code: private byte[] getHeader(Entry entry) throws IOException {
          zipRandomFile.seek(entry.offset);
          byte[] header = new byte[30];
          zipRandomFile.readFully(header);
          if (get4ByteLittleEndian(header, 0) != 0x04034b50)
              throw new ZipException("corrupted zip file");
          if ((get2ByteLittleEndian(header, 6) & 1) != 0)
              throw new ZipException("encrypted zip file"); // offset 6 in the header of the ZipFileEntry
          return header;
      }
docs: ----------------------------------------------------------------------------