用递归机制逆序输出一个字符串

package fa.ct;

public class Nixu {

    static String input="abcdefg";
    public static  String ltof(String input){
        if(input.isEmpty()){
            return input;
        }
        return ltof (input.substring (1)) + input.charAt (0);
    }
    public static void main(String[] args) {
        System.out.println(input);
        System.out.println(ltof(input));
    }

}