MENU
MENU

Java 8 – How to convert OffsetDateTime to GregorianCalendar and vice-versa ?

August 18, 2022 SJ Java 8, Java 8 Date/Time 0

In this article, we will learn how to convert OffsetDateTime to GregorianCalendar in Java 1.8 version and vice-versa

OffsetDateTime to GregorianCalendar conversion & vice-versa :

  • There are 3 new methods introduced in Java 1.8 version for GregorianCalendar class, those are
    1. from(ZonedDateTime) – This static method obtains an instance of GregorianCalendar with the default locale from a ZonedDateTime object
    2. toZonedDateTime() – This method converts invoking GregorianCalendar object to a ZonedDateTime that represents the same point on the time-line as that of GregorianCalendar object
    3. getCalendarType() – Returns "gregory" as the calendar type

1. Convert OffsetDateTime to GregorianCalendar :

  • GregorianCalendar.from() method accepts ZonedDateTime as input-argument and returns GregorianCalendar
  • First, convert OffsetDateTime to ZonedDateTime using toZonedDateTime() method of OffsetDateTime and pass converted ZonedDateTime to GregorianCalendar.from() method which will return GregorianCalendar
  • Converted GregorianCalendar will have,
    • Date & Time & Zone/Offset parts remain same as that of OffsetDateTime
  • In short, OffsetDateTime -> ZonedDateTime -> GregorianCalendar
  • Lets see an example for conversion of OffsetDateTime to GregorianCalendar in the below illustration

ConvertOffsetDateTimeToGregorianCalendar.java

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
package in.bench.resources.java8.offsetdatetime.examples;
 
import java.time.OffsetDateTime;
import java.util.GregorianCalendar;
 
public class ConvertOffsetDateTimeToGregorianCalendar {
 
    public static void main(String[] args) {
 
        // 1. get Offset Date/time
        OffsetDateTime offsetDateTime = OffsetDateTime.now();
        System.out.println("Offset Date/time is :- \n"
                + offsetDateTime);
 
 
        // 2. convert OffsetDateTime -> ZonedDateTime -> GregorianCalendar
        GregorianCalendar gregorianCalendar = GregorianCalendar
                .from(offsetDateTime.toZonedDateTime());
 
 
        // 3. print to console
        System.out.print("\nConversion of OffsetDateTime to GregorianCalendar is :- \n"
                + gregorianCalendar.getTime());
    }
}

Output:

?
1
2
3
4
5
Offset Date/time is :-
2022-08-17T13:38:11.195774500+05:30
 
Conversion of OffsetDateTime to GregorianCalendar is :-
Wed Aug 17 13:38:11 IST 2022

2. Convert GregorianCalendar to OffsetDateTime :

  • Instantiate GregorianCalendar object for conversion to OffsetDateTime
  • Conversion steps –
    • First, convert GregorianCalendar to ZonedDateTime using toZonedDateTime() method
    • And then convert ZonedDateTime to OffsetDateTime using toOffsetDateTime() method
  • In short, GregorianCalendar -> ZonedDateTime -> OffsetDateTime
  • Lets see an example for conversion of GregorianCalendar to toOffsetDateTime in the below illustration

ConvertGregorianCalendarToOffsetDateTime.java

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
package in.bench.resources.java8.offsetdatetime.examples;
 
import java.time.OffsetDateTime;
import java.util.GregorianCalendar;
 
public class ConvertGregorianCalendarToOffsetDateTime {
 
    public static void main(String[] args) {
 
        // 1. Instantiate GregorianCalendar
        GregorianCalendar gregorianCalendar = new GregorianCalendar();
        System.out.println("Current Date/Time is :- \n"
                + gregorianCalendar.getTime());
 
 
        // 2. convert GregorianCalendar -> ZonedDateTime -> OffsetDateTime
        OffsetDateTime OffsetDateTime  = gregorianCalendar
                .toZonedDateTime()
                .toOffsetDateTime();
 
 
        // 3. print to console
        System.out.print("\nConversion of GregorianCalendar to an OffsetDateTime is :- \n"
                + OffsetDateTime);
    }
}

Output:

?
1
2
3
4
5
Current Date/Time is :-
Wed Aug 17 13:40:17 IST 2022
 
Conversion of GregorianCalendar to an OffsetDateTime is :-
2022-08-17T13:40:17.827+05:30

Related Articles:

References:

Happy Coding !!
Happy Learning !!

Java 8 – How to convert OffsetDateTime to XMLGregorianCalendar and vice-versa ?
Java 8 – How to convert OffsetDateTime to Calendar and vice-versa ?

Related posts:

  1. Java 8 – How to convert ZonedDateTime to an OffsetDateTime ?
  2. Java 8 – How to convert java.util.Date to an OffsetDateTime in different ways ?
  3. Java 8 – How to convert OffsetDateTime to XMLGregorianCalendar and vice-versa ?
  4. Java 8 – How to convert OffsetDateTime to ZonedDateTime ?