如何在Java中的插座上连续来回发送对象？

Question

我在这里尝试做的是创建一个将成为基本游戏的应用程序，首先我必须使网络功能功能。我正在努力在服务器和客户端之间来回发送对象。我要实现的设计是2个过程，每个过程有2个线程，主线程，然后是一个侦听器线程。我希望侦听器线程聆听传入的对象，因为这将用于事件总线。目前，为了使其正常工作，我只使用一个简单的消息类，该类别包含一个称为文本的单字符串字段。我遇到的问题是，客户端侦听器线程似乎没有启动，并且对象永远不会发送任何一种方式。在这里真正挣扎的学习网络编程，任何帮助都非常感谢。

服务器端

package Server;

import java.net.*;
import java.util.List;

import Utilities.Message;

import java.io.*;

public class BattleshipServer 
{
    
    public static void executeThreadedServer(int port) throws Exception
    {
        ServerSocket server = new ServerSocket(port);
        System.out.println("Awaiting connection");
        Socket socket = server.accept();
        System.out.println("Connection established");
        
        BufferedReader kb = new BufferedReader(new InputStreamReader(System.in));
        ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(socket.getOutputStream()));
        ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
        
        //Start the listener thread
        ServerListener sListener = new ServerListener(kb, out, in);
        sListener.run();
        
        Message msg = new Message("temp");
        
        while(!msg.getText().equalsIgnoreCase("exit"))
        {
            msg = new Message(kb.readLine());
            out.writeObject(msg);
            out.flush();
        }
        
    }
}

------------------------------------------------------------------------------------------------------------

package Server;

import java.io.BufferedReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

import Utilities.Message;

public class ServerListener implements Runnable 
{

    private BufferedReader keyBoard;
    private ObjectOutputStream out;
    private ObjectInputStream in;
    
    public ServerListener(BufferedReader keyboard, ObjectOutputStream out, ObjectInputStream in)
    {
        this.keyBoard = keyboard;
        this.out = out;
        this.in = in;
    }
    
    @Override
    public void run() 
    {
        System.out.println("Server listener started");
        try {
            while(true)
            {
                Message msg;
                
                while((msg = (Message)this.in.readObject()) != null)
                {
                    System.out.println(msg.getText());
                }
                
            }
        } 
        catch (Exception e) 
        {
            e.printStackTrace();
        }

    }

}

客户端

package Client;

import java.net.*;
import java.util.ArrayList;
import java.util.List;

import Utilities.Message;

import java.io.*;

public class BattleshipClient 
{
    
    public static void executeThreadedClient(String address, int port) throws Exception
    {
        Socket socket = new Socket(address, port);
        
        BufferedReader kb = new BufferedReader(new InputStreamReader(System.in));
        ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(socket.getInputStream()));
        ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
        
        ClientListener cListener = new ClientListener(kb,out,in);
        cListener.run();
        
        Message msg = new Message("temp");
        while(!msg.getText().equalsIgnoreCase("exit"))
        {
            msg = new Message(kb.readLine());
            out.writeObject(msg);
            out.flush();
        }
        socket.close();
    }
    
}

------------------------------------------------------------------------------------------------------------

package Client;

import java.io.BufferedReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

import Utilities.Message;

public class ClientListener implements Runnable 
{
    
    private BufferedReader keyBoard;
    private ObjectOutputStream out;
    private ObjectInputStream in;
    
    public ClientListener(BufferedReader keyboard, ObjectOutputStream out, ObjectInputStream in)
    {
        this.keyBoard = keyboard;
        this.out = out;
        this.in = in;
    }

    @Override
    public void run() 
    {
        System.out.println("Client listener started");
        try
        {
            while(true)
            {
                Message msg = (Message)in.readObject();
                System.out.println(msg.getText());
            }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }

}

Answer 1

尽管您的clientListener和ServerListeners正在实现可运行的功能，但它们并未在单独的线程中运行。在您的实现中，它只是另一个函数调用，因此在“侦听器”（）之后的代码从未被调用。

因此，而不是这样做：

ClientListener cListener = new ClientListener(kb,out,in);
cListener.run();

您需要做类似的事情：

Thread clientThread = new Thread(new ClientListener(kb,out,in));
clientThread.start(); 

在服务器端，您需要做类似的事情。