code: public void execute()
          throws MojoExecutionException
      {
          File jarFile = createArchive();
  
          String classifier = getClassifier();
          if ( classifier != null )
          {
              projectHelper.attachArtifact( getProject(), "jar", classifier, jarFile );
          }
          else
          {
              getProject().getArtifact().setFile( jarFile );
          }
      }
docs: Generates the JAR.
  
  @throws org.apache.maven.plugin.MojoExecutionException if any.