Deque implementation

Deque.java

package dsandalgs;

public class Deque<E> {
	int INIT_QUEUE_SIZE = 8;
	int first = 0;
	int size = 0;
	E[] queue;

	public Deque(){
		this.queue = (E[]) new Object[this.INIT_QUEUE_SIZE];
	}
	
	public void addFirst(E item) throws IllegalStateException{
		if (this.size == this.queue.length){
			throw new IllegalStateException("Queue is full");
		}
		this.queue[first] = item;
		this.first = (this.first + 1) % this.queue.length;
		size++;
	}

	public E removeFirst(){
		this.first = (this.first -1 + this.queue.length) % this.queue.length;
		E item = this.queue[this.first];
		return item;
	}
	
	
	public void addLast(E item){
		int rear = (this.first - this.size + this.queue.length - 1) % this.queue.length;
		this.queue[rear] = item;
		this.size++;
	}
	
	@Override
	public String toString(){
		String myString = "";
		for (int i=0; i< this.queue.length; i++){
			myString = myString + " " + this.queue[i];
		}
		return myString;
	}

	public E removeLast(){
		int rear = (this.first - this.size + this.queue.length) % this.queue.length;
		E item = this.queue[rear];
		this.queue[rear] = null;
		this.size--;
		return item;

	}
	
	public static void main(String[] args){
		Deque<Integer> myDeque = new Deque<Integer>();
		myDeque.addLast(5);
		myDeque.addFirst(1);
		myDeque.addFirst(2);
		System.out.println(myDeque);
	}
		
	
}