JavaFile1

import java.util.LinkedList;
import java.util.Queue;
import java.util.UUID;

public class Main {

    private static Queue<String> synQueue = new LimitedQueue<>(2);

    public static void main(String[] args) throws InterruptedException {
        Producer producer = new Producer();
        Consumer consumer = new Consumer();
        producer.start();
        consumer.start();

        Thread.sleep(300);

        producer.kill();
        consumer.kill();
    }

    private static class Producer extends Thread {

        private volatile boolean isRunning = true;

        public void run() {
            while (isRunning) {
                String uuid = UUID.randomUUID().toString();
                synchronized (synQueue) {
                    synQueue.add(uuid);
                    System.out.println("added " + uuid);
                    System.out.println("size is now " + synQueue.size());
                }
            }
        }

        void kill() {
            isRunning = false;
        }
    }

    private static class Consumer extends Thread {

        private volatile boolean isRunning = true;

        public void run() {
            while (isRunning) {
                if(synQueue.size()>0) {
                    synchronized (synQueue) {
                        String s = synQueue.poll();
                        System.out.println("got " + s);
                        System.out.println("size is now " + synQueue.size());
                    }
                }
            }
        }

        void kill() {
            isRunning = false;
        }
    }
    private static class LimitedQueue<E> extends LinkedList<E> {
        private int limit;

        LimitedQueue(int limit) {
            this.limit = limit;
        }

        @Override
        public boolean add(E o) {
            if(super.size()<limit) {
                super.add(o);
                return true;
            }
            return false;
        }
    }
}