public class Node<T> {

    public T data;

    public Node next;

}

public class LinkQueue<T> {

    private static Node head;

    private static Node tail;

    private static int size;

    /**

     * 初始化

     */

    public void initQueue() {

        Node node = new Node();

        node.data = null;

        node.next = null;

        head = tail = node;

        size = 0;

    }

    /**

     * 是否空

     *

     * @return

     */

    public static boolean isEmpty() {

        return head == tail;

    }

    /**

     * 入队列

     *

     * @param element

     */

    public void insertQueue(T element) {

        Node temp = new Node();

        temp.data = element;

        tail.next = temp;   //放节点

        tail = temp;        //移动尾指针

        size++;

    }

    /**

     *

     */

    public void popQueue() {

        if (isEmpty()) {

            System.out.println("队列已空，！！！");

            return;

        }

        Node temp = head.next;         //创建节点指向头结点所指向

        System.out.println("出队列： "+temp.data);

        head.next = temp.next;

        if (tail == temp) {

            tail = head;

        }

        size--;

    }

    /**

     * 元素个数

     */

    public static void sizeQueue() {

        System.out.println("元素个数："+size);

    }

    /**

     * 遍历元素

     */

    public static void printQueue() {

        for (Node current = head.next;current != null;current = current.next){

            System.out.print(current.data+" ");

        }

        System.out.println();

    }

    public static void main(String[] args) {

        LinkQueue linkQueue = new LinkQueue();

        linkQueue.initQueue();

        linkQueue.insertQueue(1);

        printQueue();

        linkQueue.insertQueue(2);

        printQueue();

        linkQueue.insertQueue(3);

        printQueue();

        linkQueue.insertQueue(4);

        printQueue();

        linkQueue.popQueue();

        printQueue();

        linkQueue.popQueue();

        printQueue();

        linkQueue.insertQueue(5);

        printQueue();

        sizeQueue();

    }

1

1 2

1 2 3

1 2 3 4

出队列： 1

2 3 4

出队列： 2

3 4

3 4 5

元素个数：3