synchronizedemo4.java

JAVA程序设计课程中各章节的程序实例。

/**
*A advanced simple synchronize program 
*2004.12.24. xhcprince
*/

class Q
{
	int n;
	boolean flag = false;
	
	synchronized int get()
	{
		if(!flag)
		{
			try
			{
				wait();	//how much time will it wait?
			}
		
			catch(InterruptedException e)
			{
				System.out.println(e.getMessage());
			}
		}
		
		this.n = n;
		
		System.out.println("Get: " + n);
		flag = false;
		notify();
		
		return n;
	}

	synchronized void put(int n)
	{
		if(flag)
		{
			try
			{
				wait();
			}
		
			catch(InterruptedException e)
			{
				System.out.println(e.getMessage());
			}
		}
	
		this.n = n;
		
		flag = true;
		System.out.println("Put: " + n);
		notify();
	}
}

class Producer implements Runnable //don't forget to implements from Runnable!
{
	Q obj;
	
	Producer(Q obj)
	{
		this.obj = obj;
		
		new Thread(this).start();
	}
	
	public void run()
	{
		int i = 0;
		
		while(i <= 6)
		{
			obj.put(i);
			++i;
		}
	}
}

class Consumer implements Runnable //don't forget to implements from Runnable!
{
	Q obj;
	
	Consumer(Q obj)
	{
		this.obj = obj;

		new Thread(this).start();
	}
	
	public void run()
	{
		int t = 0;
		
		while(t <= 6)
		{
			obj.get();
			++t;
		}
	}	
}

class SynchronizeDemo4
{
	public static void main(String args[])
	{
		Q obj = new Q();	//the obj must be initialized explicitly!don't forget it!
		
		new Producer(obj);
		new Consumer(obj);
	}
}