package com.rick.utils;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

/**

 * -------------------------------------------

 * Title : MD5Util

 * Description : MD5加密算法

 * Create on : 2017年4月5日 上午9:53:42

 * Copyright (C) strongunion

 * @author RICK

 * 修改历史:

 * 修改人 修改日期 修改描述

 * -------------------------------------------

 */

public class MD5Util {

     // 全局数组

    private final static String[] strDigits = { "0", "1", "2", "3", "4", "5",

            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

    public MD5Util() {

    }

    // 返回形式为数字跟字符串

    private static String byteToArrayString(byte bByte) {

        int iRet = bByte;

        if (iRet < 0) {

            iRet += 256;

        }

        int iD1 = iRet / 16;

        int iD2 = iRet % 16;

        return strDigits[iD1] + strDigits[iD2];

    }

    // 返回形式只为数字

    private static String byteToNum(byte bByte) {

        int iRet = bByte;

        System.out.println("iRet1=" + iRet);

        if (iRet < 0) {

            iRet += 256;

        }

        return String.valueOf(iRet);

    }

    // 转换字节数组为16进制字串

    private static String byteToString(byte[] bByte) {

        StringBuffer sBuffer = new StringBuffer();

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

            sBuffer.append(byteToArrayString(bByte[i]));

        }

        return sBuffer.toString();

    }

    public static String getMD5Code(String strObj) {

        String resultString = null;

        try {

            resultString = new String(strObj);

            MessageDigest md = MessageDigest.getInstance("MD5");

            // md.digest() 该函数返回值为存放哈希值结果的byte数组

            resultString = byteToString(md.digest(strObj.getBytes()));

        } catch (NoSuchAlgorithmException ex) {

            ex.printStackTrace();

        }

        return resultString;

    }

    public static void main(String[] args) {

        MD5Util getMD5 = new MD5Util();

        System.out.println(getMD5.getMD5Code("123456"));

    }

}