To find the size of a queue in Java, you can use the size() method of the Queue interface. The size() method returns the number of elements in the queue.
Here's an example of how to find the size of a queue in Java:
Queue<String> queue = new LinkedList<>();
queue.add("Apple");
queue.add("Banana");
queue.add("Orange");
int size = queue.size();
System.out.println("The size of the queue is " + size);
In the above example, a Queue object is created using the LinkedList implementation. Three elements are added to the queue using the add() method. The size of the queue is then obtained using the size() method and printed to the console.
The output of this example will be "The size of the queue is 3".
Note that the size() method has a time complexity of O(1), which means it runs in constant time. This means that finding the size of a queue is an efficient operation, regardless of the size of the queue.