Something

  static String[] permute(String str) {    int len = str.length();        if (len > 2) {      String[][] result = new String[len][len-1];            for (int i = 0; i < len; i++) {        String help = str.substring(0, i) + str.substring(i+1);        String[] permhelp = permute(help);   // Rekursion        for (int j = 0; j < len-1; j++)          result[i][j] = str.charAt(i) + permhelp[j];      }            String[] result2 = new String[fak(len)];      int k = 0;      for (int i = 0; i < len; i++)        for (int j = 0; j < len-1; j++) {          result2[k] = result[i][j];          k++;        }            return result2;    }    return result;  }