在Java中，可以使用数组和指针来实现循环队列。以下是一个简单的循环队列的实现示例：
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 void enqueue(int item) {if (isFull()) {System.out.println("Queue is full");return;}rear = (rear + 1) % capacity;queue[rear] = item;size++;}public int dequeue() {if (isEmpty()) {System.out.println("Queue is empty");return -1;}int item = queue[front];front = (front + 1) % capacity;size--;return item;}public int front() {if (isEmpty()) {System.out.println("Queue is empty");return -1;}return queue[front];}public int rear() {if (isEmpty()) {System.out.println("Queue is empty");return -1;}return queue[rear];}public boolean isEmpty() {return size == 0;}public boolean isFull() {return size == capacity;}}使用示例：
public class Main {public static void main(String[] args) {CircularQueue queue = new CircularQueue(5);queue.enqueue(1);queue.enqueue(2);queue.enqueue(3);System.out.println(queue.front()); // Output: 1System.out.println(queue.rear()); // Output: 3queue.dequeue();System.out.println(queue.front()); // Output: 2System.out.println(queue.isFull()); // Output: false}}在以上示例中，CircularQueue 类中的 enqueue() 方法用于向队列中添加元素，dequeue() 方法用于从队列中删除元素，front() 和 rear() 方法用于返回队列的第一个元素和最后一个元素。isEmpty() 和 isFull() 方法分别用于检查队列是否为空和是否已满。
