java例程练习（多线程综合练习[生产者消费者问题]）

/*
 * 生产者与消费者问题
 * 此问题用到Object类的wait(),notify()
 * 还要注意一个问题：
 * sleep()与wait()的区别：
 * 		sleep()过程中，对象仍未解锁
 * 		wait ()过程中，对象解锁，其他线程可以访问当前对象，当唤醒时需重新锁定
 */
public class Test {
	public static void main(String[] args) {
		ThingsStack ts = new ThingsStack();
		Producer p = new Producer(ts);
		Consumer c = new Consumer(ts);
		new Thread(p).start();
		new Thread(p).start();
		new Thread(p).start();
		
		new Thread(c).start();
		new Thread(c).start();
		new Thread(c).start();
	}
}

class Things {
	int id;
	Things(int id) {
		this.id = id;
	}
	
	public String toString() {
		return "Things :" + id;
	}
}

class ThingsStack {
	int index = 0;
	Things [] arrThings = new Things[6];
	
	public synchronized void push(Things t) {
		
		//if被打断后会跳出继续执行，用while语句更安全
//		if(index == arrThings.length) {
//			try {
//				this.wait();//Object类的wait();
//			} catch(InterruptedException e) {
//				e.printStackTrace();
//			}	
//		}
		
		while(index == arrThings.length) {
			try {
				this.wait();//Object类的wait();
			} catch(InterruptedException e) {
				e.printStackTrace();
			}	
		}
		
		//this.notify();
		this.notifyAll();
		arrThings[index] = t;
		index ++;
	}
	
	public synchronized Things pop() {
		//if被打断后会跳出继续执行，用while语句更安全
//		if(index == 0) {
//			try {
//				this.wait();//Object类的wait();
//			} catch(InterruptedException e) {
//				e.printStackTrace();
//			}	
//		}
		
		while(index == 0) {
			try {
				this.wait();//Object类的wait();
			} catch(InterruptedException e) {
				e.printStackTrace();
			}	
		}
		
		//this.notify();
		this.notifyAll();
		
		index --;
		return arrThings[index];
	}
}

class Producer implements Runnable {
	ThingsStack ts = null;
	
	Producer(ThingsStack ts) {
		this.ts = ts;
	}
	
	public void run() {
		for(int i = 0; i < 20; i++) {
			Things t = new Things(i);
			ts.push(t);
			
System.out.println("正在生产：" + t);	

			try {
				Thread.sleep((int)Math.random() * 1000);
			} catch(InterruptedException e) {
				e.printStackTrace();
			}
			
		}
	}
}

class Consumer implements Runnable {
	ThingsStack ts = null;
	
	Consumer(ThingsStack ts) {
		this.ts = ts;
	}
	
	public void run() {
		for(int i = 0; i < 20; i++) {
			Things t = ts.pop();
			
System.out.println("正在消费：" + t);
			
			try {
				Thread.sleep((int)Math.random() * 1000);
			} catch(InterruptedException e) {
				e.printStackTrace();
			}
			
		}
	}
}