单链表的Java类结构如下：
下面上源码：
1.定义链表结点类，每一个结点包含数据data和下一个结点的引用。
package singlelinkedlist;
/**
* @date on 16:08 2018/8/14
* @author yuyong
* @describe 模拟单链表的节点信息，这里讲属性设为public不用设置get和set方法。
*/
public class Node {
/**
* 包含两个属性一个是结点数据，和下一个结点的引用
*/
public Node next;
public int data;
/**
* constructor
*/
public Node(int data) {
this.data = data;
}
}
2. 自定义异常类
package singlelinkedlist;
/**
* @date on 16:43 2018/8/14
* @author yuyong
* @describe 自定义异常类
*/
public class MyException extends Exception{
private String errorMessage;
public MyException(String message) {
super(message);
this.errorMessage = message;
}
@Override
public String getMessage() {
return errorMessage;
}
}
3. 链表类包含增删改查、打印、排序反转等功能！以及Junit测试！
package singlelinkedlist;
import org.junit.Test;
/**
* @date on 16:13 2018/8/14
* @author yuyong
* @describe 单链表的一些操作方法
*/
public class SingleLinkedList {
/**
* 链表的头节点
*/
private Node head ;
private int length = 0;
/**
* 获取链表的长度
*/
public int length(){
return length;
}
/**
* 尾插法增加结点操作
* @param data
*/
public void addLastNode(int data){
Node tNode = new Node(data);
if (head == null){
head = tNode;
length++;
return;
}
Node temp = head;
while (temp.next != null){
temp = temp.next;
}
temp.next = tNode;
length++;
}
/**
* 头插法增加结点的操作
* @param data
*/
public void addHeadNode(int data){
Node tNode = new Node(data);
if (head == null){
head = tNode;
length++;
return;
}
Node temp = head;
tNode.next = temp;
head = tNode;
length++;
}
/**
* 插入结点到链表的指定位置
* @param index
* @param data
*/
public void insertNodeByIndex(int index,int data){
//先判断指定位置是否合法
if (index < 1 || index > length+1){
try {
throw new MyException("指定位置不合法，插入结点失败");
} catch (MyException e) {
e.printStackTrace();
}
}
if (index == 1){
addHeadNode(data);
return;
}
if (index == length+1){
addLastNode(data);
return;
}
Node temp = head;
Node tNode = new Node(data);
int tlength = 1;
while (temp.next != null){
if (index == ++tlength){
//当前结点向后移动一位
tNode.next = temp.next;
temp.next = tNode;
length++;
return;
}
temp = temp.next;
}
}
/**
* 删除指定位置的结点
* @param index
*/
public void delNodeByIndex(int index){
//先判断指定索引合不合法
if (index < 1 || index > length){
try {
throw new MyException("指定位置参数不合法");
} catch (MyException e) {
e.printStackTrace();
}
}
Node temp = head;
int tlength = 1;
while (temp.next != null){
//如果到达了指定结点则进行删除
if (index == ++tlength){
temp.next = temp.next.next;
length--;
return;
}
temp = temp.next;
}
}
/**
* 删除链表重复结点
* @return
*/
public boolean deleteRepeatNode(){
Node temp = head;
while (temp != null){
Node tNode = head;
while (tNode.next != temp && tNode.next != null){
if (tNode.next.data == temp.data){
tNode.next = tNode.next.next;
}else {
tNode = tNode.next;
}
}
temp = temp.next;
}
return true;
}
/**
* 遍历单链表，打印链表中的值
*/
public void printData(){
Node temp = head;
System.out.print(temp.data);
while (temp.next != null){
System.out.print(","+temp.next.data);
temp = temp.next;
}
System.out.println(",长度："+length());
}
/**
* 修改指定结点的值
* @param index
* @param data
*/
public boolean updateNode(int index,int data){
//判断指定位置是否存在结点
if (index < 0 || index > length){
try {
throw new MyException("不存在该指定结点，修改值失败");
} catch (MyException e) {
e.printStackTrace();
}
}
Node temp = head;
int i=1;
while(index != i){
temp = temp.next;
i++;
}
temp.data = data;
return true;
}
/**
* 单链表的选择排序---正序
* 注意排序的只是data而不是结点本身,不要混淆！！
* @return
*/
public boolean selectedSortNode(){
Node temp = head;
while (temp != null){
Node tNode = temp.next;
while (tNode != null){
//判断大小交换data
if (temp.data > tNode.data){
int da = tNode.data;
tNode.data = temp.data;
temp.data = da;
}
tNode = tNode.next;
}
temp = temp.next;
}
return true;
}
/**
* 冒泡排序法排序----倒序
* @return
*/
public boolean bubbleSortNode(){
Node temp = head;
int len_temp = 1;
while (temp != null){
Node tNode = temp.next;
int len_tNode = 1;
if (len_tNode++ < length-len_temp){
while (tNode != null){
if (temp.data < tNode.data){
int da = temp.data;
temp.data = tNode.data;
tNode.data = da;
}
tNode = tNode.next;
}
}
temp = temp.next;
len_temp++;
}
return true;
}
/**
* 反转排序，将第一个和倒数第一个位置交换，以此类推
* @return
*/
public boolean reverseSortNode(){
Node temp = head;
for (int i = 1; i<=length/2; i++){
//找到倒数第i个结点
Node q = head;
int len = 1;
while (q != null && len != length-i+1){
len++;
q = q.next;
}
int da = q.data;
q.data = temp.data;
temp.data = da;
temp = temp.next;
}
return true;
}
public boolean isEmpty(){
if (head == null){
return true;
}
return false;
}
@Test
public void test(){
SingleLinkedList linkedList = new SingleLinkedList();
linkedList.addLastNode(5);
linkedList.addLastNode(21);
linkedList.addLastNode(22);
linkedList.addLastNode(9);
linkedList.addLastNode(7);
System.out.println(linkedList.length());
linkedList.printData();
System.out.println(linkedList.isEmpty());
linkedList.addHeadNode(78);
linkedList.addHeadNode(101);
System.out.println("*************************************");
linkedList.printData();
System.out.println(linkedList.isEmpty());
System.out.println("*************************************");
linkedList.insertNodeByIndex(8,222);
linkedList.printData();
System.out.println("*************************************");
linkedList.insertNodeByIndex(2,600);
linkedList.printData();
// linkedList.delNodeByIndex(10);
linkedList.updateNode(2,1000);
linkedList.selectedSortNode();
linkedList.printData();
linkedList.bubbleSortNode();
linkedList.printData();
linkedList.reverseSortNode();
linkedList.printData();
linkedList.addLastNode(22);
linkedList.printData();
linkedList.deleteRepeatNode();
linkedList.printData();
}
}