jdsl.simple.ref
Class ArrayQueue

java.lang.Object
  |
  +--jdsl.simple.ref.ArrayQueue

public class ArrayQueue
extends java.lang.Object
implements Queue

Implementation of the Queue interface using an array. The queue can store at most a given number of elements; if the user tries to insert more than that, number, an exception is thrown.

Author:
Natasha Gelfand

Field Summary
static int CAPACITY
          Default maximum capacity of the queue.
 
Constructor Summary
ArrayQueue()
          This constructor initializes the queue with the default capacity specified by the CAPACITY constant.
ArrayQueue(int cap)
          This constructor initializes the queue with the capacity specified by the user.
 
Method Summary
 java.lang.Object dequeue()
          Removes the element which is the first element in the queue and return a reference to it.
 void enqueue(java.lang.Object obj)
          Inserts a new object at the rear of the queue.
 java.lang.Object front()
          Return the element which is the first in the queue
 boolean isEmpty()
          This function returns true if and only if the queue is empty
 int size()
          Return the size of the queue, that is the number of elements it has.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

CAPACITY

public static final int CAPACITY
Default maximum capacity of the queue.
Constructor Detail

ArrayQueue

public ArrayQueue()
This constructor initializes the queue with the default capacity specified by the CAPACITY constant.

ArrayQueue

public ArrayQueue(int cap)
This constructor initializes the queue with the capacity specified by the user.
Parameters:
cap - Capacity of the queue
Method Detail

size

public int size()
Return the size of the queue, that is the number of elements it has.
Specified by:
size in interface Queue
Returns:
Number of elements in the queue

isEmpty

public boolean isEmpty()
This function returns true if and only if the queue is empty
Specified by:
isEmpty in interface Queue
Returns:
true if the queue is empty, false otherwise

front

public java.lang.Object front()
                       throws QueueEmptyException
Return the element which is the first in the queue
Specified by:
front in interface Queue
Returns:
The first queue element

dequeue

public java.lang.Object dequeue()
                         throws QueueEmptyException
Removes the element which is the first element in the queue and return a reference to it.
Specified by:
dequeue in interface Queue
Returns:
First element in the queue

enqueue

public void enqueue(java.lang.Object obj)
Inserts a new object at the rear of the queue.
Specified by:
enqueue in interface Queue
Parameters:
obj - Object to insert