Java实现一个简单的聊天小程序

服务端代码：

package com.example.nettypractice.tcp;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
import java.util.Scanner;

/**
 * @description: TCP服务端
 * @author: YangWanYi
 * @create: 2021-11-24 22:16
 **/
public class ServerTcp {
    public static void main(String[] args) {
        ServerSocket serverSocket = null;
        Socket accept = null;
        InputStream is = null;
        OutputStream os = null;
        Scanner scanner = new Scanner(System.in);
        try {
            System.out.println("服务端启动成功……");
            serverSocket = new ServerSocket(9999);
            accept = serverSocket.accept();
            System.out.println("接收到客户端的连接请求……");
            String msg;
            os = accept.getOutputStream();
            is = accept.getInputStream();
            byte[] bytes = new byte[1024];
            int len;
            while (true) {
                System.out.println("请输入：");
                msg = scanner.nextLine();
                os.write(msg.getBytes(StandardCharsets.UTF_8));
                len = is.read(bytes);
                System.out.println("来自客户端的消息：" + new String(bytes, 0, len));
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                accept.close();
                serverSocket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
    }
}

客户端代码：

package com.example.nettypractice.tcp;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
import java.util.Scanner;

/**
 * @description: TCP客户端
 * @author: YangWanYi
 * @create: 2021-11-24 22:25
 **/
public class ClientTcp {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        Socket clientSocket = null;
        InputStream is = null;
        OutputStream os = null;
        try {
            clientSocket = new Socket("localhost", 9999);
            System.out.println("客户端启动成功……");
            is = clientSocket.getInputStream();
            os = clientSocket.getOutputStream();
            byte[] bytes = new byte[1024];
            String msg;
            int len;
            while (true) {
                len = is.read(bytes);
                System.out.println("服务端发来消息：" + new String(bytes, 0, len));
                System.out.println("请输入：");
                msg = scanner.nextLine();
                os.write(msg.getBytes(StandardCharsets.UTF_8));
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                os.close();
                is.close();
                clientSocket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}