Permutaion in java

package test;
import java.util.*;

public class permutation {
 public static void main(String args[]) {
   permuteString("", "ab");
 }

 public static void permuteString(String beginningString, String endingString) {
   if (endingString.length() <= 1)
    {
     System.out.println("print->"+beginningString + endingString+""+endingString.length());}
   else
   {  for (int i = 0; i < endingString.length(); i++) {
       try {
         String newString = endingString.substring(0, i) + endingString.substring(i + 1);
       
       
         permuteString(beginningString + endingString.charAt(i), newString);
       } catch (StringIndexOutOfBoundsException exception) {
         exception.printStackTrace();
       }
     }
 }
}
}