// -------- Shared Buffer Class --------
class Buffer {

    private int value;
    private boolean hasValue = false;

    // Producer puts value
    synchronized void put(int value) {
        while (hasValue) {
            try {
                wait(); // wait if buffer is full
            } catch (InterruptedException e) {
                System.out.println(e);
            }
        }

        this.value = value;
        hasValue = true;
        System.out.println("Produced: " + value);

        notify(); // notify consumer
    }

    // Consumer gets value
    synchronized int get() {
        while (!hasValue) {
            try {
                wait(); // wait if buffer is empty
            } catch (InterruptedException e) {
                System.out.println(e);
            }
        }

        System.out.println("Consumed: " + value);
        hasValue = false;

        notify(); // notify producer
        return value;
    }
}

// -------- Producer Thread --------
class Producer extends Thread {

    Buffer buffer;

    Producer(Buffer buffer) {
        this.buffer = buffer;
    }

    public void run() {
        int i = 1;
        while (true) {
            buffer.put(i++);
            try {
                Thread.sleep(500);
            } catch (InterruptedException e) {
                System.out.println(e);
            }
        }
    }
}

// -------- Consumer Thread --------
class Consumer extends Thread {

    Buffer buffer;

    Consumer(Buffer buffer) {
        this.buffer = buffer;
    }

    public void run() {
        while (true) {
            buffer.get();
            try {
                Thread.sleep(500);
            } catch (InterruptedException e) {
                System.out.println(e);
            }
        }
    }
}

// -------- Main Class --------
public class ProducerConsumerDemo {

    public static void main(String[] args) {
        Buffer buffer = new Buffer();

        Producer producer = new Producer(buffer);
        Consumer consumer = new Consumer(buffer);

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