permutation thing in java did this some years ago

stringhandler2.java

/**
 * This 
 */
import java.util.*;
public class StringHandler2{
   //public ArrayList<String> arrayPurms = new ArrayList<String>();
    public static ArrayList<String> SetPermute(HashSet <String> resultSet){
        System.out.println("We're in SetPermute. With argument " + resultSet.toString());
        ArrayList <String> arrayPurms = new ArrayList <String> ();
        if (resultSet.size() == 1) {
            Iterator <String> itr5 = resultSet.iterator();
            arrayPurms.add(itr5.next());
            return arrayPurms;
        }
        
        Iterator <String> itr = resultSet.iterator();
        while (itr.hasNext()){
            HashSet <String> newSet = new HashSet <String>();
            newSet =(HashSet <String>)resultSet.clone();
            String cursor = itr.next();
            System.out.println("cursor= " + cursor);
            newSet.remove(cursor);
            
            //Iterator <String> itr2 = SetPermute(newSet).arrayPurms.iterator();
            ArrayList <String> arrayPurmsB = SetPermute(newSet);
            Iterator <String> itr2 = arrayPurmsB.iterator();
            ArrayList <String> arrayPurms2 = new ArrayList <String> ();
            while(itr2.hasNext()){
                String cursor2 = itr2.next();
                System.out.println("cursor 2 = " + cursor2);
                arrayPurms2.add(cursor+cursor2);
            }
            Iterator <String> itr3 = arrayPurms2.iterator();
            while(itr3.hasNext()){
                String cursor3 = itr3.next();
                System.out.println("cursor3 = " + cursor3);
                arrayPurms.add(cursor3);
            }
        }
        return arrayPurms;
    }
    public static void main(String args[]) {
        if (args.length == 0 ) { System.out.println(" No string provided, try again.");   System.exit(0); }//end if
        System.out.println("This is initialisation.  Hi, this is StringHandler2.");   String s = args[0];
        //Split the string and send to a char Array and then to a HashSet from the charArray
        char[] charArray = s.toCharArray();  HashSet <String> resultSet  = new HashSet<String>();
        for ( int i= 0; i< charArray.length; i++) resultSet.add(Character.toString(charArray[i]));
        //now some testing
    
        testModule1(s, charArray, resultSet);
        
        ArrayList<String> arrayPermutations = SetPermute(resultSet);
        System.out.println("This is the size of arrayPermutations: " + arrayPermutations.size());
        System.out.println("It should be equal to the factorial of " + resultSet.size() + ".");
        Iterator <String> itr4 = arrayPermutations.iterator();
        int m = 1;
        while (itr4.hasNext()){
            System.out.println("This is from the string array ["+m+"]: " + itr4.next());
            m++;
        }
      
    }//end void main
    
    // testing bs; pulling together multiple methods into a single method for call from main
    public static void testModule1(String s, char[] charArray, HashSet resultSet){
        
        testingInitialisation(s, charArray, resultSet);
        iteration(resultSet);
        
    }
    
    //some testing bs
    public static void testingInitialisation(String s, char[] charArray, HashSet resultSet) {
            System.out.println("We are now into testingInitialisation.");
            System.out.println("This is the string entered: " + s);
               for (int i = 0 ;  i < charArray.length; i++) {
                 System.out.println("This is charArray["+i+"]  " +  charArray[i]);
             }
            System.out.println("this is the toString of charArray" + charArray.toString() + "which as you can see is just some object identifier, nothing interesting");
            System.out.println("This is resultSet: " + resultSet);
    }
    //test method
    
    //another disposable test method
    public static void iteration(HashSet resultSet){
        Iterator itr = resultSet.iterator();
        int i = 0;
        while(itr.hasNext()) {
            System.out.println("i = " + i +"  and this index tags value      " + itr.next());
            i++;
        }  // end while
    }  // end permuteee 
     
}// end Class StringHandler2