文件存储时用的Md5加密方法

package com.cx.bank.util;

import java.security.MessageDigest;


public class MD5Util {
   
	public static String encode(byte[] source){
		
		String s=null;
		char hexDigest[]={'0','1','2','3','4','5','6','7'
				,'8','9','a','b','c','d','e','f'};
		try{
			MessageDigest md= MessageDigest.getInstance("MD5");
			md.update(source);
			byte tmp[] =md.digest();
			char str[]=new char[32];
			int k=0;
			for(int i=0;i<16;i++){
				byte byte0=tmp[i];
				str[k++]=hexDigest[byte0>>>4&0xf];
				str[k++]=hexDigest[byte0&0xf];
				
			}
			s=new String(str);
		}catch(Exception e){
			e.printStackTrace();
		}
		return s;
	}
	
	
	public static String getMD5(String source){
		
		return (source==null ||"".equals(source)) ?"":encode(source.getBytes());
	}
}