//掛起、開啟、停止一個線程
class MyThread implements Runnable{
	Thread thrd;
	volatile boolean suspended;  //為真時線程掛起
	volatile boolean stopped;    //為真時線程停止
	MyThread(String name){
		thrd = new Thread(this,name);
		suspended = false;
		stopped = false;
		thrd.start();
	}
	
	//線程進入點
	public void run(){
		System.out.println(thrd.getName()+"  開始。");
		try{
			for(int i=1; i<1000;i++){
				System.out.print(i+"  ");
				if((i%10)==0){
					System.out.println();
					Thread.sleep(250);
				}
				//用同步塊檢查suspended stopped.
				synchronized(this){
					while(suspended){
						wait();
					}
					if(stopped) break;
				}
			}
		}catch(InterruptedException e){
			System.out.println(thrd.getName()+"  被打斷。");
		}
		System.out.println(thrd.getName()+"  退出。");
	}
	//停止線程
	synchronized void myStop(){
		stopped = true;
		
		//接著讓一個掛起的線程停止。
		suspended = false;
		notify();		
	}
	synchronized void mySuspended(){
		suspended = true;
	}
	//開啟線程
	synchronized void myResuse(){
		suspended = false;
		notify();
	}
}
public class Suspend {
	public static void main(String args[]){
		MyThread ob1 = new MyThread("我的線程");
		
		try{
			Thread.sleep(1000);
			
			ob1.mySuspended();
			System.out.println("掛起線程");
			Thread.sleep(1000);
			
			ob1.myResuse();
			System.out.println("開啟線程");
			Thread.sleep(1000);
			
			ob1.mySuspended();
			System.out.println("掛起線程");
			Thread.sleep(1000);
			
			ob1.myResuse();
			System.out.println("開啟線程");
			Thread.sleep(1000);
			
			ob1.mySuspended();
			System.out.println("停止線程");
			ob1.myStop();
		}catch(InterruptedException e){
			System.out.println("主線程被打斷。");	
			}
		
		//等待線程結束
		try{
			ob1.thrd.join();
		}catch(InterruptedException e){
			System.out.println("主線程被打斷。");
		}
		System.out.println("主線程結束。");
	}
}