自己写的java md

import java.io.*;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;  

public class MD5Encrypt
{

	
	public static String byteArrayToString(byte[] b)
     {
     	StringBuffer resultSb=new StringBuffer();
     	for(int i=0;i<b.length;i++)
     	{
     		resultSb.append(byteToNumString(b[i]));
     	}
     	return resultSb.toString();
     }
		
		 private static String byteToNumString(byte b)
	 {
	 	int a=b;
	 	if(a<0)
	 	a=256+a;
	 	return String.valueOf(a);
	 }
	 
	
    public static String MD5Encode(String originString)
	  {
		String resultString=null;
	    try
			{
				resultString=new String(originString);
				MessageDigest md=MessageDigest.getInstance("MD5");
			    resultString=byteArrayToString(md.digest(resultString.getBytes()));
				
				
			}catch(Exception e)
			{
				e.printStackTrace();
			}
			return resultString;
	 }


     public static void main(String[] args)throws Exception  //一定要抛出异常
     {
     	MD5Encrypt md5encrypt=new MD5Encrypt();
     	boolean i=true;
     	int sum=0;
     	while(i)
     	{
     
     	InputStreamReader r=new InputStreamReader(System.in);
		BufferedReader c=new BufferedReader(r);
		String input=c.readLine();
		
		String outcome=md5encrypt.MD5Encode(input);
		int l=outcome.length();
		byte[] b=outcome.getBytes();
		for(int j=0;j<l;j++)
		{
			sum+=b[j];
		}
		System.out.println(md5encrypt.MD5Encode(input));
		String sum1=String.valueOf(sum);
		String sum2=sum1.substring(0,3);
		int sum3=Integer.parseInt(sum2);
		System.out.println(sum3);
	   }
	}

     
	
}