recursion - Generating Power Set of a String Recursively in Java -

i'm trying recursive implementation of power set generator working off of pseudocode given, when given string "abc", rather having sets

{}, {a}, {b}, {c}, {a,b}, {a,c}, {b,c}, , {a,b,c},

i {}, {0}, {1}, {2}, {0,1}, etc.

public static arraylist generatesubsets(string setstring) {       arraylist = new arraylist<string>();       arraylist temp = new arraylist<string>();       if(setstring.length() > 0) {          temp = generatesubsets(setstring.substring(0,setstring.length() - 1));          for(int = 0; < temp.size(); i++) {             system.out.println("temp i: "+temp.get(i));             a.add(temp.get(i));             a.add(temp.get(i) + " " + (setstring.length() - 1));          }          return a;       }       else          a.add("");          return a;    } 

this based directly on pseudocode, why isn't working correctly?

edit: test

public static void main(string[] args) {   arraylist 1 = generatesubsets("abcd");   for(int = 0; < one.size(); i++) {      system.out.print(one.get(i)+ ", ");      if(i%5 == 0) {         system.out.println("");      }   } 

}

and output of (without line breaks)

, 3, 2, 2 3, 1, 1 3, 1 2, 1 2 3, 0, 0 3, 0 2, 0 2 3, 0 1, 0 1 3, 0 1 2, 0 1 2 3,

statement (setstring.length() - 1) gives index of char. , concatenating receive power set of indexes. need use setstring.charat(setstring.length()-1) receive char @ given position.