public abstract class TimeZoneNames extends Object implements Serializable
TimeZoneNames
is an abstract class representing the time zone display name data model defined
by UTS#35 Unicode Locale Data Markup Language (LDML).
The model defines meta zone, which is used for storing a set of display names. A meta zone can be shared
by multiple time zones. Also a time zone may have multiple meta zone historic mappings.
For example, people in the United States refer the zone used by the east part of North America as "Eastern Time". The tz database contains multiple time zones "America/New_York", "America/Detroit", "America/Montreal" and some others that belong to "Eastern Time". However, assigning different display names to these time zones does not make much sense for most of people.
In CLDR (which uses LDML for representing locale data), the display name "Eastern Time" is stored as long generic display name of a meta zone identified by the ID "America_Eastern". Then, there is another table maintaining the historic mapping to meta zones for each time zone. The time zones in the above example ("America/New_York", "America/Detroit"...) are mapped to the meta zone "America_Eastern".
Sometimes, a time zone is mapped to a different time zone in the past. For example, "America/Indiana/Knox" had been moving "Eastern Time" and "Central Time" back and forth. Therefore, it is necessary that time zone to meta zones mapping data are stored by date range.
Note:
TimeZoneFormat
assumes an instance of TimeZoneNames
is immutable. If you want to provide
your own TimeZoneNames
implementation and use it with TimeZoneFormat
, you must follow
the contract.
The methods in this class assume that time zone IDs are already canonicalized. For example, you may not get proper
result returned by a method with time zone ID "America/Indiana/Indianapolis", because it's not a canonical time zone
ID (the canonical time zone ID for the time zone is "America/Indianapolis". See
TimeZone.getCanonicalID(String)
about ICU canonical time zone IDs.
In CLDR, most of time zone display names except location names are provided through meta zones. But a time zone may have a specific name that is not shared with other time zones. For example, time zone "Europe/London" has English long name for standard time "Greenwich Mean Time", which is also shared with other time zones. However, the long name for daylight saving time is "British Summer Time", which is only used for "Europe/London".
getTimeZoneDisplayName(String, NameType)
is designed for accessing a name only used by a single time zone.
But is not necessarily mean that a subclass implementation use the same model with CLDR. A subclass implementation
may provide time zone names only through getTimeZoneDisplayName(String, NameType)
, or only through
getMetaZoneDisplayName(String, NameType)
, or both.
The default TimeZoneNames
implementation returned by getInstance(ULocale)
uses the locale data
imported from CLDR. In CLDR, set of meta zone IDs and mappings between zone IDs and meta zone IDs are shared by all
locales. Therefore, the behavior of getAvailableMetaZoneIDs()
, getAvailableMetaZoneIDs(String)
,
getMetaZoneID(String, long)
, and getReferenceZoneID(String, String)
won't be changed no matter
what locale is used for getting an instance of TimeZoneNames
.
Modifier and Type | Class and Description |
---|---|
static class |
TimeZoneNames.Factory
Deprecated.
This API is ICU internal only.
|
static class |
TimeZoneNames.MatchInfo
A
MatchInfo represents a time zone name match used by
find(CharSequence, int, EnumSet) . |
static class |
TimeZoneNames.NameType
Time zone display name types
|
Modifier | Constructor and Description |
---|---|
protected |
TimeZoneNames()
Sole constructor for invocation by subclass constructors.
|
Modifier and Type | Method and Description |
---|---|
Collection<TimeZoneNames.MatchInfo> |
find(CharSequence text,
int start,
EnumSet<TimeZoneNames.NameType> types)
Finds time zone name prefix matches for the input text at the
given offset and returns a collection of the matches.
|
abstract Set<String> |
getAvailableMetaZoneIDs()
Returns an immutable set of all available meta zone IDs.
|
abstract Set<String> |
getAvailableMetaZoneIDs(String tzID)
Returns an immutable set of all available meta zone IDs used by the given time zone.
|
String |
getDisplayName(String tzID,
TimeZoneNames.NameType type,
long date)
Returns the display name of the time zone at the given date.
|
void |
getDisplayNames(String tzID,
TimeZoneNames.NameType[] types,
long date,
String[] dest,
int destOffset)
Deprecated.
This API is ICU internal only.
|
String |
getExemplarLocationName(String tzID)
Returns the exemplar location name for the given time zone.
|
static TimeZoneNames |
getInstance(Locale locale)
Returns an instance of
TimeZoneNames for the specified
Locale . |
static TimeZoneNames |
getInstance(ULocale locale)
Returns an instance of
TimeZoneNames for the specified locale. |
abstract String |
getMetaZoneDisplayName(String mzID,
TimeZoneNames.NameType type)
Returns the display name of the meta zone.
|
abstract String |
getMetaZoneID(String tzID,
long date)
Returns the meta zone ID for the given canonical time zone ID at the given date.
|
abstract String |
getReferenceZoneID(String mzID,
String region)
Returns the reference zone ID for the given meta zone ID for the region.
|
abstract String |
getTimeZoneDisplayName(String tzID,
TimeZoneNames.NameType type)
Returns the display name of the time zone.
|
static TimeZoneNames |
getTZDBInstance(ULocale locale)
Returns an instance of
TimeZoneNames containing only short specific
zone names (TimeZoneNames.NameType.SHORT_STANDARD and TimeZoneNames.NameType.SHORT_DAYLIGHT ),
compatible with the IANA tz database's zone abbreviations (not localized). |
void |
loadAllDisplayNames()
Deprecated.
This API is ICU internal only.
|
protected TimeZoneNames()
public static TimeZoneNames getInstance(ULocale locale)
TimeZoneNames
for the specified locale.locale
- The locale.TimeZoneNames
public static TimeZoneNames getInstance(Locale locale)
TimeZoneNames
for the specified
Locale
.locale
- The Locale
.TimeZoneDisplayNames
public static TimeZoneNames getTZDBInstance(ULocale locale)
TimeZoneNames
containing only short specific
zone names (TimeZoneNames.NameType.SHORT_STANDARD
and TimeZoneNames.NameType.SHORT_DAYLIGHT
),
compatible with the IANA tz database's zone abbreviations (not localized).
public abstract Set<String> getAvailableMetaZoneIDs()
public abstract Set<String> getAvailableMetaZoneIDs(String tzID)
tzID
- The canonical time zone ID.public abstract String getMetaZoneID(String tzID, long date)
tzID
- The canonical time zone ID.date
- The date.public abstract String getReferenceZoneID(String mzID, String region)
mzID
- The meta zone ID.region
- The region.public abstract String getMetaZoneDisplayName(String mzID, TimeZoneNames.NameType type)
mzID
- The meta zone ID.type
- The display name type. See TimeZoneNames.NameType
.public final String getDisplayName(String tzID, TimeZoneNames.NameType type, long date)
Note: This method calls the subclass's getTimeZoneDisplayName(String, NameType)
first. When the
result is null, this method calls getMetaZoneID(String, long)
to get the meta zone ID mapped from the
time zone, then calls getMetaZoneDisplayName(String, NameType)
.
tzID
- The canonical time zone ID.type
- The display name type. See TimeZoneNames.NameType
.date
- The datepublic abstract String getTimeZoneDisplayName(String tzID, TimeZoneNames.NameType type)
getDisplayName(String, NameType, long)
,
this method does not get a name from a meta zone used by the time zone.tzID
- The canonical time zone ID.type
- The display name type. See TimeZoneNames.NameType
.public String getExemplarLocationName(String tzID)
tzID
- The canonical time zone IDpublic Collection<TimeZoneNames.MatchInfo> find(CharSequence text, int start, EnumSet<TimeZoneNames.NameType> types)
text
- the text.start
- the starting offset within the text.types
- the set of name types, or null
for all name types.TimeZoneNames.NameType
,
TimeZoneNames.MatchInfo
@Deprecated public void loadAllDisplayNames()
@Deprecated public void getDisplayNames(String tzID, TimeZoneNames.NameType[] types, long date, String[] dest, int destOffset)
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