code: private File createArchive() throws Exception {
          getLog().info("Creating archive.");
          Artifact artifact = mavenProject.getArtifact();
          String clsfr = noclassifier ? "" : ("-" + classifier);
          String archiveName = artifact.getArtifactId() + "-" + artifact.getVersion() + clsfr + ".jar";
          File jarFile = new File(mavenProject.getBuild().getDirectory(), archiveName);
          MavenArchiver archiver = new MavenArchiver();
          jarArchiver.addDirectory(stagingDirectory);
          archiver.setArchiver(jarArchiver);
          archiver.setOutputFile(jarFile);
          archiver.createArchive(mavenSession, mavenProject, archiveConfig);
          
          if (noclassifier) {
              artifact.setFile(jarFile);
          } else {
              projectHelper.attachArtifact(mavenProject, jarFile, classifier);
          }
          
          FileUtils.deleteDirectory(stagingDirectory);
          return jarFile;
      }
docs: Creates the archive from data in the staging directory.
  
  @return The archive file.
  @throws Exception Unspecified exception.