Android Queue vs Stack

Question

Why does java.util.Stack allows me to create a new Stack in an android activity with a simple constructor like:

Stack < ImageView> stack = new Stack< ImageView>();

and i cannot do the same with java.util.Queue? Shouldn't a queue have a similar constructor? Strange enough on http://developer.android.com/reference/java/util/Stack.html it says the Stack has a public constructor and on http://developer.android.com/reference/java/util/Queue.html i don't see a similar constructor for a queue.. why is that? what is the way to have a Queue of ImageView elements for example? Thanks.

Answer 1

Because Queue is an interface, you should initial it with a LinkedList:

Queue<String> qe = new LinkedList<String>();

qe.add("b");
qe.add("a");
qe.add("c");

//Traverse queue
Iterator it = qe.iterator();

System.out.println("Initial Size of Queue :" + qe.size());

while(it.hasNext())
{
   String iteratorValue = (String) it.next();
   System.out.println("Queue Next Value :" + iteratorValue);
}

Answer 2

It is because Queue is just an interface. To create a Queue object you need a class, what implements the methods of a Queue.

Some actual implementations of a Queue: link