import java.io.*;
class Queue 
{ 
    int front, rear, size; 
    int  capacity; 
    int array[]; 
       
    public Queue(int capacity) { 
         this.capacity = capacity; 
         front = this.size = 0;  
         rear = capacity - 1; 
         array = new int[this.capacity]; 
            
    } 
       
    // Queue is full when size becomes equal to  
    // the capacity  
    boolean isFull(Queue queue) 
    {  return (queue.size == queue.capacity); 
    } 
       
    // Queue is empty when size is 0 
    boolean isEmpty(Queue queue) 
    {  return (queue.size == 0); } 
       
    // Method to add an item to the queue.  
    // It changes rear and size 
    void enqueue( int items) 
    { 
        if (isFull(this)) 
            return; 
        this.rear = (this.rear + 1)%this.capacity; 
        this.array[this.rear] = items; 
        this.size = this.size + 1; 
        System.out.println(items+ " enqueued to the queue"); 
    } 
       
    // Method to remove an item from queue.   
    // It changes front and size 
    int dequeue() 
    { 
        if (isEmpty(this)) 
            return Integer.MIN_VALUE; 
           
        int item = this.array[this.front]; 
        this.front = (this.front + 1)%this.capacity; 
        this.size = this.size - 1; 
        return item; 
    } 
       
    // Method to get front of queue 
    int front() 
    { 
        if (isEmpty(this)) 
            return Integer.MIN_VALUE; 
           
        return this.array[this.front]; 
    } 
        
    // Method to get rear of queue 
    int rear() 
    { 
        if (isEmpty(this)) 
            return Integer.MIN_VALUE; 
           
        return this.array[this.rear]; 
    } 
} 
   
    
// Driver class 
public class Test 
{ 
    public static void main(String[] args)  
    { 
        Queue q1 = new Queue(1000); 
            
        q1.enqueue(7); 
        q1.enqueue(8); 
        q1.enqueue(18); 
        q1.enqueue(25); 
        
        System.out.println(q1.dequeue() +  
                     " dequeued from the queue\n"); 
        
        System.out.println("Front item is " +  
                               q1.front()); 
           
        System.out.println("Rear item is " +  
                                q1.rear()); 
    } 
}

7 enqueued to the queue
8 enqueued to the queue
18 enqueued to the queue
12 enqueued to the queue
7 dequeued from the queue

Front item is 8
Rear item is 25