Circular Queue implementation

import java.util.Arrays;

/**
 * Key points : 
 * 1. Max capecity can be size-1. As 1 space in queue will alway be empty
 * 2. Next index = (currentIndex+1)%size
 * 3. Empty condition : front == rear 
 * 4. Full condition : (front+1)%size == rear
 */
class CircularQueue {
    // for dequeue operation
    private int front;
    // for enqueue operation 
    private int rear;
    private int capacity;
    private int[] array;
    private static final int DEFAULT_CAPACITY = 6; // we can insert 5 elements
    
    public CircularQueue() {
        this(DEFAULT_CAPACITY);
    }
    
    public CircularQueue(int capacity) {
        this.front = this.rear = 0;
        this.capacity = capacity < DEFAULT_CAPACITY ? DEFAULT_CAPACITY : capacity;
        array = new int[capacity];
    }
    
    public void enqueue(int data) {
        if(isFull()) {
            System.out.println(data + " is not inserted. Queue is full");
        } else {
            rear = (rear + 1) % capacity;
            array[rear] = data;
        }
    }
    
    public int dequeue() {
        if(empty()) {
            System.out.println("Queue is empty.");
            return -1;
        }
        front = (front + 1) % capacity;
        return array[front];
    }
    
    public boolean isFull() {
       return (rear + 1) % capacity == front;
    }
    
    public boolean empty() {
       return front == rear;
    }
    
    public void display() {
        if(empty()) {
            return;
        }
        int i = (front + 1) % capacity;
        do {
            System.out.print(array[i] + " ");
            i = (i + 1) % capacity;
        } while(i != (rear + 1) % capacity);
    }
    
    public static void main (String[] args) {
        int[] array = new int[] {1, 3, 5, 7, 9};
        CircularQueue queue = new CircularQueue();
        Arrays.stream(array).forEach(d -> queue.enqueue(d));
        
        // Display
        System.out.println("Display queue");
        queue.display();
        
        // Overflow
        System.out.println("\nInsert 10");
        queue.enqueue(10);
        
        // Dequeue
        System.out.println("Deleting all from queue");
        for(int i = 0; i < 5; i++) {
            queue.dequeue();
        }
        
        // Underflow
        System.out.println("Try deleting again when no elements in queue");
        queue.dequeue();
    }
}

Output
Display queue
1 3 5 7 9 
Insert 10
10 is not inserted. Queue is full
Deleting all from queue
Try deleting again when no elements in queue
Queue is empty.