直接上代码举例说明：
public class CircularLinkedList {
//java中循环单链表
private class Node {//创建一个内部节点类
private Node next = null;
private Object value = null;
public Node() {
}
public Node(Object value) {
this.value = value;
}
}
private Node head = null;//新建一个null的头结点
public CircularLinkedList() {//初始化头结点信息
head = new Node(null);
head.next = head;
}
public void insertNode(Object insertValue) {//在尾部添加节点
Node node = new Node(insertValue);
if (head.next == head) {
head.next = node;
node.next = head;
} else {
Node temp = head;
while (temp.next != head) {
temp = temp.next;
}
temp.next = node;
node.next = head;
}
}
public void deleteNode(Object deleteValue) {//删除值为deleteValue的节点
Node temp = head;
while (temp.next != head) {
if (temp.next.value.equals(deleteValue)) {
temp.next = temp.next.next;
} else {
temp = temp.next;
}
}
}
public Object getIndexValue(int index) {//查找位置为index的节点值
if (index < 0 || index >= getSize()) {
return null;
} else {
Node node = new Node();
int count = 0;
Node temp = head;
while (temp.next != head) {
if (count == index) {
node.value = temp.next.value;
break;
}
temp = temp.next;
}
return node.value;
}
}
public int getValue(Object value) {//查找值为value的节点
int count = 0;
Node temp = head;
while (temp.next != head) {
if (temp.next.value.equals(value)) {
return count;
}
count++;
temp = temp.next;
}
return -1;
}
public int getSize() {//获取循环单链表的长度
Node temp = head;
int size = 0;
while (temp.next != head) {
size++;
temp = temp.next;
}
return size;
}
public boolean isContain(Object value) {//查找是否包含值为value的节点
Node temp = head;
while (temp.next != head) {
if (temp.next.value.equals(value)) {
return true;
}
temp = temp.next;
}
return false;
}
public void disPlay() {//打印所有节点数据
Node temp = head;
while (temp.next != head) {
System.out.print(temp.next.value + "\t");
temp = temp.next;
}
System.out.println();
}
public static void main(String[] args) {
CircularLinkedList c=new CircularLinkedList();
c.insertNode(10);
c.insertNode(21);
c.insertNode(12);
c.insertNode(13);
c.insertNode(40);
c.disPlay();
// System.out.println(c.getSize());
// System.out.println(c.getIndexValue(-1));
// System.out.println(c.getValue(40));
// c.deleteNode(10);
// c.disPlay();
// c.deleteNode(40);
// c.disPlay();
// c.deleteNode(12);
// c.disPlay();
System.out.println(c.isContain(21));
}
} 
