package com.peanut.common.utils;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5Util {

    private static MessageDigest mdigest = null;
    private static char digits[] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
    private static MessageDigest getMdInst(){
        if(null == mdigest){
            try{
                mdigest = MessageDigest.getInstance("MD5");
            }catch(NoSuchAlgorithmException e){
                e.printStackTrace();
            }
        }
        return mdigest;
    }

    public static String encode(String s){
        if(null == s){
            return "";
        }

        try{
            byte[] bytes = s.getBytes();
            getMdInst().update(bytes);
            byte[] md = getMdInst().digest();
            int j = md.length;
            char str[] = new char[j * 2];
            int k = 0;
            for(int i = 0; i < j; i++) {
                byte byte0 = md[i];
                str[k++] = digits[byte0 >>> 4 & 0xf];
                str[k++] = digits[byte0 & 0xf];
            }
            return new String(str);
        }catch(Exception e){
            e.printStackTrace();
            return null;
        }
    }

}