SimpleTimeZone is a concrete subclass of TimeZone
that represents a time zone for use with a Gregorian calendar.
The class holds an offset from GMT, called raw offset, and start
and end rules for a daylight saving time schedule. Since it only holds
single values for each, it cannot handle historical changes in the offset
from GMT and the daylight saving schedule, except that the setStartYear
method can specify the year when the daylight
saving time schedule starts in effect.
To construct a SimpleTimeZone with a daylight saving time
schedule, the schedule can be described with a set of rules,
start-rule and end-rule. A day when daylight saving time
starts or ends is specified by a combination of month,
day-of-month, and day-of-week values. The month
value is represented by a Calendar MONTH
field
value, such as Calendar#MARCH
. The day-of-week value is
represented by a Calendar DAY_OF_WEEK
value,
such as SUNDAY
. The meanings of value combinations
are as follows.
-SUNDAY
.-WEDNESDAY
. The following are examples of parameters for constructing time zone objects.
// Base GMT offset: -8:00
// DST starts: at 2:00am in standard time
// on the first Sunday in April
// DST ends: at 2:00am in daylight time
// on the last Sunday in October
// Save: 1 hour
SimpleTimeZone(-28800000,
"America/Los_Angeles",
Calendar.APRIL, 1, -Calendar.SUNDAY,
7200000,
Calendar.OCTOBER, -1, Calendar.SUNDAY,
7200000,
3600000)
// Base GMT offset: +1:00
// DST starts: at 1:00am in UTC time
// on the last Sunday in March
// DST ends: at 1:00am in UTC time
// on the last Sunday in October
// Save: 1 hour
SimpleTimeZone(3600000,
"Europe/Paris",
Calendar.MARCH, -1, Calendar.SUNDAY,
3600000, SimpleTimeZone.UTC_TIME,
Calendar.OCTOBER, -1, Calendar.SUNDAY,
3600000, SimpleTimeZone.UTC_TIME,
3600000)
setStartRule.
startTime and endTime are specified to be
represented in the wall clock time. The amount of daylight saving is
assumed to be 3600000 milliseconds (i.e., one hour). This constructor is
equivalent to:
SimpleTimeZone(rawOffset,
ID,
startMonth,
startDay,
startDayOfWeek,
startTime,
SimpleTimeZone.#WALL_TIME
,
endMonth,
endDay,
endDayOfWeek,
endTime,
SimpleTimeZone.#WALL_TIME
,
3600000)
startTime and endTime are assumed to be
represented in the wall clock time. This constructor is equivalent to:
SimpleTimeZone(rawOffset,
ID,
startMonth,
startDay,
startDayOfWeek,
startTime,
SimpleTimeZone.#WALL_TIME
,
endMonth,
endDay,
endDayOfWeek,
endTime,
SimpleTimeZone.#WALL_TIME
,
dstSavings)
startTime and
endTime. The mode specifies either wall
time
or standard time
or UTC
time
.getDisplayName() indicating
a long name, such as "Pacific Standard Time."getDisplayName() indicating
a short name, such as "PST."SimpleTimeZone instance.SimpleTimeZone objects.TimeZone for this host.
The source of the default TimeZone
may vary with implementation.GregorianCalendar.
Note: In general, clients should use
Calendar.get(ZONE_OFFSET) + Calendar.get(DST_OFFSET)
instead of calling this method.
TimeZone for the given ID.true if this zone has the same rules and offset as another zone.wait methods.
The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:
synchronized statement
that synchronizes on the object.
Class, by executing a
synchronized static method of that class.
Only one thread at a time can own an object's monitor.
wait methods.
The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
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.setEndRule(endMonth, endDay, 0, endTime)setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2*60*60*1000);setStartRule(startMonth, startDay, 0, startTime)setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2*60*60*1000);
The current thread must own this object's monitor. The thread
releases ownership of this monitor and waits until another thread
notifies threads waiting on this object's monitor to wake up
either through a call to the notify method or the
notifyAll method. The thread then waits until it can
re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait();
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.The current thread must own this object's monitor.
This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:
A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout);
... // Perform action appropriate to condition
}
(For more information on this topic, see Section 3.2.3 in Doug Lea's
"Concurrent Programming in Java (Second Edition)" (Addison-Wesley,
2000), or Item 50 in Joshua Bloch's "Effective Java Programming
Language Guide" (Addison-Wesley, 2001).
If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.
Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
This method is similar to the wait method of one
argument, but it allows finer control over the amount of time to
wait for a notification before giving up. The amount of real time,
measured in nanoseconds, is given by:
1000000*timeout+nanos
In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).
The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:
notify method
or the notifyAll method.
timeout
milliseconds plus nanos nanoseconds arguments, has
elapsed.
The thread then waits until it can re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout, nanos);
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.