一个让我头痛了好久的关于网络、多线程及I/0的问题，哪位帮忙看看~

Question

count = 0;
         s = new Socket[5];
         while(count <= 4){
                new Thread(new Runnable(){
                 public void run(){
                 try{
                 int temp = count;
if(temp<=4)
s[temp] = new Socket(host,1111);
                            
                            PrintWriter out = new PrintWriter(s[temp].getOutputStream(),true);
                            out.println(temp);
                            BufferedInputStream in = new BufferedInputStream(s[temp].getInputStream());
                                                    
                            RandomAccessFile raf = new RandomAccessFile(fileName,"rw");
                            //raf.setLength(fileSize);                            byte[] buf = new byte[1024];
                            int i;
                            raf.seek((fileSize*temp/5-1)==-1 ? 0 : fileSize*temp/5-1);
                            long tmpSize = fileSize/5;
                            while ((i=in.read(buf))!=-1 && (tmpSize--!=0 || temp==4)){
                                    raf.write(buf,0,i);
                            }
                            raf.close();
                            in.close();
                            s[temp].close();
System.out.println(temp + " finished");
 }
  catch(Exception e){
e.printStackTrace();
}
                 }
                }).start();
                try{
                 Thread.sleep(500);
                }
                catch(Exception e){
                 e.printStackTrace();
                }
                count++;
         }上面是我在一个方法里定义的代码，想让它实现的目的是，创建5个与服务端的连接，用多线程读取来自服务端的数据并写到文件里。前四个线程都很正常，会在run方法的最后执行System.out.println(temp + " finished");这一句，但第五个线程不知道怎么搞的，运行时老是会出现一个java.net.SocketException: Connection reset。报错是在这一句：while ((i=in.read(buf))!=-1 && (tmpSize--!=0 || temp==4))
也就是说i = in.read(buf) != -1 ，但是我前几个线程都很正常啊为什么在这里会出现异常呢？

Answer 1

linux下也测试过了，不会出异常但是第5个线程的读写就没进行~~