Java – 服务器仅在客户端停止时响应

Question

我最近编写了一个简单的Java服务器和一个客户端来测试服务器。服务器应该接收来自客户端的消息，并发送回消息的随机子字符串。问题是这样的:当我使用客户端程序发送消息时，服务器没有响应。然后，当我终止客户端程序时，服务器会立即采取行动，并尝试将数据发送回客户端。服务器正确读取数据，但只有当我停止客户端程序时才开始处理它。

这是客户端代码:

import java.io.*;
import java.net.*;

class ServerTest{

public static void main(String args[]) throws Exception{

    Socket clientSocket = new Socket(myIpAdress, 8001);

    //Send the message to the server
    BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()));

    String sendMessage = "randSubstring:StackOverflowIsAwsome";

    bw.write(sendMessage);
    bw.flush();
    System.out.println("Message sent: "+sendMessage);


    String message = new BufferedReader(new InputStreamReader(clientSocket.getInputStream())).readLine();

    System.out.println("Message received from the server : " +message);

    clientSocket.close();

    }

}

我的服务器代码由两个类组成。这是听众:

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

public class ServerListener {
public static void main(String args[]) throws Exception {
    String clientSentence;
    ServerSocket socket = new ServerSocket(8001);

    while(true) {
        Socket connectionSocket = socket.accept();
        BufferedReader input = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
        //DataOutputStream output = new DataOutputStream(connectionSocket.getOutputStream());
        clientSentence = input.readLine();

        if(clientSentence.startsWith("randSubstring:")){

            Thread connection = new Thread(new ServerConnection(connectionSocket, clientSentence));
            connection.start();
        }

        Thread.sleep(300);
    }

}
}

这是在客户端停止之前不会启动的线程:

import java.io.BufferedOutputStream;
import java.io.BufferedWriter;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.util.Random;

public class ServerConnection implements Runnable{

private Socket serverConnection;
private String sentence;

public ServerConnection(Socket connection, String clientSentence){

serverConnection = connection;
sentence = clientSentence;

}

@Override
public void run() {
    Random r = new Random();
    String substring = sentence.substring(0, r.nextInt(sentence.length()));

try {
        OutputStream os = serverConnection.getOutputStream();
        OutputStream out = new BufferedOutputStream(os);
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(out));
        bw.write(substring);
        bw.close();
        out.close();
        os.close();


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

}

}

我正在使用装有 Yosemite 的 Macintosh。发生这种情况是因为我尝试在同一台计算机上运行这些程序，还是如果从不同的计算机运行这些程序会出现此问题？如有任何帮助，我们将不胜感激。

Answer 1

在服务器中，您执行 readLine(..)，这意味着它将等待行结束符。

但是在您的发件人代码中，您只需发送一个没有行结尾的字符串。

因此，要么确保您也发送行尾字符，要么您的服务器等待其他内容作为“分隔符”