How to solve the producer consumer problem using thread in Java

Problem Description

How to solve the producer consumer problem using thread?

Solution

Following example demonstrates how to solve the producer consumer problem using thread.

public class ProducerConsumerTest {
   public static void main(String[] args) {
      CubbyHole c = new CubbyHole();
      Producer p1 = new Producer(c, 1);
      Consumer c1 = new Consumer(c, 1);
      p1.start(); 
      c1.start();
   }
}
class CubbyHole {
   private int contents;
   private boolean available = false;
   
   public synchronized int get() {
      while (available == false) {
         try {
            wait();
         } catch (InterruptedException e) {}
      }
      available = false;
      notifyAll();
      return contents;
   }
   public synchronized void put(int value) {
      while (available == true) {
         try {
            wait();
         } catch (InterruptedException e) { } 
      }
      contents = value;
      available = true;
      notifyAll();
   }
}
class Consumer extends Thread {
   private CubbyHole cubbyhole;
   private int number;
   
   public Consumer(CubbyHole c, int number) {
      cubbyhole = c;
      this.number = number;
   }
   public void run() {
      int value = 0;
      for (int i = 0; i < 10; i++) {
         value = cubbyhole.get();
         System.out.println("Consumer #" + this.number + " got: " + value);
      }
   }
}
class Producer extends Thread {
   private CubbyHole cubbyhole;
   private int number;
   public Producer(CubbyHole c, int number) {
      cubbyhole = c;
      this.number = number;
   } 
   public void run() {
      for (int i = 0; i < 10; i++) {
         cubbyhole.put(i);
         System.out.println("Producer #" + this.number + " put: " + i);
         try {
            sleep((int)(Math.random() * 100));
         } catch (InterruptedException e) { }
      } 
   }
} 

Result

The above code sample will produce the following result.

Producer #1 put: 0
Consumer #1 got: 0
Producer #1 put: 1
Consumer #1 got: 1
Producer #1 put: 2
Consumer #1 got: 2
Producer #1 put: 3
Consumer #1 got: 3
Producer #1 put: 4
Consumer #1 got: 4
Producer #1 put: 5
Consumer #1 got: 5
Producer #1 put: 6
Consumer #1 got: 6
Producer #1 put: 7
Consumer #1 got: 7
Producer #1 put: 8
Consumer #1 got: 8
Producer #1 put: 9
Consumer #1 got: 9