package com.jkcredit.utils;

import java.security.MessageDigest;

/**
 * @description: MD5加密
 * @author:
 * @create: 2019-05-14 11:05
 * @version: V1.0
 **/

public class Md5Utils {

    /**
     * 生成md5,全部大写
     * @param message
     * @return
     */
    public static String md5(String message) {
        try {
            // 1 创建提供信息摘要算法的对象，初始化为md5算法对象
            MessageDigest md = MessageDigest.getInstance("MD5");

            // 2 将消息变成byte数组
            byte[] input = message.getBytes();

            // 3 计算后获得字节数,这就是那128位了
            byte[] buff = md.digest(input);

            // 4 把数组每字节（一个字节占八位）换16进制连成md5字符
            return byte2hex(buff);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * 二进制转十六进制字符
     * @param bytes
     * @return
     */
    private static String byte2hex(byte[] bytes) {
        StringBuilder sign = new StringBuilder();
        for (int i = 0; i < bytes.length; i++) {
            String hex = Integer.toHexString(bytes[i] & 0xFF);
            if (hex.length() == 1) {
                sign.append("0");
            }
            sign.append(hex.toUpperCase());
        }
        return sign.toString();
    }


}