在java实现自定义链表（单向链表）

import java.io.*;

import com.toplx.game.utils.Node;

public class List {

/* 用变量来实现表头 */

private Node Head = null;

private Node Tail = null;

private Node Pointer = null;

private int Length = 0;

/* 清空整个链表 */

public void deleteAll() {

Head = null;

Tail = null;

Pointer = null;

Length = 0;

}

/* 链表复位，使第一个结点成为当前结点 */

public void reset() {

Pointer = null;

}

/* 判断链表是否为空 */

public boolean isEmpty() {

return (Length == 0);

}

/* 判断当前结点是否为最后一个结点 */

public boolean isEnd() {

if (Length == 0)

throw new java.lang.NullPointerException();

else if (Length == 1)

return true;

else

return (cursor() == Tail);

}

/* 返回当前结点的下一个结点的值，并使其成为当前结点 */

public Object nextNode() {

if (Length == 1)

throw new java.util.NoSuchElementException();

else if (Length == 0)

throw new java.lang.NullPointerException();

else {

Node temp = cursor();

Pointer = temp;

if (temp != Tail)

return (temp.next.data );

else

throw new java.util.NoSuchElementException();

}

}

/* 返回当前结点的值 */

public Object currentNode() {

Node temp = cursor();

return temp.data;

}

/* 在当前结点前插入一个结点，并使其成为当前结点 */

public void insert(Object d) {

Node e = new Node(d);

if (Length == 0) {

Tail = e;

Head = e;

} else {

Node temp = cursor();

e.next = temp;

if (Pointer == null)

Head = e;

else

Pointer.next = e;

}

Length++;

}

/* 返回链表的大小 */

public int size() {

return (Length);

}

/**

* 将当前结点移出链表，下一个结点

* 成为当前结点，如果移出的结点是

* 最后一个结点，则第一个结点 成

* 为当前结点

*/

public Object remove() {

Object temp;

if (Length == 0)

throw new java.util.NoSuchElementException();

else if (Length == 1) {

temp = Head.data;

deleteAll();

} else {

Node cur = cursor();

temp = cur.data;

if (cur == Head)

Head = cur.next;

else if (cur == Tail) {

Pointer.next = null;

Tail = Pointer;

reset();

} else

Pointer.next = cur.next;

Length--;

}

return temp;

}

/* 返回当前结点的指针 */

private Node cursor() {

if (Head == null)

throw new java.lang.NullPointerException();

else if (Pointer == null)

return Head;

else

return Pointer.next;

}

public class Node

{

public Object data;

public Node next;

public Node(Object d)

{

data = d;

next = null;

}

}

/* 链表的简单应用举例 */

public static void main(String[] args) {

List a = new List();

for (int i = 1; i <= 10; i++)

a.insert(new Integer(i));

System.out.println(a.currentNode());

while (!a.isEnd())

System.out.println(a.nextNode());

a.reset();

while (!a.isEnd()) {

a.remove();

}

a.remove();

a.reset();

if (a.isEmpty())

System.out.println("There is no Node in List /n");

System.out.println(" You can press return to quit/n");

try {

System.out.println("I am waitting for you :) >>>>>>");

System.in.read(); // 确保用户看清程序运行结果

System.out.println("exit success!");

} catch (IOException e) {

}

}

}