gistfile1.java

public class ProducerConsumer
{
	public static final int BUFFER_SIZE = 1000;

	public interface Producer
	{
		/** Appends a random integer at the end of the buffer */
		void produce(Queue<Integer> buffer);
	}

	public interface Consumer
	{
		/** Removes the last element from the buffer */
		void consume(Queue<Integer> buffer);
	}

	public static class ProducerImpl implements Producer
	{
		Random r = new Random(System.nanoTime());

		@Override
		public void produce(Queue<Integer> buffer)
		{
			buffer.add(r.nextInt());
			System.out.println("ProducerImpl1: Adding another item to the end of the queue");
		}
	}

	public static class ConsumerImpl implements Consumer
	{

		@Override
		public void consume(Queue<Integer> buffer)
		{
			buffer.remove();
			System.out.println("ConsumerImpl1: Consuming the last item");
		}
	}

	public static class ProducerImpl2 implements Producer
	{
		Random r = new Random(System.nanoTime());

		@Override
		public void produce(Queue<Integer> buffer)
		{
			buffer.add(r.nextInt());
			System.out.println("ProducerImpl2: Adding another item to the end of the queue");
		}
	}

	public static class ConsumerImpl2 implements Consumer
	{

		@Override
		public void consume(Queue<Integer> buffer)
		{
			buffer.remove();
			System.out.println("ConsumerImpl2: Consuming the last item");
		}
	}

	public static void main(String[] args)
	{
		final int PRODUCERS = 10;
		final int CONSUMERS = 20;

		final Queue<Integer> buffer = new LinkedList<Integer>();

		for (int i = 0; i < PRODUCERS; i++)
			new Thread(new Runnable()
			{
				public void run()
				{
					Producer p = new ProducerImpl();
					while (true)
					{
						p.produce(buffer);
						if (buffer.size() > BUFFER_SIZE)
							throw new IllegalStateException("The Buffer must not be greater than " + BUFFER_SIZE);
					}
				}
			}).start();

		for (int i = 0; i < CONSUMERS; i++)
			new Thread(new Runnable()
			{
				public void run()
				{
					Consumer c = new ConsumerImpl();
					while (true)
						c.consume(buffer);
				}
			}).start();

		
		
		
		final Queue<Integer> buffer2 = new LinkedList<Integer>();
		for (int i = 0; i < PRODUCERS; i++)
			new Thread(new Runnable()
			{
				public void run()
				{
					Producer p = new ProducerImpl2();
					while (true)
					{
						p.produce(buffer2);
						if (buffer2.size() > BUFFER_SIZE)
							throw new IllegalStateException("The Buffer must not be greater than " + BUFFER_SIZE);
					}
				}
			}).start();

		for (int i = 0; i < CONSUMERS; i++)
			new Thread(new Runnable()
			{
				public void run()
				{
					Consumer c = new ConsumerImpl2();
					while (true)
						c.consume(buffer2);
				}
			}).start();
	}
}