Java多线程服务器无法按预期工作

Question

I am trying to write a multi-threaded server which should be capable of accepting multiple HTTP requests at a time. 我正在尝试编写一个多线程服务器，该服务器应该能够一次接受多个HTTP请求。

Server code: 服务器代码：

package test.thread.server;

    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.ServerSocket;
    import java.net.Socket;

    public class MyServer implements Runnable {
        private int serverPort = 8080;
        private ServerSocket serverSocket;
        private Thread runningThread;
        private boolean isStopped;

        public MyServer(int port){
            this.serverPort = port;
        }


        @Override
        public void run() {
            synchronized (this) {
                this.runningThread = Thread.currentThread();
            }

            openServerSocket();


            while(!isStopped){

                Socket clientSocket = null;

                try {
                    clientSocket = this.serverSocket.accept();
                } catch (IOException e) {
                    e.printStackTrace();
                }


                //start a new thread for processing each request
                new Thread(new RequestHandler(clientSocket)).start();
            }

        }

    public synchronized void stop(){
        this.isStopped = true;
        try {
            this.serverSocket.close();
        } catch (IOException e) {
            throw new RuntimeException("Error closing server", e);
        }
    }


    private void openServerSocket(){
        try {
            this.serverSocket = new ServerSocket(this.serverPort);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

Worker that handles the request: 处理请求的工作人员：

It reads the data from input stream and prints it. 它从输入流中读取数据并进行打印。 After that it should go for a 30 second sleep[represents some work which does not need CPU]. 之后，它应该进行30秒钟的睡眠（表示不需要CPU的某些工作）。 After sleep time, server will respond to client. 睡眠时间过后，服务器将响应客户端。

package test.thread.server;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.util.Date;

public class RequestHandler implements Runnable {
    Socket clientSocket;

    static int counter = 0;

    public RequestHandler(Socket clientSocket){
        this.clientSocket = clientSocket;
    }

    @Override
    public void run() {

        try {
            InputStream input = this.clientSocket.getInputStream();
            OutputStream output = this.clientSocket.getOutputStream();


            DataInputStream inFromClient = new DataInputStream(input);
            System.out.println(new Date()+": " +Thread.currentThread().getName() + " - Started : "+inFromClient.readUTF());

            Thread.sleep(30000);

            /*output.write(("HTTP/1.1 200 OK\n\n<html><body>" +
                    "Multi-threaded Server " +
                    "</body></html>").getBytes());*/

            DataOutputStream outFromServer = new DataOutputStream(output);
            outFromServer.writeUTF("Output");
            outFromServer.flush();

            output.close();
            input.close();

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


    }

}

HTTP Client: HTTP客户端：

Client is not bothered about the server sleep time and will send 5 consecutive requests. 客户端不必担心服务器的睡眠时间，它将连续发送5个请求。

package test.thread.server;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Date;

public class MyClient {

    public static void main(String[] args) throws UnknownHostException, IOException {
        // TODO Auto-generated method stub
        for(int i=0; i<5; i++){
            Socket clientSocket = new Socket("localhost", 8080);
             DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
             DataInputStream inFromServer = new DataInputStream(clientSocket.getInputStream());


             outToServer.writeUTF("Input");
             outToServer.flush();

             String output = inFromServer.readUTF();
             System.out.println(new Date()+": "+output);
             clientSocket.close();
        }
    }

}

Now i am expecting the server to process the next client request when one thread goes on sleep. 现在，我希望服务器在一个线程进入睡眠状态时处理下一个客户端请求。 But unfortunately server is accepting next request only after the previous request is processed. 但是很遗憾，服务器仅在处理前一个请求之后才接受下一个请求。

Expecting o/p: 期望o / p：

Server should not wait for current request process to complete before printing 'Thread-X - Started : Input' for next request. 服务器不应等待当前请求过程完成，然后再为下一个请求打印“ Thread-X-Started：Input”。

Current o/p: 当前输出：

Server: Wed Feb 15 18:17:06 IST 2017: Thread-1 - Started : Input
Client: Wed Feb 15 18:17:36 IST 2017: Output
Server:Wed Feb 15 18:17:36 IST 2017: Thread-2 - Started : Input
Client:Wed Feb 15 18:18:06 IST 2017: Output
Server:Wed Feb 15 18:18:06 IST 2017: Thread-3 - Started : Input
Client:Wed Feb 15 18:18:36 IST 2017: Output
Server:Wed Feb 15 18:18:43 IST 2017: Thread-4 - Started : Input
Client:Wed Feb 15 18:19:13 IST 2017: Output
Server:Wed Feb 15 18:19:13 IST 2017: Thread-5 - Started : Input
Client:Wed Feb 15 18:19:43 IST 2017: Output

What can be the issue? 可能是什么问题？

Answer 1

I believe the problem is in your client. 我相信问题出在您的客户身上。 The client only sends the next request after the previous one was answered. 客户端仅在回答前一个请求后才发送下一个请求。 The inFromServer.readUTF() blocks until data is available, which is only the case when your server sends an actual answer. inFromServer.readUTF()阻塞，直到有可用数据为止，这仅在服务器发送实际答案时才会发生。

I recommend you debug your program. 我建议您调试程序。

Java多线程服务器无法按预期工作

问题描述

1 个解决方案

解决方案1
3 已采纳 2017-02-15 13:23:37

Java多线程服务器无法按预期工作

问题描述

1 个解决方案

解决方案1 3 已采纳 2017-02-15 13:23:37

解决方案1
3 已采纳 2017-02-15 13:23:37