发现java的Bug！

java的问题确实不少，不过建议你通过代码来佐证你的观点，要不你就是忻口开河了

归结bug问题的一般是他的程序有问题！

不是吧？老兄？我上星期还用JMenu注册了个MouseListener呢，根本没有你说的
问题啊。拜托你把自己的程序调好了再来喊叫啊！

要不要我证明给你看这不是bug??????我上星期刚用到过MouseListener

MouseListener是可以用，但是其中的mouseEntered不能用！
注意，是菜单不是菜单项！

发现BUG你可以去SUN公司去拿钱啦，哈哈

那不废话，我要是上个星期没用过，我闲着没事跟你叫什么真啊？说过了我上个星期刚刚用过了，前天看你帖子的时候我又把自己的代码翻出来验证了一下，真真的连个虫毛也没看到，上哪捉虫去？明明可以用，你偏要抬杠，你是不是没给Menu注册鼠标监听啊？

package javamediaplayer;import javax.swing.UIManager;
import java.awt.*;
public class MediaApp {
  boolean packFrame = false;  //Construct the application
  public MediaApp() {
    MediaFrame frame = new MediaFrame();
    //Validate frames that have preset sizes
    //Pack frames that have useful preferred size info, e.g. from their layout
    if (packFrame) {
      frame.pack();
    }
    else {
      frame.validate();
    }
    //Center the window
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    Dimension frameSize = frame.getSize();
    if (frameSize.height > screenSize.height) {
      frameSize.height = screenSize.height;
    }
    if (frameSize.width > screenSize.width) {
      frameSize.width = screenSize.width;
    }
    frame.setLocation((screenSize.width - frameSize.width) / 2, (screenSize.height - frameSize.height) / 2);
    frame.setVisible(true);
  }  //Main method
  public static void main(String[] args) {
    try {
      UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    }
    catch(Exception e) {
      e.printStackTrace();
    }
    new MediaApp();
  }
}
package javamediaplayer;import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MediaFrame extends JFrame {
  JPanel contentPane;
  JMenuBar jMenuBar1 = new JMenuBar();
  JMenu jMenuFile = new JMenu();
  JMenuItem jMenuFileExit = new JMenuItem();
  JMenu jMenuHelp = new JMenu();
  JMenuItem jMenuHelpAbout = new JMenuItem();
  JLabel statusBar = new JLabel();
  BorderLayout borderLayout1 = new BorderLayout();  //Construct the frame
  public MediaFrame() {
    enableEvents(AWTEvent.WINDOW_EVENT_MASK);
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }  //Component initialization
  private void jbInit() throws Exception  {
    contentPane = (JPanel) this.getContentPane();
    contentPane.setLayout(borderLayout1);
    this.setSize(new Dimension(400, 300));
    this.setTitle("Frame Title");
    statusBar.setText(" ");
    jMenuFile.setText("File");
    jMenuFile.addFocusListener(new MediaFrame_jMenuFile_focusAdapter(this));
    jMenuFileExit.setText("Exit");
    jMenuFileExit.addActionListener(new MediaFrame_jMenuFileExit_ActionAdapter(this));
    jMenuHelp.setText("Help");
    jMenuHelpAbout.setText("About");
    jMenuHelpAbout.addActionListener(new MediaFrame_jMenuHelpAbout_ActionAdapter(this));
    jMenuFile.add(jMenuFileExit);
    jMenuHelp.add(jMenuHelpAbout);
    jMenuBar1.add(jMenuFile);
    jMenuBar1.add(jMenuHelp);
    this.setJMenuBar(jMenuBar1);
    contentPane.add(statusBar, BorderLayout.SOUTH);
  }  //File | Exit action performed
  public void jMenuFileExit_actionPerformed(ActionEvent e) {
    System.exit(0);
  }  //Help | About action performed
  public void jMenuHelpAbout_actionPerformed(ActionEvent e) {
  }  //Overridden so we can exit when window is closed
  protected void processWindowEvent(WindowEvent e) {
    super.processWindowEvent(e);
    if (e.getID() == WindowEvent.WINDOW_CLOSING) {
      jMenuFileExit_actionPerformed(null);
    }
  }  void jMenuFile_focusGained(FocusEvent e) {
       System.exit(0);
  }
}class MediaFrame_jMenuFileExit_ActionAdapter implements ActionListener {
  MediaFrame adaptee;  MediaFrame_jMenuFileExit_ActionAdapter(MediaFrame adaptee) {
    this.adaptee = adaptee;
  }
  public void actionPerformed(ActionEvent e) {
    adaptee.jMenuFileExit_actionPerformed(e);
  }
}class MediaFrame_jMenuHelpAbout_ActionAdapter implements ActionListener {
  MediaFrame adaptee;  MediaFrame_jMenuHelpAbout_ActionAdapter(MediaFrame adaptee) {
    this.adaptee = adaptee;
  }
  public void actionPerformed(ActionEvent e) {
    adaptee.jMenuHelpAbout_actionPerformed(e);
  }
}class MediaFrame_jMenuFile_focusAdapter extends java.awt.event.FocusAdapter {
  MediaFrame adaptee;  MediaFrame_jMenuFile_focusAdapter(MediaFrame adaptee) {
    this.adaptee = adaptee;
  }
  public void focusGained(FocusEvent e) {
    adaptee.jMenuFile_focusGained(e);
  }
}

上面是源代码！
void jMenuFile_focusGained(FocusEvent e) {
System.exit(0);
}
没有得到执行

不能响应focusGained，mouseEntered等事件！
上面的是测试focusGained的，mouseEntered也试过，没响应！

import java.awt.event.*;import javax.swing.*;public class E_MenuBar extends JMenuBar implements ActionListener {
    private ExamFrame owner;
    private JMenu mnuFunction, mnuConfiguration, mnuHelp;
    private JMenuItem miF_OpenEP, miF_StartExam, miF_SubmitEP, miF_Exit, miC_Configuration, miC_SetPassword,
     miH_HelpC, miH_About;

    public static E_ConfigDialog configDialog;

    private ConfigPasswordDialog configPasswordDialog;
    private SetCP setPasswordDialog;

    public E_MenuBar(ExamFrame owner) {
        this.owner = owner;
        //*****************************************************************
        mnuFunction = new JMenu("功能");
        mnuConfiguration = new JMenu("配置");
        mnuHelp = new JMenu("帮助");

        miF_OpenEP = new JMenuItem("打开考卷...", new ImageIcon("openss.bic"));
        miF_StartExam = new JMenuItem("开始考试", new ImageIcon("startss.bic"));
        miF_SubmitEP = new JMenuItem("提交考卷", new ImageIcon("submitEPss.bic"));
        miF_Exit = new JMenuItem("退出", new ImageIcon("exitss.bic"));

        miC_Configuration = new JMenuItem("配置...", new ImageIcon("configss.bic"));
        miC_SetPassword = new JMenuItem("设定管理密码...");

        miH_HelpC = new JMenuItem("帮助主题", new ImageIcon("helpss.bic"));
        miH_About = new JMenuItem("关于...");

        configDialog = new E_ConfigDialog();
        configPasswordDialog = new ConfigPasswordDialog(owner);
        setPasswordDialog = new SetCP(owner, configPasswordDialog);
        //*****************************************************************
        miF_OpenEP.setToolTipText(ExamFrame.TTT_MB_LOAD_TQ);
        miF_StartExam.setToolTipText(ExamFrame.TTT_START_EXAM);
        miF_SubmitEP.setToolTipText(ExamFrame.TTT_SUBMIT_EXAMINATION_PAPER);
        miF_Exit.setToolTipText(ExamFrame.TTT_MB_EXIT);
        miC_Configuration.setToolTipText(ExamFrame.TTT_MB_CONFIG);
        miC_SetPassword.setToolTipText(ExamFrame.TTT_MB_SET_PASSWORD);
        miH_HelpC.setToolTipText(ExamFrame.TTT_MB_HELP_CONTENTS);
        miH_About.setToolTipText(ExamFrame.TTT_MB_ABOUT);

        miF_StartExam.setEnabled(false);
        miF_SubmitEP.setEnabled(false);
        //*****************************************************************
        mnuFunction.add(miF_OpenEP);
        mnuFunction.addSeparator();
        mnuFunction.add(miF_StartExam);
        mnuFunction.add(miF_SubmitEP);
        mnuFunction.addSeparator();
        mnuFunction.add(miF_Exit);

        mnuConfiguration.add(miC_Configuration);
        mnuConfiguration.addSeparator();
        mnuConfiguration.add(miC_SetPassword);

        mnuHelp.add(miH_HelpC);
        mnuHelp.addSeparator();
        mnuHelp.add(miH_About);

        add(mnuFunction); add(mnuConfiguration); add(mnuHelp);
        //*****************************************************************
        miF_OpenEP.addActionListener(this);
        miF_StartExam.addActionListener(this);
        miF_SubmitEP.addActionListener(this);
        miF_Exit.addActionListener(this);
        miC_Configuration.addActionListener(this);
        miC_SetPassword.addActionListener(this);
        miH_HelpC.addActionListener(this);
        miH_About.addActionListener(this);

        miF_OpenEP.addMouseListener(new MouseProcessor());
        miF_StartExam.addMouseListener(new MouseProcessor());
        miF_SubmitEP.addMouseListener(new MouseProcessor());
        miF_Exit.addMouseListener(new MouseProcessor());
        miC_Configuration.addMouseListener(new MouseProcessor());
        miC_SetPassword.addMouseListener(new MouseProcessor());
        miH_HelpC.addMouseListener(new MouseProcessor());
        miH_About.addMouseListener(new MouseProcessor());
    }

    public void setEPLoaded(boolean b) {
        miF_StartExam.setEnabled(b);
        miF_SubmitEP.setEnabled(!b);
    }

    public void setExamStarted(boolean b) {
        miF_StartExam.setEnabled(!b);
        miF_SubmitEP.setEnabled(b);
        configDialog.setExamStarted(b);
    }

    public void setExamOver(boolean b) {
        miF_StartExam.setEnabled(!b);
        miF_SubmitEP.setEnabled(!b);
        configDialog.setExamStarted(!b);
    }

    private class MouseProcessor extends MouseAdapter {
public void mouseEntered(MouseEvent e) {
if(e.getSource().equals(miF_OpenEP)) {
    owner.setStatusBarText(ExamFrame.TTT_MB_LOAD_TQ);
} else if(e.getSource().equals(miF_StartExam)) {
    owner.setStatusBarText(ExamFrame.TTT_START_EXAM);
} else if(e.getSource().equals(miF_SubmitEP)) {
    owner.setStatusBarText(ExamFrame.TTT_SUBMIT_EXAMINATION_PAPER);
} else if(e.getSource().equals(miF_Exit)) {
    owner.setStatusBarText(ExamFrame.TTT_MB_EXIT);
} else if(e.getSource().equals(miC_Configuration)) {
    owner.setStatusBarText(ExamFrame.TTT_MB_CONFIG);
} else if(e.getSource().equals(miC_SetPassword)) {
    owner.setStatusBarText(ExamFrame.TTT_MB_SET_PASSWORD);
} else if(e.getSource().equals(miH_HelpC)) {
    owner.setStatusBarText(ExamFrame.TTT_MB_HELP_CONTENTS);
} else if(e.getSource().equals(miH_About)) {
    owner.setStatusBarText(ExamFrame.TTT_MB_ABOUT);
}
}

public void mouseExited(MouseEvent e) {
owner.setStatusBarText("");
}
}    public void actionPerformed(ActionEvent e) {
        if(e.getSource().equals(miF_OpenEP)) {
            owner.openEP();
        } else if(e.getSource().equals(miF_StartExam)) {
            owner.setExamStarted(true);
        } else if(e.getSource().equals(miF_SubmitEP)) {
            owner.setExamOver(true);
        } else if(e.getSource().equals(miF_Exit)) {
            System.exit(0);
        } else if(e.getSource().equals(miC_Configuration)) {
            configPasswordDialog.setVisible(true);
        } else if(e.getSource().equals(miC_SetPassword)) {
            setPasswordDialog.setVisible(true);
        } else if(e.getSource().equals(miH_HelpC)) {
            JOptionPane.showMessageDialog(new JButton("OK"), "制作中……，谢谢使用！");
        } else if(e.getSource().equals(miH_About)) {
            JOptionPane.showMessageDialog(new JButton("OK"), "模拟考试系统模拟考试程序 " + ExamFrame.VERSION
             + "");
        }
    }
}上上星期刚用到，绝对没问题。

请 mrwest(James West) 看清楚！
我是说的JMenu！
而你是用的JMenuItem！
这是两个不同的东西！

一般初学者总能发现"bug",嘿嘿

是啊，初学者总能发现“bug”，真牛。

问一下楼主，JMenu 的mouseEntered事件会存在吗？
“bug”不是那么好找的，虚心学习吧......

Jbuilder 6实例入门中有用JMenu 的focusGained事件来实现动态禁用JMenuItem的代码，发现没有
focusGained没有发生作用！

呵呵，补充呵两句JMenuItem 实现了FocusListener而且是private 的JMenu没有实现它，如果你想在JMenu里的FocusListener起作用可以继承一下JMenu

调试易

发现java的Bug！

解决方案 »