JAVA中使用MD5加密工具类实现对数据的加密处理

package com.ssm.util;

import java.security.MessageDigest;

public class MD5Util {
    //将字节数组转成十六进制字符串
    private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++)
            resultSb.append(byteToHexString(b[i]));

        return resultSb.toString();
    }
    //对单个字节转换成整数进行取商取余数计算
    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0)
            n += 256;
        int d1 = n / 16;
        int d2 = n % 16;
        //根据下标d1，d2去数组hexDigits的数据
        return hexDigits[d1] + hexDigits[d2];
    }

    public static String MD5Encode(String origin, String charsetname) {
        String resultString = null;
        try {
            resultString = new String(origin);
         // 获得MD5摘要算法的 MessageDigest 对象
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetname == null || "".equals(charsetname))
                //将加密之后的字节数据转换成16进制的字符串
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes()));
            else
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes(charsetname)));
        } catch (Exception exception) {
        }
        return resultString;
    }

    private static final String hexDigits[] = {"0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};
}

CREATE TABLE `user` (
  `id` int(20) NOT NULL AUTO_INCREMENT COMMENT ‘编号‘,
  `userName` varchar(50) COLLATE utf8_unicode_ci NOT NULL COMMENT ‘用户名‘,
  `password` varchar(50) COLLATE utf8_unicode_ci NOT NULL COMMENT ‘密码‘,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci

package com.ssm.pojo;

public class User {
    private Integer id;
    private String userName;
    private String password;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    
    
    

}

package com.ssm.dao;

import com.ssm.pojo.User;

public interface UserDao {
    //用户注册
    public int register(User user) ;
    //登陆
    public User login(User user);

}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ssm.dao.UserDao">
    <resultMap type="com.ssm.pojo.User" id="UserResult">
        <result property="id" column="id" />
        <result property="userName" column="userName" />
        <result property="password" column="password" />

    </resultMap>

    <select id="login" parameterType="com.ssm.pojo.User" resultMap="UserResult">
        select * from
        user where userName=#{userName} and password=#{password} limit 1
    </select>

    <insert id="register" parameterType="com.ssm.pojo.User">
        insert into user(userName,password)
        values(#{userName},#{password})
    </insert>
</mapper> 

package com.ssm.service.impl;

import com.ssm.pojo.User;

public interface UserService {
    public User login(User user); 
     public int register(User user);

}

package com.ssm.service.impl;

import javax.annotation.Resource;

import org.springframework.stereotype.Service;

import com.ssm.dao.UserDao;
import com.ssm.pojo.User;
@Service("userService")
public class UserServiceImpl implements UserService {
    @Resource
    private UserDao userDao;

    public User login(User user) {
        // TODO Auto-generated method stub
        return userDao.login(user);
    }

    public int register(User user) {
        // TODO Auto-generated method stub
        return userDao.register(user);
    }
    

}