diff --git a/maven-compat/src/main/java/org/apache/maven/artifact/repository/metadata/GroupRepositoryMetadata.java b/maven-compat/src/main/java/org/apache/maven/artifact/repository/metadata/GroupRepositoryMetadata.java
index 490b47f305..fd88ddcb97 100644
--- a/maven-compat/src/main/java/org/apache/maven/artifact/repository/metadata/GroupRepositoryMetadata.java
+++ b/maven-compat/src/main/java/org/apache/maven/artifact/repository/metadata/GroupRepositoryMetadata.java
@@ -75,11 +75,11 @@ public class GroupRepositoryMetadata
                                   String artifactId,
                                   String name )
     {
-        List plugins = getMetadata().getPlugins();
+        List<Plugin> plugins = getMetadata().getPlugins();
         boolean found = false;
-        for ( Iterator i = plugins.iterator(); i.hasNext() && !found; )
+        for ( Iterator<Plugin> i = plugins.iterator(); i.hasNext() && !found; )
         {
-            Plugin plugin = (Plugin) i.next();
+            Plugin plugin = i.next();
             if ( plugin.getPrefix().equals( goalPrefix ) )
             {
                 found = true;
diff --git a/maven-compat/src/main/java/org/apache/maven/profiles/DefaultProfileManager.java b/maven-compat/src/main/java/org/apache/maven/profiles/DefaultProfileManager.java
index 9cbd7c814f..7a9ec09039 100644
--- a/maven-compat/src/main/java/org/apache/maven/profiles/DefaultProfileManager.java
+++ b/maven-compat/src/main/java/org/apache/maven/profiles/DefaultProfileManager.java
@@ -93,7 +93,7 @@ public class DefaultProfileManager
         return requestProperties;
     }
 
-    public Map getProfilesById()
+    public Map<String, Profile> getProfilesById()
     {
         return profilesById;
     }
@@ -138,13 +138,11 @@ public class DefaultProfileManager
     /* (non-Javadoc)
     * @see org.apache.maven.profiles.ProfileManager#explicitlyActivate(java.util.List)
     */
-    public void explicitlyActivate( List profileIds )
+    public void explicitlyActivate( List<String> profileIds )
     {
-        for ( Object profileId1 : profileIds )
+        for ( String profileId1 : profileIds )
         {
-            String profileId = (String) profileId1;
-
-            explicitlyActivate( profileId );
+            explicitlyActivate( profileId1 );
         }
     }
 
@@ -164,13 +162,11 @@ public class DefaultProfileManager
     /* (non-Javadoc)
     * @see org.apache.maven.profiles.ProfileManager#explicitlyDeactivate(java.util.List)
     */
-    public void explicitlyDeactivate( List profileIds )
+    public void explicitlyDeactivate( List<String> profileIds )
     {
-        for ( Object profileId1 : profileIds )
+        for ( String profileId1 : profileIds )
         {
-            String profileId = (String) profileId1;
-
-            explicitlyDeactivate( profileId );
+            explicitlyDeactivate( profileId1 );
         }
     }
 
@@ -212,13 +208,11 @@ public class DefaultProfileManager
     /* (non-Javadoc)
      * @see org.apache.maven.profiles.ProfileManager#addProfiles(java.util.List)
      */
-    public void addProfiles( List profiles )
+    public void addProfiles( List<Profile> profiles )
     {
-        for ( Object profile1 : profiles )
+        for ( Profile profile1 : profiles )
         {
-            Profile profile = (Profile) profile1;
-
-            addProfile( profile );
+            addProfile( profile1 );
         }
     }
 
diff --git a/maven-compat/src/main/java/org/apache/maven/profiles/ProfileManager.java b/maven-compat/src/main/java/org/apache/maven/profiles/ProfileManager.java
index 603343fd19..98064eff84 100644
--- a/maven-compat/src/main/java/org/apache/maven/profiles/ProfileManager.java
+++ b/maven-compat/src/main/java/org/apache/maven/profiles/ProfileManager.java
@@ -34,16 +34,16 @@ public interface ProfileManager
 
     void explicitlyActivate( String profileId );
 
-    void explicitlyActivate( List profileIds );
+    void explicitlyActivate( List<String> profileIds );
 
     void explicitlyDeactivate( String profileId );
 
-    void explicitlyDeactivate( List profileIds );
+    void explicitlyDeactivate( List<String> profileIds );
 
     List getActiveProfiles()
         throws ProfileActivationException;
 
-    void addProfiles( List profiles );
+    void addProfiles( List<Profile> profiles );
 
     Map getProfilesById();
 
diff --git a/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/DefaultLegacyArtifactCollector.java b/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/DefaultLegacyArtifactCollector.java
index 04d0d6b70f..0d6cea8107 100644
--- a/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/DefaultLegacyArtifactCollector.java
+++ b/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/DefaultLegacyArtifactCollector.java
@@ -342,9 +342,9 @@ public class DefaultLegacyArtifactCollector
 
                         // Conflict Resolution
                         ResolutionNode resolved = null;
-                        for ( Iterator j = conflictResolvers.iterator(); ( resolved == null ) && j.hasNext(); )
+                        for ( Iterator<ConflictResolver> j = conflictResolvers.iterator(); ( resolved == null ) && j.hasNext(); )
                         {
-                            ConflictResolver conflictResolver = (ConflictResolver) j.next();
+                            ConflictResolver conflictResolver = j.next();
 
                             resolved = conflictResolver.resolveConflict( previous, node );
                         }
@@ -424,9 +424,9 @@ public class DefaultLegacyArtifactCollector
 
             Artifact parentArtifact = node.getArtifact();
 
-            for ( Iterator i = node.getChildrenIterator(); i.hasNext(); )
+            for ( Iterator<ResolutionNode> i = node.getChildrenIterator(); i.hasNext(); )
             {
-                ResolutionNode child = (ResolutionNode) i.next();
+                ResolutionNode child = i.next();
 
                 try
                 {
diff --git a/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/transform/ArtifactTransformationManager.java b/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/transform/ArtifactTransformationManager.java
index f0ac9c89c8..95f15f98ee 100644
--- a/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/transform/ArtifactTransformationManager.java
+++ b/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/transform/ArtifactTransformationManager.java
@@ -78,5 +78,5 @@ public interface ArtifactTransformationManager
                                  ArtifactRepository localRepository )
         throws ArtifactDeploymentException;
 
-    List getArtifactTransformations();
+    List<ArtifactTransformation> getArtifactTransformations();
 }
diff --git a/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/transform/DefaultArtifactTransformationManager.java b/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/transform/DefaultArtifactTransformationManager.java
index e9b1afbce6..024778de9a 100644
--- a/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/transform/DefaultArtifactTransformationManager.java
+++ b/maven-compat/src/main/java/org/apache/maven/repository/legacy/resolver/transform/DefaultArtifactTransformationManager.java
@@ -79,7 +79,7 @@ public class DefaultArtifactTransformationManager
         }
     }
 
-    public List getArtifactTransformations()
+    public List<ArtifactTransformation> getArtifactTransformations()
     {
         return artifactTransformations;
     }
diff --git a/maven-compat/src/main/java/org/apache/maven/usability/plugin/ExpressionDocumenter.java b/maven-compat/src/main/java/org/apache/maven/usability/plugin/ExpressionDocumenter.java
index d0aeb31609..65bd9cf620 100644
--- a/maven-compat/src/main/java/org/apache/maven/usability/plugin/ExpressionDocumenter.java
+++ b/maven-compat/src/main/java/org/apache/maven/usability/plugin/ExpressionDocumenter.java
@@ -44,7 +44,7 @@ public class ExpressionDocumenter
 
     private static Map<String, Expression> expressionDocumentation;
 
-    public static Map load()
+    public static Map<String, Expression> load()
         throws ExpressionDocumentationException
     {
         if ( expressionDocumentation == null )
@@ -117,17 +117,15 @@ public class ExpressionDocumenter
 
         ExpressionDocumentation documentation = paramdocReader.read( reader, true );
 
-        List expressions = documentation.getExpressions();
+        List<Expression> expressions = documentation.getExpressions();
 
         Map<String, Expression> bySyntax = new HashMap<>();
 
         if ( expressions != null && !expressions.isEmpty() )
         {
-            for ( Object expression : expressions )
+            for ( Expression expression : expressions )
             {
-                Expression expr = (Expression) expression;
-
-                bySyntax.put( expr.getSyntax(), expr );
+                bySyntax.put( expression.getSyntax(), expression );
             }
         }
 
diff --git a/maven-compat/src/test/java/org/apache/maven/artifact/resolver/ArtifactResolverTest.java b/maven-compat/src/test/java/org/apache/maven/artifact/resolver/ArtifactResolverTest.java
index df49dbd55a..72a2017f61 100644
--- a/maven-compat/src/test/java/org/apache/maven/artifact/resolver/ArtifactResolverTest.java
+++ b/maven-compat/src/test/java/org/apache/maven/artifact/resolver/ArtifactResolverTest.java
@@ -241,7 +241,7 @@ public class ArtifactResolverTest
 
         printErrors( result );
 
-        Iterator i = result.getArtifacts().iterator();
+        Iterator<Artifact> i = result.getArtifacts().iterator();
         assertEquals( "n should be first", n, i.next() );
         assertEquals( "m should be second", m, i.next() );
 
diff --git a/maven-core/src/main/java/org/apache/maven/lifecycle/mapping/LifecyclePhase.java b/maven-core/src/main/java/org/apache/maven/lifecycle/mapping/LifecyclePhase.java
index a68a71c00f..e0cc8ddcdf 100644
--- a/maven-core/src/main/java/org/apache/maven/lifecycle/mapping/LifecyclePhase.java
+++ b/maven-core/src/main/java/org/apache/maven/lifecycle/mapping/LifecyclePhase.java
@@ -50,7 +50,7 @@ public class LifecyclePhase
     
     public void set( String goals )
     {
-        mojos = new ArrayList<LifecycleMojo>();
+        mojos = new ArrayList<>();
         
         String[] mojoGoals = StringUtils.split( goals, "," );
         
diff --git a/maven-core/src/main/java/org/apache/maven/plugin/PluginManager.java b/maven-core/src/main/java/org/apache/maven/plugin/PluginManager.java
index 1a3100e911..48b8e5ef83 100644
--- a/maven-core/src/main/java/org/apache/maven/plugin/PluginManager.java
+++ b/maven-core/src/main/java/org/apache/maven/plugin/PluginManager.java
@@ -60,7 +60,7 @@ public interface PluginManager
     Object getPluginComponent( Plugin plugin, String role, String roleHint )
         throws PluginManagerException, ComponentLookupException;
 
-    Map getPluginComponents( Plugin plugin, String role )
+    Map<String, Object> getPluginComponents( Plugin plugin, String role )
         throws ComponentLookupException, PluginManagerException;
 
     /**
diff --git a/maven-core/src/main/java/org/apache/maven/plugin/internal/DefaultMavenPluginManager.java b/maven-core/src/main/java/org/apache/maven/plugin/internal/DefaultMavenPluginManager.java
index edb5cfe231..e7eecb5d18 100644
--- a/maven-core/src/main/java/org/apache/maven/plugin/internal/DefaultMavenPluginManager.java
+++ b/maven-core/src/main/java/org/apache/maven/plugin/internal/DefaultMavenPluginManager.java
@@ -203,8 +203,7 @@ public class DefaultMavenPluginManager
         {
             if ( pluginFile.isFile() )
             {
-                JarFile pluginJar = new JarFile( pluginFile, false );
-                try
+                try ( JarFile pluginJar = new JarFile( pluginFile, false ) )
                 {
                     ZipEntry pluginDescriptorEntry = pluginJar.getEntry( getPluginDescriptorLocation() );
 
@@ -215,10 +214,6 @@ public class DefaultMavenPluginManager
                         pluginDescriptor = parsePluginDescriptor( is, plugin, pluginFile.getAbsolutePath() );
                     }
                 }
-                finally
-                {
-                    pluginJar.close();
-                }
             }
             else
             {
@@ -274,11 +269,7 @@ public class DefaultMavenPluginManager
 
             return pluginDescriptor;
         }
-        catch ( IOException e )
-        {
-            throw new PluginDescriptorParsingException( plugin, descriptorLocation, e );
-        }
-        catch ( PlexusConfigurationException e )
+        catch ( IOException | PlexusConfigurationException e )
         {
             throw new PluginDescriptorParsingException( plugin, descriptorLocation, e );
         }
@@ -369,7 +360,7 @@ public class DefaultMavenPluginManager
             if ( cacheRecord != null )
             {
                 pluginDescriptor.setClassRealm( cacheRecord.realm );
-                pluginDescriptor.setArtifacts( new ArrayList<Artifact>( cacheRecord.artifacts ) );
+                pluginDescriptor.setArtifacts( new ArrayList<>( cacheRecord.artifacts ) );
                 for ( ComponentDescriptor<?> componentDescriptor : pluginDescriptor.getComponents() )
                 {
                     componentDescriptor.setRealm( cacheRecord.realm );
@@ -450,13 +441,7 @@ public class DefaultMavenPluginManager
             ( (DefaultPlexusContainer) container ).discoverComponents( pluginRealm, new SessionScopeModule( container ),
                                                                        new MojoExecutionScopeModule( container ) );
         }
-        catch ( ComponentLookupException e )
-        {
-            throw new PluginContainerException( plugin, pluginRealm,
-                                                "Error in component graph of plugin " + plugin.getId() + ": "
-                                                    + e.getMessage(), e );
-        }
-        catch ( CycleDetectedInComponentGraphException e )
+        catch ( ComponentLookupException | CycleDetectedInComponentGraphException e )
         {
             throw new PluginContainerException( plugin, pluginRealm,
                                                 "Error in component graph of plugin " + plugin.getId() + ": "
@@ -466,12 +451,12 @@ public class DefaultMavenPluginManager
 
     private List<org.eclipse.aether.artifact.Artifact> toAetherArtifacts( final List<Artifact> pluginArtifacts )
     {
-        return new ArrayList<org.eclipse.aether.artifact.Artifact>( RepositoryUtils.toArtifacts( pluginArtifacts ) );
+        return new ArrayList<>( RepositoryUtils.toArtifacts( pluginArtifacts ) );
     }
 
     private List<Artifact> toMavenArtifacts( DependencyNode root, PreorderNodeListGenerator nlg )
     {
-        List<Artifact> artifacts = new ArrayList<Artifact>( nlg.getNodes().size() );
+        List<Artifact> artifacts = new ArrayList<>( nlg.getNodes().size() );
         RepositoryUtils.toArtifacts( artifacts, Collections.singleton( root ), Collections.<String>emptyList(), null );
         for ( Iterator<Artifact> it = artifacts.iterator(); it.hasNext(); )
         {
@@ -486,7 +471,7 @@ public class DefaultMavenPluginManager
 
     private Map<String, ClassLoader> calcImports( MavenProject project, ClassLoader parent, List<String> imports )
     {
-        Map<String, ClassLoader> foreignImports = new HashMap<String, ClassLoader>();
+        Map<String, ClassLoader> foreignImports = new HashMap<>();
 
         ClassLoader projectRealm = project.getClassRealm();
         if ( projectRealm != null )
@@ -661,7 +646,7 @@ public class DefaultMavenPluginManager
             {
                 if ( "basic".equals( configuratorId ) )
                 {
-                    throw new PluginParameterException( mojoDescriptor, new ArrayList<Parameter>( missingParameters ) );
+                    throw new PluginParameterException( mojoDescriptor, new ArrayList<>( missingParameters ) );
                 }
                 else
                 {
@@ -736,7 +721,7 @@ public class DefaultMavenPluginManager
             return;
         }
 
-        List<Parameter> invalidParameters = new ArrayList<Parameter>();
+        List<Parameter> invalidParameters = new ArrayList<>();
 
         for ( Parameter parameter : mojoDescriptor.getParameters() )
         {
@@ -811,7 +796,7 @@ public class DefaultMavenPluginManager
             (Map<String, ExtensionRealmCache.CacheRecord>) project.getContextValue( KEY_EXTENSIONS_REALMS );
         if ( pluginRealms == null )
         {
-            pluginRealms = new HashMap<String, ExtensionRealmCache.CacheRecord>();
+            pluginRealms = new HashMap<>();
             project.setContextValue( KEY_EXTENSIONS_REALMS, pluginRealms );
         }
 
@@ -890,11 +875,7 @@ public class DefaultMavenPluginManager
                 {
                     pluginDescriptor = extractPluginDescriptor( artifacts.get( 0 ), plugin );
                 }
-                catch ( PluginDescriptorParsingException e )
-                {
-                    // ignore, see above
-                }
-                catch ( InvalidPluginDescriptorException e )
+                catch ( PluginDescriptorParsingException | InvalidPluginDescriptorException e )
                 {
                     // ignore, see above
                 }
diff --git a/maven-core/src/main/java/org/apache/maven/plugin/internal/DefaultPluginManager.java b/maven-core/src/main/java/org/apache/maven/plugin/internal/DefaultPluginManager.java
index e2f4526cfe..a8ac9ebd03 100644
--- a/maven-core/src/main/java/org/apache/maven/plugin/internal/DefaultPluginManager.java
+++ b/maven-core/src/main/java/org/apache/maven/plugin/internal/DefaultPluginManager.java
@@ -19,8 +19,6 @@ package org.apache.maven.plugin.internal;
  * under the License.
  */
 
-import java.util.Map;
-
 import org.apache.maven.artifact.repository.ArtifactRepository;
 import org.apache.maven.artifact.resolver.ArtifactNotFoundException;
 import org.apache.maven.artifact.resolver.ArtifactResolutionException;
@@ -59,6 +57,8 @@ import org.codehaus.plexus.component.annotations.Component;
 import org.codehaus.plexus.component.annotations.Requirement;
 import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
 
+import java.util.Map;
+
 /**
  * @author Benjamin Bentmann
  */
@@ -121,7 +121,7 @@ public class DefaultPluginManager
         }
     }
 
-    public Map getPluginComponents( Plugin plugin, String role )
+    public Map<String, Object> getPluginComponents( Plugin plugin, String role )
         throws ComponentLookupException, PluginManagerException
     {
         MavenSession session = legacySupport.getSession();
diff --git a/maven-settings-builder/src/main/java/org/apache/maven/settings/validation/DefaultSettingsValidator.java b/maven-settings-builder/src/main/java/org/apache/maven/settings/validation/DefaultSettingsValidator.java
index 5c4f10f8f4..1e31f504ff 100644
--- a/maven-settings-builder/src/main/java/org/apache/maven/settings/validation/DefaultSettingsValidator.java
+++ b/maven-settings-builder/src/main/java/org/apache/maven/settings/validation/DefaultSettingsValidator.java
@@ -147,7 +147,7 @@ public class DefaultSettingsValidator
 
         if ( proxies != null )
         {
-            Set<String> proxyIds = new HashSet<String>();
+            Set<String> proxyIds = new HashSet<>();
             
             for ( Proxy proxy : proxies )
             {