/** 
 * This program is an example from the book "Internet 
 * programming with Java" by Svetlin Nakov. It is freeware. 
 * For more information: http://www.nakov.com/books/inetjava/ 
 */ 
import java.util.*; 
 
class SharedQueue { 
    private static final int QUEUE_SIZE = 5; 
    private Vector mQueue = new Vector(); 
 
    public synchronized void put(String aObject) 
            throws InterruptedException { 
        while (mQueue.size() == QUEUE_SIZE) 
            wait(); 
        mQueue.addElement(aObject); 
        notify(); 
    } 
 
    public synchronized Object get() 
            throws InterruptedException { 
        while (mQueue.size() == 0) 
            wait(); 
        String message = (String) mQueue.firstElement(); 
        mQueue.removeElement(message); 
        notify(); 
        return message; 
    } 
} 
 
class Producer extends Thread { 
    private SharedQueue mSharedQueue; 
 
    public Producer(SharedQueue aSharedQueue) { 
        mSharedQueue = aSharedQueue; 
    } 
 
    public void run() { 
        try { 
            while (true) { 
                String message = new Date().toString(); 
                System.out.println("producer : put " + message); 
                mSharedQueue.put(message); 
                sleep(500); 
            } 
        } catch (InterruptedException e) { 
        } 
    } 
} 
 
class Consumer extends Thread { 
    private SharedQueue mSharedQueue; 
 
    public Consumer(SharedQueue aSharedQueue) { 
        mSharedQueue = aSharedQueue; 
    } 
 
    public void run() { 
        try { 
            while (true) { 
                String message = 
                    (String) mSharedQueue.get(); 
                System.out.println( 
                    getName() + " : get " + message); 
                sleep(2000); 
            } 
        } catch (InterruptedException e) { 
        } 
    } 
} 
 
public class ProducerConsumerTest { 
    public static void main(String args[]) { 
        SharedQueue sharedQueue = new SharedQueue(); 
        Producer producer = new Producer(sharedQueue); 
        producer.start(); 
        Consumer consumer1 = new Consumer(sharedQueue); 
        consumer1.setName("consumer Mincho"); 
        consumer1.start(); 
        Consumer consumer2 = new Consumer(sharedQueue); 
        consumer2.setName("consumer Pencho"); 
        consumer2.start(); 
    } 
}