code: public static int[] arrayFromStringOfIntegers(String str) throws IllegalArgumentException {
          StringTokenizer tokenizer = new StringTokenizer(str, ",");
          int n = tokenizer.countTokens();
          int[] list = new int[n];
          for (int i = 0; i < n; i++) {
              String token = tokenizer.nextToken();
              list[i] = Integer.parseInt(token);
          }
          return list;
      }
docs: Split string of comma-delimited ints into an a int array
  
  @param str
  @return
  @throws IllegalArgumentException