java的MD5加密

public static String getMD5Str(String str) {
   MessageDigest messageDigest = null;

   try {
    messageDigest = MessageDigest.getInstance("MD5");

    messageDigest.reset();

    messageDigest.update(str.getBytes("UTF-8"));
   } catch (NoSuchAlgorithmException e) {
    System.out.println("NoSuchAlgorithmException caught!");
    System.exit(-1);
   } catch (UnsupportedEncodingException e) {
    e.printStackTrace();
   }

   byte[] byteArray = messageDigest.digest();

   StringBuffer md5StrBuff = new StringBuffer();

   for (int i = 0; i < byteArray.length; i++) {
    if (Integer.toHexString(0xFF & byteArray[i]).length() == 1)
     md5StrBuff.append("0").append(
       Integer.toHexString(0xFF & byteArray[i]));
    else
     md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));
   }

   return md5StrBuff.toString();
}

具体不明~~~~

直接用吧~