/// <summary> /// Parses a custom time zone identifier and returns a corresponding zone. /// This method doesn't support the RFC 822 time zone format. (e.g., +hhmm) /// </summary> /// <param name="id"> a string of the <a href="#CustomID">custom ID form</a>. </param> /// <returns> a newly created TimeZone with the given offset and /// no daylight saving time, or null if the id cannot be parsed. </returns> private static TimeZone ParseCustomTimeZone(String id) { int length; // Error if the length of id isn't long enough or id doesn't // start with "GMT". if ((length = id.Length()) < (GMT_ID_LENGTH + 2) || id.IndexOf(GMT_ID) != 0) { return(null); } ZoneInfo zi; // First, we try to find it in the cache with the given // id. Even the id is not normalized, the returned ZoneInfo // should have its normalized id. zi = ZoneInfoFile.getZoneInfo(id); if (zi != null) { return(zi); } int index = GMT_ID_LENGTH; bool negative = false; char c = id.CharAt(index++); if (c == '-') { negative = true; } else if (c != '+') { return(null); } int hours = 0; int num = 0; int countDelim = 0; int len = 0; while (index < length) { c = id.CharAt(index++); if (c == ':') { if (countDelim > 0) { return(null); } if (len > 2) { return(null); } hours = num; countDelim++; num = 0; len = 0; continue; } if (c < '0' || c > '9') { return(null); } num = num * 10 + (c - '0'); len++; } if (index != length) { return(null); } if (countDelim == 0) { if (len <= 2) { hours = num; num = 0; } else { hours = num / 100; num %= 100; } } else { if (len != 2) { return(null); } } if (hours > 23 || num > 59) { return(null); } int gmtOffset = (hours * 60 + num) * 60 * 1000; if (gmtOffset == 0) { zi = ZoneInfoFile.getZoneInfo(GMT_ID); if (negative) { zi.ID = "GMT-00:00"; } else { zi.ID = "GMT+00:00"; } } else { zi = ZoneInfoFile.getCustomTimeZone(id, negative ? -gmtOffset : gmtOffset); } return(zi); }