Java用链表实现队列

定义节点类：

public class Node {
	T data;
	Node next;
	public Node(){}
	public Node(T t){
		this.data = t;
	}
}

定义自己的链表队列类：

public class My_linkedQueue implements My_queue {

	private Node head;
	private Node rear;
	private int size;

	public My_linkedQueue() {
		head = null;
		rear = null;
		size = 0;
	}

	@Override
	public void add(T t) {
		Node node = new Node(t);
		if (isEmpty()) {		//如果队列为空，头指针第一次需要后移一位
			head = node;
		} else {
			rear.next = node;
		}
		rear = node;
		size++;

	}

	@Override
	public T remove() {
		T tmp;
		if(isEmpty()){
			new NullPointerException("queue is empty!");
			tmp = null;
		} else {
			tmp = (T) head.data;
			head = head.next;
			size--;
		}
		return tmp;
	}

	@Override
	public int size() {
		return size;
	}

	@Override
	public boolean isEmpty() {
		return head == null;
	}

	@Override
	public T front() {
		return (T) head.data;
	}

}

定义测试类：

public class arrayTest {
	public static void main(String[] args){
		My_linkedQueue ar = new My_linkedQueue();
		ar.add(1);
		ar.add(2);
		ar.add(3);
		ar.add(4);
		ar.add(1);
		ar.add(2);
		ar.add(3);
		ar.add(4);
		while(!ar.isEmpty()){
			Integer tmp = ar.remove();
			System.out.println(tmp);
		}
	}
}