New Date-Time API in Java 8
New date-time API is introduced in Java 8 to overcome the following drawbacks of old date-time API :
- Not thread safe : Unlike old java.util.Date which is not thread safe the new date-time API is immutable and doesn’t have setter methods.
- Less operations : In old API there are only few date operations but the new API provides us with many date operations.
Java 8 under the package java.time introduced a new date-time API, most important classes among them are :
- Local : Simplified date-time API with no complexity of timezone handling.
- Zoned : Specialized date-time API to deal with various timezones.
- LocalDate/LocatTime and LocalDateTime API : Use it when time zones are NOT required.
// Java code for LocalDate
// / LocalTime Function
import
java.time.*;
import
java.time.format.DateTimeFormatter;
public
class
Date {
public
static
void
LocalDateTimeApi()
{
// the current date
LocalDate date = LocalDate.now();
System.out.println(
"the current date is "
+
date);
// the current time
LocalTime time = LocalTime.now();
System.out.println(
"the current time is "
+
time);
// will give us the current time and date
LocalDateTime current = LocalDateTime.now();
System.out.println(
"current date and time : "
+
current);
// to print in a particular format
DateTimeFormatter format =
DateTimeFormatter.ofPattern(
"dd-MM-yyyy HH:mm:ss"
);
String formatedDateTime = current.format(format);
System.out.println(
"in foramatted manner "
+
formatedDateTime);
// printing months days and seconds
Month month = current.getMonth();
int
day = current.getDayOfMonth();
int
seconds = current.getSecond();
System.out.println(
"Month : "
+month+
" day : "
+
day+
" seconds : "
+seconds);
// printing some specified date
LocalDate date2 = LocalDate.of(
1950
,
1
,
26
);
System.out.println(
"the repulic day :"
+date2);
// printing date with current time.
LocalDateTime specificDate =
current.withDayOfMonth(
24
).withYear(
2016
);
System.out.println(
"specfic date with "
+
"current time : "
+specificDate);
}
// Driver code
public
static
void
main(String[] args)
{
LocalDateTimeApi();
}
}
Output:the current date is 2018-04-09 the current time is 06:21:10.409 current date and time : 2018-04-09T06:21:10.410 in foramatted manner 09-04-2018 06:21:10 Month : APRIL day : 9 seconds : 10 the repulic day :1950-01-26 specfic date with current time : 2016-04-24T06:21:10.410
- Zoned date-time API : Use it when time zones are to be considered
// Java code for Zoned date-time API
import
java.time.LocalDateTime;
import
java.time.ZoneId;
import
java.time.ZonedDateTime;
import
java.time.format.DateTimeFormatter;
public
class
Zone {
// Function to get Zoned Date and Time
public
static
void
ZonedTimeAndDate()
{
LocalDateTime date = LocalDateTime.now();
DateTimeFormatter format1 =
DateTimeFormatter.ofPattern(
"dd-MM-yyyy HH:mm:ss"
);
String formattedCurrentDate = date.format(format1);
System.out.println(
"formatted current Date and"
+
" Time : "
+formattedCurrentDate);
// to get the current zone
ZonedDateTime currentZone = ZonedDateTime.now();
System.out.println(
"the current zone is "
+
currentZone.getZone());
// getting time zone of specific place
// we use withZoneSameInstant(): it is
// used to return a copy of this date-time
// with a different time-zone,
// retaining the instant.
ZoneId tokyo = ZoneId.of(
"Asia/Tokyo"
);
ZonedDateTime tokyoZone =
currentZone.withZoneSameInstant(tokyo);
System.out.println(
"tokyo time zone is "
+
tokyoZone);
DateTimeFormatter format =
DateTimeFormatter.ofPattern(
"dd-MM-yyyy HH:mm:ss"
);
String formatedDateTime = tokyoZone.format(format);
System.out.println(
"formatted tokyo time zone "
+
formatedDateTime);
}
// Driver code
public
static
void
main(String[] args)
{
ZonedTimeAndDate();
}
}
Output:formatted current Date and Time : 09-04-2018 06:21:13 the current zone is Etc/UTC tokyo time zone is 2018-04-09T15:21:13.220+09:00[Asia/Tokyo] formatted tokyo time zone 09-04-2018 15:21:13
- Period and Duration classes :
Period : It deals with date based amount of time.
Duration : It deals with time based amount of time.
// Java code for period and duration
import
java.time.LocalDate;
import
java.time.LocalTime;
import
java.time.Month;
import
java.time.Duration;
import
java.time.Period;
public
class
Geekforgeeks {
public
static
void
checkingPeriod()
{
LocalDate date1 = LocalDate.now();
LocalDate date2 =
LocalDate.of(
2014
, Month.DECEMBER,
12
);
Period gap = Period.between(date2, date1);
System.out.println(
"gap between dates "
+
"is a period of "
+gap);
}
// Function to check duration
public
static
void
checkingDuraion()
{
LocalTime time1 = LocalTime.now();
System.out.println(
"the current time is "
+
time1);
Duration fiveHours = Duration.ofHours(
5
);
// adding five hours to the current
// time and storing it in time2
LocalTime time2 = time1.plus(fiveHours);
System.out.println(
"after adding five hours "
+
"of duration "
+ time2);
Duration gap = Duration.between(time2, time1);
System.out.println(
"duraion gap between time1"
+
" & time2 is "
+ gap);
}
// Driver code
public
static
void
main(String[] args)
{
checkingPeriod();
checkingDuraion();
}
}
Output:gap between dates is a period of P3Y3M28D the current time is 06:21:18.248 after adding five hours of duration 11:21:18.248 duraion gap between time1 & time2 is PT-5H
- ChronoUnits Enum : java.time.temporal.ChronoUnit enum is added in Java 8 to replace integer values used in old API to represent day, month etc.
// Java code for ChronoUnits Enum
import
java.time.LocalDate;
import
java.time.temporal.ChronoUnit;
public
class
Geeksforgeeks {
// Function to check ChronoUnit
public
static
void
checkingChronoEnum()
{
LocalDate date = LocalDate.now();
System.out.println(
"current date is :"
+
date);
// adding 2 years to the current date
LocalDate year =
date.plus(
2
, ChronoUnit.YEARS);
System.out.println(
"next to next year is "
+
year);
// adding 1 month to the current data
LocalDate nextMonth =
date.plus(
1
, ChronoUnit.MONTHS);
System.out.println(
"the next month is "
+
nextMonth);
// adding 1 week to the current date
LocalDate nextWeek =
date.plus(
1
, ChronoUnit.WEEKS);
System.out.println(
"next week is "
+ nextWeek);
// adding 2 decades to the current date
LocalDate Decade =
date.plus(
2
, ChronoUnit.DECADES);
System.out.println(
"20 years after today "
+
Decade);
}
// Driver code
public
static
void
main(String[] args) {
checkingChronoEnum();
}
}
Output:current date is :2018-04-09 next to next year is 2020-04-09 the next month is 2018-05-09 next week is 2018-04-16 20 years after today 2038-04-09
- TemporalAdjuster : It is used to perform various date related operations.
// Java code Temporal Adjuster
import
java.time.LocalDate;
import
java.time.temporal.TemporalAdjusters;
import
java.time.DayOfWeek;
public
class
Geek
{
// Function to check date and time
// according to our requirement
public
static
void
checkingAdjusters()
{
LocalDate date = LocalDate.now();
System.out.println(
"the current date is "
+
date);
// to get the first day of next month
LocalDate dayOfNextMonth =
date.with(TemporalAdjusters.
firstDayOfNextMonth());
System.out.println(
"firstDayOfNextMonth : "
+
dayOfNextMonth );
// get the next saturday
LocalDate nextSaturday =
date.with(TemporalAdjusters.
next(DayOfWeek.SATURDAY));
System.out.println(
"next satuday from now is "
+
nextSaturday);
// first day of current month
LocalDate firstDay =
date.with(TemporalAdjusters.
firstDayOfMonth());
System.out.println(
"firstDayOfMonth : "
+
firstDay);
// last day of current month
LocalDate lastDay =
date.with(TemporalAdjusters.
lastDayOfMonth());
System.out.println(
"lastDayOfMonth : "
+
lastDay);
}
// Driver code
public
static
void
main(String[] args)
{
checkingAdjusters();
}
}
Output:the current date is 2018-04-09 firstDayOfNextMonth : 2018-05-01 next satuday from now is 2018-04-14 firstDayOfMonth : 2018-04-01 lastDayOfMonth : 2018-04-30
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