目前我正在创建一个简单的聊天程序，允许您在服务器之间进行通信。我在访问username变量时遇到问题，因为它在另一个文件中的一个文件中使用。用户将输入他的名字，这是在ChatGUI文件中完成的，然后当他进入聊天室时，会创建一个EchoFrame，它位于EchoFrame文件中。同样在EchoFrame文件中，我想将用户名附加到用户消息，并在他们连接到聊天室以及何时离开聊天室时进行通知。我希望我能清楚地解释我的问题，所需的任何其他信息请告诉我！
EchoFrame
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:ViewModels;assembly=AsyncFS"
xmlns:fsxaml="http://github.com/fsprojects/FsXaml"
Title="MVVM and XAML Type provider" Height="200" Width="400">
<Window.DataContext>
<local:MainViewModel/>
</Window.DataContext>
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
</Grid.RowDefinitions>
<WindowsFormsHost Child="{Binding LineChart}" />
</Grid>
ChatGUI
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
public class EchoFrame extends Frame{
EchoPanel ep;
Button sendMessage;
public EchoFrame(){
setSize(500,500);
setTitle("Echo Client");
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent we){
System.exit(0);
}
});
ep = new EchoPanel();
add(ep, BorderLayout.CENTER);
setVisible(true);
}
public static void main(String[] args){
EchoFrame ef = new EchoFrame();
}
}
class EchoPanel extends Panel implements ActionListener, Runnable{
TextField tf;
TextArea ta;
Button connect, disconnect;
Socket s;
BufferedReader br;
PrintWriter pw;
Thread t;
String fromServer;
String username;
public EchoPanel(){
setLayout(new BorderLayout());
tf = new TextField();
tf.setEditable(false);
tf.addActionListener(this);
add(tf, BorderLayout.NORTH);
ta = new TextArea();
ta.setEditable(false);
add(ta, BorderLayout.CENTER);
Panel buttonPanel = new Panel();
connect = new Button("Connect");
connect.addActionListener(this);
buttonPanel.add(connect);
disconnect = new Button("Disconnect");
disconnect.setEnabled(false);
disconnect.addActionListener(this);
buttonPanel.add(disconnect);
add(buttonPanel, BorderLayout.SOUTH);
}
public void actionPerformed(ActionEvent ae){
if(ae.getSource() == connect){
try{
s = new Socket("127.0.0.1", 8189);
ta.append(username + " has entered the chat room. \n");
br = new BufferedReader(new InputStreamReader(s.getInputStream()));
pw = new PrintWriter(s.getOutputStream(), true);
}catch(UnknownHostException uhe){
System.out.println(uhe.getMessage());
}catch(IOException ioe){
System.out.println(ioe.getMessage());
}
t = new Thread(this);
t.start();
tf.setEditable(true);
connect.setEnabled(false);
disconnect.setEnabled(true);
}else if(ae.getSource() == disconnect){
try{
pw.close();
br.close();
s.close();
}catch(IOException ioe){
System.out.println(ioe.getMessage());
}
t = null;
ta.append(username + " has disconnected from chat room. \n");
tf.setEditable(false);
connect.setEnabled(true);
disconnect.setEnabled(false);
}else if(ae.getSource() == tf){
String fromTf = tf.getText();
pw.println(fromTf);
tf.setText("");
}else{
//additional events
}
}
public void run (){
fromServer = "";
try{
while((fromServer = br.readLine()) != null){
ta.append(username + ":" + fromServer + "\n");
}
}catch(IOException ioe){
System.out.println(ioe.getMessage());
}
}
}
聊天服务器
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class ChatGUI extends JFrame {
private int currentCard = 1;
private JPanel cardPanel;
private CardLayout cl;
JTextField usernameField;
String username;
public ChatGUI() {
setTitle("Chat Program");
setSize(500, 120);
cardPanel = new JPanel();
cl = new CardLayout();
cardPanel.setLayout(cl);
JPanel chooseUsername = new JPanel();
JLabel usernameLabel = new JLabel("Please enter your username:");
chooseUsername.add(usernameLabel);
cardPanel.add(chooseUsername, "Log in");
usernameField = new JTextField(15);
usernameField.setEditable(true);
add(usernameField, BorderLayout.CENTER);
JPanel buttonPanel = new JPanel();
JButton logInBtn = new JButton("Enter Chat Room");
buttonPanel.add(logInBtn);
logInBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
currentCard = 2;
cl.show(cardPanel, "" + (currentCard));
username = usernameField.getText(); //gets username
EchoFrame ef = new EchoFrame(); //creates message room
}
});
getContentPane().add(cardPanel, BorderLayout.NORTH);
getContentPane().add(buttonPanel, BorderLayout.SOUTH);
}
public static void main(String[] args) {
ChatGUI cl = new ChatGUI();
cl.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
cl.setVisible(true);
}
}
聊天处理程序
import java.io.*;
import java.net.*;
import java.util.*;
public class ChatServer{
Socket s;
ArrayList <ChatHandler>handlers;
public ChatServer(){
try{
ServerSocket ss = new ServerSocket(8189);
handlers = new ArrayList<ChatHandler>();
for(;;){
s = ss.accept();
new ChatHandler(s, handlers).start();
}
}catch(IOException ioe){
System.out.println(ioe.getMessage());
}
}
public static void main(String[] args){
ChatServer tes = new ChatServer();
}
}
答案 0 :(得分：1)
将userName设为静态，然后通过ChatUI.userName访问它。实际上，userName不应该在ChatUI中。或者，更重要的选择是获取MySQL，设置数据库，并通过JDBC连接到它，如果您将拥有多个用户。
您也可以尝试按照以下示例进行操作：Simple Client And Server Chat Program和Creating a simple Chat Client/Server Solution。它们涵盖了关键主题，例如多线程。
答案 1 :(得分：0)
我认为您应该有一个服务器程序和一个客户端程序，因此您需要发送给每个客户端的所有变量都可以进入服务器。
当客户端连接到服务器时，您将该客户端（用户名，ipadress等）添加到已连接客户端列表中，并创建一个新线程来侦听/发送到该客户端。然后从服务器你可以发送给所有用户（线程）用户名和他写的如果你有一个函数sendToAll（idThreadSender，threadX.text）或你可以发送到线程（threadX，threadY.text）我认为你有一个坏结构，就是这样。
希望我帮忙。