Java Coding Problems

207. Invoking multiple Callable tasks

Since the producers (checkers) don't work at the same time with the consumers (packers), we can just simulate their work via a for that adds 100 checked bulbs in a queue:

private static final BlockingQueue<String> queue   = new LinkedBlockingQueue<>();...private static void simulatingProducers() {  for (int i = 0; i < MAX_PROD_BULBS; i++) {    queue.offer("bulb-" + rnd.nextInt(1000));  }}

Now, the consumers must pack each bulb and return it. This means that the Consumer is a Callable:

private static class Consumer implements Callable {  @Override  public String call() throws InterruptedException {    String bulb = queue.poll();    Thread.sleep(100);    if (bulb != null) { logger.info(() -> "Packed: " + bulb + " by consumer: ...