//服务器端
package com.example.demo;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class ServerSoket {
	public static void main(String[] args) {
		ServerSoket serverSoket = new ServerSoket();
		serverSoket.init();
	}

	private void init() {
		// TODO Auto-generated method stub
		ServerSocket server = null;
		BufferedReader bf = null;
		BufferedWriter bw = null;
		try {
			server = new ServerSocket(9898);
			Socket socket = server.accept();
		
			bf = new BufferedReader(new InputStreamReader(socket.getInputStream()));
			bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
			String line = null;
			if((line = bf.readLine())!=null){
				System.out.println(line);
				bw.write("respond:"+line +"\n");
				bw.flush();
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}
//客户端
package com.example.demo;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.InetAddress;
import java.net.Socket;

public class ClientScoket {
	public static void main(String[] args) {
		ClientScoket clientScoket = new ClientScoket();
		clientScoket.start();
	}

	private void start() {
		// TODO Auto-generated method stub
		Socket client =null; 
		BufferedReader bf  = null;
		BufferedWriter bw = null;
		BufferedReader bfServer = null;
		bf = new BufferedReader(new InputStreamReader(System.in));
		try {
		client = new Socket(InetAddress.getLocalHost(), 9898);
		bfServer = new BufferedReader(new InputStreamReader(client.getInputStream()));
		
		
		
		bw = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));
		
		String line = null;
		
		String res = null;
			while(!(line=bf.readLine()).equalsIgnoreCase(("bye"))){
//			这里非常重要，一定要加上这个\n
				bw.write(line +"\n");
				bw.flush();
				res = bfServer.readLine();
				System.out.println(res);
			}
		
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			try {
				bf.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		
		
	}
}

为什么服务器端返回消息之后就关了，然后客户端再发，就报Connection reset by peer: socket write error异常