@Test public void testListener() throws Exception { final int maxItems = 10; final CountDownLatch itemAddedLatch = new CountDownLatch(maxItems); final CountDownLatch itemRemovedLatch = new CountDownLatch(maxItems); final IQueue queue = client.getQueue(randomString()); String id = queue.addItemListener( new ItemListener() { public void itemAdded(ItemEvent itemEvent) { itemAddedLatch.countDown(); } public void itemRemoved(ItemEvent item) { itemRemovedLatch.countDown(); } }, true); new Thread() { public void run() { for (int i = 0; i < maxItems; i++) { queue.offer(i); queue.remove(i); } } }.start(); assertTrue(itemAddedLatch.await(5, TimeUnit.SECONDS)); assertTrue(itemRemovedLatch.await(5, TimeUnit.SECONDS)); queue.removeItemListener(id); }