匿名类的实例监视窗口事件

package ex1;import java.awt.*;import java.awt.event.*;import javax.swing.*;public class EX3 {   public static void main(String args[]) {      WindowButton win=new WindowButton("猜数字");   }}class WindowButton extends JFrame implements ActionListener {   /** *  */private static final long serialVersionUID = 1L;int number;   JLabel hintLabel;   JTextField inputGuess;   JButton buttonGetNumber,buttonEnter;      WindowButton(String s) {      super(s);      addWindowListener( new WindowAdapter(){ //匿名类的实例监视窗口事件                            public void windowClosing(WindowEvent e) {                                dispose();                            }                         }                        );        setLayout(new FlowLayout());      buttonGetNumber=new JButton("得到一个随机数");      add(buttonGetNumber);      hintLabel=new JLabel("输入你的猜测：",JLabel.CENTER);      hintLabel.setBackground(Color.cyan);      inputGuess=new JTextField("0",10);       add(hintLabel);      add(inputGuess);      buttonEnter=new JButton("确定");       add(buttonEnter);       buttonEnter.addActionListener(this);      buttonGetNumber.addActionListener(this);      setBounds(100,100,450,250);      setVisible(true);      validate();    }    public void actionPerformed(ActionEvent e) {         if(e.getSource()==buttonGetNumber) {            number=(int)(Math.random()*100)+1;            hintLabel.setText("输入你的猜测：");         }         else if(e.getSource()==buttonEnter) {            int guess=0;            try {  guess=Integer.parseInt(inputGuess.getText());                   if(guess==number) {                      hintLabel.setText("猜对了！");                   }                   else if(guess>number) {                      hintLabel.setText("猜大了！");                      inputGuess.setText(null);                    }                   else if(guess<number) {                       hintLabel.setText("猜小了！");                       inputGuess.setText(null);                    }               }             catch(NumberFormatException event) {                   hintLabel.setText("请输入数字字符");             }          }    } }