public?class?ArmyRunnable?implements?Runnable?{

	//volatile保證了線程可以正確的讀取其他線程寫入的值
	//可見性??JMM，happens-before原則？？？？？？？？？？？？？？？？？？？？？？？？？？
	volatile?boolean?keepRunning;

	@Override
	public?void?run()?{
		while(keepRunning){
			//發動五連擊
			for(int?i=0;i<5;i++){
				System.out.println(Thread.currentThread().getName()+"攻擊對方【"+i+"】次！");
			}
			//讓出處理器時間，讓線程們“公平競爭”
			Thread.yield();
		}
		
		System.out.println(Thread.currentThread().getName()+"戰斗結束了！");
	}

}

/**
?*?軍演舞臺
?*/
public?class?Stage?extends?Thread{
	
	@Override
	public?void?run()?{
		//創建紅藍方攻擊的實例
		ArmyRunnable?redAttack0?=?new?ArmyRunnable();
		ArmyRunnable?blueAttack0?=?new?ArmyRunnable();
		//創建線程
		Thread?redAttack?=?new?Thread(redAttack0,"紅方軍團");
		Thread?blueAttack?=?new?Thread(blueAttack0,"藍方軍團");
		//啟動線程，開始作戰
		redAttack.start();
		blueAttack.start();
		//關閉舞臺線程，保證軍演專心進行
		try?{
//			this.sleep(50);
			Thread.sleep(50);
		}?catch?(InterruptedException?e)?{
			e.printStackTrace();
		}
		//關閉線程，鳴金收兵
		redAttack0.keepRunning=false;
		blueAttack0.keepRunning=false;
		//保證藍方運行結束？？？？？？？？？？？？？？？？？？？？？？？？
		try?{
			blueAttack.join();
		}?catch?(InterruptedException?e)?{
			e.printStackTrace();
		}
		
	}
	
	public?static?void?main(String[]?args)?{
		//啟動舞臺，開始觀戰
		new?Stage().start();
	}

}