下面的通信架构存在问题:
客户端与服务端的线程模型是: N-N的关系,客户端并发越多,系统瘫痪的越快。
引入线程池处理多个客户端消息
代码实现
public class ClientDemo1 {public static void main(String[] args) {try {System.out.println("====客户端启动===");// 1、创建Socket通信管道请求有服务端的连接// public Socket(String host, int port)// 参数一:服务端的IP地址// 参数二:服务端的端口Socket socket = new Socket("127.0.0.1", 6666);// 2、从socket通信管道中得到一个字节输出流 负责发送数据OutputStream os = socket.getOutputStream();// 3、把低级的字节流包装成打印流PrintStream ps = new PrintStream(os);Scanner sc = new Scanner(System.in);while (true) {System.out.println("请说:");String msg = sc.nextLine();// 4、发送消息ps.println(msg);ps.flush();}// 关闭资源。// socket.close();} catch (Exception e) {e.printStackTrace();}}
}
public class ServerDemo2 {// 使用静态变量记住一个线程池对象private static ExecutorService pool = new ThreadPoolExecutor(300,1500, 6, TimeUnit.SECONDS,new ArrayBlockingQueue<>(2), Executors.defaultThreadFactory(), new ThreadPoolExecutor.AbortPolicy());public static void main(String[] args) {try {System.out.println("===服务端启动成功===");// 1、注册端口ServerSocket serverSocket = new ServerSocket(6666);// a.定义一个死循环由主线程负责不断的接收客户端的Socket管道连接。while (true) {// 2、每接收到一个客户端的Socket管道,Socket socket = serverSocket.accept();System.out.println(socket.getRemoteSocketAddress()+ "它来了,上线了!");// 任务对象负责读取消息。Runnable target = new ServerReaderRunnable(socket);pool.execute(target);}} catch (Exception e) {e.printStackTrace();}}
}
public class ServerReaderRunnable implements Runnable{private Socket socket;public ServerReaderRunnable(Socket socket){this.socket = socket;}@Overridepublic void run() {try {// 3、从socket通信管道中得到一个字节输入流InputStream is = socket.getInputStream();// 4、把字节输入流包装成缓冲字符输入流进行消息的接收BufferedReader br = new BufferedReader(new InputStreamReader(is));// 5、按照行读取消息String msg;while ((msg = br.readLine()) != null){System.out.println(socket.getRemoteSocketAddress() + "说了:: " + msg);}} catch (Exception e) {System.out.println(socket.getRemoteSocketAddress() + "下线了!!!");}}
}
使用线程池的优势及场景
服务端可以复用线程处理多个客户端,可以避免系统瘫痪。
适合客户端通信时长较短的场景。