单链表翻转比如有如下链表：

需要按照C B A 输出，我们可以有好几种方法：

package org.andy.test;    import java.util.ArrayList;  import java.util.List;    /**   * @author andy   * @version：2015-2-4 上午9:41:12   *    *    */    public class LinkedReverse {     /**    * @param args    */   public static void main(String[] args) {    // TODO Auto-generated method stub    N n = new N();    n.name = "A";      N n1 = new N();    n1.name = "B";      N n2 = new N();    n2.name = "C";      N n3 = new N();    n3.name = "D";        n1.nextN = n2;    n.nextN = n1;    n2.nextN = n3;    N old = n;    while (old != null) {     System.out.println(old.name);     old = old.nextN;    }      System.out.println("链表翻转1");    N new1 = reverseOne(n);    while (new1 != null) {     System.out.println(new1.name);     new1 = new1.nextN;    }      /*    System.out.println("链表翻转2");    N new2 = reverseTwo(n, null);    while (new2 != null) {     System.out.println(new2.name);     new2 = new2.nextN;    }      System.out.println("链表翻转3");    N new3 = reverseThree(n);    while (new3 != null) {     System.out.println(new3.name);     new3 = new3.nextN;    }        */   }     //采用交换前后值   public static N reverseOne(N n) {    if (n != null) {     N preN = n; //前一个节点     N curN = n.nextN; //当前节点     N nextN ;   //后一个节点     while (null != curN) {      nextN = curN.nextN;      curN.nextN = preN;      preN = curN;      curN = nextN;     }          n.nextN = null;     n = preN;          return n;         }    return null;   }     //采用递归实现   public static N reverseTwo(N n, N newN) {    // 采用递归 返回 返回条件是最后一个几点nextN为空    if (n == null) {     return newN;    }      N nextN = n.nextN;    n.nextN = newN;    return reverseTwo(nextN, n);   }     //最烂的实现方式   public static N reverseThree(N n) {    if (n == null) {     return null;    }    // 定义一个集合 ，放在集合里面在单个反向指回    List<N> nList = new ArrayList<N>();    N p = n;    while (p != null) {     N node = new N();// 当前节点     node.name = p.name;     nList.add(node);     p = p.nextN;    }      // 在返现输出节点    n = null;    for (N rn : nList) {     if (n != null) {      // 如果n不为空时      rn.nextN = n;     }     n = rn;    }      return n;   }    }    // 定义一个节点  class N {   public String name;   public N nextN;  }