Java网络编程之使用Socket搭建一个简易聊天室

上一篇介绍Socket基本用法的文章：
https://www.jianshu.com/p/58f3068d26d8

使用Socket来搭建一个cmd的简易聊天窗口：

实现效果：

需要的类有：
1、监听客户端连接线程
2、客户端类
3、客户端管理类

主方法：
public static void main(String[] args) throws IOException {

    //开启一个接收连接的子线程
    Thread thread = new Thread(new MyThread());
    thread.start();

}

监听客户端连接的线程类：
static class MyThread implements Runnable {

    //服务端
    ServerSocket server = new ServerSocket(8000);

    MyThread() throws IOException {
    }

    @Override
    public void run() {

        while (true){

            //客户端
            try {
                Socket client = server.accept();
                //添加客户端
                SocketClient socketClient = new SocketClient(client);
                socketClient.start();       //开始运行客户端
                ClientManage.getInstance().add(socketClient);
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
    }
}

//客户端，继承Thread类，每一个聊天窗口都用一个线程执行
static class SocketClient extends Thread {

    private Socket client;
    private PrintStream print;  //打印流
    private BufferedReader br;
    private boolean flag = true;

    //初始化
    public SocketClient(Socket client) throws IOException {
        this.client = client;

        //客户端输出流
        print = new PrintStream(client.getOutputStream());
        print.write(getString("连接成功啦！"));
        print.println();

        br = new BufferedReader(new InputStreamReader(client.getInputStream(),"GBK"));

    }

    //关闭客户端
    private void closeClient() throws IOException {
        br.close();
        print.close();
        client.close();
    }

    @Override
    public void run() {

        while (flag){
            String str;
            try {
                str = br.readLine();
                if ("exit".equalsIgnoreCase(str)){

                    flag = false;

                    print.println();
                    print.write(getString("退出连接！"));
                    ClientManage.chatPrint(this,"退出了群聊！");
                    closeClient();  //关闭客户端
                }else {

                    print.write(getString("你输入了：" + str));
                    print.println();

                    //聊天室，群发消息给各个线程
                    if (str!=null){
                        ClientManage.chatPrint(this,str);
                    }

                }

            } catch (IOException e) {
                e.printStackTrace();
            }

        }

    }

    //输出
    public void out(String str,String name) throws IOException {
        print.write(getString(name + "输入了：" + str));
        print.println();
    }

    //格式转换，不然输出乱码
    private static byte[] getString(String str) throws UnsupportedEncodingException {
        return str.getBytes("GBK");
    }
}

//客户端管理类
static class ClientManage{

    private static Vector<SocketClient> clientList = new Vector<>();

    public ClientManage(){
    }

    //遍历输出聊天消息，实现群聊功能
    public static void chatPrint(SocketClient socketClient,String str) throws IOException {
        for (SocketClient vector : clientList){
           if (!vector.equals(socketClient)){
               vector.out(str,socketClient.getName());
           }
        }
    }

    public static Vector<SocketClient> getInstance(){
        return clientList;
    }

}