便利的转换[Java编程]

//: JButtonDemo.java
// Looks like Java 1.1 but with J's added
package c13.swing;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;

public class JButtonDemo extends Applet {
  JButton 
    b1 = new JButton("JButton 1"),
    b2 = new JButton("JButton 2");
  JTextField t = new JTextField(20);
  public void init() {
    ActionListener al = new ActionListener() {
      public void actionPerformed(ActionEvent e){
        String name = 
          ((JButton)e.getSource()).getText();
        t.setText(name + " Pressed");
      }
    };
    b1.addActionListener(al);
    add(b1);
    b2.addActionListener(al);
    add(b2);
    add(t);
  }
  public static void main(String args[]) {
    JButtonDemo applet = new JButtonDemo();
    JFrame frame = new JFrame("TextAreaNew");
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e){
        System.exit(0);
      }
    });
    frame.getContentPane().add(
      applet, BorderLayout.CENTER);
    frame.setSize(300,100);
    applet.init();
    applet.start();
    frame.setVisible(true);
  }
} ///:~