/**

   * 使用md5的算法进行加密

   */

  public static String md5(String plainText) {

  byte[] secretBytes = null;

  try {

  secretBytes = MessageDigest.getInstance("md5").digest(

  plainText.getBytes());

  } catch (NoSuchAlgorithmException e) {

  throw new RuntimeException("没有md5这个算法！");

  }

  String md5code = new BigInteger(1, secretBytes).toString(16);

  for (int i = 0; i < 32 - md5code.length(); i++) {

  md5code = "0" + md5code;

  }

  return md5code;

  }