Java版MD5加密算法

 

调用方法为：

 

Encript.md5("www.young-sun.com");

 

 

 

package com.youngsun.lbt; 

import java.security.MessageDigest;

publicclass Encript { 
    //十六进制下数字到字符的映射数组
    privatefinalstatic String[] hexDigits = {"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"}; 
    /**把inputString加密*/
    publicstatic String md5(String inputStr){ 
        return encodeByMD5(inputStr); 
    } 
    /** 
    * 验证输入的密码是否正确
    * @param password 真正的密码（加密后的真密码）
    * @param inputString 输入的字符串
    * @return验证结果，boolean类型
*/
    publicstaticboolean authenticatePassword(String password,String inputString){ 
        if(password.equals(encodeByMD5(inputString))){ 
            returntrue; 
        }else{ 
            returnfalse; 
        } 
    } 
    /**对字符串进行MD5编码*/
    privatestatic String encodeByMD5(String originString){ 
        if (originString!=null) { 
            try { 
                //创建具有指定算法名称的信息摘要
                MessageDigest md5 = MessageDigest.getInstance("MD5"); 
                //使用指定的字节数组对摘要进行最后更新，然后完成摘要计算
                byte[] results = md5.digest(originString.getBytes()); 
                //将得到的字节数组变成字符串返回  
                String result = byteArrayToHexString(results); 
                return result; 
            } catch (Exception e) { 
                e.printStackTrace(); 
            } 
        } 
        returnnull; 
    } 
    /** 
    * 轮换字节数组为十六进制字符串
    * @param b 字节数组
    * @return十六进制字符串
*/
    privatestatic String byteArrayToHexString(byte[] b){ 
        StringBuffer resultSb = new StringBuffer(); 
        for(int i=0;i<b.length;i++){ 
            resultSb.append(byteToHexString(b[i])); 
        } 
        return resultSb.toString(); 
    } 
    //将一个字节转化成十六进制形式的字符串
    privatestatic String byteToHexString(byte b){ 
        int n = b; 
        if(n<0) 
        n=256+n; 
        int d1 = n/16; 
        int d2 = n%16; 
        return hexDigits[d1] + hexDigits[d2]; 
    } 
}