What's the Java equivalent of C++'s STL Queue?

Question

I was browsing through the Java docs to look for the Java equivalent for C++'s STL Queue , but all I found was an interface called Queue and a bunch of implementations I can't make heads or tails of.

Does Java have an implementation for Queue that's just a FIFO data structure without the added bells and whistles? I only need the enqueue , dequeue and front operations and the data structure should allow duplicates.

Answer 1

Queue will work. Use any implementation you like. LinkedList or ConcurrentLinkedQueue for example.

enqueue = offer(..)
dequeue = poll()
front = peek()

Answer 2

That docs page lists all the classes that implement the interface. So, for instance, you can do the following ( DISCLAIMER: hasn't been near a compiler ):

Queue<E> q = new LinkedList<E>();

E x1 = new E();
E x2 = new E();
E x3;

q.offer(x1);
q.offer(x2);

x3 = q.poll();

Answer 3

You can just use LinkedList . Sure, it has lots of functionality you don't need, but it's not hurting you either.

Answer 4

java.util.LinkedList类可能就是你想要的，方法是“add”，“remove”和“element”。

Answer 5

What you're probably looking for is a double-ended queue. See the Deque interface and it's implementing classes.