2345广告联盟:问一个很弱的java问题！

找不到符号是怎么回事？在每一个方法行，如public void windowOpened
import java.awt.event.WindowListener;
import java.util.EventListener;
import java.awt.Window;

MyWindowListener.java
public class MyWindowListener implements WindowListener {
/**
* Method windowOpened
*
*
* @param e
*
*/
public void windowOpened(WindowEvent e) {
// TODO: Add your code here
}

/**
* Method windowClosing
*
*
* @param e
*
*/
public void windowClosing(WindowEvent e) {
// TODO: 在这添加您的代码
e.getWindow().setVisible(false);
//e.getSource().
((Window)e.getComponent()).dispose();
System.exit(0);
}

/**
* Method windowClosed
*
*
* @param e
*
*/
public void windowClosed(WindowEvent e) {
// TODO: 在这添加您的代码
}

/**
* Method windowIconified
*
*
* @param e
*
*/
public void windowIconified(WindowEvent e) {
// TODO: 在这添加您的代码
}

/**
* Method windowDeiconified
*
*
* @param e
*
*/
public void windowDeiconified(WindowEvent e) {
// TODO: 在这添加您的代码
}

/**
* Method windowActivated
*
*
* @param e
*
*/
public void windowActivated(WindowEvent e) {
// TODO: 在这添加您的代码
}

/**
* Method windowDeactivated
*
*
* @param e
*
*/
public void windowDeactivated(WindowEvent e) {
// TODO: 在这添加您的代码
}
}

TestFrame.java
import java.awt.*;

public class TestFrame {

public static void main(String[] args) {
// TODO: ass
Frame f = new Frame("TestFrame");
f.setSize(400,400);
f.add(new Button("Ok"));
f.setVisible(true);
f.addWindowListener(new MyWindowListener());
}

}