code: private void extractJarContents(final List<String> entries, final File destdir) throws IOException {
          if (!destdir.exists()) {
              if (!destdir.mkdir()) {
                  //log.warn("Unable to create cache dir for plugin: " + destdir.getAbsolutePath());
              }
          }
  
          //debug("extracting lib files from jar: " + pluginJar);
          for (final String path : entries) {
              //debug("Expand zip " + pluginJar.getAbsolutePath() + " to dir: " + destdir + ", file: " + path);
              ZipUtil.extractZipFile(zipFile.getAbsolutePath(), destdir, path);
          }
  
      }
docs: Extract specific entries from the jar to a destination directory. Creates the
  destination directory if it does not exist
  
  @param entries the entries to extract
  @param destdir destination directory