MD5加密技术(加盐)

import org.apache.commons.lang3.StringUtils;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;import java.util.Random;public class MD5Util {    public static void main(String[] args) {        //字符串加密        String str = "123456";        String salt = getSalt();        System.out.println(salt);        System.out.println(getMD5CodeBySalt(str,salt));    }    //对字符串进行MD5编码    public static String getMD5Code(String str){        if(StringUtils.isBlank(str)){            return null;        }        try {            //创建具有指定算法名称的信息摘要            MessageDigest md = MessageDigest.getInstance("MD5");            //使用指定的字节数组对摘要进行最后的更新，然后完成摘要计算            byte[] results = md.digest(str.getBytes());            //将得到的字节数组编程字符串返回            String resultString = byteArrayToHexString(results);            return resultString.toUpperCase();        } catch (NoSuchAlgorithmException e) {            e.printStackTrace();        }        return null;    }    //对字符串进行MD5编码加盐操作    public static String getMD5CodeBySalt(String str,String salt){        if(StringUtils.isBlank(str)){            return null;        }        return getMD5Code(getMD5Code(str)+salt);    }    //转换字节数组为十六进制字符串    private static String byteArrayToHexString(byte[] results){        StringBuffer resultNew = new StringBuffer();        for(int i = 0;i < results.length;i++){            resultNew.append(byteToHexString(results[i]));        }        return resultNew.toString();    }    //16进制下数字到字符的映射数组    private static String[] HEXDIGITS = new String[]{"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};    //将字节转化成十六进制的字符串    private static String byteToHexString(byte b){        int byteNum = b;        if(byteNum < 0){            byteNum = byteNum + 256;        }        int d1 = byteNum / 16;        int d2 = byteNum % 16;        return HEXDIGITS[d1]+HEXDIGITS[d2];    }    //传入的字符串加密后和Md5字符串的比较，常用语登录时密码的核对    private static boolean compareStringWithMD5Code(String str,String MD5Code){        boolean isEquals = false;        if(StringUtils.isBlank(str)){            return isEquals;        }        if(MD5Code.equals(getMD5Code(str))){            isEquals = true;        }        return isEquals;    }    //生成一个10位的随机salt    public static String getSalt(){        String salt = "";        Random rand = new Random();        for(int i=0;i<10;i++){            int num = rand.nextInt(3);            switch(num){                case 0:                    char c1 = (char)(rand.nextInt(26)+'a');//生成随机小写字母                    salt += c1;                    break;                case 1:                    char c2 = (char)(rand.nextInt(26)+'A');//生成随机大写字母                    salt += c2;                    break;                case 2:                    salt += rand.nextInt(10);//生成随机数字            }        }        return salt;    }}