public class StringReversal {

/**

* 反转字符串(循环交换)

* 其他字符串反转的方法

* 1、java的api：StringBuffer的reverse方法

* 2、利用栈的特性(先进后出)

* 3、反向遍历字符串

* @param from

* @return

*/

public static String reChange(String from){

char[] froms = from.toCharArray();

int length = froms.length;

for (int i = 0; i < length/2; i++){

char temp = froms[i];

froms[i] = froms[length - 1 -i];

froms[length - 1 -i] = temp;

}

return String.valueOf(froms);

}

/**

* 循环左移index位字符串

* 思想：先部分反转，后整体反转

* @param from

* @param index

* @return

*/

public static String leftMoveIndex(String from,int index){

String first = from.substring(0,index);

String second = from.substring(index);

first = reChange(first);

second = reChange(second);

from = first + second;

from = reChange(from);

return from;

}

/**

* 循环右移index位字符串

* 思想：先整体反转，后部分反转

* @param from

* @param index

* @return

*/

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) {

String leftString = "abcdefg";

System.out.println("左移2位字符串结果："+leftMoveIndex(leftString,2));

String rightString = "abcdefg";

System.out.println("右移2位字符串结果："+rightMoveIndex(rightString,2));

}

}