Enable checkstyle during build

- checkstyle verification will be done on each build
- reformat code according to rules
- reorder imports

pom.xml

@@ -266,17 +266,11 @@
   </dependencies>
 
   <build>
-    <pluginManagement>
-      <plugins>
-        <plugin>
-          <groupId>org.codehaus.modello</groupId>
-          <artifactId>modello-maven-plugin</artifactId>
-          <version>2.0.0</version>
-        </plugin>
-      </plugins>
-    </pluginManagement>
-
     <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-checkstyle-plugin</artifactId>
+      </plugin>
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>animal-sniffer-maven-plugin</artifactId>

src/main/java/org/codehaus/mojo/versions/AbstractVersionsDependencyUpdaterMojo.java

@@ -172,7 +172,8 @@ public boolean isProcessingParent()
     /**
      * Should the artifacts produced in the current reactor be excluded from processing.
      *
-     * @return returns <code>true</code> if the artifacts produced in the current reactor should be excluded from processing.
+     * @return returns <code>true</code> if the artifacts produced in the current reactor
+     * should be excluded from processing.
      * @since 1.0-alpha-3
      */
     public boolean isExcludeReactor()
@@ -182,7 +183,7 @@ public boolean isExcludeReactor()
 
     /**
      * Should the dependency be updated itself or is it handled by properties.
-     * 
+     *
      * @param dependency Dependency
      * @return true if the version starts with '${'
      * @since 2.8
@@ -220,8 +221,8 @@ protected Artifact findArtifact( Dependency dependency )
      * Try to find the dependency artifact that matches the given dependency.
      *
      * @param dependency Dependency
-     * @throws MojoExecutionException Mojo execution exception
      * @return Artifact
+     * @throws MojoExecutionException Mojo execution exception
      * @since 1.0-alpha-3
      */
     protected Artifact toArtifact( Dependency dependency )
@@ -301,9 +302,11 @@ protected String toString( Dependency d )
      */
     protected boolean isProducedByReactor( Dependency dependency )
     {
-        for ( Object reactorProject : reactorProjects ) {
+        for ( Object reactorProject : reactorProjects )
+        {
             MavenProject project = (MavenProject) reactorProject;
-            if ( compare(project, dependency) ) {
+            if ( compare( project, dependency ) )
+            {
                 return true;
             }
         }
@@ -315,7 +318,7 @@ protected boolean isProducedByReactor( Dependency dependency )
      * Compare a project to a dependency. Returns true only if the groupId and artifactId are all equal.
      *
      * @param project the project
-     * @param dep the dependency
+     * @param dep     the dependency
      * @return true if project and dep refer to the same artifact
      */
     private boolean compare( MavenProject project, Dependency dep )
@@ -332,7 +335,7 @@ private boolean compare( MavenProject project, Dependency dep )
      * equal.
      *
      * @param artifact Artifact
-     * @param dep Dependency
+     * @param dep      Dependency
      * @return true if artifact and dep refer to the same artifact
      */
     private boolean compare( Artifact artifact, Dependency dep )
@@ -381,7 +384,7 @@ protected boolean isIncluded( Artifact artifact )
 
     /**
      * Indicates whether any includes were specified via the 'includes' or 'includesList' options.
-     * 
+     *
      * @return true if includes were specified, false otherwise.
      */
     protected boolean hasIncludes()

src/main/java/org/codehaus/mojo/versions/AbstractVersionsDisplayMojo.java

@@ -37,7 +37,7 @@
 public abstract class AbstractVersionsDisplayMojo
     extends AbstractVersionsUpdaterMojo
 {
-    String NL = System.getProperty( "line.separator" );
+    static final String NL = System.getProperty( "line.separator" );
 
     private static final int DEFAULT_OUTPUT_LINE_WIDTH = 80;
 
@@ -70,7 +70,8 @@ public abstract class AbstractVersionsDisplayMojo
      *
      * @since 2.10.0
      */
-    @Parameter( property = "versions.outputLineWidth", defaultValue = AbstractVersionsDisplayMojo.DEFAULT_OUTPUT_LINE_WIDTH + "" )
+    @Parameter( property = "versions.outputLineWidth",
+                defaultValue = AbstractVersionsDisplayMojo.DEFAULT_OUTPUT_LINE_WIDTH + "" )
     private int outputLineWidth;
 
     private boolean outputFileError = false;
@@ -129,7 +130,7 @@ else if ( !outputFile.getParentFile().isDirectory() )
             {
                 outputEncoding = System.getProperty( "file.encoding" );
                 getLog().warn( "File encoding has not been set, using platform encoding " + outputEncoding
-                    + ", i.e. build is platform dependent!" );
+                                   + ", i.e. build is platform dependent!" );
             }
         }
     }
@@ -152,8 +153,8 @@ protected void logLine( boolean error, String line )
             try
             {
                 Files.write( outputFile.toPath(),
-                        ( error ? "> " + line + NL : line + NL ).getBytes( outputEncoding ),
-                        StandardOpenOption.APPEND, StandardOpenOption.CREATE );
+                             ( error ? "> " + line + NL : line + NL ).getBytes( outputEncoding ),
+                             StandardOpenOption.APPEND, StandardOpenOption.CREATE );
             }
             catch ( IOException e )
             {
@@ -166,7 +167,8 @@ protected void logLine( boolean error, String line )
     /**
      * @return Offset of the configured output line width compared to the default with of 80.
      */
-    protected int getOutputLineWidthOffset() {
+    protected int getOutputLineWidthOffset()
+    {
         return this.outputLineWidth - DEFAULT_OUTPUT_LINE_WIDTH;
     }
 

src/main/java/org/codehaus/mojo/versions/AbstractVersionsReport.java

@@ -19,6 +19,10 @@
  * under the License.
  */
 
+import java.io.File;
+import java.util.List;
+import java.util.Locale;
+
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.artifact.manager.WagonManager;
 import org.apache.maven.artifact.metadata.ArtifactMetadataRetrievalException;
@@ -44,10 +48,6 @@
 import org.codehaus.mojo.versions.api.VersionsHelper;
 import org.codehaus.plexus.i18n.I18N;
 
-import java.io.File;
-import java.util.List;
-import java.util.Locale;
-
 /**
  * Base class for all versions reports.
  *

src/main/java/org/codehaus/mojo/versions/AbstractVersionsReportRenderer.java

@@ -211,6 +211,7 @@ protected void safeBold()
         }
     }
 
+    @SuppressWarnings( "checkstyle:MethodName" )
     protected void safeBold_()
     {
         try
@@ -235,6 +236,7 @@ protected void safeItalic()
         }
     }
 
+    @SuppressWarnings( "checkstyle:MethodName" )
     protected void safeItalic_()
     {
         try
@@ -306,6 +308,7 @@ protected void renderDependencyDetailTable( Dependency dependency, ArtifactVersi
         renderDependencyDetailTable( dependency, details, true, true, true );
     }
 
+    @SuppressWarnings( "checkstyle:MethodLength" )
     protected void renderDependencyDetailTable( Dependency dependency, ArtifactVersions details, boolean includeScope,
                                                 boolean includeClassifier, boolean includeType )
     {
@@ -601,6 +604,7 @@ protected void renderPropertySummaryTableHeader()
         sink.tableRow_();
     }
 
+    @SuppressWarnings( "checkstyle:MethodLength" )
     protected void renderPropertyDetailTable( Property property, PropertyVersions versions )
     {
         final SinkEventAttributes headerAttributes = new SinkEventAttributeSet();

src/main/java/org/codehaus/mojo/versions/AbstractVersionsUpdaterMojo.java

@@ -19,6 +19,15 @@
  * under the License.
  */
 
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLStreamException;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.Writer;
+import java.util.List;
+
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.artifact.manager.WagonManager;
 import org.apache.maven.artifact.metadata.ArtifactMetadataRetrievalException;
@@ -38,7 +47,6 @@
 import org.apache.maven.plugins.annotations.Parameter;
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.project.MavenProjectBuilder;
-import org.apache.maven.project.path.PathTranslator;
 import org.apache.maven.repository.RepositorySystem;
 import org.apache.maven.settings.Settings;
 import org.codehaus.mojo.versions.api.ArtifactVersions;
@@ -55,14 +63,6 @@
 import org.codehaus.plexus.util.WriterFactory;
 import org.codehaus.stax2.XMLInputFactory2;
 
-import javax.xml.stream.XMLInputFactory;
-import javax.xml.stream.XMLStreamException;
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.Writer;
-import java.util.List;
-
 /**
  * Abstract base class for Versions Mojos.
  *
@@ -277,14 +277,14 @@ public void execute()
     /**
      * Finds the latest version of the specified artifact that matches the version range.
      *
-     * @param artifact The artifact.
-     * @param versionRange The version range.
-     * @param allowingSnapshots <code>null</code> for no override, otherwise the local override to apply.
+     * @param artifact              The artifact.
+     * @param versionRange          The version range.
+     * @param allowingSnapshots     <code>null</code> for no override, otherwise the local override to apply.
      * @param usePluginRepositories Use plugin repositories
      * @return The latest version of the specified artifact that matches the specified version range or
-     *         <code>null</code> if no matching version could be found.
+     * <code>null</code> if no matching version could be found.
      * @throws ArtifactMetadataRetrievalException If the artifact metadata could not be found.
-     * @throws MojoExecutionException if something goes wrong.
+     * @throws MojoExecutionException             if something goes wrong.
      * @since 1.0-alpha-1
      */
     protected ArtifactVersion findLatestVersion( Artifact artifact, VersionRange versionRange,
@@ -308,7 +308,7 @@ protected ArtifactVersion findLatestVersion( Artifact artifact, VersionRange ver
      * Gets the property value that is defined in the pom. This is an extension point to allow updating a file external
      * to the reactor.
      *
-     * @param pom The pom.
+     * @param pom      The pom.
      * @param property The property.
      * @return The value as defined in the pom or <code>null</code> if not defined.
      * @since 1.0-alpha-1
@@ -323,7 +323,7 @@ protected String getPropertyValue( StringBuilder pom, String property )
      *
      * @param outFile The file to process.
      * @throws MojoExecutionException If things go wrong.
-     * @throws MojoFailureException If things go wrong.
+     * @throws MojoFailureException   If things go wrong.
      * @since 1.0-alpha-1
      */
     protected void process( File outFile )
@@ -375,7 +375,7 @@ protected void process( File outFile )
      * Creates a {@link org.codehaus.mojo.versions.rewriting.ModifiedPomXMLEventReader} from a StringBuilder.
      *
      * @param input The XML to read and modify.
-     * @param path Path pointing to the source of the XML
+     * @param path  Path pointing to the source of the XML
      * @return The {@link org.codehaus.mojo.versions.rewriting.ModifiedPomXMLEventReader}.
      */
     protected final ModifiedPomXMLEventReader newModifiedPomXER( StringBuilder input, String path )
@@ -398,13 +398,13 @@ protected final ModifiedPomXMLEventReader newModifiedPomXER( StringBuilder input
      * Writes a StringBuilder into a file.
      *
      * @param outFile The file to read.
-     * @param input The contents of the file.
+     * @param input   The contents of the file.
      * @throws IOException when things go wrong.
      */
     protected final void writeFile( File outFile, StringBuilder input )
         throws IOException
     {
-        try (Writer writer = WriterFactory.newXmlWriter( outFile ) )
+        try ( Writer writer = WriterFactory.newXmlWriter( outFile ) )
         {
             IOUtil.copy( input.toString(), writer );
         }
@@ -414,44 +414,44 @@ protected final void writeFile( File outFile, StringBuilder input )
      * Updates the pom.
      *
      * @param pom The pom to update.
-     * @throws MojoExecutionException If things go wrong.
-     * @throws MojoFailureException If things go wrong.
+     * @throws MojoExecutionException              If things go wrong.
+     * @throws MojoFailureException                If things go wrong.
      * @throws javax.xml.stream.XMLStreamException If things go wrong.
-     * @throws ArtifactMetadataRetrievalException if something goes wrong.
+     * @throws ArtifactMetadataRetrievalException  if something goes wrong.
      * @since 1.0-alpha-1
      */
     protected abstract void update( ModifiedPomXMLEventReader pom )
         throws MojoExecutionException, MojoFailureException, XMLStreamException, ArtifactMetadataRetrievalException;
 
     /**
-     * @deprecated
-     *  This method no longer supported.
-     *  use shouldApplyUpdate( Artifact artifact, String currentVersion, ArtifactVersion updateVersion, Boolean forceUpdate )
-     *
-     * Returns <code>true</code> if the update should be applied.
-     *
-     * @param artifact The artifact.
+     * @param artifact       The artifact.
      * @param currentVersion The current version of the artifact.
-     * @param updateVersion The proposed new version of the artifact.
+     * @param updateVersion  The proposed new version of the artifact.
      * @return <code>true</code> if the update should be applied.
      * @since 1.0-alpha-1
+     * @deprecated This method no longer supported.
+     * use shouldApplyUpdate( Artifact artifact, String currentVersion, ArtifactVersion updateVersion, Boolean
+     * forceUpdate )
+     * <p>
+     * Returns <code>true</code> if the update should be applied.
      */
     @Deprecated
     protected boolean shouldApplyUpdate( Artifact artifact, String currentVersion, ArtifactVersion updateVersion )
     {
-        return shouldApplyUpdate(artifact,currentVersion,updateVersion,false);
+        return shouldApplyUpdate( artifact, currentVersion, updateVersion, false );
     }
 
     /**
      * Returns <code>true</code> if the update should be applied.
      *
-     * @param artifact The artifact.
+     * @param artifact       The artifact.
      * @param currentVersion The current version of the artifact.
-     * @param updateVersion The proposed new version of the artifact.
+     * @param updateVersion  The proposed new version of the artifact.
      * @return <code>true</code> if the update should be applied to the pom.
      * @since 2.9
      */
-    protected boolean shouldApplyUpdate( Artifact artifact, String currentVersion, ArtifactVersion updateVersion, boolean forceUpdate )
+    protected boolean shouldApplyUpdate( Artifact artifact, String currentVersion, ArtifactVersion updateVersion,
+                                         boolean forceUpdate )
     {
         getLog().debug( "Proposal is to update from " + currentVersion + " to " + updateVersion );
 
@@ -495,8 +495,8 @@ protected boolean shouldApplyUpdate( Artifact artifact, String currentVersion, A
      * Based on the passed flags, determines which segment is unchangable. This can be used when determining an upper
      * bound for the "latest" version.
      *
-     * @param allowMajorUpdates Allow major updates
-     * @param allowMinorUpdates Allow minor updates
+     * @param allowMajorUpdates       Allow major updates
+     * @param allowMinorUpdates       Allow minor updates
      * @param allowIncrementalUpdates Allow incremental updates
      * @return Returns the segment that is unchangable. If any segment can change, returns -1.
      */

src/main/java/org/codehaus/mojo/versions/CommitMojo.java

@@ -19,6 +19,9 @@
  * under the License.
  */
 
+import java.io.File;
+import java.io.IOException;
+
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugin.MojoFailureException;
@@ -27,9 +30,6 @@
 import org.apache.maven.project.MavenProject;
 import org.codehaus.plexus.util.FileUtils;
 
-import java.io.File;
-import java.io.IOException;
-
 /**
  * Removes the initial backup of the pom, thereby accepting the changes.
  *