Circular Queue

package DataS;
public class CircularQueue {

    private int[] queue;
    private int front;
    private int rear;
    private int size;
    private int capacity;

    public CircularQueue(int capacity) {
        this.capacity = capacity;
        queue = new int[capacity];
        front = 0;
        rear = -1;
        size = 0;
    }

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

    public boolean isFull() {
        return size == capacity;
    }

    public void enqueue(int item) {
        if (isFull()) {
            throw new IllegalStateException("Queue is full. Cannot enqueue " + item);
        }
        rear = (rear + 1) % capacity;
        queue[rear] = item;
        size++;
    }

    public int dequeue() {
        if (isEmpty()) {
            throw new IllegalStateException("Queue is empty. Cannot dequeue.");
        }
        int item = queue[front];
        front = (front + 1) % capacity;
        size--;
        return item;
    }

    public int peek() {
        if (isEmpty()) {
            throw new IllegalStateException("Queue is empty. Cannot peek.");
        }
        return queue[front];
    }

    public void display() {
        if (isEmpty()) {
            System.out.println("Queue is empty.");
            return;
        }
        System.out.print("Queue: ");
        int count = 0;
        int i = front;
        while (count < size) {
            System.out.print(queue[i] + " ");
            i = (i + 1) % capacity;
            count++;
        }
        System.out.println();
    }

    public static void main(String[] args) {
        CircularQueue queue = new CircularQueue(5);
        queue.enqueue(10);
        queue.enqueue(12);
        queue.enqueue(13);
        queue.enqueue(14);
        queue.enqueue(15);
        
        queue.display(); 
        System.out.println("Dequeue: " + queue.dequeue()); 
        queue.display();
        System.out.println("Peek: " + queue.peek()); 
    }
}