TCP多线程上传的文件的问题

Question

我用TCP多线程上传图片，原图片内存400KB，但是传出来的图片居然是2G左右，请问这是什么原因？代码如下：

服务器端：

import java.io.*;

import java.net.*;

public class TCP_serverThreadSocket {

public static void main(String[] args) throws IOException {

ServerSocket ss=new ServerSocket(9999);

while(true){

Socket s=ss.accept();

Thread ts=new Thread(new Listenn(s));

ts.start();

}

}

}

class Listenn implements Runnable{

Socket socket=null;

public Listenn(Socket socket){

this.socket=socket;

}

public void run() {

try {

InputStream is = socket.getInputStream();

FileOutputStream fos=new FileOutputStream("D:\\JAVA Eclipse2\\新建文件夹\\new.jpg");

byte []buf2=new byte[1024];

int b=is.read(buf2);

while(b!=-1){

fos.write(buf2, 0, b);

}

socket.shutdownInput();

socket.close();

is.close();

fis.close();

}

catch (IOException e) {

e.printStackTrace();

}

}

}

客户端：

import java.io.*;

import java.net.Socket;

import java.util.*;

//客户端

public class TCP_UploadDataSocket  {

public static void main(String[] args)throws Exception {

Socket socket=new Socket("localhost",9999);

byte []buf=new byte[1024];

FileInputStream fis=new FileInputStream("D:\\JAVA Eclipse2\\新建文件夹\\source.jpg");

OutputStream os=socket.getOutputStream();

int len2=0;

while(( len2=fis.read(buf))!=-1){

os.write(buf, 0, len2);

}

socket.shutdownInput();

socket.close();

os.close();

}

}