counter.java

Java 程序设计源码 只提供了部分

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

public class Counter extends Applet {
  private int count = 0;
  private Button
      onOff = new Button("Stop count"),
      start = new Button("Start count");

  private TextField t = new TextField(10);
  private boolean runFlag = true;

  public void init() {
    add(t);
    start.addActionListener(new StartL());
    add(start);
    onOff.addActionListener(new OnOffL());
    add(onOff);
  }

  public void go() {
    while(true) {
      try {
        Thread.currentThread().sleep(100);
      }
      catch(InterruptedException ie) {
        if(runFlag) {
          t.setText(Integer.toString(count++));
        }
      }
    }
  }

    class StartL implements ActionListener {
      public void actionPerformed(ActionEvent e) {
        go();
      }
    }

    class OnOffL implements ActionListener {
      public void actionPerformed(ActionEvent e) {
        runFlag = !runFlag;
      }
    }

    public static void main(String[] args) {
      Counter applet = new Counter();

      Frame aFrame = new Frame("Counter");

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

      aFrame.add(applet, BorderLayout.CENTER);
      aFrame.setSize(300, 200);
      applet.init();
      applet.start();
      aFrame.setVisible(true);
    }
  }