Obsidian-Knowledge-Base/X-Knowledge-Base/raw/Joplin/编程学习项目/Java学习笔记/Java基础--下部/31.网络编程（控制台版聊天室）.md

1.客户端

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

class ClientMyRunnable implements Runnable{
    Socket socket;
    public ClientMyRunnable(Socket socket) {
        this.socket = socket;
    }

    @Override
    public void run() {

        //循环，重复的接受
        while (true) {
            try {
                //接收服务器发送过来的聊天记录
                BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                String msg = br.readLine();
                System.out.println(msg);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

import java.io.*;
import java.net.Socket;
import java.util.Scanner;

public class Client {
    public static void main(String[] args) throws IOException {
        Socket socket = new Socket("127.0.0.1", 10001);
        System.out.println("服务器已经连接成功");


        while (true) {
            System.out.println("==============欢迎来到黑马聊天室================");
            System.out.println("1登录");
            System.out.println("2注册");
            System.out.println("请输入您的选择：");
            Scanner sc = new Scanner(System.in);
            String choose = sc.nextLine();
            switch (choose) {
                case "1" -> login(socket);
                case "2" -> System.out.println("用户选择了注册");
                default -> System.out.println("没有这个选项");
            }
        }
    }

    public static void login(Socket socket) throws IOException {
        //获取输出流
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
        //键盘录入
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入用户名");
        String username = sc.nextLine();
        System.out.println("请输入密码");
        String password = sc.nextLine();

        //拼接
        StringBuilder sb = new StringBuilder();
        //username=zhangsan&password=123
        sb.append("username=").append(username).append("&password=").append(password);

        //第一次写的是执行登录操作
        bw.write("login");
        bw.newLine();
        bw.flush();

        //第二次写的是用户名和密码的信息
        //往服务器写出用户名和密码
        bw.write(sb.toString());
        bw.newLine();
        bw.flush();

        //接收数据
        //获取输入流
        BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        String message = br.readLine();
        System.out.println(message);
        //1：登录成功  2 密码有误   3 用户名不存在
        if ("1".equals(message)) {
            System.out.println("登录成功，开始聊天");
            //开一条单独的线程，专门用来接收服务端发送过来的聊天记录
            new Thread(new ClientMyRunnable(socket)).start();
            //开始聊天
            talk2All(bw);
        } else if ("2".equals(message)) {
            System.out.println("密码输入错误");
        } else if ("3".equals(message)) {
            System.out.println("用户名不存在");
        }

    }

    //往服务器写出消息
    private static void talk2All(BufferedWriter bw) throws IOException {
        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("请输入您要说的话");
            String str = sc.nextLine();
            //把聊天内容写给服务器
            bw.write(str);
            bw.newLine();
            bw.flush();
        }
    }
}

2.服务端

package com.itheima.server;

import java.io.*;
import java.net.Socket;
import java.util.Properties;

class ServerMyRunnable implements Runnable {
    Socket socket;
    Properties prop;

    public ServerMyRunnable(Socket socket, Properties prop) {
        this.prop = prop;
        this.socket = socket;
    }

    @Override
    public void run() {
        try {
            BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));

            while (true) {
                String choose = br.readLine();
                switch (choose) {
                    case "login" -> login(br);
                    case "register" -> System.out.println("用户选择了注册操作");
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    //获取用户登录时，传递过来的信息。
    //并进行判断
    public void login(BufferedReader br) throws IOException {
        System.out.println("用户选择了登录操作");
        String userinfo = br.readLine();
        //username=zhangsan&password=123
        String[] userInfoArr = userinfo.split("&");
        String usernameInput = userInfoArr[0].split("=")[1];
        String passwordInput = userInfoArr[1].split("=")[1];
        System.out.println("用户输入的用户名为:" + usernameInput);
        System.out.println("用户输入的密码为:" + passwordInput);

        if (prop.containsKey(usernameInput)) {
            //如果用户名存在，继续判断密码
            String rightPassword = prop.get(usernameInput) + "";
            if (rightPassword.equals(passwordInput)) {
                //提示用户登录成功，可以开始聊天
                writeMessage2Client("1");
                //登录成功的时候，就需要把客户端的连接对象Socket保存起来
                Server.list.add(socket);
                //写一个while(){}表示正在聊天
                //接收客户端发送过来的消息，并打印在控制台
                talk2All(br, usernameInput);
            } else {
                //密码输入有误
                writeMessage2Client("2");
            }
        } else {
            //如果用户名不存在，直接回写
            writeMessage2Client("3");
        }
    }

    private void talk2All(BufferedReader br, String username) throws IOException {
        while (true) {
            String message = br.readLine();
            System.out.println(username + "发送过来消息：" + message);

            //群发
            for (Socket s : Server.list) {
                //s依次表示每一个客户端的连接对象
                writeMessage2Client(s, username + "发送过来消息：" + message);
            }
        }
    }

    public void writeMessage2Client(String message) throws IOException {
        //获取输出流
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
        bw.write(message);
        bw.newLine();
        bw.flush();
    }

    public void writeMessage2Client(Socket s, String message) throws IOException {
        //获取输出流
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
        bw.write(message);
        bw.newLine();
        bw.flush();
    }
}

package com.itheima.server;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Properties;

public class Server {

    static ArrayList<Socket> list = new ArrayList<>();

    public static void main(String[] args) throws IOException {
        ServerSocket ss = new ServerSocket(10001);

        //1.把本地文件中正确的用户名和密码获取到
        Properties prop = new Properties();
        FileInputStream fis = new FileInputStream("sockethomework\\servicedir\\userinfo.txt");
        prop.load(fis);
        fis.close();

        //2.只要来了一个客户端，就开一条线程处理
        while (true) {
            Socket socket = ss.accept();
            System.out.println("有客户端来链接");
            new Thread(new ServerMyRunnable(socket, prop)).start();
        }
    }
}