Java线程正在重复 Swing 形式

Question

我正在使用 java 线程同时管理多个 (3) 程序。1 用于 Java swing 表单(绘制 UI 以进行输入)，1 用于在系统托盘上设置图标(从 UI 获取输入后立即启动)，1 用于处理输入并将其反射(reflect)到 SystemTray 图标(以弹出窗口的形式)向该托盘图标发送消息)。

之前，我尝试过不使用单独的线程，但我面临的问题是“如果执行控制一次前进(从 UI 到下一个进程)，其中使用 thread.sleep() 方法(持有控制权)执行一些重复任务实际上是整个时间)。因此，早期的表单(UI)仍然没有响应(我们当时甚至无法关闭表单)。

因此，我想为三个线程中的每一个实现单独的线程。但当我尝试启动表单(UI)时，它实际上会无限循环地重复。

这里是代码:

 public class ImprovedImplementation {

    public static void main(String[] args) {
    System.out.println("Main thread is started...");  
    new LauncherUI();        
    }

 }

class LauncherUI implements Runnable {

private JFrame mainFrame;
private JLabel headerLabel;
private JLabel statusLabel;
private JPanel controlPanel;

String textFieldValue = null;

Thread launcher ;
LauncherUI()
 { 
  prepareGUI();
  launcher = new Thread(this, "Launcher Thread");
  System.out.println("launcher thread created" + launcher);
  launcher.start();
  }
  public void run()
  {
  try
  {      
    LauncherUI swingControlDemo = new LauncherUI();
    swingControlDemo.showEventDemo();    
  }
  catch(Exception e)
  {
    System.out.println("launcher thread interrupted");
  }
  System.out.println("launcher run is over" );
 }   

private void prepareGUI() {

    mainFrame.setSize(450, 400);
    mainFrame.setLayout(new GridLayout(3, 1));
    mainFrame.setLocationRelativeTo(null);

    headerLabel = new JLabel("", JLabel.CENTER);
    statusLabel = new JLabel("", JLabel.CENTER);

    statusLabel.setSize(350, 100);
    mainFrame.addWindowListener(new WindowAdapter() {
        public void windowClosing(WindowEvent windowEvent) {
            System.exit(0);
        }
    });
    controlPanel = new JPanel();
    controlPanel.setLayout(new FlowLayout());

    mainFrame.add(headerLabel);
    mainFrame.add(controlPanel);
    mainFrame.add(statusLabel);
    mainFrame.setVisible(true);
    mainFrame.setResizable(false);
}

private void showEventDemo() {
    headerLabel.setText("Welcome to the Web Server Tracking System !!");
    headerLabel.setFont(new Font("serif", Font.BOLD, 20));

    JLabel l = new JLabel();
    l.setText("Enter All (Servers) URLs separated by a comma ( , ) :");
    l.setFont(new Font("Serif", Font.BOLD, 16));
    JLabel l2 = new JLabel();
    l2.setText("[for example: google.com,wikipedia.org,sjsu.edu]");
    l2.setFont(new Font("Serif", Font.BOLD, 15));
    JTextField txt = new JTextField(30);

    JButton submitButton = new JButton("Start Tracking");
    JButton cancelButton = new JButton("Close");

    submitButton.setActionCommand("Start");
    cancelButton.setActionCommand("Cancel");

    submitButton.addActionListener(new ButtonClickListener());
    submitButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent ae) {
            textFieldValue = txt.getText();
        // textFieldValue="Hello";
            // .... do some operation on value ...
        }
    });
    cancelButton.addActionListener(new ButtonClickListener());

    controlPanel.add(l);
    controlPanel.add(l2);
    controlPanel.add(txt);
    controlPanel.add(submitButton);
    controlPanel.add(cancelButton);

    mainFrame.setVisible(true);

}

private class ButtonClickListener implements ActionListener {

    public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();
        if (command.equals("Start")) {
            if (textFieldValue.equals("") || textFieldValue.indexOf(".") == -1) {
                statusLabel.setText("Please Enter Some Server Urls, Before Start Tracking.");
                if (textFieldValue.indexOf(".") == -1 && !textFieldValue.equals("")) {
                    statusLabel.setText("Please Enter Valid Urls.");
                }
                statusLabel.setForeground(Color.RED);
            } else {
                StringTokenizer urlValues = new StringTokenizer(textFieldValue, ",");
                Vector v = new Vector();
                while (urlValues.hasMoreTokens()) {
                    String token = urlValues.nextToken();
                    v.add(token);
                }
                String[] urlStrArray = (String[]) v.toArray(new String[v.size()]);
                System.out.println("Took following URLS from the User:");
                for(int m=0; m < urlStrArray.length;m++){
                    System.out.println(urlStrArray[m]);
                }
                statusLabel.setText("Tracking is started . . .  it's pinned in your System Tray ( Task bar ).");
                statusLabel.setForeground(Color.BLACK);
            }
        } else {
            System.exit(0);
        }
    }
  }
}

谁能帮帮我。我们将不胜感激。

Answer 1

你的main()执行了一个new LauncherUI()。

您的 LauncherUI 构造函数在 Runnable 上调用 start()； run() 方法调用 new LauncherUI()。该构造函数调用 start()，重复该过程；经典的无限循环。