Selenium :Reverse a String without using builtin Functions

Reverse a String without using builtin Functions

import javax.swing.JOptionPane;

import org.apache.commons.lang3.StringUtils;

public class Reverse_str
{

 public static void main(String[] args)
 {
  String sStr=JOptionPane.showInputDialog("Enetr a str");
  String sRes="";
  for (int i=sStr.length() ;i>=0;i--)
  {
   sRes=sRes+StringUtils.mid(sStr, i, 1);
  }
  System.out.print(sRes);
 }


}