Consumer.java

import java.util.concurrent.ExecutionException;

class Producer implements Runnable { 
    private final BlockingQueue<Integer> queue;

    public Producer(BlockingQueue<Integer> queue) { 
        this.queue = queue;
    }

    @Override
    public void run() { 
        for (int i = 0; i < 10; i++) { 
            queue.put(i);
            System.out.println("Produced: " + i);
            Thread.sleep(100);
        }
    }
}

public class Consumer implements Runnable{
    private final BlockingQueue<Integer> queue;
    public Consumer(BlockingQueue<Integer> queue) { 
        this.queue = queue;
    }
    @Override
    public void run() {     
        while (true) { 
            try { 
                Integer i = queue.take();
                System.out.println("Consumed: " + i);
            } catch (InterruptedException e) { 
                e.printStackTrace();
            }
        }
    }
}

public class exercise {

    public static void main(String[] args) { 
        BlockingQueue<Integer> queue = new LinkedBlockingQueue<>(5);

        Thread producer = new Thread(new exercise(queue));
        Thread consumer = new Thread(new exercise(queue));

        producer.start();
        consumer.start();
    }
}