MD5的使用

首先是我的源代码

/***
* MD5加码生成32位md5码
*/
public static String backMD5(String inStr){

  MessageDigest md5 = null;

  try{

      md5 = MessageDigest.getInstance("MD5");

  }catch (Exception e){

  System.out.println(e.toString());
  e.printStackTrace();

  return "";
}

  char[] charArray = inStr.toCharArray();
  byte[] byteArray = new byte[charArray.length];

  for (int i = 0; i < charArray.length; i++)
      byteArray[i] = (byte) charArray[i];

  byte[] md5Bytes = md5.digest(byteArray);
  StringBuffer hexValue = new StringBuffer();

  for (int i = 0; i < md5Bytes.length; i++){

      int val = ((int) md5Bytes[i]) & 0xff;
      if (val < 16)
          hexValue.append("0");
          hexValue.append(Integer.toHexString(val));
  }

  return hexValue.toString();

}

/**
* 加密解密算法执行一次加密，两次解密
*/
public static String DecryptMD5(String inStr){

  char[] a = inStr.toCharArray();
  for (int i = 0; i < a.length; i++){

      a[i] = (char) (a[i] ^ 't');
  }
  String s = new String(a);

  return s;

}

// 测试主函数
public static void main(String args[]) {

//可以在这里设置自己的数据
  List<String> list=new ArrayList<String>();

  list.add("liuhao");
  list.add("liu hao");

  for (int i = 0; i < list.size(); i++) {

    System.out.println("原始：" + list.get(i));
  System.out.println("MD5后：" + backMD5(list.get(i)));
    System.out.println("加密的：" + DecryptMD5(list.get(i)));
      System.out.println("解密的：" + DecryptMD5(DecryptMD5(list.get(i))));
}

}

输出的结果为

好啦..就是这么的简单