Java Reference
In-Depth Information
java.util.Calendar get()
method. When some method or class is deprec-
ated, that means it should no longer be used because it might be removed in some fu-
ture release of the Java language. However, a few of the methods contained within the
Date
class have not been tagged as deprecated, so the
Date
class will most likely be
included in future releases of Java. The methods that were left intact include the com-
parison methods
after(), before(), compareTo(), setTime()
, and
equals()
. Solution #2 to this recipe demonstrates how to instantiate a
Date
object
and print out the current date and time.
As mentioned previously, the
Date
class has many methods that have become de-
precated and should no longer be used. In solution #3 of this recipe, the
java.util.Calendar
class is demonstrated as one successor for obtaining much
of this information. The
Calendar
class was introduced in JDK 1.1, at which time
many of the
Date
methods were deprecated. As you can see from solution #3, the
Calendar
class contains all the same functionality that is included in the
Date
class,
except the
Calendar
class is much more flexible. The
Calendar
class is actually
an abstract class that contains methods that are used for converting between a specific
time and date, and manipulating the calendar in various ways. The
Calendar
, as
demonstrated in solution #3, is one such class that extends the
Calendar
class and
therefore provides this functionality. The
Calendar
class has gained a few new meth-
Method Name
Description
Returns un-modifiable set containing all supported
calendar types.
getAvailableCalendarTypes()
Returns the calendar type of this calendar.
getCalendarType()
Converts to an instant.
toInstant()
For some applications, the
Date
class will work fine. For instance, the
Date
class
can be useful when working with timestamps. However, if the application requires de-
tailed manipulation of dates and times then it is advisable to use a
LocalDateTime
or the
Calendar
class, which both include all the functionality of the
Date class
and more features as well. All solutions to this recipe are technically sound; choose the
one that best suits the needs of your application.
