Implementing an ArrayQueue in java

Problem:

Write a program that implements an ArrayQueue in java.

Output:

Not available.

Solution:

public class ArrayQueue<E> implements Queue<E> {
private E[] elements;
private int front;
private int back;
private static final int INITIAL_CAPACITY = 4;

public ArrayQueue() {
elements = (E[]) new Object[INITIAL_CAPACITY];
}

public ArrayQueue(int capacity) {
elements = (E[]) new Object[capacity];
}

public void add(E element) {
if (size() == elements.length - 1) {
resize();
}
elements[back] = element;
if (back < elements.length - 1) {
++back;
} else {
back = 0; //wrap
}
}

public E element() {
if (size() == 0) {
throw new java.util.NoSuchElementException();
}
return elements[front];
}

public boolean isEmpty() {
return (size() == 0);
}

public E remove() {
if (size() == 0) {
throw new java.util.NoSuchElementException();
}
E element = elements[front];
elements[front] = null;
++front;
if (front == back) { // queue is empty
front = back = 0;
}