如何讓我的聊天接受多個客戶？

Question

我正在嘗試創建一個多客戶端到服務器的聊天。 這在一對一聊天時工作正常，但是當我嘗試運行另一個客戶端並連接它時，它不會通過/連接。 我在線程上遺漏了什么嗎？ 我只添加了沒有導入的 Server 和 Client 類，有一個主類詢問用戶是要成為服務器還是客戶端（加入）並詢問端口......

    public Server(int port, String name) {
        frame = new JFrame("Messenger");
        frame.setSize(600, 400);
        hostport = port; 
        userText = new JTextField(); //Input text field
        userText.setEditable(false); //Can't write until connected with someone
        userText.addActionListener(
                new ActionListener() {
                    public void actionPerformed(ActionEvent event) {
                        sendMessage(event.getActionCommand(), name);
                        userText.setText("");
                    }
                    
                }
            );
        JButton jbutton = new JButton("Browse File");
        JPanel messagePanel = new JPanel(new BorderLayout());
        jbutton.addActionListener(
                new ActionListener() {
                    public void actionPerformed(ActionEvent event) {
                        JFileChooser file = new JFileChooser();
                        file.setCurrentDirectory(new File(System.getProperty("user.home")));
                        FileNameExtensionFilter filter = new FileNameExtensionFilter("*.Images", "jpg","gif","png");
                        file.addChoosableFileFilter(filter);
                        int result = file.showSaveDialog(null);
                         if(result == JFileChooser.APPROVE_OPTION){
                              File selectedFile = file.getSelectedFile();
                              String path = selectedFile.getAbsolutePath();
                              userText.setText(path);
                          }
                          else if(result == JFileChooser.CANCEL_OPTION){
                              System.out.println("No File Select");
                          }
                        }
                }
          );
                
                messagePanel.add(userText, BorderLayout.CENTER);
                messagePanel.add(jbutton, BorderLayout.EAST);
                chatWindow = new JTextArea();
                add(new JScrollPane(chatWindow));
                chatWindow.setSize(400, 300);
                frame.add(chatWindow, BorderLayout.CENTER);
                frame.add(messagePanel, BorderLayout.SOUTH);
                frame.setVisible(true);
    
                t = new Thread(new Runnable() {
                     @Override
                        public void run(){
                            startRunning(name);
                        }
                    });
                 
                }
    
    
    //set up and run de server 
    public void startRunning(String servName) {
        try {
            server = new ServerSocket(hostport);
            while(true) {
                try {
                    waitForConnection(servName);
                    setupStreams();
                    whileChatting();    
                }catch(EOFException eofException) {
                    showMessage("\n Connection Ended");
                }finally {
                    close();
                }
            }
            
        }catch(IOException ioException) {
            ioException.printStackTrace(); //prints error
        }
    }
    //wait for connection
    private void waitForConnection(String servName) throws IOException{
        showMessage("Waiting for someone to connect");
        socket = server.accept();
        showMessage("\nNow connected to: " + socket.getInetAddress() + servName);
    }
    //get stream to send and receive data 
    private void setupStreams() throws IOException{
        output = new ObjectOutputStream(socket.getOutputStream());
        output.flush();
        input = new ObjectInputStream(socket.getInputStream());
        showMessage("\n Streams Are now Set up \n");
    }
    
    //during the chat conversation
    private void whileChatting() throws IOException{
        String message = "You are now connected ";
        showMessage(message);
        ableToType(true);
        do {
            try {
                message = (String) input.readObject();
                showMessage("\n" + message);
            }catch(ClassNotFoundException classNotFoundException) {
                showMessage("\n Error on input \n");
            }
            
        }while(!message.equals("CLIENT - END"));
    }
    
    //Close streams and sockets in java after done chatting
    private void close() {
        showMessage("\n Closing connections... \n");
        ableToType(false);
        try {
            output.close(); //stream close
            input.close(); //stream close 
            socket.close(); //connection close
            
        }catch(IOException ioException) {
            ioException.printStackTrace(); //prints error
        }
    }
    
    //sends message to the client 
    private void sendMessage(String message, String name) {
        try {
            output.writeObject(name + ": " + message);
            output.flush(); //cleans input stream, flush all the extra bites 
            showMessage("\n " + name + ": " + message);
        }catch(IOException ioException) {
            chatWindow.append("\n Error ");
        }
    }
    
    //updates chat window (displays messages)
    private void showMessage(final String text) {
        SwingUtilities.invokeLater( //allows thread that updates parts of the GUI
                new Runnable() {
                    public void run() {
                        chatWindow.append(text);
                    }
                }
            );
        
    }
    
    //lets the user type text into their box 
    private void ableToType(final boolean tof) {
        SwingUtilities.invokeLater( //allows thread that updates parts of the GUI
                new Runnable() {
                    public void run() {
                        userText.setEditable(tof);
                    }
                }
            );
    }
    

    public Client(String IPAdress, int port, String name){
        frame = new JFrame("Client");
        frame.setSize(600, 400);
        
        serverIP = IPAdress;
        HostPort = port;
        userText = new JTextField(); //Input text field
        userText.setEditable(false); //Can't write until connected with someone
        userText.addActionListener(
                new ActionListener() {
                    public void actionPerformed(ActionEvent event) {
                        sendData(event.getActionCommand(), name);
                        userText.setText("");
                    }
                }
            );
        JButton jbutton = new JButton("Browse File");
        JPanel messagePanel = new JPanel(new BorderLayout());
        jbutton.addActionListener(
                new ActionListener() {
                    public void actionPerformed(ActionEvent event) {
                        JFileChooser file = new JFileChooser();
                        file.setCurrentDirectory(new File(System.getProperty("user.home")));
                        FileNameExtensionFilter filter = new FileNameExtensionFilter("*.Images", "jpg","gif","png");
                        file.addChoosableFileFilter(filter);
                        int result = file.showSaveDialog(null);
                         if(result == JFileChooser.APPROVE_OPTION){
                              File selectedFile = file.getSelectedFile();
                              String path = selectedFile.getAbsolutePath();
                              userText.setText(path);
                          }
                          else if(result == JFileChooser.CANCEL_OPTION){
                              System.out.println("No File Select");
                          }
                        }
                }
          );
        
        //add JTextField to CENTER and button to EAST
        messagePanel.add(userText, BorderLayout.CENTER);
        messagePanel.add(jbutton, BorderLayout.EAST);
        chatWindow = new JTextArea();
        add(new JScrollPane(chatWindow));
        chatWindow.setSize(400, 300);
        frame.add(chatWindow, BorderLayout.CENTER);
        frame.add(messagePanel, BorderLayout.SOUTH);
        frame.setVisible(true);
        
        t = new Thread(new Runnable() {
            @Override
            public void run(){
                startRunnable();
            }
        });
     
    }

    //connect to server 
    public void startRunnable() {
        try {
            while(true) {
        try {
            connectToServer();
            setupStreams();
            whileChatting();

        }catch(EOFException eofException) {
            showMessage("\n Connection Ended");
        }finally {
            close();
        }
            }
        }catch(IOException ioException) {
            ioException.printStackTrace(); //prints error
        }
    }
 //connection to server 
    private void connectToServer() throws IOException{
        showMessage("\n Attempting connection");
        connection = new Socket(InetAddress.getByName(serverIP),HostPort);
        showMessage("\nNow connected to " + connection.getInetAddress().getHostName());
    }
    
    
    //get stream to send and receive data 
        private void setupStreams() throws IOException{
            try {
            output = new ObjectOutputStream(connection.getOutputStream());
            output.flush();
            input = new ObjectInputStream(connection.getInputStream());
            showMessage("llegue?");
            showMessage("\n Streams Are now Set up \n");
            }catch(IOException ioException) {
                chatWindow.append("\n Error seting up stream");
            }
        }
        
        //during the chat conversation
        private void whileChatting() throws IOException{
            ableToType(true);
            do {
                try {
                    message = (String) input.readObject();
                    showMessage("\n" + message);
                }catch(ClassNotFoundException classNotFoundException) {
                    showMessage("\n Error on input \n");
                }
                
            }while(!message.equals("SERVER - END"));
        }

        //Close streams and sockets in java after done chatting
        private void close() {
            showMessage("\n Closing connections... \n");
            ableToType(false);
            try {
                output.close(); //stream close
                input.close(); //stream close 
                connection.close(); //connection close
                
                
            }catch(IOException ioException) {
                ioException.printStackTrace(); //prints error
            }
        }
        
        //sends message to the client 
        private void sendData(String message, String name) {
            try {
                output.writeObject(name + ": "+message);
                output.flush(); //cleans input stream, flush all the extra bites 
                showMessage("\n" + name + ": "+ message);
            }catch(IOException ioException) {
                chatWindow.append("\n Error ");
            }
        }
        
        //updates chat window (displays messages)
        private void showMessage(final String M) {
            SwingUtilities.invokeLater( //allows thread that updates parts of the GUI
                    new Runnable() {
                        public void run() {
                            chatWindow.append(M);
                        }
                    }
                );
            
        }
        
        //lets the user type text into their box 
        private void ableToType(final boolean tof) {
            SwingUtilities.invokeLater( //allows thread that updates parts of the GUI
                    new Runnable() {
                        public void run() {
                            userText.setEditable(tof);
                        }
                    }
                );
        }
        
        
}

Answer 1

我相信您僅在當前客戶端斷開連接時使用server.accept() 。

為了接收更多的連接，你需要主動監聽新的連接。 因此，在這種情況下，您需要一個主動偵聽和接受新連接的線程，以及另一個檢查您已經擁有的套接字是否有任何數據的線程。

也許在這種情況下使用 UDP 會更好，因為您可以為每個人打開一個端口並在那里監聽，並讓每個客戶端在它發送的數據上標識自己，這樣您就不需要監聽端口連接和也同時給每個客戶。