public static DateTime parseRfc3339()

in google-http-client/src/main/java/com/google/api/client/util/DateTime.java [287:338]
48 lines of code
10 McCabe index (conditional complexity)

  public static DateTime parseRfc3339(String str) throws NumberFormatException {
    Matcher matcher = RFC3339_PATTERN.matcher(str);
    if (!matcher.matches()) {
      throw new NumberFormatException("Invalid date/time format: " + str);
    }

    int year = Integer.parseInt(matcher.group(1)); // yyyy
    int month = Integer.parseInt(matcher.group(2)) - 1; // MM
    int day = Integer.parseInt(matcher.group(3)); // dd
    boolean isTimeGiven = matcher.group(4) != null; // 'T'HH:mm:ss.milliseconds
    String tzShiftRegexGroup = matcher.group(9); // 'Z', or time zone shift HH:mm following '+'/'-'
    boolean isTzShiftGiven = tzShiftRegexGroup != null;
    int hourOfDay = 0;
    int minute = 0;
    int second = 0;
    int milliseconds = 0;
    Integer tzShiftInteger = null;

    if (isTzShiftGiven && !isTimeGiven) {
      throw new NumberFormatException("Invalid date/time format, cannot specify time zone shift" +
            " without specifying time: " + str);
    }

    if (isTimeGiven) {
      hourOfDay = Integer.parseInt(matcher.group(5)); // HH
      minute = Integer.parseInt(matcher.group(6)); // mm
      second = Integer.parseInt(matcher.group(7)); // ss
      if (matcher.group(8) != null) { // contains .milliseconds?
        milliseconds = Integer.parseInt(matcher.group(8).substring(1)); // milliseconds
      }
    }
    Calendar dateTime = new GregorianCalendar(GMT);
    dateTime.set(year, month, day, hourOfDay, minute, second);
    dateTime.set(Calendar.MILLISECOND, milliseconds);
    long value = dateTime.getTimeInMillis();

    if (isTimeGiven && isTzShiftGiven) {
      int tzShift;
      if (Character.toUpperCase(tzShiftRegexGroup.charAt(0)) == 'Z') {
        tzShift = 0;
      } else {
        tzShift = Integer.parseInt(matcher.group(11)) * 60 // time zone shift HH
            + Integer.parseInt(matcher.group(12)); // time zone shift mm
        if (matcher.group(10).charAt(0) == '-') { // time zone shift + or -
          tzShift = -tzShift;
        }
        value -= tzShift * 60000L; // e.g. if 1 hour ahead of UTC, subtract an hour to get UTC time
      }
      tzShiftInteger = tzShift;
    }
    return new DateTime(!isTimeGiven, value, tzShiftInteger);
  }