1. Java Concurrency Utilities - java.util.concurrent
2. Java BlockingQueue
3. ArrayBlockingQueue
4. DelayQueue
5. LinkedBlockingQueue
6. PriorityBlockingQueue
7. SynchronousQueue
8. BlockingDeque
9. LinkedBlockingDeque
10. ConcurrentMap
11. ConcurrentNavigableMap
12. CountDownLatch
13. CyclicBarrier
14. Exchanger
15. Semaphore
16. Java ExecutorService
17. Java Callable
18. Java Future
19. ThreadPoolExecutor
20. ScheduledExecutorService
21. Java Fork and Join using ForkJoinPool
22. Java Lock
23. ReadWriteLock
24. AtomicBoolean
25. AtomicInteger
26. AtomicLong
27. AtomicReference
28. AtomicStampedReference
29. AtomicIntegerArray
30. AtomicLongArray
31. AtomicReferenceArray

The PriorityBlockingQueue class implements the BlockingQueue interface. Read the BlockingQueue text for more information about the interface.

The PriorityBlockingQueue is an unbounded concurrent queue. It uses the same ordering rules as the java.util.PriorityQueue class. You cannot insert null into this queue.

All elements inserted into the PriorityBlockingQueue must implement the java.lang.Comparable interface. The elements thus order themselves according to whatever priority you decide in your Comparable implementation.

Notice that the PriorityBlockingQueue does not enforce any specific behaviour for elements that have equal priority (compare() == 0).

Also notice, that in case you obtain an Iterator from a PriorityBlockingQueue, the Iterator does not guarantee to iterate the elements in priority order.

Here is an example of how to use the PriorityBlockingQueue:

BlockingQueue queue   = new PriorityBlockingQueue();

    //String implements java.lang.Comparable
    queue.put("Value");

    String value = queue.take();