Java Reference
In-Depth Information
2014-12-27T05:36:42.199Z[GMT]
Yesterday: 2014-12-26T05:36:42.253Z
How It Works
The Date-Time API introduces a new class named
Instant
, which represents the
start of a nanosecond on the timeline in machine-based time. Being based on machine
time, the value for an
Instant
counts from the
EPOCH
(January 1, 1970 00:00:00Z).
Any values prior to the
EPOCH
are negative, and after the
EPOCH
the values are posit-
ive. The
Instant
class is perfect for obtaining a machine timestamp, as it includes all
pertinent date and time information to the nanosecond.
An
Instant
class is static and immutable, so to obtain the current timestamp, the
now()
method can be called. Doing so returns a copy of the current
Instant
. The
Instant
also includes conversion and calculation methods, each returning copies of
the
Instant
or other types. In the solution, the
now()
method returns the current
timestamp, and then a couple of examples follow, showing how to perform calculations
and obtain information on the
Instant
.
The
Instant
is an important new feature in JDK 8, as it makes it easy to work
with current time and date data. The other date and time classes, such as
LocalDateTime
, are useful as well. However, the
Instant
is the most accurate
timestamp as it's based on nanosecond accuracy.
4-13. Converting Dates and Times Based
on the Time Zone
Problem
The application you are developing has the potential to be utilized throughout the
world. In some areas of the application, static dates and times need to be displayed,
rather than the system date and time. In such cases, those static dates and times need to
be converted to suit the particular time zone in which the application user is currently
residing.
Solution