队列的链式存储方式的实现(Java语言描述)

链队列的结构示意图：

先进先出。

QueueInterface.java//操作方法接口

package 队列的实现;

public interface QueueInterface {
	public void enQueue(Object t);
	public Object delQueue();
	public int size();
	public boolean isEmpty();
	public Object head();
	public void clear();

}

 

Node.java//节点类

package 队列的实现;

public class Node<T> {
	T data;
	Node next;
}

Queue.java//队列的定义和接口实现

package 队列的实现;

public class Queue<T> implements QueueInterface{
    Node<T> front,rear;//对头指针，队尾指针
    //构造一个空的链队列
    public Queue(){
    	front = new Node<T>();
    	rear = new Node<T>();
    	rear = front;
    }
	//实现接口里的操作
    public boolean isEmpty(){
		if(front == rear)
			return true;
		else
			return false;
	}
    public int size(){
    	int i = 0;
    	Node<T> p = front.next;
    	while(p != null){
    		p = p.next;
    		i++;
    	}
    	return i;
    }
    public Object head(){
    	if(this.isEmpty() == false)
    	return front.next.data;
    	System.out.println("队列为空，不存在队头元素！");
    	return 0;
    }
	public void enQueue(Object obj){
		Node<T> p = new Node<T>();
		p.data = (T)obj;
		rear.next = p;
		p.next = null;
		rear = p;
	}
	public Object delQueue(){
		T t;
		Node<T> p = new Node<T>();
		if(this.isEmpty() == true){
			System.out.println("队列为空，不能进行删除操作！");
			return 0;
		}
		else{
			p = front.next;
			front.next = p.next;
			if(p.next == null)//出队后队列为空
				rear = front;
			t = p.data;
			p = null;
			return t;
		}
	}
	public void clear(){
		front = rear;
	}

}

TestQueue.java//测试类

package 队列的实现;

public class TestQueue {

	public static void main(String[] args) {
		Queue<Integer> queue = new Queue<Integer>();
		for(int i=1; i<=10; i++){
			queue.enQueue(i);
		}
		System.out.println(queue.size());
		System.out.println(queue.isEmpty());
		for(int i=1; i<=10; i++){
			System.out.print(queue.delQueue() + " ");
		}
		System.out.println();
		System.out.println(queue.isEmpty());
		for(int i=1; i<=10; i++){
			queue.enQueue(i);
		}
		System.out.println(queue.isEmpty());
		queue.clear();
		System.out.println(queue.isEmpty());

	}

}

实现结果：

10
false
1 2 3 4 5 6 7 8 9 10
true
false
true