Rotate a string left and right in java

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package com.programs; public class RotateString { public static void main(String[] args) { String s1 = "abcd"; String s2 = "bcda"; System.out.println(isRotation(s1,s2)); rotateStringRight(s1,s1.length()); rotateStringLeft(s1,s1.length()); } private static void rotateStringLeft(String s1, int n) { int i =1; System.out.println("Rotating string '" + s1 + "' left "); while (i <=n){ s1 = s1.substring(1) + s1.charAt(0) ; System.out.println(s1); i++; } } private static void rotateStringRight(String s1, int n) { int i =1; System.out.println("Rotating string '" + s1 + "' right "); while (i <=n){ s1 = s1.charAt(s1.length()-1) + s1.substring(0,s1.length()-1) ; System.out.println(s1); i++; } } public static boolean isRotation(String s1,String s2) { return (s1.length() == s2.length()) && ((s1+s1).indexOf(s2) != -1); } } Output ============= true Rotating string 'abcd' right dabc cdab bcda abcd Rotating string 'abcd' left bcda cdab dabc abcd