayList<>( 0 );
         }
         else
         {
@@ -330,7 +332,7 @@ public final class DefaultDependencyNode
         {
             if ( data.isEmpty() )
             {
-                data = new HashMap<Object, Object>( 1, 2 ); // nodes can be numerous so let's be space conservative
+                data = new HashMap<>( 1, 2 ); // nodes can be numerous so let's be space conservative
             }
             data.put( key, value );
         }

maven-resolver-api/src/main/java/org/eclipse/aether/graph/Dependency.java

@@ -26,6 +26,8 @@ import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.NoSuchElementException;
 import static java.util.Objects.requireNonNull;
+
+import java.util.Objects;
 import java.util.Set;
 
 import org.eclipse.aether.artifact.Artifact;
@@ -170,7 +172,7 @@ public final class Dependency
      */
     public Dependency setOptional( Boolean optional )
     {
-        if ( eq( this.optional, optional ) )
+        if ( Objects.equals( this.optional, optional ) )
         {
             return this;
         }
@@ -220,7 +222,7 @@ public final class Dependency
     @Override
     public String toString()
     {
-        return String.valueOf( getArtifact() ) + " (" + getScope() + ( isOptional() ? "?" : "" ) + ")";
+        return getArtifact() + " (" + getScope() + ( isOptional() ? "?" : "" ) + ")";
     }
 
     @Override
@@ -237,13 +239,8 @@ public final class Dependency
 
         Dependency that = (Dependency) obj;
 
-        return artifact.equals( that.artifact ) && scope.equals( that.scope ) && eq( optional, that.optional )
-            && exclusions.equals( that.exclusions );
-    }
-
-    private static <T> boolean eq( T o1, T o2 )
-    {
-        return ( o1 != null ) ? o1.equals( o2 ) : o2 == null;
+        return Objects.equals( artifact, that.artifact ) && Objects.equals( scope, that.scope )
+                && Objects.equals( optional, that.optional ) && Objects.equals( exclusions, that.exclusions );
     }
 
     @Override
@@ -276,7 +273,7 @@ public final class Dependency
         {
             if ( exclusions.size() > 1 && !( exclusions instanceof Set ) )
             {
-                exclusions = new LinkedHashSet<Exclusion>( exclusions );
+                exclusions = new LinkedHashSet<>( exclusions );
             }
             this.exclusions = exclusions.toArray( new Exclusion[exclusions.size()] );
         }

maven-resolver-api/src/main/java/org/eclipse/aether/installation/InstallRequest.java

@@ -24,7 +24,6 @@ import java.util.Collection;
 import java.util.Collections;
 
 import org.eclipse.aether.RepositorySystem;
-import org.eclipse.aether.RepositorySystemSession;
 import org.eclipse.aether.RequestTrace;
 import org.eclipse.aether.artifact.Artifact;
 import org.eclipse.aether.metadata.Metadata;
@@ -91,7 +90,7 @@ public final class InstallRequest
         {
             if ( artifacts.isEmpty() )
             {
-                artifacts = new ArrayList<Artifact>();
+                artifacts = new ArrayList<>();
             }
             artifacts.add( artifact );
         }
@@ -139,7 +138,7 @@ public final class InstallRequest
         {
             if ( this.metadata.isEmpty() )
             {
-                this.metadata = new ArrayList<Metadata>();
+                this.metadata = new ArrayList<>();
             }
             this.metadata.add( metadata );
         }

maven-resolver-api/src/main/java/org/eclipse/aether/installation/InstallResult.java

@@ -24,15 +24,13 @@ import java.util.Collection;
 import java.util.Collections;
 import static java.util.Objects.requireNonNull;
 
-import org.eclipse.aether.RepositorySystem;
-import org.eclipse.aether.RepositorySystemSession;
 import org.eclipse.aether.artifact.Artifact;
 import org.eclipse.aether.metadata.Metadata;
 
 /**
  * The result of installing artifacts and their accompanying metadata into the a remote repository.
  * 
- * @see RepositorySystem#install(RepositorySystemSession, InstallRequest)
+ * @see org.eclipse.aether.RepositorySystem#install(org.eclipse.aether.RepositorySystemSession, InstallRequest)
  */
 public final class InstallResult
 {
@@ -106,7 +104,7 @@ public final class InstallResult
         {
             if ( artifacts.isEmpty() )
             {
-                artifacts = new ArrayList<Artifact>();
+                artifacts = new ArrayList<>();
             }
             artifacts.add( artifact );
         }
@@ -155,7 +153,7 @@ public final class InstallResult
         {
             if ( this.metadata.isEmpty() )
             {
-                this.metadata = new ArrayList<Metadata>();
+                this.metadata = new ArrayList<>();
             }
             this.metadata.add( metadata );
         }