code: public static void repack(File srcZip, File dstZip, int compressionLevel) {
  
      log.debug("Repacking '{}' into '{}'.", srcZip, dstZip);
  
      RepackZipEntryCallback callback = new RepackZipEntryCallback(dstZip, compressionLevel);
  
      try {
        iterate(srcZip, callback);
      }
      finally {
        callback.closeStream();
      }
    }
docs: Repacks a provided ZIP file into a new ZIP with a given compression level.
  <p>
  
  @param srcZip
  source ZIP file.
  @param dstZip
  destination ZIP file.
  @param compressionLevel
  compression level.