/**
* This method allows the queue to be printed out as a string.
*
* @return The string that represents all the values held in the array.
*/
public String toString() {
String result = "";
LinearNode<T> current = head;
while (current != null) {
result = result + (current.getElement()).toString() + "\n";
current = current.getNext();
}
return result;
}
/**
* This method allows the element at the top of the queue to de removed.
*
* @return The element that is removed
* @throws EmptyCollectionException The exception when the queue is empty.
*/
public T dequeue() throws EmptyCollectionException {
if (isEmpty()) {
throw new EmptyCollectionException("queue");
}
T result = head.getElement();
head = head.getNext();
count--;
if (isEmpty()) {
tail = null;
}
return result;
}
/**
* This method allows an element that is sent in to be added to the queue.
*
* @param element The element to be added
*/
public void enqueue(T element) {
LinearNode<T> node = new LinearNode<T>(element);
if (isEmpty()) {
head = node;
} else {
tail.setNext(node);
}
tail = node;
count++;
}
/**
* This method returns the element at the top of the queue if there is an element there.
*
* @return The first element in the queue.
*/
public T first() {
if (isEmpty()) {
throw new EmptyCollectionException("queue");
}
return head.getElement();
}