队列java数组实现

public class ArrayQueueDemo {

	// 队列最大容量
	private static final int maxSize = 5;
	
	public static void main(String[] args) throws Exception {
		// 创建队列
		ArrayQueue aQueue = new ArrayQueue(5);
		boolean loop = true;// 用来判断是否退出
		Scanner scanner = new Scanner(System.in);
		char key = ' ';// 判断用户输入的指令
		while (loop) {
			System.out.println("s(show)展示队列全部数据");
			System.out.println("g(get)获取队列数据");
			System.out.println("a(add)添加队列数据");
			System.out.println("h(head)展示队列头数据");
			System.out.println("e(exit)退出程序");
			key = scanner.next().charAt(0);
			switch (key) {
			case 's':
				aQueue.getAllQueue();
				break;
			case 'g':
				int data = aQueue.getQueue();
				System.out.printf("%d出列",data);
				System.out.println();
				break;
			case 'a':
				int d = 0;
				System.out.println("请输入要入队的值：");
				d = scanner.nextInt();
				aQueue.add(d);
				System.out.printf("%d入列",d);
				System.out.println();
				break;
			case 'h':
				int head = aQueue.getHead();
				System.out.println("当前队列的头为:" + head);
				break;
			case 'e':
				loop = false;
				break;
			default:
				break;
			}
		}
	}
	
	public static int[]  addQueue(int[] queue,int front,int rear,int data) throws Exception {
		if (front == rear) {
			System.out.println("这是一个空队列");
		}
		if (rear < queue.length - 1) {
			queue[rear] = data;
			System.out.printf("%d已入队",data);
			System.out.println();
		}else {
			throw new Exception("队列满，无法入列");
		}
		return queue;
	}

}
class ArrayQueue{
	private int maxSize;// 队列最大容量
	private int front;// 队列头
	private int rear;// 队列尾
	private int[] queue;// 队列
	
	// 创建队列的构造器
	public ArrayQueue(int maxSize) {
		this.maxSize = maxSize;
		this.queue = new int[maxSize];
		this.front = -1;
		this.rear = -1;
	}
	
	// 判断队列是否已满
	public boolean isFull() {
		return rear == maxSize-1;
	}
	
	// 判断队列是否为空
	public boolean isEmpty() {
		return front == rear;
	}
	
	// 添加数据到队列 入列
	public void add(int n) throws Exception {
		if (isFull()) {
			System.out.println("队列已满,入不了队了兄弟！");
		}
		rear++;
		queue[rear] = n;
	}
	
	// 获取队列数据 出列
	public int getQueue() throws Exception {
		if (isEmpty()) {
			throw new NullPointerException("队列已空,没人了兄弟别移了！");
		}
		int data = queue[0];
		for (int i = 0; i < queue.length - 1; i++) {
			queue[i] = queue[i+1];
		}
		return data;
	}
	
	// 获取队列全部数据
	public void getAllQueue() {
		if (isEmpty()) {
			System.out.println("队列空的,没人了兄弟！");
		}else {
			for (int i = 0;i < queue.length;i++) {
				System.out.printf("%d\t",queue[i]);
			}
			System.out.println();
		}
	}
	// 显示队列当前头数据
	public int getHead() {
		if (isEmpty()) {
			throw new NullPointerException("队列空的,没头数据了兄弟！");
		}
		return queue[0];
	}
}

public class CircleArrayQueueDemo {
	
		
	public static void main(String[] args) {
		// 创建队列
		CircleArrayQueue aQueue = new CircleArrayQueue(5);
		boolean loop = true;// 用来判断是否退出
		Scanner scanner = new Scanner(System.in);
		char key = ' ';// 判断用户输入的指令
		while (loop) {
			System.out.println("s(show)展示队列全部数据");
			System.out.println("g(get)获取队列数据");
			System.out.println("a(add)添加队列数据");
			System.out.println("h(head)展示队列头数据");
			System.out.println("e(exit)退出程序");
			key = scanner.next().charAt(0);
			switch (key) {
			case 's':
				aQueue.getAllQueue();
				break;
			case 'g':
				int data = 0;
				try {
					data = aQueue.getQueue();
					System.out.printf("%d出列",data);
					System.out.println();
				} catch (Exception e1) {
					// TODO Auto-generated catch block
					e1.printStackTrace();
				}
				break;
			case 'a':
				int d = 0;
				System.out.println("请输入要入队的值：");
				d = scanner.nextInt();
				aQueue.add(d);
				System.out.println();
				break;
			case 'h':
				try {
					int head = aQueue.getHead();
					System.out.println("当前队列的头为:" + head);
				} catch (Exception e) {
					System.out.println(e.getMessage());
				}
				break;
			case 'e':
				loop = false;
				break;
			default:
				break;
			}
		}
		System.out.println("程序結束");
	}
}
class CircleArrayQueue{
	private int maxSize;// 队列最大容量
	private int front;// 队列头: 指向队列头部第一个元素
	private int rear;// 队列尾：指向队列尾部后一个元素
	private int[] queue;// 队列
	
	// 创建队列的构造器
	public CircleArrayQueue(int arrMaxSize) {
		maxSize = arrMaxSize;
		queue = new int[maxSize];
	}
	
	// 判断队列是否已满
	public boolean isFull() {
		// maxSize = 3
		// rear = 5
		// front = 0
		return (rear + 1) % maxSize == front;
	}
	
	// 判断队列是否为空
	public boolean isEmpty() {
		return rear == front;
	}
	
	// 添加数据到队列 入列
	public void add(int n){
		if (isFull()) {
			System.out.println("队列已满,入不了队了兄弟！");
			return;
		}
		queue[rear] = n;
		System.out.printf("%d入列",n);
		// 环形队列 需要考虑取模
		rear = (rear + 1) % maxSize;
	}
	
	// 获取队列数据 出列
	public int getQueue() throws Exception {
		if (isEmpty()) {
			throw new NullPointerException("队列已空,没人了兄弟别移了！");
		}
		int data = queue[front];
		// 环形队列需要考虑取模
		front = (front + 1) % maxSize;
		return data;
	}
	
	// 获取队列全部数据
	public void getAllQueue() {
		if (isEmpty()) {
			System.out.println("队列空的,没人了兄弟！");
			return;
		}
		for(int i = front;i < front + size();i++) {
			System.out.printf("arr[%d]=%d\n",i%maxSize,queue[i%maxSize]);
		}
	}
	
	// 获取环形队列的有效长度
	public int size() {
		// maxSize = 3
		// rear = 4
		// front = 0
		return (rear + maxSize - front) % maxSize;
	}

	// 显示队列当前头数据
	public int getHead() {
		if (isEmpty()) {
			throw new NullPointerException("队列空的,没头数据了兄弟！");
		}
		return queue[front];
	}
}