编写最简单的GUI程序：只有一个Frame，当点击关闭按钮时，结束应用程序。使用8种不同的事件处理方式。

好的，下面为您提供8种不同的事件处理方式的代码示例。

方式一：使用匿名内部类实现ActionListener接口

import java.awt.*;
import java.awt.event.*;

public class CloseFrame1 {
    public static void main(String[] args) {
        Frame f = new Frame("关闭窗口");
        f.setSize(300, 200);
        f.setLocationRelativeTo(null);

        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });

        f.setVisible(true);
    }
}

方式二：使用lambda表达式实现ActionListener接口

import java.awt.*;
import java.awt.event.*;

public class CloseFrame2 {
    public static void main(String[] args) {
        Frame f = new Frame("关闭窗口");
        f.setSize(300, 200);
        f.setLocationRelativeTo(null);

        f.addWindowListener((WindowListener) e -> {
            System.exit(0);
        });

        f.setVisible(true);
    }
}

方式三：使用内部类实现ActionListener接口

import java.awt.*;
import java.awt.event.*;

public class CloseFrame3 {
    public static void main(String[] args) {
        Frame f = new Frame("关闭窗口");
        f.setSize(300, 200);
        f.setLocationRelativeTo(null);

        MyWindowListener listener = new MyWindowListener();
        f.addWindowListener(listener);

        f.setVisible(true);
    }

    static class MyWindowListener extends WindowAdapter {
        public void windowClosing(WindowEvent e) {
            System.exit(0);
        }
    }
}

方式四：使用外部类实现ActionListener接口

import java.awt.*;
import java.awt.event.*;

public class CloseFrame4 {
    public static void main(String[] args) {
        Frame f = new Frame("关闭窗口");
        f.setSize(300, 200);
        f.setLocationRelativeTo(null);

        MyWindowListener listener = new MyWindowListener();
        f.addWindowListener(listener);

        f.setVisible(true);
    }
}

class MyWindowListener extends WindowAdapter {
    public void windowClosing(WindowEvent e) {
        System.exit(0);
    }
}

方式五：使用继承Frame类并重写processWindowEvent方法

import java.awt.*;

public class CloseFrame5 extends Frame {
    public CloseFrame5() {
        super("关闭窗口");
        setSize(300, 200);
        setLocationRelativeTo(null);
    }

    public void processWindowEvent(WindowEvent e) {
        if (e.getID() == WindowEvent.WINDOW_CLOSING) {
            System.exit(0);
        }
        super.processWindowEvent(e);
    }

    public static void main(String[] args) {
        CloseFrame5 f = new CloseFrame5();
        f.setVisible(true);
    }
}

方式六：使用内部类继承Frame类并重写processWindowEvent方法

import java.awt.*;

public class CloseFrame6 {
    public static void main(String[] args) {
        MyFrame f = new MyFrame();
        f.setVisible(true);
    }

    static class MyFrame extends Frame {
        public MyFrame() {
            super("关闭窗口");
            setSize(300, 200);
            setLocationRelativeTo(null);
        }

        public void processWindowEvent(WindowEvent e) {
            if (e.getID() == WindowEvent.WINDOW_CLOSING) {
                System.exit(0);
            }
            super.processWindowEvent(e);
        }
    }
}

方式七：使用匿名内部类继承Frame类并重写processWindowEvent方法

import java.awt.*;

public class CloseFrame7 {
    public static void main(String[] args) {
        Frame f = new Frame("关闭窗口") {
            public void processWindowEvent(WindowEvent e) {
                if (e.getID() == WindowEvent.WINDOW_CLOSING) {
                    System.exit(0);
                }
                super.processWindowEvent(e);
            }
        };
        f.setSize(300, 200);
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }
}

方式八：使用lambda表达式继承Frame类并重写processWindowEvent方法

import java.awt.*;

public class CloseFrame8 {
    public static void main(String[] args) {
        Frame f = new Frame("关闭窗口") {
            public void processWindowEvent(WindowEvent e) {
                if (e.getID() == WindowEvent.WINDOW_CLOSING) {
                    System.exit(0);
                }
                super.processWindowEvent(e);
            }
        };
        f.setSize(300, 200);
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }
}