java如何修复SocketException连接重置问题？

Question

尝试与服务器通信时，连接重置。 但是客户端毫无例外地执行代码。成功执行客户端后，打印终端中的所有字节。但是，在服务器端，首先会创建两个连接。实际上，我想为服务器和客户端编写一个程序，从客户端实现并行连接。 为什么ScocketException：连接重置发生在服务器端？我该如何解决这个问题

服务器：

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import java.util.zip.Adler32;
import java.util.zip.CRC32;
import java.util.zip.Checksum;

public class Server {
    private static String dir = "E:\\DestinatioFolder\\";

    public static void main(String[] args) throws IOException {
        ServerSocket servsock = new ServerSocket(5050);
        Socket socket = null;

        while(true) {
            socket = servsock.accept();
            System.out.println("New Connection....");

            BufferedInputStream bis = new BufferedInputStream(socket.getInputStream());
            DataInputStream dis = new DataInputStream(bis);
            Thread t = new ClientHandler(socket, bis, dis);
            t.start();
        }
    }
}

class ClientHandler extends Thread {
    final String dir = "E:\\DestinationFolder\\";  // you may change this
    final BufferedInputStream bis;
    final DataInputStream dis;
    final Socket socket;
    public ClientHandler(Socket socket, BufferedInputStream bis, DataInputStream dis ) {
        this.socket = socket;
        this.bis = bis;
        this.dis = dis;
    }

    @Override
    public void run() {
        try{
            long fileLength = dis.readLong();
            String fileName = dis.readUTF();

            System.out.println("FILE Name: "+fileName);

            File file = new File(dir + fileName);

            FileOutputStream fos = new FileOutputStream(file);
            BufferedOutputStream bos = new BufferedOutputStream(fos);

            for(int i=0;i<fileLength; i++) {
                int b = bis.read();
                bos.write(b);
                System.out.println("Byte:"+b);
            }
            bos.close();
        } catch(Exception e){
            System.out.println("Server: "+e);
        }
    }

}

客户：

import java.io.*;
import java.net.Socket;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Client1 {
    private static String dir = "E:\\SourceFolder\\";

    public static void main(String[] args) throws IOException, InterruptedException {
        Socket[] sock = new Socket[5];
        for(int i=0;i<2;i++) {
            sock[i] = new Socket("localhost",5050);
        }
        File[] files = new File(dir).listFiles();
        sendFile(files,sock);
    }

    private static void sendFile(File[] files, Socket[] sock) throws InterruptedException, IOException {

        for(int i=0;i<2;i++) {
            BufferedOutputStream bos = new BufferedOutputStream(
                    sock[i].getOutputStream());
            DataOutputStream dos = new DataOutputStream(bos);
            Thread t = new ClientThread(files[i], bos, dos, i);
            t.start();
        }
    }
}

class ClientThread extends Thread {
    final BufferedOutputStream bos;
    final DataOutputStream dos;
    final File file;
    final int t;

    public ClientThread(File file, BufferedOutputStream bos,
                        DataOutputStream dos, int t) {
        this.dos = dos;
        this.bos = bos;
        this.file = file;
        this.t = t;
    }

    @Override
    public void run() {
        try {
            long length = file.length();
            System.out.println("Thread: "+this.t+ " FILE Length: "+length);
            dos.writeLong(length);

            String fileName = file.getName();
            System.out.println("Thread: "+this.t+ " FILE: "+fileName);
            dos.writeUTF(fileName);

            FileInputStream fis = new FileInputStream(file);
            BufferedInputStream bis = new BufferedInputStream(fis);

            int b = 0;
            while((b = bis.read()) > 0) {
                bos.write(b);
                System.out.println("Thread: " + this.t + " Byte:"+b);
            }
            bis.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}