java.util.TimeZone Maven / Gradle / Ivy
/*
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This work corresponds to the API signatures of JSR 219: Foundation
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*/
package java.util;
import java.io.Serializable;
import java.lang.ref.SoftReference;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.text.SimpleDateFormat;
/**
* TimeZone represents a time zone offset, and also figures out daylight
* savings.
*
*
* Typically, you get a TimeZone using 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 getTimeZone
* 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 getAvailableIDs method to iterate through
* all the supported time zone IDs. 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 a custom time zone ID can be specified to
* produce a TimeZone. The syntax of a custom time zone ID is:
*
*
* CustomID:
* GMT Sign Hours : Minutes
* GMT Sign Hours Minutes
* GMT Sign Hours
* Sign: one of
* + -
* Hours:
* Digit
* Digit Digit
* Minutes:
* Digit Digit
* Digit: one of
* 0 1 2 3 4 5 6 7 8 9
*
*
* Hours must be between 0 to 23 and Minutes must be
* between 00 to 59. For example, "GMT+10" and "GMT+0010" mean ten
* hours and ten minutes ahead of GMT, respectively.
*
* The format is locale independent and digits must be taken from the
* Basic Latin block of the Unicode standard. No daylight saving time
* transition schedule can be specified with a custom time zone ID. If
* the specified string doesn't match the syntax, "GMT"
* is used.
*
* When creating a TimeZone, the specified custom time
* zone ID is normalized in the following syntax:
*
* NormalizedCustomID:
* GMT Sign TwoDigitHours : Minutes
* Sign: one of
* + -
* TwoDigitHours:
* Digit Digit
* Minutes:
* Digit Digit
* Digit: one of
* 0 1 2 3 4 5 6 7 8 9
*
* For example, TimeZone.getTimeZone("GMT-8").getID() returns "GMT-08:00".
*
* Three-letter time zone IDs
*
* 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
* @see SimpleTimeZone
* @version 1.58, 10/25/05
* @author Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu
* @since JDK1.1
*/
public abstract class TimeZone implements Serializable, Cloneable
{
/**
* A style specifier for getDisplayName() indicating
* a short name, such as "PST."
* @see #LONG
* @since 1.2
*/
public static final int SHORT = 0;
/**
* A style specifier for getDisplayName() indicating
* a long name, such as "Pacific Standard Time."
* @see #SHORT
* @since 1.2
*/
public static final int LONG = 1;
/**
* 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;
static final long serialVersionUID = 3581463369166924961L;
/**
* Sole constructor. (For invocation by subclass constructors, typically
* implicit.)
*/
public TimeZone() { }
/**
* 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.
*
* This method returns a historically correct offset if an
* underlying TimeZone implementation subclass
* supports historical Daylight Saving Time schedule and GMT
* offset changes.
*
* @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 milliseconds in day in standard
* local time.
*
* @return the offset in milliseconds to add to GMT to get local time.
*
* @see Calendar#ZONE_OFFSET
* @see Calendar#DST_OFFSET
*/
public abstract 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.
*
* This method returns a historically correct offset value if an
* underlying TimeZone implementation subclass supports historical
* Daylight Saving Time schedule and GMT offset changes.
*
* @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
* @since 1.4
*/
public int getOffset(long date) {
return 0;
}
/**
* Sets the base time zone offset to GMT.
* This is the offset to add to UTC to get local time.
*
* If an underlying TimeZone implementation subclass
* supports historical GMT offset changes, the specified GMT
* offset is set as the latest GMT offset and the difference from
* the known latest GMT offset value is used to adjust all
* historical GMT offset values.
*
* @param offsetMillis the given base time zone offset to GMT.
*/
public abstract void setRawOffset(int offsetMillis);
/**
* Returns the amount of time in milliseconds to add to UTC to get
* standard time in this time zone. Because this value is not
* affected by daylight saving time, it is called raw
* offset.
*
* If an underlying TimeZone implementation subclass
* supports historical GMT offset changes, the method returns the
* raw offset value of the current date. In Honolulu, for example,
* its raw offset changed from GMT-10:30 to GMT-10:00 in 1947, and
* this method always returns -36000000 milliseconds (i.e., -10
* hours).
*
* @return the amount of raw offset time in milliseconds to add to UTC.
* @see Calendar#ZONE_OFFSET
*/
public abstract int getRawOffset();
/**
* Gets the ID of this time zone.
* @return the ID of this time zone.
*/
public String getID() {
return null;
}
/**
* 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) { }
/**
* Returns a name of this time zone suitable for presentation to the user
* in the default locale.
* This method returns the long name, not including daylight savings.
* If the display name is not available for the locale,
* then this method returns a string in the
* normalized custom ID format.
* @return the human-readable name of this time zone in the default locale.
* @since 1.2
*/
public final String getDisplayName() {
return null;
}
/**
* 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,
* then this method returns a string in the
* normalized custom ID format.
* @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.
* @since 1.2
*/
public final String getDisplayName(Locale locale) {
return null;
}
/**
* Returns a name of this time zone suitable for presentation to the user
* in the default locale.
* If the display name is not available for the locale, then this
* method returns a string in the
* normalized custom ID format.
* @param daylight if true, return the daylight savings name.
* @param style either LONG or SHORT
* @return the human-readable name of this time zone in the default locale.
* @since 1.2
*/
public final String getDisplayName(boolean daylight, int style) {
return null;
}
/**
* 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
* normalized custom ID format.
* @param daylight if true, return the daylight savings name.
* @param style either LONG or SHORT
* @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.
* @since 1.2
*/
public String getDisplayName(boolean daylight, int style, Locale locale) {
return null;
}
/**
* Returns the amount of time to be added to local standard time
* to get local wall clock time.
*
* 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
* @since 1.4
*/
public int getDSTSavings() {
return 0;
}
/**
* Queries if this time zone uses daylight savings time.
*
* If an underlying TimeZone implementation subclass
* supports historical Daylight Saving Time schedule changes, the
* method refers to the latest Daylight Saving Time schedule
* information.
*
* @return true if this time zone uses daylight savings time,
* false, otherwise.
*/
public abstract boolean useDaylightTime();
/**
* 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.
*/
public abstract boolean inDaylightTime(Date date);
/**
* Gets the TimeZone for the given ID.
*
* @param ID the ID for a TimeZone, either an abbreviation
* such as "PST", a full name such as "America/Los_Angeles", or a custom
* ID such as "GMT-8:00". Note that the support of abbreviations is
* for JDK 1.1.x compatibility only and full names should be used.
*
* @return the specified TimeZone, or the GMT zone if the given ID
* cannot be understood.
*/
public static synchronized TimeZone getTimeZone(String ID) {
return null;
}
/**
* Gets the available IDs according to the given time zone offset.
* @param rawOffset the given time zone GMT offset.
* @return an array of IDs, where the time zone for that ID has
* the specified GMT offset. For example, "America/Phoenix" and "America/Denver"
* both have GMT-07:00, but differ in daylight savings behavior.
*/
public static synchronized String[] getAvailableIDs(int rawOffset) {
return null;
}
/**
* Gets all the available IDs supported.
* @return an array of IDs.
*/
public static synchronized String[] getAvailableIDs() {
return null;
}
/**
* Gets the default TimeZone for this host.
* The source of the default TimeZone
* may vary with implementation.
* @return a default TimeZone.
* @see #setDefault
*/
public static synchronized TimeZone getDefault() {
return null;
}
/**
* Sets the TimeZone that is
* returned by the getDefault method. If zone
* is null, reset the default to the value it had originally when the
* VM first started.
* @param zone the new default time zone
* @see #getDefault
*/
public static synchronized void setDefault(TimeZone zone) { }
/**
* 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
* @since 1.2
*/
public boolean hasSameRules(TimeZone other) {
return false;
}
/**
* Creates a copy of this TimeZone.
*
* @return a clone of this TimeZone
*/
public Object clone() {
return null;
}
}