System.getProperty("user.timezone")
* or getDefaultTimeZoneId(). Note that giving one of
* the standard tz data names from ftp://elsie.nci.nih.gov/pub/ is
- * preferred. The time zone name can be given as follows:
- * (standard zone name)[(GMT offset)[(daylight time zone name)]]
+ * preferred.
+ * The time zone name can be given as follows:
+ * (standard zone name)[(GMT offset)[(DST zone name)[DST offset]]]
+ *
* * If only a (standard zone name) is given (no numbers in the * String) then it gets mapped directly to the TimeZone with that * name, if that fails null is returned. *
+ * Alternately, a POSIX-style TZ string can be given, defining the time zone:
+ * std offset dst offset,date/time,date/time
+ * See the glibc manual, or the man page for tzset for details
+ * of this format.
+ *
* A GMT offset is the offset to add to the local time to get GMT. * If a (GMT offset) is included (either in seconds or hours) then * an attempt is made to find a TimeZone name matching both the name @@ -843,93 +850,278 @@ */ static TimeZone getDefaultTimeZone(String sysTimeZoneId) { - // First find start of GMT offset info and any Daylight zone name. - int startGMToffset = 0; - int sysTimeZoneIdLength = sysTimeZoneId.length(); - for (int i = 0; i < sysTimeZoneIdLength && startGMToffset == 0; i++) + String stdName = null; + String dstName; + int stdOffs; + int dstOffs; + try { - char c = sysTimeZoneId.charAt(i); - if (Character.isDigit(c)) - startGMToffset = i; - else if ((c == '+' || c == '-') - && i + 1 < sysTimeZoneIdLength - && Character.isDigit(sysTimeZoneId.charAt(i + 1))) - startGMToffset = i; + int idLength = sysTimeZoneId.length(); + + int index = 0; + int prevIndex; + char c; + + // get std + do + c = sysTimeZoneId.charAt(index++); + while (c != '+' && c != '-' && c != ',' && c != ':' + && ! Character.isDigit(c) && c != '\0' && index < idLength); + + stdName = sysTimeZoneId.substring(0, --index); + prevIndex = index; + + if (index >= idLength) + return (TimeZone)timezones().get(stdName); + + // get the std offset + do + c = sysTimeZoneId.charAt(index++); + while ((c == '-' || c == '+' || c == ':' || Character.isDigit(c)) + && index < idLength); + if (index < idLength) + index--; + + { // convert the dst string to a millis number + String offset = sysTimeZoneId.substring(prevIndex, index); + prevIndex = index; + + if (offset.charAt(0) == '+' || offset.charAt(0) == '-') + stdOffs = parseTime(offset.substring(1)); + else + stdOffs = parseTime(offset); + + if (offset.charAt(0) == '-') + stdOffs = -stdOffs; + + // TZ timezone offsets are positive when WEST of the meridian. + stdOffs = -stdOffs; + } + + // Done yet? (Format: std offset) + if (index >= idLength) + { + // Do we have an existing timezone with that name and offset? + TimeZone tz = (TimeZone) timezones().get(stdName); + if (tz != null) + if (tz.getRawOffset() == stdOffs) + return tz; + + // Custom then. + return new SimpleTimeZone(stdOffs, stdName); + } + + // get dst + do + c = sysTimeZoneId.charAt(index++); + while (c != '+' && c != '-' && c != ',' && c != ':' + && ! Character.isDigit(c) && c != '\0' && index < idLength); + + // Done yet? (Format: std offset dst) + if (index >= idLength) + { + // Do we have an existing timezone with that name and offset + // which has DST? + TimeZone tz = (TimeZone) timezones().get(stdName); + if (tz != null) + if (tz.getRawOffset() == stdOffs && tz.useDaylightTime()) + return tz; + + // Custom then. + return new SimpleTimeZone(stdOffs, stdName); + } + + // get the dst offset + dstName = sysTimeZoneId.substring(prevIndex, --index); + prevIndex = index; + do + c = sysTimeZoneId.charAt(index++); + while ((c == '-' || c == '+' || c == ':' || Character.isDigit(c)) + && index < idLength); + if (index < idLength) + index--; + + { // convert the dst string to a millis number + String offset = sysTimeZoneId.substring(prevIndex, index); + prevIndex = index; + + if (offset.charAt(0) == '+' || offset.charAt(0) == '-') + dstOffs = parseTime(offset.substring(1)); + else + dstOffs = parseTime(offset); + + if (offset.charAt(0) == '-') + dstOffs = -dstOffs; + + // TZ timezone offsets are positive when WEST of the meridian. + dstOffs = -dstOffs; + } + + // Done yet? (Format: std offset dst offset) + // FIXME: We don't support DST without a rule given. Should we? + if (index >= idLength) + { + // Time Zone existing with same name, dst and offsets? + TimeZone tz = (TimeZone) timezones().get(stdName); + if (tz != null) + if (tz.getRawOffset() == stdOffs && tz.useDaylightTime() + && tz.getDSTSavings() == (dstOffs - stdOffs)) + return tz; + + return new SimpleTimeZone(stdOffs, stdName); + } + + // get the DST rule + if (sysTimeZoneId.charAt(index) == ',' + || sysTimeZoneId.charAt(index) == ';') + { + index++; + int offs = index; + while (sysTimeZoneId.charAt(index) != ',' + && sysTimeZoneId.charAt(index) != ';') + index++; + String startTime = sysTimeZoneId.substring(offs, index); + index++; + String endTime = sysTimeZoneId.substring(index); + + index = startTime.indexOf('/'); + int startMillis; + int endMillis; + String startDate; + String endDate; + if (index != -1) + { + startDate = startTime.substring(0, index); + startMillis = parseTime(startTime.substring(index + 1)); + } + else + { + startDate = startTime; + // if time isn't given, default to 2:00:00 AM. + startMillis = 2 * 60 * 60 * 1000; + } + index = endTime.indexOf('/'); + if (index != -1) + { + endDate = endTime.substring(0, index); + endMillis = parseTime(endTime.substring(index + 1)); + } + else + { + endDate = endTime; + // if time isn't given, default to 2:00:00 AM. + endMillis = 2 * 60 * 60 * 1000; + } + + int[] start = getDateParams(startDate); + int[] end = getDateParams(endDate); + return new SimpleTimeZone(stdOffs, stdName, start[0], start[1], + start[2], startMillis, end[0], end[1], + end[2], endMillis, (dstOffs - stdOffs)); + } } - - String tzBasename; - if (startGMToffset == 0) - tzBasename = sysTimeZoneId; - else - tzBasename = sysTimeZoneId.substring (0, startGMToffset); - - int startDaylightZoneName = 0; - for (int i = sysTimeZoneIdLength - 1; - i >= 0 && !Character.isDigit(sysTimeZoneId.charAt(i)); --i) - startDaylightZoneName = i; - - boolean useDaylightTime = startDaylightZoneName > 0; - - // Integer.parseInt() doesn't handle leading +. - if (sysTimeZoneId.charAt(startGMToffset) == '+') - startGMToffset++; - - int gmtOffset = 0; - if (startGMToffset > 0) + + // FIXME: Produce a warning here? + catch (IndexOutOfBoundsException _) { - gmtOffset = Integer.parseInt - (startDaylightZoneName == 0 - ? sysTimeZoneId.substring(startGMToffset) - : sysTimeZoneId.substring(startGMToffset, - startDaylightZoneName)); - - // Offset could be in hours or seconds. Convert to millis. - // The offset is given as the time to add to local time to get GMT - // we need the time to add to GMT to get localtime. - if (Math.abs(gmtOffset) < 24) - gmtOffset *= 60 * 60; - gmtOffset *= -1000; } - - // Try to be optimistic and get the timezone that matches the base name. - // If we only have the base name then just accept this timezone. - // Otherwise check the gmtOffset and day light attributes. - TimeZone tz = (TimeZone) timezones().get(tzBasename); - if (tz != null - && (tzBasename == sysTimeZoneId - || (tz.getRawOffset() == gmtOffset - && tz.useDaylightTime() == useDaylightTime))) - return tz; - - // Maybe there is one with the daylight zone name? - if (useDaylightTime) + catch (NumberFormatException _) { - String daylightZoneName; - daylightZoneName = sysTimeZoneId.substring(startDaylightZoneName); - if (!daylightZoneName.equals(tzBasename)) - { - tz = (TimeZone) timezones().get(tzBasename); - if (tz != null - && tz.getRawOffset() == gmtOffset - && tz.useDaylightTime()) - return tz; - } } - - // If no match, see if a valid timezone has similar attributes as this - // and then use it instead. We take the first one that looks OKish. - if (startGMToffset > 0) + + return null; + } + + /** + * Parses and returns the params for a POSIX TZ date field, + * in the format int[]{ month, day, dayOfWeek }, following the + * SimpleTimeZone constructor rules. + */ + private static int[] getDateParams(String date) + { + int[] dayCount = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; + int month; + + if (date.charAt(0) == 'M' || date.charAt(0) == 'm') { - String[] ids = getAvailableIDs(gmtOffset); - for (int i = 0; i < ids.length; i++) - { - tz = (TimeZone) timezones().get(ids[i]); - if (tz.useDaylightTime() == useDaylightTime) - return tz; - } + int day; + + // Month, week of month, day of week + month = Integer.parseInt(date.substring(1, date.indexOf('.'))); + int week = Integer.parseInt(date.substring(date.indexOf('.') + 1, + date.lastIndexOf('.'))); + int dayOfWeek = Integer.parseInt(date.substring(date.lastIndexOf('.') + + 1)); + if (week == 5) + day = -1; // last day of month is -1 in java, 5 in TZ + else + // first day of week starting on or after. + day = (week - 1) * 7 + 1; + + dayOfWeek++; // Java day of week is one-based, Sunday is first day. + month--; // Java month is zero-based. + return new int[] { month, day, dayOfWeek }; } - - return null; + + // julian day, either zero-based 0<=n<=365 (incl feb 29) + // or one-based 1<=n<=365 (no feb 29) + int julianDay; // Julian day, + + if (date.charAt(0) != 'J' || date.charAt(0) != 'j') + { + julianDay = Integer.parseInt(date.substring(1)); + julianDay++; // make 1-based + // Adjust day count to include feb 29. + dayCount = new int[] + { + 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 + }; + } + else + // 1-based julian day + julianDay = Integer.parseInt(date); + + int i = 11; + while (i > 0) + if (dayCount[i] < julianDay) + break; + else + i--; + julianDay -= dayCount[i]; + month = i; + return new int[] { month, julianDay, 0 }; + } + + /** + * Parses a time field hh[:mm[:ss]], returning the result + * in milliseconds. No leading sign. + */ + private static int parseTime(String time) + { + int millis = 0; + int i = 0; + + while (i < time.length()) + if (time.charAt(i) == ':') + break; + else + i++; + millis = 60 * 60 * 1000 * Integer.parseInt(time.substring(0, i)); + if (i >= time.length()) + return millis; + + int iprev = ++i; + while (i < time.length()) + if (time.charAt(i) == ':') + break; + else + i++; + if (i >= time.length()) + return millis; + + millis += 60 * 1000 * Integer.parseInt(time.substring(iprev, i)); + millis += 1000 * Integer.parseInt(time.substring(++i)); + return millis; } /**