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 Functionimport 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 APIimport 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 Timepublic 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 durationimport 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 Enumimport 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 Adjusterimport 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
