Simple interaction between server and client

Tool idea

1. Client code

import java.io.*;
import java.net.Inet4Address;
import java.net.InetSocketAddress;
import java.net.Socket;

public class Client {
    public static void main(String[] args) throws IOException{
        Socket socket = new Socket();
        //超时时间
        socket.setSoTimeout(3000);
        //连接本地，连接端口2000，超时时间3000
        socket.connect(new InetSocketAddress(Inet4Address.getLocalHost(),2000),3000);

        System.out.println("已发起服务器连接，并进入后续流程");
        System.out.println("客户端信息："+ socket.getLocalAddress() + "p:" + socket.getLocalPort());
        System.out.println("服务器端信息"+ socket.getInetAddress() + "p:" + socket.getPort());

        try{
            todo(socket);
        }catch (Exception e){
            System.out.println("异常关闭");
        }

        socket.close();
        System.out.println("客户端已退出");
    }


    private static void todo(Socket client) throws IOException {
        //构建键盘输入流
        InputStream in = System.in;
        BufferedReader input = new BufferedReader(new InputStreamReader(in));

        //得到Socket输出流，并打印出去
        OutputStream outputStream = client.getOutputStream();
        PrintStream socketPrintStream = new PrintStream(outputStream);

        //得到Socket输入流，并转换为BufferedReader
        InputStream inputStream = client.getInputStream();
        BufferedReader sockerBufferedReader = new BufferedReader(new InputStreamReader(inputStream));

        boolean flag = true;
        do {
            //键盘读取一行
            String str = input.readLine();
            //发送到服务器
            socketPrintStream.println(str);
            //从服务器读取一行
            String echo = sockerBufferedReader.readLine();
            if ("bye".equalsIgnoreCase(echo)) {
                flag = false;
            }else{
                System.out.println(echo);
            }
        }while (flag);

        socketPrintStream.close();
        sockerBufferedReader.close();
    }

}

2. Server-side code

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;

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

        ServerSocket server = new ServerSocket(2000);

        System.out.println("服务器准备就绪");
        System.out.println("服务器端信息"+ server.getInetAddress() + "p:" + server.getLocalPort());

        //等待客户端连接
        for (;;) {
            //得到客户端
            Socket client = server.accept();
            //客户端构建异步线程
            ClientHandler clientHandler = new ClientHandler(client);
            //启动线程
            clientHandler.start();
        }
    }

    private static class ClientHandler extends Thread{
        private Socket socket;
        private boolean flag = true;

        ClientHandler(Socket socket){
            this.socket = socket;
        }

        @Override
        public void run(){
            super.run();
            System.out.println("新客户端连接"+ socket.getInetAddress() + "p:" + socket.getPort());
            try{
                //得到打印流
                PrintStream sockerOutput = new PrintStream(socket.getOutputStream());
                //得到输入流,用于接收数据
                BufferedReader sockInput = new BufferedReader(new InputStreamReader(
                        socket.getInputStream()));
                boolean flag = true;
                do {
                    //键盘读取一行
                    String str = sockInput.readLine();
                    if ("bye".equalsIgnoreCase(str)) {
                        flag = false;
                        sockerOutput.println("bye");
                    }else{
                        //打印到屏幕，同时回送数据
                        System.out.println(str);
                        sockerOutput.println("回送:"+str.length());
                    }
                }while (flag);

                sockInput.close();
                sockerOutput.close();

            }catch(Exception e){
                System.out.println("连接异常断开");
            }finally {
                //连接关闭
                try{
                    socket.close();
                }catch (IOException e){
                    e.printStackTrace();
                }
            }
            System.out.println("客户端已退出" + socket.getInetAddress() + "p:" + socket.getPort());
        }
    }

}

running result: