FairQueue implements BlockingQueue<E> { @Override public int drainTo (Collection<? super E> c) { return drainTo (c, Integer.MAX_VALUE); } FairQueue(); @Override int size(); @Override int remainingCapacity(); @Override void put(E e); @Override boolean offer(E e); @Override boolean offer(E e, long timeout, TimeUnit unit); @Override E take(); @Override E peek(); @Override E poll(); @Override E poll(long timeout, TimeUnit unit); @Override int drainTo(Collection<? super E> c); @Override int drainTo(Collection<? super E> c, int maxElements); @Override void clear(); @Override boolean contains(Object o); @Override Object[] toArray(); @Override T[] toArray(T[] a); @Override Iterator<E> iterator(); @Override E remove(); @Override E element(); @Override boolean isEmpty(); @Override boolean containsAll(Collection<?> c); @Override boolean addAll(Collection<? extends E> c); @Override boolean removeAll(Collection<?> c); @Override boolean retainAll(Collection<?> c); @Override boolean add(E e); @Override boolean remove(Object o);  }
@Test public void testDrainTo () { ArrayList<FairQueueTestString> list = new ArrayList<FairQueueTestString> (); queue.offer (new FairQueueTestString ("key1", "item1")); queue.offer (new FairQueueTestString ("key1", "item2")); queue.offer (new FairQueueTestString ("key1", "item3")); queue.offer (new FairQueueTestString ("key2", "item4")); queue.offer (new FairQueueTestString ("key2", "item5")); Assert.assertEquals (queue.size (), 5); Assert.assertEquals (queue.drainTo (list), 5); Assert.assertEquals (queue.size (), 0); Assert.assertEquals (list.size (), 5); Assert.assertEquals (list.get (0).getItem (), "item1"); Assert.assertEquals (list.get (1).getItem (), "item4"); Assert.assertEquals (list.get (2).getItem (), "item2"); }