java 窗口关闭的六种方法

1.使用JFrame的enableEvents和processWindowEvent
//Frame1.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Frame1 extends JFrame {
  public Frame1() {
    enableEvents(AWTEvent.WINDOW_EVENT_MASK);
    this.setSize(new Dimension(400, 300));
    this.setTitle("Frame1");
  }
  protected void processWindowEvent(WindowEvent e) {
    super.processWindowEvent(e);
    if (e.getID() == WindowEvent.WINDOW_CLOSING) {
      System.exit(0);
    }
  }
}
2.直接实现WindowListener接口
//Frame1.java
import java.awt.*;
import java.awt.event.*;
public class Frame1 extends Frame implements WindowListener {
  public Frame1() {
    this.setSize(new Dimension(400, 300));
    this.setTitle("Frame1");
    this.addWindowListener(this);
  }
  public void windowClosing(WindowEvent windowEvent) {
    System.exit(0);
  }
  public void windowOpened(WindowEvent windowEvent) {  }
  public void windowClosed(WindowEvent windowEvent) {  }
  public void windowIconified(WindowEvent windowEvent) {  }
  public void windowDeiconified(WindowEvent windowEvent) {  }
  public void windowActivated(WindowEvent windowEvent) {  }
  public void windowDeactivated(WindowEvent windowEvent) {  }
}
3.直接继承窗体适配器WindowAdapter
//Frame1.java
import java.awt.*;
import java.awt.event.*;
public class Frame1 extends  WindowAdapter {
  public Frame1() {
    Frame f=new Frame();
    f.setSize(new Dimension(400, 300));
    f.setTitle("Frame1");
    f.addWindowListener(this);
    f.setVisible(true);
  }
  public static void main(St