線程的啟動和停止

import java.lang.Thread;
import java.lang.Runnable;
import java.util.Date;

public class DefineAndStartThread{
class ThreadA extends Thread{
private Date runDate;
//繼承Thread的子類必須實現run方法，Thread中的run方法未做任何事
public void run(){
System.out.println("ThreadA begin");
this.runDate = new Date();
System.out.println("ThreadA run: "+this.runDate);
System.out.println("ThreadA end");
}
}

class ThreadB implements Runnable{
private Date runDate;
public void run(){
System.out.println("ThreadB begin");
this.runDate = new Date();
System.out.println("ThreadB run: "+this.runDate);
System.out.println("ThreadB end");
}
}

public void startThreadA(){
//這里是面向對象的多態特征，子類對象可以直接賦給父類變量，但運行時依然表現為子類特性
//聲明變量類型為父類，實際變量類型為子類對象
Thread threadA = new ThreadA();
//啟用線程后，jvm會調用該線程的run方法，執行線程
threadA.start();
}

public void startThreadB(){
Runnable rb = new ThreadB();
Thread threadB = new Thread(rb);
//啟用線程后，會引起調用該線程的run方法，執行線程
threadB.start();
}

public static void main(String[] args){
DefineAndStartThread test = new DefineAndStartThread();
test.startThreadA();
test.startThreadB();
}
}

import java.lang.Thread;
import java.util.Date;

public class StopThread{
    //因為該類的start、stop、main方法都要用到ThreadA的實例對象，所以聲明為類變量
    private ThreadA thread = new ThreadA();
    class ThreadA extends Thread{
        //用來對外設置是否執行run方法的標識
        private boolean running = false;
        private Date runDate;
        //重寫Thread父類的start方法，在父類start方法之上設置運行標識為true
        public void start(){
            this.running = true;
            super.start();
            }
        //線程一旦啟動則不停的循環執行，直到執行標識為false，則停止運行
        public void run(){
            System.out.println("ThreadA begin");
            try{
                int i=0;
                while(this.running){
                this.runDate = new Date();
//                System.out.println("ThreadA run: "+this.runDate);
                System.out.println("ThreadA run: "+ i++);
                Thread.sleep(200);
                }
            }catch(InterruptedException e){
                e.printStackTrace();
                }
            System.out.println("ThreadA end");
            }
            
        public void setRunning(boolean running){
            this.running = running;
            }
        }
        
        public void start(){
            this.thread.start();
            }
        
        //修改執行標識為false則停止執行run方法    
        public void stop(){
            this.thread.setRunning(false);
            }
        public static void main(String[] args){
            StopThread stopThread = new StopThread();
            //線程一直運行直到結果結束
            stopThread.start();
            //當前線程休眠1秒
            try{
                Thread.sleep(1000);
            }catch(InterruptedException e){
                e.printStackTrace();
                }
            stopThread.stop();
            }
    
    }