code: protected void scanJar(final File file, final String packagePath) throws IOException {
          final ZipFile zip = new ZipFile(file);
          final Enumeration<? extends ZipEntry> entries = zip.entries();
          while ( entries.hasMoreElements() ) {
              final ZipEntry entry = entries.nextElement();
              final String name = entry.getName();
              if (name.startsWith(packagePath)) {
                  handleItem(name);
              }
          }
      }
docs: Scans the entries in a ZIP/JAR file for classes under the parent package.
  @param file the jar file to be scanned
  @param packagePath the top level package to start from