Java 实现循环队列

public class QueueTest {

    private  int[]  elements;
    private  int    maxSize;    //最大容量，实际存储是最大容量-1，需要一个空位作为判断位
    private  int    front;      //队列首位元素
    private  int    rear;       //这里rear指向最后一个数据的后面一个位置，即队列中有一个为空占位
    private  int    size;       //队列元素总数


    public QueueTest(int maxSize){
       this.maxSize=maxSize;
       this.elements=new int[maxSize];
       this.front=0;
       this.rear=0;     //指向以添加元素的下一个下标
       this.size=0;
  }

    public boolean isFull(){       //判断队列是否已满
      return  (rear+1)%maxSize==front;
   }

    public boolean isEmpty(){    //判断队列是否为空
      return  front==rear;
    }


    public void  add(int element){
      if(isFull()){
          System.out.println("full....");
          return;
      }else{
         elements[rear]= element;
         rear=(rear+1)%maxSize;
         size++;
      }
    }

    public void   pop(){
      if(isEmpty()){
          throw new RuntimeException("empty.....");
      }else{
        System.out.println("出队列元素"+elements[front]);
        elements[front]=0;
        front=(front+1)%maxSize;
        size--;

      }


    }

     public  int size(){
     return  this.size;
   }

    @Override
    public String toString() {
      return   Arrays.toString(elements);
    }

    public static void main(String[] args) {
        QueueTest queueTest = new QueueTest(6);
        queueTest.add(5);
        queueTest.add(4);
        queueTest.add(3);
        queueTest.add(52);
        queueTest.add(54);
        System.out.println(queueTest);
        queueTest.pop();
        queueTest.pop();
        queueTest.pop();
        queueTest.pop();
        queueTest.pop();
        System.out.println(queueTest);


  }
}