JLocalDateTime Class API Guide in Java 8
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In this article, we will learn more about the commonly-used LocalDateTime Class
APIs with examples. LocalDateTime
represents a combination of date and time.
This is the most commonly used class when we need a combination of date and time. The class offers a variety of APIs, and we will look at some of the most commonly used ones.
The java.time.LocalDateTime
class is an immutable class that represents a date-time without time-zone information, such as ‘2018-08-12T10:35:55.'
Below, the class diagram shows a list of APIs that the LocalDateTime
class provides.
1. LocalDateTime APIs to Get Current Date-Time and Specific Date-Time Object
LocalDateTime
class provides the following APIs to create the current date-time and specific date-time object respectively.
-
static LocalDateTime now()
: Obtains the current date-time from the system clock in the default time-zone. -
static LocalDateTime now(Clock clock)
: Obtains the current date-time from the specified clock. -
static LocalDateTime now(ZoneId zone)
: Obtains the current date-time from the system clock in the specified time-zone.
import java.time.Clock; import java.time.LocalDateTime; import java.time.Month; import java.time.ZoneId; /** * Program to demonstrate LocalDateTime Class APIs. * @author javaguides.net * */ public class LocalDateTimeExample { public static void main(String[] args) { createLocalDateTime(); } private static void createLocalDateTime() { // Current date time LocalDateTime dateTime = LocalDateTime.now(); System.out.println(dateTime); // Current date time from specified time-zone LocalDateTime dateTime2 = LocalDateTime.now(ZoneId.of("UTC")); System.out.println(dateTime2); // Current date time from specified clock LocalDateTime dateTime3 = LocalDateTime.now(Clock.systemUTC()); System.out.println(dateTime3); // Specific date time LocalDateTime dateTime4 = LocalDateTime.of(2017, Month.JULY, 12, 10, 35, 55); System.out.println(dateTime4); } }
Output:
2018-08-10T18:08:43.787 2018-08-10T12:38:43.789 2018-08-10T12:38:43.789 2017-07-12T10:35:55
2. LocalDateTime APIs to Get a Year, Month, Day From LocalDateTime
LocalDateTime
class provides the following APIs to get a year, month, day from the LocalDateTime
.
-
int getYear()
: Gets the year field. -
Month getMonth()
: Gets the month-of-year field using theMonth
enum. -
int getDayOfMonth()
: Gets the day-of-month field. -
DayOfWeek getDayOfWeek()
: Gets the day-of-week field, which is the enumDayOfWeek
. -
int getDayOfYear()
: Gets the day-of-year field.
import java.time.LocalDateTime; /** * Program to demonstrate LocalDateTime Class APIs. * @author javaguides.net * */ public class LocalDateTimeExample { public static void main(String[] args) { getYearMonthDayFromLocalDateTime(); } private static void getYearMonthDayFromLocalDateTime() { LocalDateTime dateTime = LocalDateTime.now(); System.out.println("Year : " + dateTime.getYear()); System.out.println("Month : " + dateTime.getMonth().getValue()); System.out.println("Day of Month : " + dateTime.getDayOfMonth()); System.out.println("Day of Week : " + dateTime.getDayOfWeek()); System.out.println("Day of Year : " + dateTime.getDayOfYear()); } }
Output:
Year : 2018 Month : 8 Day of Month : 10 Day of Week : FRIDAY Day of Year : 222
3. LocalDateTime APIs to Get Hour, Minute, Second From LocalDateTime
LocalDateTime
class provides the following APIs to get Hour, Minute, Second, from LocalDateTime
.
int getHour() int getMinute() int getNano() int getSecond()
import java.time.LocalDateTime; /** * Program to demonstrate LocalDateTime Class APIs. * @author javaguides.net * */ public class LocalDateTimeExample { public static void main(String[] args) { getHourMinuteSecondfromLocalDateTime(); } private static void getHourMinuteSecondfromLocalDateTime() { LocalDateTime dateTime = LocalDateTime.now(); System.out.println("Hour : " + dateTime.getHour()); System.out.println("Minute : " + dateTime.getMinute()); System.out.println("Second : " + dateTime.getSecond()); System.out.println("Nano : " + dateTime.getNano()); } }
4. LocalDateTime APIs to Add or Subtract Years, Months, Days, Hours, Minutes and Seconds to LocalDateTime
Below example shows how to add or subtract years, months, days, hours, minutes and seconds to LocalDateTime
class.
/** * Program to demonstrate LocalDateTime Class APIs. * @author javaguides.net * */ public class LocalDateTimeExample { public static void main(String[] args) { addOrSubstractUsingLocalDateTime(); } private static void addOrSubstractUsingLocalDateTime() { LocalDateTime dateTime = LocalDateTime.now(); // LocalDateTime's plus methods System.out.println("Addition of days : " + dateTime.plusDays(5)); System.out.println("Addition of months : " + dateTime.plusMonths(15)); System.out.println("Addition of years : " + dateTime.plusYears(5)); System.out.println("Addition of Hours : " + dateTime.plusHours(2)); System.out.println("Addition of Minutes : " + dateTime.plusMinutes(30)); System.out.println("Addition of Seconds : " + dateTime.plusSeconds(20)); // LocalDateTime's minus methods System.out.println("Subtraction of days : " + dateTime.minusDays(5)); System.out.println("Subtraction of months : " + dateTime.minusMonths(15)); System.out.println("Subtraction of years : " + dateTime.minusYears(5)); System.out.println("Subtraction of Hours : " + dateTime.minusHours(2)); System.out.println("Subtraction of Minutes : " + dateTime.minusMinutes(30)); System.out.println("Subtraction of Seconds : " + dateTime.minusSeconds(20)); } }
Output:
Addition of days : 2018-08-15T18:14:13.385 Addition of months : 2019-11-10T18:14:13.385 Addition of years : 2023-08-10T18:14:13.385 Addition of Hours : 2018-08-10T20:14:13.385 Addition of Minutes : 2018-08-10T18:44:13.385 Addition of Seconds : 2018-08-10T18:14:33.385 Subtraction of days : 2018-08-05T18:14:13.385 Subtraction of months : 2017-05-10T18:14:13.385 Subtraction of years : 2013-08-10T18:14:13.385 Subtraction of Hours : 2018-08-10T16:14:13.385 Subtraction of Minutes : 2018-08-10T17:44:13.385 Subtraction of Seconds : 2018-08-10T18:13:53.385
5. LocalDateTime APIs to Compare LocalDateTime Objects in Java
LocalDateTime
class provides below APIs compare LocalDateTime
objects in Java.
-
boolean isAfter(ChronoLocalDateTime other)
: Checks if this date-time is after the specified date-time. -
boolean isBefore(ChronoLocalDateTime other)
: Checks if this date-time is before the specified date-time. -
boolean isEqual(ChronoLocalDateTime other)
: Checks if this date-time is equal to the specified date-time. -
int compareTo(ChronoLocalDateTime other)
: Compares this date-time to another date-time.
import java.time.LocalDateTime; /** * Program to demonstrate LocalDateTime Class APIs. * @author javaguides.net * */ public class LocalDateTimeExample { public static void main(String[] args) { compareLocalDateTimeObjects(); } private static void compareLocalDateTimeObjects() { LocalDateTime dateTime1 = LocalDateTime.of(2017, 05, 22, 10, 55, 25); LocalDateTime dateTime2 = LocalDateTime.of(2017, 06, 11, 05, 35, 26); LocalDateTime dateTime3 = LocalDateTime.of(2017, 05, 22, 10, 55, 25); // Using isBefore() method if (dateTime1.isBefore(dateTime2)) { System.out.println("dateTime1 is before dateTime2"); } // Using isAfter() method if (dateTime2.isAfter(dateTime3)) { System.out.println("dateTime2 is after dateTime3"); } // Using isEqual() method if (dateTime1.isEqual(dateTime3)) { System.out.println("dateTime1 is equal to dateTime3"); } // Using compareTo() method if (dateTime1.compareTo(dateTime3) == 0) { System.out.println("dateTime1 is equal to dateTime3"); } } }
Output:
dateTime1 is before dateTime2 dateTime2 is after dateTime3 dateTime1 is equal to dateTime3 dateTime1 is equal to dateTime3
6. LocalDateTime API to Convert From LocalDateTime to LocalDate in Java
LocalDateTime
class provides the following APIs to convert from LocalDateTime
to LocalDate
in Java.
-
LocalDate toLocalDate()
: Gets theLocalDate
part of this date-time.
import java.time.LocalDate; import java.time.LocalDateTime; /** * Program to demonstrate LocalDateTime Class APIs. * @author javaguides.net * */ public class LocalDateTimeExample { public static void main(String[] args) { convertLocalDateTimeToLocalDate(); } private static void convertLocalDateTimeToLocalDate() { LocalDateTime dateTime = LocalDateTime.now(); System.out.println(dateTime); LocalDate localDate = dateTime.toLocalDate(); System.out.println(localDate); } }
Output:
2018-08-10T18:16:35.802 2018-08-10
Learn more about the LocalDate class APIs on this Java 8 - LocalDate Class API Guide .
7. LocalDateTime APIs to Convert From LocalDateTime to LocalTime in Java
LocalDateTime
class provides the following APIs to convert from LocalDateTime
to LocalTime
in Java.
-
LocalTime toLocalTime()
: Gets theLocalTime
part of this date-time.
import java.time.LocalDateTime; import java.time.LocalTime; /** * Program to demonstrate LocalDateTime Class APIs. * @author javaguides.net * */ public class LocalDateTimeExample { public static void main(String[] args) { convertLocalDateTimeToLocalTime(); } private static void convertLocalDateTimeToLocalTime() { LocalDateTime dateTime = LocalDateTime.now(); System.out.println(dateTime); LocalTime localDate = dateTime.toLocalTime(); System.out.println(localDate); } }
Output:
2018-08-10T18:17:08.598 18:17:08.598
Learn more about the LocalTime
class APIs on Java 8 - LocalTime Class API Guide
Related Java 8 Date and Time API Guides
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