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/LocalTime and LocalDateTime API : Use it when time zones are NOT required.
Java
// 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 formatted 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 republic day :" +date2);
// printing date with current time.
LocalDateTime specificDate =
current.withDayOfMonth( 24 ).withYear( 2016 );
System.out.println( "specific date with " +
"current time : " +specificDate);
} // Driver code
public static void main(String[] args)
{
LocalDateTimeApi();
}
} |
Output
the current date is 2021-09-23 the current time is 20:52:39.954238 current date and time : 2021-09-23T20:52:39.956909 in formatted manner 23-09-2021 20:52:39 Month : SEPTEMBER day : 23 seconds : 39 the republic day :1950-01-26 specific date with current time : 2016-09-24T20:52:39.956909
- Zoned date-time API : Use it when time zones are to be considered
Java
// 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
// 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 checkingDuration()
{
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( "duration gap between time1" +
" & time2 is " + gap);
} // Driver code
public static void main(String[] args)
{
checkingPeriod();
checkingDuration();
}
} |
Output
gap between dates is a period of P6Y6M25D the current time is 18:34:24.813548 after adding five hours of duration 23:34:24.813548 duration 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
// 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 date
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
// 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 saturday 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 2021-07-09 firstDayOfNextMonth : 2021-08-01 next saturday from now is 2021-07-10 firstDayOfMonth : 2021-07-01 lastDayOfMonth : 2021-07-31