TimeZone represents a time zone offset, and also computes daylight
* savings.
*
*
Typically, you get a TimeZone using {@link #getDefault()}
* which creates a TimeZone based on the time zone where the program
* is running. For example, for a program running in Japan, getDefault
* creates a TimeZone object based on Japanese Standard Time.
*
*
You can also get a TimeZone using {@link #getTimeZone(String)}
* along with a time zone ID. For instance, the time zone ID for the
* U.S. Pacific Time zone is "America/Los_Angeles". So, you can get a
* U.S. Pacific Time TimeZone object with:
*
*
*
* TimeZone tz = TimeZone.getTimeZone("America/Los_Angeles");
*
*
* You can use the {@link #getAvailableIDs()} method to iterate through
* all the supported time zone IDs, or getCanonicalID method to check
* if a time zone ID is supported or not. You can then choose a
* supported ID to get a TimeZone.
* If the time zone you want is not represented by one of the
* supported IDs, then you can create a custom time zone ID with
* the following syntax:
*
* ** * For example, you might specify GMT+14:00 as a custom * time zone ID. The* GMT[+|-]hh[[:]mm] **
TimeZone that is returned
* when you specify a custom time zone ID uses the specified
* offset from GMT(=UTC) and does not observe daylight saving
* time. For example, you might specify GMT+14:00 as a custom
* time zone ID to create a TimeZone representing 14 hours ahead
* of GMT (with no daylight saving time). In addition,
* getCanonicalID can also be used to
* normalize a custom time zone ID.
*
* For compatibility with JDK 1.1.x, some other three-letter time zone IDs
* (such as "PST", "CTT", "AST") are also supported. However, their
* use is deprecated because the same abbreviation is often used
* for multiple time zones (for example, "CST" could be U.S. "Central Standard
* Time" and "China Standard Time"), and the Java platform can then only
* recognize one of them.
*
* @see Calendar
* @see GregorianCalendar
* @author Mark Davis, Deborah Goldsmith, Chen-Lieh Huang, Alan Liu
*/
abstract public class TimeZone implements Serializable, Cloneable, Freezable
* The default implementation always returns 3600000 milliseconds
* (i.e., one hour) if this time zone observes Daylight Saving
* Time. Otherwise, 0 (zero) is returned.
*
* If an underlying TimeZone implementation subclass supports
* historical Daylight Saving Time changes, this method returns
* the known latest daylight saving value.
*
* @return the amount of saving time in milliseconds
*/
public int getDSTSavings() {
if (useDaylightTime()) {
return 3600000;
}
return 0;
}
/**
* Queries if this time zone uses daylight savings time.
* @return true if this time zone uses daylight savings time,
* false, otherwise.
* Note:The default implementation of
* ICU TimeZone uses the tz database, which supports historic
* rule changes, for system time zones. With the implementation,
* there are time zones that used daylight savings time in the
* past, but no longer used currently. For example, Asia/Tokyo has
* never used daylight savings time since 1951. Most clients would
* expect that this method to return The default implementation in this class returns
* Note: This method was added for {@link java.util.TimeZone} compatibility
* support. The {@link java.util.TimeZone#useDaylightTime()} method only checks the last known
* rule(s), therefore it may return false even the zone observes daylight saving time currently.
* {@link java.util.TimeZone} added
* ICU's TimeZone subclass implementations override this method to support the same behavior
* with {@link java.util.TimeZone#observesDaylightTime()}. Unlike {@link #useDaylightTime()},
* the implementation does not take past daylight saving time into account, so
* that this method may return Note:A The returned count includes the given ID; it is always >= 1
* for valid IDs. The given ID must be a system time zone. If it
* is not, returns zero.
* @param id a system time zone ID
* @return the number of zones in the equivalency group containing
* 'id', or zero if 'id' is not a valid system ID
* @see #getEquivalentID
*/
public static int countEquivalentIDs(String id) {
return ZoneMeta.countEquivalentIDs(id);
}
/**
* Returns an ID in the equivalency group that
* includes the given ID. An equivalency group contains zones
* that have the same GMT offset and rules.
*
* The given index must be in the range 0..n-1, where n is the
* value returned by Note: For most of system time zone IDs, this method returns an ID same as {@link TimeZone#getCanonicalID(String)}.
* {@link TimeZone#getCanonicalID(String)} is based on canonical time zone IDs defined in Unicode CLDR.
* These canonical time zone IDs in CLDR were based on very old version of the time zone database.
* In the IANA time zone database, some IDs were updated since then. This API returns a newer
* time zone ID. For example, CLDR defines "Asia/Calcutta" as the canonical time zone ID. This
* method returns "Asia/Kolkata" instead.
* "Etc/Unknown" is a special time zone ID defined by CLDR. There are no corresponding zones
* in the IANA time zone database. when the input is "Etc/Unknown", this method returns "Etc/Unknown",
* but it really means no mappings available. Caller of this method should interpret "Etc/Unknown"
* as an error.
*
* @param id The input time zone ID.
* @return The preferred time zone ID in the IANA time zone database, or {@link TimeZone#UNKNOWN_ZONE_ID}
* if the input ID is not a system ID.
* @see #getCanonicalID(String)
* @hide draft / provisional / internal are hidden on Android
*/
public static String getIanaID(String id) {
String ianaId = TimeZone.UNKNOWN_ZONE_ID;
if (id == null || id.length() == 0 || id.equals(TimeZone.UNKNOWN_ZONE)) {
return ianaId;
}
String tmpIanaId = ZoneMeta.getIanaID(id);
if (tmpIanaId != null) {
ianaId = tmpIanaId;
}
return ianaId;
}
/**
* [icu] Returns the region code associated with the given
* system time zone ID. The region code is either ISO 3166
* 2-letter country code or UN M.49 3-digit area code.
* When the time zone is not associated with a specific location,
* for example - "Etc/UTC", "EST5EDT", then this method returns
* "001" (UN M.49 area code for World).
* @param id the system time zone ID.
* @return the region code associated with the given
* system time zone ID.
* @throws IllegalArgumentException if There are system time zones that cannot be mapped to Windows zones. When the input
* system time zone ID is unknown or unmappable to a Windows time zone, then this
* method returns This implementation utilizes
* Zone-Tzid mapping data. The mapping data is updated time to time. To get the latest changes,
* please read the ICU user guide section
* Updating the Time Zone Data.
*
* @param id A system time zone ID
* @return A Windows time zone ID mapped from the input system time zone ID,
* or Not all Windows time zones can be mapped to system time zones. When the input
* Windows time zone ID is unknown or unmappable to a system time zone, then this
* method returns This implementation utilizes
* Zone-Tzid mapping data. The mapping data is updated time to time. To get the latest changes,
* please read the ICU user guide section
* Updating the Time Zone Data.
*
* @param winid A Windows time zone ID
* @param region A region code, or getTimeZone.
*/
public static final int TIMEZONE_ICU = 0;
/**
* [icu] A time zone implementation type indicating the {@link java.util.TimeZone}
* used by getTimeZone.
*/
public static final int TIMEZONE_JDK = 1;
/**
* A style specifier for getDisplayName() indicating
* a short name, such as "PST."
* @see #LONG
*/
public static final int SHORT = 0;
/**
* A style specifier for getDisplayName() indicating
* a long name, such as "Pacific Standard Time."
* @see #SHORT
*/
public static final int LONG = 1;
/**
* [icu] A style specifier for getDisplayName() indicating
* a short generic name, such as "PT."
* @see #LONG_GENERIC
*/
public static final int SHORT_GENERIC = 2;
/**
* [icu] A style specifier for getDisplayName() indicating
* a long generic name, such as "Pacific Time."
* @see #SHORT_GENERIC
*/
public static final int LONG_GENERIC = 3;
/**
* [icu] A style specifier for getDisplayName() indicating
* a short name derived from the timezone's offset, such as "-0800."
* @see #LONG_GMT
*/
public static final int SHORT_GMT = 4;
/**
* [icu] A style specifier for getDisplayName() indicating
* a long name derived from the timezone's offset, such as "GMT-08:00."
* @see #SHORT_GMT
*/
public static final int LONG_GMT = 5;
/**
* [icu] A style specifier for getDisplayName() indicating
* a short name derived from the timezone's short standard or daylight
* timezone name ignoring commonlyUsed, such as "PDT."
*/
public static final int SHORT_COMMONLY_USED = 6;
/**
* [icu] A style specifier for getDisplayName() indicating
* a long name derived from the timezone's fallback name, such as
* "United States (Los Angeles)."
*/
public static final int GENERIC_LOCATION = 7;
/**
* [icu] The time zone ID reserved for unknown time zone.
* @see #getTimeZone(String)
*/
public static final String UNKNOWN_ZONE_ID = "Etc/Unknown";
/**
* The canonical ID for GMT(UTC) time zone.
*/
static final String GMT_ZONE_ID = "Etc/GMT";
/**
* [icu] The immutable (frozen) "unknown" time zone.
* It behaves like the GMT/UTC time zone but has the UNKNOWN_ZONE_ID = "Etc/Unknown".
* {@link TimeZone#getTimeZone(String)} returns a mutable clone of this
* time zone if the input ID is not recognized.
*
* @see #UNKNOWN_ZONE_ID
* @see #getTimeZone(String)
*/
public static final TimeZone UNKNOWN_ZONE = new ConstantZone(0, UNKNOWN_ZONE_ID).freeze();
/**
* [icu] The immutable GMT (=UTC) time zone. Its ID is "Etc/GMT".
*/
public static final TimeZone GMT_ZONE = new ConstantZone(0, GMT_ZONE_ID).freeze();
/**
* [icu] System time zone type constants used by filtering zones in
* {@link TimeZone#getAvailableIDs(SystemTimeZoneType, String, Integer)}
*/
public enum SystemTimeZoneType {
/**
* Any system zones.
*/
ANY,
/**
* Canonical system zones.
*/
CANONICAL,
/**
* Canonical system zones associated with actual locations.
*/
CANONICAL_LOCATION,
}
/**
* Gets the time zone offset, for current date, modified in case of
* daylight savings. This is the offset to add to UTC to get local time.
* @param era the era of the given date.
* @param year the year in the given date.
* @param month the month in the given date.
* Month is 0-based. e.g., 0 for January.
* @param day the day-in-month of the given date.
* @param dayOfWeek the day-of-week of the given date.
* @param milliseconds the millis in day in standard local time.
* @return the offset to add to GMT to get local time.
*/
abstract public int getOffset(int era, int year, int month, int day,
int dayOfWeek, int milliseconds);
/**
* Returns the offset of this time zone from UTC at the specified
* date. If Daylight Saving Time is in effect at the specified
* date, the offset value is adjusted with the amount of daylight
* saving.
*
* @param date the date represented in milliseconds since January 1, 1970 00:00:00 GMT
* @return the amount of time in milliseconds to add to UTC to get local time.
*
* @see Calendar#ZONE_OFFSET
* @see Calendar#DST_OFFSET
* @see #getOffset(long, boolean, int[])
*/
public int getOffset(long date) {
int[] result = new int[2];
getOffset(date, false, result);
return result[0]+result[1];
}
/**
* Returns the time zone raw and GMT offset for the given moment
* in time. Upon return, local-millis = GMT-millis + rawOffset +
* dstOffset. All computations are performed in the proleptic
* Gregorian calendar. The default implementation in the TimeZone
* class delegates to the 8-argument getOffset().
*
* @param date moment in time for which to return offsets, in
* units of milliseconds from January 1, 1970 0:00 GMT, either GMT
* time or local wall time, depending on {@code local}.
* @param local if true, {@code date} is local wall time; otherwise it
* is in GMT time.
* @param offsets output parameter to receive the raw offset, that
* is, the offset not including DST adjustments, in offsets[0],
* and the DST offset, that is, the offset to be added to
* {@code rawOffset} to obtain the total offset between local and GMT
* time, in offsets[1]. If DST is not in effect, the DST offset is
* zero; otherwise it is a positive value, typically one hour.
*/
public void getOffset(long date, boolean local, int[] offsets) {
offsets[0] = getRawOffset();
if (!local) {
date += offsets[0]; // now in local standard millis
}
// When local == true, date might not be in local standard
// millis. getOffset taking 6 parameters used here assume
// the given time in day is local standard time.
// At STD->DST transition, there is a range of time which
// does not exist. When 'date' is in this time range
// (and local == true), this method interprets the specified
// local time as DST. At DST->STD transition, there is a
// range of time which occurs twice. In this case, this
// method interprets the specified local time as STD.
// To support the behavior above, we need to call getOffset
// (with 6 args) twice when local == true and DST is
// detected in the initial call.
int fields[] = new int[6];
for (int pass = 0; ; pass++) {
Grego.timeToFields(date, fields);
offsets[1] = getOffset(GregorianCalendar.AD,
fields[0], fields[1], fields[2],
fields[3], fields[5]) - offsets[0];
if (pass != 0 || !local || offsets[1] == 0) {
break;
}
// adjust to local standard millis
date -= offsets[1];
}
}
/**
* Sets the base time zone offset to GMT.
* This is the offset to add to UTC to get local time.
* @param offsetMillis the given base time zone offset to GMT.
*/
abstract public void setRawOffset(int offsetMillis);
/**
* Gets unmodified offset, NOT modified in case of daylight savings.
* This is the offset to add to UTC to get local time.
* @return the unmodified offset to add to UTC to get local time.
*/
abstract public int getRawOffset();
/**
* Gets the ID of this time zone.
* @return the ID of this time zone.
*/
public String getID() {
return ID;
}
/**
* Sets the time zone ID. This does not change any other data in
* the time zone object.
* @param ID the new time zone ID.
*/
public void setID(String ID) {
if (ID == null) {
throw new NullPointerException();
}
if (isFrozen()) {
throw new UnsupportedOperationException("Attempt to modify a frozen TimeZone instance.");
}
this.ID = ID;
}
/**
* Returns a name of this time zone suitable for presentation to the user
* in the default DISPLAY locale.
* This method returns the long generic name.
* If the display name is not available for the locale,
* a fallback based on the country, city, or time zone id will be used.
* @return the human-readable name of this time zone in the default locale.
* @see Category#DISPLAY
*/
public final String getDisplayName() {
return _getDisplayName(LONG_GENERIC, false, ULocale.getDefault(Category.DISPLAY));
}
/**
* Returns a name of this time zone suitable for presentation to the user
* in the specified locale.
* This method returns the long generic name.
* If the display name is not available for the locale,
* a fallback based on the country, city, or time zone id will be used.
* @param locale the locale in which to supply the display name.
* @return the human-readable name of this time zone in the given locale
* or in the default locale if the given locale is not recognized.
*/
public final String getDisplayName(Locale locale) {
return _getDisplayName(LONG_GENERIC, false, ULocale.forLocale(locale));
}
/**
* Returns a name of this time zone suitable for presentation to the user
* in the specified locale.
* This method returns the long name, not including daylight savings.
* If the display name is not available for the locale,
* a fallback based on the country, city, or time zone id will be used.
* @param locale the ulocale in which to supply the display name.
* @return the human-readable name of this time zone in the given locale
* or in the default ulocale if the given ulocale is not recognized.
*/
public final String getDisplayName(ULocale locale) {
return _getDisplayName(LONG_GENERIC, false, locale);
}
/**
* Returns a name of this time zone suitable for presentation to the user
* in the default DISPLAY locale.
* If the display name is not available for the locale,
* then this method returns a string in the localized GMT offset format
* such as GMT[+-]HH:mm.
* @param daylight if true, return the daylight savings name.
* @param style the output style of the display name. Valid styles are
* SHORT, LONG, SHORT_GENERIC,
* LONG_GENERIC, SHORT_GMT, LONG_GMT,
* SHORT_COMMONLY_USED or GENERIC_LOCATION.
* @return the human-readable name of this time zone in the default locale.
* @see Category#DISPLAY
*/
public final String getDisplayName(boolean daylight, int style) {
return getDisplayName(daylight, style, ULocale.getDefault(Category.DISPLAY));
}
/**
* Returns a name of this time zone suitable for presentation to the user
* in the specified locale.
* If the display name is not available for the locale,
* then this method returns a string in the localized GMT offset format
* such as GMT[+-]HH:mm.
* @param daylight if true, return the daylight savings name.
* @param style the output style of the display name. Valid styles are
* SHORT, LONG, SHORT_GENERIC,
* LONG_GENERIC, SHORT_GMT, LONG_GMT,
* SHORT_COMMONLY_USED or GENERIC_LOCATION.
* @param locale the locale in which to supply the display name.
* @return the human-readable name of this time zone in the given locale
* or in the default locale if the given locale is not recognized.
* @exception IllegalArgumentException style is invalid.
*/
public String getDisplayName(boolean daylight, int style, Locale locale) {
return getDisplayName(daylight, style, ULocale.forLocale(locale));
}
/**
* Returns a name of this time zone suitable for presentation to the user
* in the specified locale.
* If the display name is not available for the locale,
* then this method returns a string in the localized GMT offset format
* such as GMT[+-]HH:mm.
* @param daylight if true, return the daylight savings name.
* @param style the output style of the display name. Valid styles are
* SHORT, LONG, SHORT_GENERIC,
* LONG_GENERIC, SHORT_GMT, LONG_GMT,
* SHORT_COMMONLY_USED or GENERIC_LOCATION.
* @param locale the locale in which to supply the display name.
* @return the human-readable name of this time zone in the given locale
* or in the default locale if the given locale is not recognized.
* @exception IllegalArgumentException style is invalid.
*/
public String getDisplayName(boolean daylight, int style, ULocale locale) {
if (style < SHORT || style > GENERIC_LOCATION) {
throw new IllegalArgumentException("Illegal style: " + style);
}
return _getDisplayName(style, daylight, locale);
}
/**
* internal version (which is called by public APIs) accepts
* SHORT, LONG, SHORT_GENERIC, LONG_GENERIC, SHORT_GMT, LONG_GMT,
* SHORT_COMMONLY_USED and GENERIC_LOCATION.
*/
private String _getDisplayName(int style, boolean daylight, ULocale locale) {
if (locale == null) {
throw new NullPointerException("locale is null");
}
String result = null;
if (style == GENERIC_LOCATION || style == LONG_GENERIC || style == SHORT_GENERIC) {
// Generic format
TimeZoneFormat tzfmt = TimeZoneFormat.getInstance(locale);
long date = System.currentTimeMillis();
Outputfalse for such case.
* The default implementation of this method returns true
* when the time zone uses daylight savings time in the current
* (Gregorian) calendar year.
*/
abstract public boolean useDaylightTime();
/**
* Queries if this time zone is in daylight saving time or will observe
* daylight saving time at any future time.
* true if {@link #useDaylightTime()}
* or {@link #inDaylightTime(Date) inDaylightTime(new Date())} returns true.
* observesDaylightTime() to resolve the issue.
* In ICU, {@link #useDaylightTime()} works differently. The ICU implementation checks if the
* zone uses daylight saving time in the current calendar year. Therefore, it will never return
* false if daylight saving time is currently used.
* false even when {@link #useDaylightTime()} returns
* true.
*
* @return true if this time zone is in daylight saving time or will observe
* daylight saving time at any future time.
* @see #useDaylightTime
*/
public boolean observesDaylightTime() {
return useDaylightTime() || inDaylightTime(new Date());
}
/**
* Queries if the given date is in daylight savings time in
* this time zone.
* @param date the given Date.
* @return true if the given date is in daylight savings time,
* false, otherwise.
*/
abstract public boolean inDaylightTime(Date date);
/**
* Gets the TimeZone for the given ID.
*
* @param ID the ID for a TimeZone, such as "America/Los_Angeles",
* or a custom ID such as "GMT-8:00". Note that the support of abbreviations,
* such as "PST", is for JDK 1.1.x compatibility only and full names should be used.
*
* @return the specified TimeZone, or a mutable clone of the UNKNOWN_ZONE
* if the given ID cannot be understood or if the given ID is "Etc/Unknown".
* @see #UNKNOWN_ZONE
*/
public static TimeZone getTimeZone(String ID) {
return getTimeZone(ID, TZ_IMPL, false);
}
/**
* Gets the TimeZone for the given ID. The instance of TimeZone
* returned by this method is immutable. Any methods mutate the instance({@link #setID(String)},
* {@link #setRawOffset(int)}) will throw UnsupportedOperationException upon its
* invocation.
*
* @param ID the ID for a TimeZone, such as "America/Los_Angeles",
* or a custom ID such as "GMT-8:00". Note that the support of abbreviations,
* such as "PST", is for JDK 1.1.x compatibility only and full names should be used.
*
* @return the specified TimeZone, or the UNKNOWN_ZONE
* if the given ID cannot be understood.
* @see #UNKNOWN_ZONE
*/
public static TimeZone getFrozenTimeZone(String ID) {
return getTimeZone(ID, TZ_IMPL, true);
}
/**
* Gets the TimeZone for the given ID and the timezone type.
* @param ID the ID for a TimeZone, such as "America/Los_Angeles", or a
* custom ID such as "GMT-8:00". Note that the support of abbreviations, such as
* "PST", is for JDK 1.1.x compatibility only and full names should be used.
* @param type Time zone type, either TIMEZONE_ICU or
* TIMEZONE_JDK.
* @return the specified TimeZone, or a mutable clone of the UNKNOWN_ZONE if the given ID
* cannot be understood or if the given ID is "Etc/Unknown".
* @see #UNKNOWN_ZONE
*/
public static TimeZone getTimeZone(String ID, int type) {
return getTimeZone(ID, type, false);
}
/**
* Gets the TimeZone for the given ID and the timezone type.
* @param id time zone ID
* @param type time zone implementation type, TIMEZONE_JDK or TIMEZONE_ICU
* @param frozen specify if the returned object can be frozen
* @return the specified TimeZone or UNKNOWN_ZONE if the given ID
* cannot be understood.
*/
private static TimeZone getTimeZone(String id, int type, boolean frozen) {
TimeZone result;
if (type == TIMEZONE_JDK) {
result = JavaTimeZone.createTimeZone(id);
if (result != null) {
return frozen ? result.freeze() : result;
}
result = getFrozenICUTimeZone(id, false);
} else {
result = getFrozenICUTimeZone(id, true);
}
if (result == null) {
LOGGER.fine("\"" +id + "\" is a bogus id so timezone is falling back to Etc/Unknown(GMT).");
result = UNKNOWN_ZONE;
}
return frozen ? result : result.cloneAsThawed();
}
/**
* Returns a frozen ICU type TimeZone object given a time zone ID.
* @param id the time zone ID
* @param trySystem if true tries the system time zones first otherwise skip to the
* custom time zones.
* @return the frozen ICU TimeZone or null if one could not be created.
*/
static BasicTimeZone getFrozenICUTimeZone(String id, boolean trySystem) {
BasicTimeZone result = null;
if (trySystem) {
result = ZoneMeta.getSystemTimeZone(id);
}
if (result == null) {
result = ZoneMeta.getCustomTimeZone(id);
}
return result;
}
/**
* Sets the default time zone type used by getTimeZone.
* @param type time zone type, either TIMEZONE_ICU or
* TIMEZONE_JDK.
* @hide unsupported on Android
*/
public static synchronized void setDefaultTimeZoneType(int type) {
if (type != TIMEZONE_ICU && type != TIMEZONE_JDK) {
throw new IllegalArgumentException("Invalid timezone type");
}
TZ_IMPL = type;
}
/**
* [icu] Returns the default time zone type currently used.
* @return The default time zone type, either TIMEZONE_ICU or
* TIMEZONE_JDK.
* @hide unsupported on Android
*/
public static int getDefaultTimeZoneType() {
return TZ_IMPL;
}
/**
* [icu] Returns a set of time zone ID strings with the given filter conditions.
* Set returned by this method is
* immutable.
* @param zoneType The system time zone type.
* @param region The ISO 3166 two-letter country code or UN M.49 three-digit area code.
* When null, no filtering done by region.
* @param rawOffset An offset from GMT in milliseconds, ignoring the effect of daylight savings
* time, if any. When null, no filtering done by zone offset.
* @return an immutable set of system time zone IDs.
* @see SystemTimeZoneType
*/
public static Setget() to construct the corresponding TimeZone
* object.
* @param rawOffset the offset in milliseconds from GMT
* @return an array of IDs for system TimeZones with the given
* raw offset. If there are none, return a zero-length array.
* @see #getAvailableIDs(SystemTimeZoneType, String, Integer)
*/
public static String[] getAvailableIDs(int rawOffset) {
Setget() to construct the corresponding TimeZone
* object.
* @param country a two-letter ISO 3166 country code, or null
* to return zones not associated with any country
* @return an array of IDs for system TimeZones in the given
* country. If there are none, return a zero-length array.
* @see #getAvailableIDs(SystemTimeZoneType, String, Integer)
*/
public static String[] getAvailableIDs(String country) {
Setget() to construct the corresponding TimeZone
* object.
* @return an array of all system TimeZone IDs
* @see #getAvailableIDs(SystemTimeZoneType, String, Integer)
*/
public static String[] getAvailableIDs() {
SetcountEquivalentIDs(id). For
* some value of 'index', the returned value will be equal to the
* given id. If the given id is not a valid system time zone, or
* if 'index' is out of range, then returns an empty string.
* @param id a system time zone ID
* @param index a value from 0 to n-1, where n is the value
* returned by countEquivalentIDs(id)
* @return the ID of the index-th zone in the equivalency group
* containing 'id', or an empty string if 'id' is not a valid
* system ID or 'index' is out of range
* @see #countEquivalentIDs
*/
public static String getEquivalentID(String id, int index) {
return ZoneMeta.getEquivalentID(id, index);
}
/**
* If the locale contains the timezone keyword, creates a copy of that
* TimeZone.
* Otherwise, create the default TimeZone.
* @param locale a locale which may contains 'timezone' keyword/value.
* @return A TimeZone. Clients are responsible for deleting the
* TimeZone object returned.
* @deprecated This API is ICU internal only.
* @hide draft / provisional / internal are hidden on Android
*/
@Deprecated
public static TimeZone forULocaleOrDefault(ULocale locale) {
String tz = locale.getKeywordValue("timezone");
return (tz == null) ? getDefault() : getTimeZone(tz);
}
/**
* If the locale contains the timezone keyword, creates a copy of that
* TimeZone.
* Otherwise, create the default TimeZone.
* @param locale a locale which may contains 'timezone' keyword/value.
* @return A TimeZone. Clients are responsible for deleting the
* TimeZone object returned.
* @deprecated This API is ICU internal only.
* @hide draft / provisional / internal are hidden on Android
*/
@Deprecated
public static TimeZone forLocaleOrDefault(Locale locale) {
return forULocaleOrDefault(ULocale.forLocale(locale));
}
/**
* Gets the default TimeZone for this host.
* The source of the default TimeZone
* may vary with implementation.
* @return a default TimeZone.
*/
public static TimeZone getDefault() {
// Copy the reference to the current defaultZone,
// so it won't be affected by setDefault().
TimeZone tmpDefaultZone = defaultZone;
if (tmpDefaultZone == null) {
synchronized (java.util.TimeZone.class) {
synchronized(TimeZone.class) {
tmpDefaultZone = defaultZone;
if (tmpDefaultZone == null) {
if (TZ_IMPL == TIMEZONE_JDK) {
tmpDefaultZone = new JavaTimeZone();
} else {
java.util.TimeZone temp = java.util.TimeZone.getDefault();
tmpDefaultZone = getFrozenTimeZone(temp.getID());
}
defaultZone = tmpDefaultZone;
}
}
}
}
return tmpDefaultZone.cloneAsThawed();
}
/**
* Sets the TimeZone that is returned by the getDefault
* method. This method also sets a Java TimeZone equivalent to the input tz
* as the JVM's default time zone if not null. If tz is null, next
* {@link #getDefault()} method invocation will reset the default time zone
* synchronized with the JVM's default at that time.
*
* @param tz the new default time zone
* @hide unsupported on Android
*/
public static synchronized void setDefault(TimeZone tz) {
// Set default ICU time zone, used by #getDefault()
setICUDefault(tz);
if (tz != null) {
// Keep java.util.TimeZone default in sync so java.util.Date
// can interoperate with android.icu.util classes.
java.util.TimeZone jdkZone = null;
if (tz instanceof JavaTimeZone) {
jdkZone = ((JavaTimeZone)tz).unwrap();
} else if (tz instanceof android.icu.impl.OlsonTimeZone) {
// Because of the lack of APIs supporting historic
// zone offset/dst saving in JDK TimeZone,
// wrapping ICU TimeZone with JDK TimeZone will
// cause historic offset calculation in Calendar/Date.
// JDK calendar implementation calls getRawOffset() and
// getDSTSavings() when the instance of JDK TimeZone
// is not an instance of JDK internal TimeZone subclass
// (sun.util.calendar.ZoneInfo). Ticket#6459
String icuID = tz.getID();
jdkZone = java.util.TimeZone.getTimeZone(icuID);
if (!icuID.equals(jdkZone.getID())) {
// If the ID was unknown, retry with the canonicalized
// ID instead. This will ensure that JDK 1.1.x
// compatibility IDs supported by ICU (but not
// necessarily supported by the platform) work.
// Ticket#11483
icuID = getCanonicalID(icuID);
jdkZone = java.util.TimeZone.getTimeZone(icuID);
if (!icuID.equals(jdkZone.getID())) {
// JDK does not know the ID..
jdkZone = null;
}
}
}
if (jdkZone == null) {
jdkZone = TimeZoneAdapter.wrap(tz);
}
java.util.TimeZone.setDefault(jdkZone);
}
}
/**
* Sets the TimeZone that is returned by the getDefault
* method. If tz is null, next {@link #getDefault()} method invocation
* will reset the default time zone synchronized with the JVM's default at that time.
* Unlike {@link #setDefault(TimeZone)}, this method does not change the JVM's
* default time zone.
*
* @param tz the new default time zone
* @deprecated This API is ICU internal only.
* @hide draft / provisional / internal are hidden on Android
*/
@Deprecated
public static synchronized void setICUDefault(TimeZone tz) {
if (tz == null) {
defaultZone = null;
} else if (tz.isFrozen()) {
// No need to create a defensive copy
defaultZone = tz;
} else {
// Creates a defensive copy and freeze it
defaultZone = ((TimeZone)tz.clone()).freeze();
}
}
/**
* Returns true if this zone has the same rule and offset as another zone.
* That is, if this zone differs only in ID, if at all. Returns false
* if the other zone is null.
* @param other the TimeZone object to be compared with
* @return true if the other zone is not null and is the same as this one,
* with the possible exception of the ID
*/
public boolean hasSameRules(TimeZone other) {
return other != null &&
getRawOffset() == other.getRawOffset() &&
useDaylightTime() == other.useDaylightTime();
}
/**
* Overrides clone.
*/
@Override
public Object clone() {
if (isFrozen()) {
return this;
}
return cloneAsThawed();
}
/**
* Overrides equals.
* @return true if this object is the same as the obj argument; false otherwise.
*/
@Override
public boolean equals(Object obj){
if (this == obj) return true;
if (obj == null || getClass() != obj.getClass()) return false;
return (ID.equals(((TimeZone)obj).ID));
}
/**
* Overrides hashCode.
* @return a hash code value for this object.
*/
@Override
public int hashCode(){
return ID.hashCode();
}
/**
* [icu] Returns the time zone data version currently used by ICU.
*
* @return the version string, such as "2007f"
* @throws MissingResourceException if ICU time zone resource bundle
* is missing or the version information is not available.
*/
public static String getTZDataVersion() {
// The implementation had been moved to VersionInfo.
return VersionInfo.getTZDataVersion();
}
/**
* [icu] Returns the canonical system time zone ID or the normalized
* custom time zone ID for the given time zone ID.
* @param id The input time zone ID to be canonicalized.
* @return The canonical system time zone ID or the custom time zone ID
* in normalized format for the given time zone ID. When the given time zone ID
* is neither a known system time zone ID nor a valid custom time zone ID,
* null is returned.
*/
public static String getCanonicalID(String id) {
return getCanonicalID(id, null);
}
/**
* [icu] Returns the canonical system time zone ID or the normalized
* custom time zone ID for the given time zone ID.
* @param id The input time zone ID to be canonicalized.
* @param isSystemID When non-null boolean array is specified and
* the given ID is a known system time zone ID, true is set to isSystemID[0]
* @return The canonical system time zone ID or the custom time zone ID
* in normalized format for the given time zone ID. When the given time zone ID
* is neither a known system time zone ID nor a valid custom time zone ID,
* null is returned.
*/
public static String getCanonicalID(String id, boolean[] isSystemID) {
String canonicalID = null;
boolean systemTzid = false;
if (id != null && id.length() != 0) {
if (id.equals(TimeZone.UNKNOWN_ZONE_ID)) {
// special case - Etc/Unknown is a canonical ID, but not system ID
canonicalID = TimeZone.UNKNOWN_ZONE_ID;
systemTzid = false;
} else {
canonicalID = ZoneMeta.getCanonicalCLDRID(id);
if (canonicalID != null) {
systemTzid = true;
} else {
canonicalID = ZoneMeta.getCustomID(id);
}
}
}
if (isSystemID != null) {
isSystemID[0] = systemTzid;
}
return canonicalID;
}
/**
* Returns the preferred time zone ID in the IANA database for the given time zone ID.
* There are two types of preferred IDs. The first type is the one defined in zone.tab file,
* such as "America/Los_Angeles". The second types is the one defined for zones not associated
* with a specific region, but not defined with "Link" syntax, such as "Etc/GMT+10".
*
* id is not a known system ID.
* @see #getAvailableIDs(String)
*/
public static String getRegion(String id) {
String region = null;
// "Etc/Unknown" is not a system time zone ID,
// but in the zone data.
if (!id.equals(UNKNOWN_ZONE_ID)) {
region = ZoneMeta.getRegion(id);
}
if (region == null) {
// unknown id
throw new IllegalArgumentException("Unknown system zone id: " + id);
}
return region;
}
/**
* [icu] Converts a system time zone ID to an equivalent Windows time zone ID. For example,
* Windows time zone ID "Pacific Standard Time" is returned for input "America/Los_Angeles".
*
* null.
*
* null when the input ID is unknown or unmappable.
* @see #getIDForWindowsID(String, String)
*/
public static String getWindowsID(String id) {
// canonicalize the input ID
boolean[] isSystemID = {false};
id = getCanonicalID(id, isSystemID);
if (!isSystemID[0]) {
// mapping data is only applicable to tz database IDs
return null;
}
UResourceBundle top = UResourceBundle.getBundleInstance(
ICUData.ICU_BASE_NAME, "windowsZones", ICUResourceBundle.ICU_DATA_CLASS_LOADER);
UResourceBundle mapTimezones = top.get("mapTimezones");
UResourceBundleIterator resitr = mapTimezones.getIterator();
while (resitr.hasNext()) {
UResourceBundle winzone = resitr.next();
if (winzone.getType() != UResourceBundle.TABLE) {
continue;
}
UResourceBundleIterator rgitr = winzone.getIterator();
while (rgitr.hasNext()) {
UResourceBundle regionalData = rgitr.next();
if (regionalData.getType() != UResourceBundle.STRING) {
continue;
}
String[] tzids = regionalData.getString().split(" ");
for (String tzid : tzids) {
if (tzid.equals(id)) {
return winzone.getKey();
}
}
}
}
return null;
}
/**
* [icu] Converts a Windows time zone ID to an equivalent system time zone ID
* for a region. For example, system time zone ID "America/Los_Angeles" is returned
* for input Windows ID "Pacific Standard Time" and region "US" (or null),
* "America/Vancouver" is returned for the same Windows ID "Pacific Standard Time" and
* region "CA".
*
* null.
*
* null if no regional preference.
* @return A system time zone ID mapped from the input Windows time zone ID,
* or null when the input ID is unknown or unmappable.
* @see #getWindowsID(String)
*/
public static String getIDForWindowsID(String winid, String region) {
String id = null;
UResourceBundle top = UResourceBundle.getBundleInstance(
ICUData.ICU_BASE_NAME, "windowsZones", ICUResourceBundle.ICU_DATA_CLASS_LOADER);
UResourceBundle mapTimezones = top.get("mapTimezones");
try {
UResourceBundle zones = mapTimezones.get(winid);
if (region != null) {
try {
id = zones.getString(region);
if (id != null) {
// first ID delimited by space is the default one
int endIdx = id.indexOf(' ');
if (endIdx > 0) {
id = id.substring(0, endIdx);
}
}
} catch (MissingResourceException e) {
// no explicit region mapping found
}
}
if (id == null) {
id = zones.getString("001");
}
} catch (MissingResourceException e) {
// no mapping data found
}
return id;
}
// Freezable stuffs
/**
* {@inheritDoc}
*/
@Override
public boolean isFrozen() {
return false;
}
/**
* {@inheritDoc}
*/
@Override
public TimeZone freeze() {
throw new UnsupportedOperationException("Needs to be implemented by the subclass.");
}
/**
* {@inheritDoc}
*/
@Override
public TimeZone cloneAsThawed() {
try {
TimeZone other = (TimeZone) super.clone();
return other;
} catch (CloneNotSupportedException e) {
throw new ICUCloneNotSupportedException(e);
}
}
// =======================privates===============================
/**
* The string identifier of this TimeZone. This is a
* programmatic identifier used internally to look up TimeZone
* objects from the system table and also to map them to their localized
* display names. ID values are unique in the system
* table but may not be for dynamically created zones.
* @serial
*/
private String ID;
/**
* The default time zone, or null if not set.
*/
private static volatile TimeZone defaultZone = null;
/**
* TimeZone implementation type
*/
private static int TZ_IMPL = TIMEZONE_ICU;
/**
* TimeZone implementation type initialization
*/
private static final String TZIMPL_CONFIG_KEY = "android.icu.util.TimeZone.DefaultTimeZoneType";
private static final String TZIMPL_CONFIG_ICU = "ICU";
private static final String TZIMPL_CONFIG_JDK = "JDK";
static {
String type = ICUConfig.get(TZIMPL_CONFIG_KEY, TZIMPL_CONFIG_ICU);
if (type.equalsIgnoreCase(TZIMPL_CONFIG_JDK)) {
TZ_IMPL = TIMEZONE_JDK;
}
}
/*
* ConstantZone is a private TimeZone subclass dedicated for the two TimeZone class
* constants - TimeZone.GMT_ZONE and TimeZone.UNKNOWN_ZONE. Previously, these zones
* are instances of SimpleTimeZone. However, when the SimpleTimeZone constructor and
* TimeZone's static methods (such as TimeZone.getDefault()) are called from multiple
* threads at the same time, it causes a deadlock by TimeZone's static initializer
* and SimpleTimeZone's static initializer. To avoid this issue, these TimeZone
* constants (GMT/UNKNOWN) must be implemented by a class not visible from users.
* See ticket#11343.
*/
private static final class ConstantZone extends TimeZone {
private static final long serialVersionUID = 1L;
private int rawOffset;
private ConstantZone(int rawOffset, String ID) {
super(ID);
this.rawOffset = rawOffset;
}
@Override
public int getOffset(int era, int year, int month, int day, int dayOfWeek, int milliseconds) {
return rawOffset;
}
@Override
public void setRawOffset(int offsetMillis) {
if (isFrozen()) {
throw new UnsupportedOperationException("Attempt to modify a frozen TimeZone instance.");
}
rawOffset = offsetMillis;
}
@Override
public int getRawOffset() {
return rawOffset;
}
@Override
public boolean useDaylightTime() {
return false;
}
@Override
public boolean inDaylightTime(Date date) {
return false;
}
private volatile transient boolean isFrozen = false;
@Override
public boolean isFrozen() {
return isFrozen;
}
@Override
public TimeZone freeze() {
isFrozen = true;
return this;
}
@Override
public TimeZone cloneAsThawed() {
ConstantZone tz = (ConstantZone)super.cloneAsThawed();
tz.isFrozen = false;
return tz;
}
}
}
//eof