文本在我的多客户端聊天 GUI 应用程序中不可见?

Question

>EDIT我已经实现了一个多客户端聊天服务器，最终我将转变为紧急响应"服务器-客户端"临时网络。目前，我的程序已启动并正在运行，但在聊天窗口中，我在文本框中键入的内容没有出现在事件日志中(客户端或服务器都没有(。我不知道是什么导致了该错误？

我应该如何解决这个问题？

以下是代码的某些部分：

public class ServerGUI extends JFrame implements ActionListener, WindowListener{
private static final long serialVersionUID =1L;
// the stop and start buttons
private JButton stopStart;
// JTextArea for the communication interface
private JTextArea commWin, eventLog;
// the port number
private JTextField tport;
// My server
private VServer serv;
// server constructor
//
//
//
//      
commWin = new JTextArea(120,120);
commWin.setEditable(false);
appendComm("VANET Communication Window.n");
middle.add(new JScrollPane(commWin));
eventLog = new JTextArea(120,120);
eventLog.setEditable(false);
appendEvent("Events log.n");
middle.add(new JScrollPane(eventLog));
add(middle);
//
//
//
}
// append message to the two JTextArea
void appendComm(String str){
commWin.append(str);
commWin.setCaretPosition(commWin.getText().length() -1);
}
void appendEvent(String str){
eventLog.append(str);
eventLog.setCaretPosition(commWin.getText().length() -1);
}
// start or stop when clicked
public void actionPerformed(ActionEvent e){
if(serv !=null){
serv.stop();
serv = null;
tport.setEditable(true);
stopStart.setText("Start");
return;
}
int port;
try{
port = Integer.parseInt(tport.getText().trim());
} catch(Exception ex) {
appendEvent("Invalid port number");
return;
}
// create a new Server
serv = new VServer(port, this);
// and start it as a thread
new ServerRunning().start();
stopStart.setText("Stop");
tport.setEditable(false);
}
// entry point to start the server
public static void main(String[] arg){
// start server at default port
new ServerGUI(1234);
}
// in case X is clicked, the application closes
// Connection needs to be closed as well to free the port
public void windowClosing(WindowEvent e){
if(serv != null){
try{
serv.stop();
} catch(Exception ec) {}
serv = null;
}
// dispose the frame
dispose();
System.exit(0);
}
// Ignore the other WindowListener methods
// a thread to run the server
class ServerRunning extends Thread {
public void run(){
serv.start();
// in case server fails
stopStart.setText("Start");
tport.setEditable(true);
appendEvent("Server crashedn");
serv = null;
}
}
}

客户端GUI的某些部分.java：

//
//
public class ClientGUI extends JFrame implements ActionListener {
private static final long serialVersionUID =1L;
private JLabel label;
private JTextField tfield;
private JTextField tfieldserv, tport;
private JButton signin, signoff, ActiveNodes;
private JTextArea tarea;
private boolean connected;
private VClient client;
private int defaultport;
private String defaulthost;
// Constructor receiving a socket number
ClientGUI(String host, int port){
//
//
// The upper panel
JPanel upperPanel = new JPanel(new GridLayout(3,1));
// the server name and port number
JPanel serverPort = new JPanel(new GridLayout(1,5, 1,3));
// the two JTextField with default value for server address and port number
tfieldserv = new JTextField(host);
tport = new JTextField("" + port);
tport.setHorizontalAlignment(SwingConstants.RIGHT);
serverPort.add(new JLabel("Server Address: "));
serverPort.add(tfieldserv);
serverPort.add(new JLabel("Port Number: "));
serverPort.add(tport);
serverPort.add(new JLabel(""));
// adds the server and port fields to GUI
upperPanel.add(serverPort);
// the Label and TextField
label = new JLabel("Enter your username below", SwingConstants.CENTER);
upperPanel.add(label);
tfield = new JTextField("Anonymous");
tfield.setBackground(Color.WHITE);
upperPanel.add(tfield);
add(upperPanel, BorderLayout.NORTH);
// the Central Panel
tarea = new JTextArea("VANET Disaster Managementn", 120, 120);
JPanel middlePanel = new JPanel(new GridLayout(2,2));
middlePanel.add(new JScrollPane(tarea));
tarea.setEditable(false);
add(middlePanel, BorderLayout.CENTER);
// the three Buttons
signin = new JButton("Sign In");
signin.addActionListener(this);
signoff = new JButton("Sign Off");
signoff.addActionListener(this);
signoff.setEnabled(false);          // You have to sign in before being able to sign off
ActiveNodes = new JButton("Active Clients");
ActiveNodes.addActionListener(this);
ActiveNodes.setEnabled(false);      // You have to sign in before being able to see the Active Client list
// the Lower Panel
JPanel lowerPanel = new JPanel();
lowerPanel.add(signin);
lowerPanel.add(signoff);
lowerPanel.add(ActiveNodes);
add(lowerPanel, BorderLayout.SOUTH);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(600,600);
setVisible(true);
tfield.requestFocus();
}
// to append text in the text area
void append(String str){
tarea.append(str);
tarea.setCaretPosition(tarea.getText().length() -1);
}
// called by GUI if the connection fails
void connectionFailed(){
signin.setEnabled(true);
signoff.setEnabled(false);
ActiveNodes.setEnabled(false);
label.setText("Enter your username below");
tfield.setText("Anonymous");
// reset port number and host name
tport.setText("" +defaultport);
tfieldserv.setText(defaulthost);
// let the client modify them
tfieldserv.setEditable(false);
tport.setEditable(false);
// don't react to a carriage return after the username
tfield.removeActionListener(this);
connected = false;
}
// Button or JTextField clicked
public void actionPerformed(ActionEvent e){
Object obj = e.getSource();
if(obj == signoff) {
client.sendMsg(new CommMessage(CommMessage.Signoff, ""));
return;
}
if(obj == ActiveNodes) {
client.sendMsg(new CommMessage(CommMessage.ActiveNodes, ""));
return;
}
if(connected){
client.sendMsg(new CommMessage(CommMessage.Message, ""));
tfield.setText("");
return;
}
if(obj == signin) {
//
//
//
//
}
// create a new client with GUI
client = new VClient(serv, port, username, this);
if(!client.start())
return;
tfield.setText("");
label.setText("Enter your message below");
connected = true;
// disable sign in Button
signin.setEnabled(false);
// enable the two buttons
signoff.setEnabled(true);
ActiveNodes.setEnabled(true);
// disable server and port JTextField
tfieldserv.setEditable(false);
tport.setEditable(false);
// when the client enter a message
tfield.addActionListener(this);
}
}
// to start the whole thing
public static void main(String[] args) {
new ClientGUI("localhost", 1234);
}
}

如果需要其他文件来了解问题，请告诉我！ 我有的文件：

CommMessage.java
VServer.java
VClient.java
ServerGUI.java
ClientGUI.java

附加问题：到目前为止，它只是一个聊天服务器，我将其用作起点(因为我是Java编程的新手(，但我实际上想在这里构建一个完整的应用程序，该应用程序具有中央服务器(完成大部分工作(和多个客户端与之双向通信。为此，我还需要合并身份验证。我的想法是：远程客户端将发送连接请求，服务器打开一个套接字，然后客户端发送包含其名称、IP 和端口号的第一个数据包。服务器应将其与所有已注册客户端的预存储列表匹配，如果是其中一个，则允许通信向前推进。否则终止连接，请建议如何在代码中实现它。

附言"V"代表VANET(车辆临时NETwork - 我的项目主题(

Answer 1

我将回答主要问题，您的代码中有拼写错误

void appendEvent(String str){
eventLog.append(str);
eventLog.setCaretPosition(commWin.getText().length() -1);
// ^^^^ TYPO
}

应该是

void appendEvent(String str){
eventLog.append(str);
eventLog.setCaretPosition(eventLog.getText().length() -1);
}