1 package Queue;
 2 
 3 public class Queue {
 4     private int maxSize;
 5     private int front;
 6     private int rear;
 7     private int[] arr;
 8 
 9     public Queue(int maxSize){
10         this.maxSize=maxSize;
11         arr=new int[maxSize];
12     }
13 
14     public void init(){
15         front=0;
16         rear=0;
17     }
18 
19     public boolean isFull(){
20         return (rear+1)%maxSize==front;
21     }
22 
23     public boolean isEmpty(){
24         return rear==front;
25     }
26 
27     public void add(int value){
28         if(isFull())
29             System.out.println("isFull");
30         else{
31             arr[rear]=value;
32             rear=(rear+1)%maxSize;
33             System.out.println("add: "+value);
34         }
35     }
36 
37     public void delete(){
38         if(isEmpty())
39             System.out.println("isEmpty");
40         else{
41             System.out.println("delete: "+arr[front]);
42             front=(front+1)%maxSize;
43         }
44     }
45 
46     public void printQueue(){
47         if(isEmpty()){
48             System.out.println("isFull");
49         }else{
50             System.out.print("getQueue: ");
51             for (int i = (front+1)%maxSize; i <= rear; i=(i+1)%maxSize) {
52                 System.out.print(arr[i]+" ");
53             }
54             System.out.println();
55         }
56     }
57 
58     public int getHead(){
59         if(isEmpty()){
60             System.out.println("isEmpty");
61             return 0;
62         }
63         return arr[front];
64     }
65 }

在循环队列代码中：

front作为队列头部，也就是数组尾部。

rear作为队列尾部，也就是数组头部。

循环队列中具体判满条件为：数组长度等于maxSize-1,（有一个单位作为约定，数组无法被填满，即当数组长度等于maxSize-1时，就默认此队列满了）