runnabledemo.java

《J2ME图形应用基础》第二章

/*
 * RunnableDemo.java
 *
 * Created on 2005年4月10日, 下午7:02
 */

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

/**
 *
 * @author  Liu Bin
 * @version
 */
public class RunnableDemo extends MIDlet implements CommandListener {
    //Display管理
    Display display = null;
    Form form = new Form("通过Runnable创建线程");
    
    Command cmdExit = new Command("退出", Command.STOP, 1);
    Command cmdRun = new Command("运行", Command.ITEM, 2);
    Command cmdStop = new Command("停止", Command.ITEM, 2);
    MyThreaad p1, p2, p3;
    
    public RunnableDemo() {
        form.addCommand(cmdExit);
        form.addCommand(cmdRun);
        form.setCommandListener(this);
    }
    public void startApp() {
        
        display = Display.getDisplay(this); //获得当前MIDlet的Display对象
        display.setCurrent(form);           //设置form对象为当前显示对象
    }
    
    public void pauseApp() {
    }
    
    public void destroyApp(boolean unconditional) {
        notifyDestroyed();
    }
    
    /**
     * 处理命令按钮事件
     */
    public void commandAction(Command cmd, Displayable d) {
        if (cmd == cmdExit) {
            destroyApp(true);
        } else if (cmd == cmdRun) {
            //创建线程1
            p1 = new MyThreaad(1);
            //执行线程1
            new Thread(p1).start();
            
            //创建线程2
            p2 = new MyThreaad(2);
            //执行线程2
            new Thread(p2).start();
            
            //创建线程3
            p3 = new MyThreaad(3);
            //执行线程3
            new Thread(p3).start();

            form.removeCommand(cmdRun);
            form.addCommand(cmdStop);
        } else if (cmd == cmdStop) {
            form.removeCommand(cmdStop);
            form.addCommand(cmdRun);
            
            p1.stopFlag = true;
            p2.stopFlag = true;
            p3.stopFlag = true;
        }
    }
    
    
    /**
     * 实现Runnable接口
     */
    class MyThreaad implements Runnable {
        //当前线程的ID标识
        long id;
        public boolean stopFlag;
        
        MyThreaad(long id) {
            this.id = id;
        }
        
        public void run() {
            stopFlag = false;
            long i=0;
            System.out.println("线程"+ id + "开始执行完毕\n");
            while (!stopFlag) {
                System.out.println("当前线程"+id + " : " + i++);
                try {
                    Thread.sleep(100);
                } catch (Exception e) {
                }
            }
            System.out.println("线程"+ id + "执行完毕\n");
        }
    }
    
}