java - 如何在不同的电脑上使用客户端聊天

Question

我有以下代码，当从相同的 Eclipse IDE 相同的系统（PC）执行时，它可以完美运行。但是我尝试在 2 个单独的系统中运行下面的代码，但它不起作用。我不知道代码中的端口和 ip 更改应该是什么。请让我知道我需要改变什么才能使这个 java 应用程序工作？

提前致谢。

服务器

import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Server extends JFrame{

   private JTextField userText;
   private JTextArea chatWindow;
   private ObjectOutputStream output;
   private ObjectInputStream input;
   private ServerSocket server;
   private Socket connection;

   //constructor
   public Server(){
      super(" Instant Messenger");
      userText = new JTextField();
      userText.setEditable(false);
      userText.addActionListener(
         new ActionListener(){
            public void actionPerformed(ActionEvent event){
               sendMessage(event.getActionCommand());
               userText.setText("");
            }
         }
      );
      add(userText, BorderLayout.NORTH);
      chatWindow = new JTextArea();
      add(new JScrollPane(chatWindow));  //chat window needs to be scrollable so that when new messages are added it can scroll as needed
      setSize(300,150);
      setVisible(true);
   }

   //set up and run the server
   public void startRunning(){
      try{
         server = new ServerSocket(6789, 100);
         while(true){
            try{
               waitForConnection();
               setupStreams();
               whileChatting();
            }catch(EOFException eofException){
               showMessage("\n Server ended the connection! ");
            }finally{
               closeCrap();
            }
         }
      }catch(IOException ioException){
         ioException.printStackTrace();
      }
   }

   //wait for connection, then display connection information
   private void waitForConnection() throws IOException{
      showMessage(" Waiting for someone to connect... \n");
      connection = server.accept();
      showMessage(" Now connected to " + connection.getInetAddress().getHostName());
   }

   //get stream to send and receive data
   private void setupStreams() throws IOException{
      output = new ObjectOutputStream(connection.getOutputStream());
      output.flush();
      input = new ObjectInputStream(connection.getInputStream());
      showMessage("\n Streams are now setup! \n");
   }

   //during the chat conversation
   private void whileChatting() throws IOException{
      String message = " You are now connected! ";
      sendMessage(message);
      ableToType(true);
      do{
         try{
            message = (String) input.readObject();
            showMessage("\n" + message);
         }catch(ClassNotFoundException classNotFoundException){
            showMessage("\n idk wtf that user sent!");
         }
      }while(!message.equals("CLIENT - END"));
   }

   //close streams and sockets after you are done chatting
   private void closeCrap(){
      showMessage("\n Closing connections... \n");
      ableToType(false);
      try{
         output.close();
         input.close();
         connection.close();
      }catch(IOException ioException){
         ioException.printStackTrace();
      }
   }

   //send a message to client
   private void sendMessage(String message){
      try{
         output.writeObject("SERVER - " + message);
         output.flush();
         showMessage("\nSERVER - " + message);
      }catch(IOException ioException){
         chatWindow.append("\n ERROR: DUDE I CANT SEND THAT MESSAGE");
      }
   }

   //updates chatWindow
   private void showMessage(final String text){
      SwingUtilities.invokeLater(
         new Runnable(){
            public void run(){
               chatWindow.append(text);
            }
         }
      );
   }

   //let the user type stuff into their box
   private void ableToType(final boolean tof){
      SwingUtilities.invokeLater(
         new Runnable(){
            public void run(){
               userText.setEditable(tof);
            }
         }
      );
   }

}

服务器测试

import javax.swing.JFrame;

public class ServerTest {
   public static void main(String[] args) {
      Server sally = new Server();
      sally.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      sally.startRunning();
   }
}

客户

import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Client extends JFrame{

   private JTextField userText;
   private JTextArea chatWindow;
   private ObjectOutputStream output;
   private ObjectInputStream input;
   private String message = "";
   private String serverIP;
   private Socket connection;

   //constructor
   public Client(String host){
      super("Client Messenger!");
      serverIP = host;
      userText = new JTextField();
      userText.setEditable(false);
      userText.addActionListener(
         new ActionListener(){
            public void actionPerformed(ActionEvent event){
               sendMessage(event.getActionCommand());
               userText.setText("");
            }
         }
      );
      add(userText, BorderLayout.NORTH);
      chatWindow = new JTextArea();
      add(new JScrollPane(chatWindow), BorderLayout.CENTER);
      setSize(300,150);
      setVisible(true);
   }

   //connect to server
   public void startRunning(){
      try{
         connectToServer();
         setupStreams();
         whileChatting();
      }catch(EOFException eofException){
         showMessage("\n Client terminated connection");
      }catch(IOException ioException){
         ioException.printStackTrace();
      }finally{
         closeCrap();
      }
   }

   //connect to server
   private void connectToServer() throws IOException{
      showMessage("Attempting connection... \n");
      connection = new Socket(InetAddress.getByName(serverIP), 6789);
      showMessage("Connected to: " + connection.getInetAddress().getHostName() );
   }

   //set up streams to send and receive messages
   private void setupStreams() throws IOException{
      output = new ObjectOutputStream(connection.getOutputStream());
      output.flush();
      input = new ObjectInputStream(connection.getInputStream());
      showMessage("\n Dude your streams are now good to go! \n");
   }

   //while chatting with server
   private void whileChatting() throws IOException{
      ableToType(true);
      do{
         try{
            message = (String) input.readObject();
            showMessage("\n" + message);
         }catch(ClassNotFoundException classNotfoundException){
            showMessage("\n I dont know that object type");
         }
      }while(!message.equals("SERVER - END"));
   }

   //close the streams and sockets
   private void closeCrap(){
      showMessage("\n closing crap down...");
      ableToType(false);
      try{
         output.close();
         input.close();
         connection.close();
      }catch(IOException ioException){
         ioException.printStackTrace();
      }
   }

   //send messages to server
   private void sendMessage(String message){
      try{
         output.writeObject("CLIENT - " + message);
         output.flush();
         showMessage("\nCLIENT - " + message);
      }catch(IOException ioException){
         chatWindow.append("\n something messed up sending message hoss!");
      }
   }

   //change/update chatWindow
   private void showMessage(final String m){
      SwingUtilities.invokeLater(
         new Runnable(){
            public void run(){
               chatWindow.append(m);
            }
         }
      );
   }

   //gives user permission to type crap into the text box
   private void ableToType(final boolean tof){
      SwingUtilities.invokeLater(
         new Runnable(){
            public void run(){
               userText.setEditable(tof);
            }
         }
      );     
   }
}

客户端测试

import javax.swing.JFrame;

public class ClientTest {
   public static void main(String[] args) {
      Client charlie;
      charlie = new Client("127.0.0.1");
      charlie.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      charlie.startRunning();
   }
}

score 0 · Accepted Answer

我建议使用不同的端口，甚至可以让自己选择端口，而不是将其硬编码到代码中。有时它不起作用，因为该端口已在使用中。

服务器：

public void startRunning(serverPort){
 try{
 server = new ServerSocket(serverPort, 100);
}

客户：

private void connectToServer(portNumber) throws IOException{
  showMessage("Attempting connection... \n");
  connection = new Socket(InetAddress.getByName(serverIP), portNumber);
  showMessage("Connected to: " + connection.getInetAddress().getHostName() );
}

可能需要对其进行更多更改，但这就是我的做法。

score 0 · Accepted Answer

您必须向客户端对象提供运行服务器的系统的 IP 地址。在连接之前询问用户服务器 IP 和端口是更好的方法。

score 0 · Accepted Answer

如果您通过运行ClientTest类来启动客户端，那么您需要更新它以使用服务器 IP。在您当前的 ClientTest 代码中，您使用 localhost IP 连接到服务器：

  charlie = new Client("127.0.0.1");

更新它以使用服务器 IP：

  charlie = new Client("use server IP");

服务器 IP 是您运行Server课程的机器的 IP 地址。

score 0 · Accepted Answer

IP和端口应该与对方相对应。假设端口被转发，该端口应该与对方的监听端口相同。IP 应该是另一个端点的 IP。

ServerTest 应该没问题，而 ClientTest 需要将 IP 更改为服务器运行的 IP（假设端口是打开和转发的，没有被 NAT 或防火墙阻止），但端口应该保持不变。

java - 如何在不同的电脑上使用客户端聊天

4 回答 4

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