Java，ConcurrentLinkedDeque vs ConcurrentLinkedQueue - 区别？

Question

Api links for ConcurrentLinkedDeque and ConcurrentLinkedQueue :

http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ConcurrentLinkedDeque.html

http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ConcurrentLinkedQueue.html

What is the difference between the two?

The first one, DeQueue has a lot more methods, but what is the fundamental difference between the two?

Answer 1

Both collections are thread-safe. The difference is that a ConcurrentLinkedDeque implements a Deque , which supports addition and removal of elements at both ends (eg addFirst and addLast ), whereas ConcurrentLinkedQueue implements a Queue which allows insertion at one end called the tail of the queue and removal at the other end, called the head of the queue.

Answer 2

Dequeue allows insertions & deletions from both the ends of the queue that is why there are many methods.

While queue does not.