基于三次反转思想的字符串左移右移问题

package zi4fu2chuan4;
/*
* 基于三次反转思想的字符串左移2位
* 
* */
import java.util.Scanner;

public class xuan2zhuan4_001 {
/*字符串反序函数
* 输入：待操作字符串
* 输出：该字符串的反序字符串
*/
private static String reChange(String from) {
char[] froms = from.toCharArray();    //创建一个字符串对象，并转换为字符串数组
int length = froms.length;    //求出字符串数组的长度
for(int i = 0; i<length/2; i++) {    //将字符串数组分成2部分，长度为奇数也无妨
char temp = froms[i];    //存储前半部分
froms[i] = froms[length -1 -i];    //将后半部分放到前半部分
froms[length - 1 - i] = temp;    //将前半部分放到后半部分，完成
}
return String.valueOf(froms);    
}
/*字符串循环左移函数
* 功能：循环左移位index位字符串
* 输入：待操作字符串from， 左移位位数index
* 思想：先部分反转，后整体反转
* 
*/
public static String LeftMoveIndex(String from, int index){
String first = from.substring(0,index);    //获取[0,index]位置上的子字符串
String second = from.substring(index);    //获取从 index 到结束的子字符串
first = reChange(first);    //将[0,index]位的字符串反序
second = reChange(second);    //将剩余部分反序
from = first + second;    //将两部分拼接到一起
from = reChange(from);    //整体反转，得到循环左移的字符串
return from;
}
/*
* 字符串循环右移函数
* * */
public static String RightMoveIndex(String from, int index ) {
from = reChange(from);
String first = from.substring(0,index);
String second = from.substring(index);
first = reChange(first);
second = reChange(second);
from = first + second;
return from;
} 
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner sc = new Scanner(System.in);
while (sc.hasNext()) {
String str = sc.next();
System.out.println(str);
System.out.println("左移2位字符串结果："+LeftMoveIndex(str,2));
System.out.println("右移2位字符串结果："+RightMoveIndex(str,2));
}    
}
}