Socket---聊天室

ChatServer.java

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;

public class ChatServer {

    private ArrayList<TongXinThread> list = new ArrayList<>();

    public void start(){
        //启动服务线程，循环accept
        new Thread(){
            public void run() {
                try {
                    ServerSocket ss = new ServerSocket(8000);
                    System.out.println("服务已启动！");
                    while(true){
                        Socket s = ss.accept();
                        TongXinThread t = new TongXinThread(s);
                        t.start();
                        synchronized (list) {
                            list.add(t);    
                        }
                    }
                } catch (Exception e) {
                    System.out.println("无法启动服务，或服务已停止！");
                }
            };
        }.start();
    }

    class TongXinThread extends Thread{
        Socket s;
        BufferedReader in;
        PrintWriter out;
        public TongXinThread(Socket s) {
            this.s = s;
        }
        //发给当前客户端
        public void send(String msg){
            if(out != null){
                out.println(msg);
                out.flush();
            }
        }
        //发给所有客户端
        public void sendAll(String msg){
            synchronized (list) {
                for (TongXinThread t : list) {
                    t.send(msg);
                }    
            }
        }
        @Override
        public void run() {
            String name = null;
            try {
                in = new BufferedReader(new InputStreamReader(s.getInputStream(),"GBK"));
                out = new PrintWriter(new OutputStreamWriter(s.getOutputStream(),"GBK"));
                //先接收昵称
                name = in.readLine();
                //给当前客户端发送欢迎信息
                send(name+"欢迎进入激情聊天室！！");
                //群发一个上线消息
                synchronized (list) {
                    sendAll(name+"老司机进入了聊天室，在线老司机："+list.size());
                }
                //循环从客户端接收内容，群发；
                String line;
                while((line = in.readLine()) != null){
                    sendAll(name+"说："+line);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            synchronized (list) {
                //当前客户端断开，把当前线程对象移除，this指自己
                list.remove(this);
                //群发一个下线消息
                sendAll(name+"老司机离开了聊天室，在线老司机："+list.size());
            }
            
        }
    }
    
    public static void main(String[] args) {
        ChatServer server = new ChatServer();
        server.start();
    }
    
}

ChatClient.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.LinkedList;
import java.util.Scanner;

public class ChatClient {
    BufferedReader in;
    PrintWriter out;
    private LinkedList<String> list = new LinkedList<>();
    private boolean flag = false;    //用户正在输入的标记
    public void start(){
        try {
            //连接服务器
            Socket s = new Socket("10.8.21.228",8000);
            in = new BufferedReader(new InputStreamReader(s.getInputStream(),"GBK"));
            out = new PrintWriter(new OutputStreamWriter(s.getOutputStream(),"GBK"));
            System.out.println("您的昵称：");
            String name = new Scanner(System.in).nextLine();
            out.println(name);
            out.flush();
            //接收服务器的聊天内容
            new Thread(){
                public void run() {
                    receive();
                };
            }.start();
            //让用户输入聊天内容，并发送
            new Thread(){
                public void run() {
                    input();
                };
            }.start();
            //打印线程
            new Thread(){
                public void run() {
                    print();
                };
            }.start();
        } catch (Exception e) {
            System.out.println("无法连接服务器，或连接被断开！");
        }
    }
    protected void print() {
        //从集合取出数据，从头部移除数据打印
        while(true){
            synchronized (list) {
                while(flag == true || list.size() == 0){
                    try {
                        list.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                String s = list.removeFirst();
                System.out.println(s);
            }
        }
    }
    protected void receive() {
        try {
            String line;
            while((line = in.readLine()) != null){
//                System.out.println(line);
                synchronized (list) {
                    list.add(line);
                    list.notifyAll();    //在集合上发通知
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("已经断开连接!");
    }
    protected void input() {
        System.out.println("嗯回车开始输入聊天内容：");
        while(true){
            new Scanner(System.in).nextLine();
            flag = true;    //正在输入
            System.out.print("输入聊天内容：");
            String s = new Scanner(System.in).nextLine();
            out.println(s);
            out.flush();
            flag = false;
            //通知正在等待的打印线程
            synchronized (list) {
                list.notifyAll();
            }
        }
    }
    
    public static void main(String[] args) {
        ChatClient c = new ChatClient();
        c.start();
    }
}