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

August 21, 2022 SJ Java 8, Java 8 Date/Time 0

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

1. Convert Instant to XMLGregorianCalendar :

  • For conversion of Instant to XMLGregorianCalendar use DatatypeFactory
  • DatatypeFactory.newInstance().newXMLGregorianCalendar(GregorianCalendar) returns XMLGregorianCalendar object
    • First, convert Instant to ZonedDateTime using atZone() method passing ZoneId as input–argument
    • Pass converted ZonedDateTime to GregorianCalendar.from() method which returns GregorianCalendar
    • Pass converted GregorianCalendar to DatatypeFactory.newInstance().newXMLGregorianCalendar() method which returns XMLGregorianCalendar
  • Converted XMLGregorianCalendar will have,
    • Date & Time & Zone/Offset parts shifted to that particular Zone
  • In short, Instant -> ZonedDateTime -> GregorianCalendar -> XMLGregorianCalendar
  • Lets see an example for conversion of Instant to XMLGregorianCalendar in the below illustration

ConvertInstantToXmlGregorianCalendar.java

package in.bench.resources.java8.instant.examples;

import java.time.Instant;
import java.time.ZoneId;
import java.util.GregorianCalendar;

import javax.xml.datatype.DatatypeConfigurationException;
import javax.xml.datatype.DatatypeFactory;
import javax.xml.datatype.XMLGregorianCalendar;

public class ConvertInstantToXmlGregorianCalendar {

	public static void main(String[] args) throws DatatypeConfigurationException {

		// 1. get instantaneous moment at UTC/GMT
		Instant instant = Instant.now();
		System.out.println("Current Instant at UTC/GMT is :- \n" 
				+ instant);


		// 2. convert Instant -> GregorianCalendar 
		GregorianCalendar gregorianCalendar = GregorianCalendar
				.from(instant.atZone(ZoneId.systemDefault()));
		System.out.println("\nGregorianCalendar is :- \n" 
				+ gregorianCalendar.getTime());


		// 3. convert GregorianCalendar to XMLGregorianCalendar
		XMLGregorianCalendar xmlGregorianCalendar = DatatypeFactory
				.newInstance()
				.newXMLGregorianCalendar(
						gregorianCalendar
						);


		// 4. print to console
		System.out.print("\nConversion of Instant to XMLGregorianCalendar is :- \n"
				+ xmlGregorianCalendar);
	}
}

Output:

Current Instant at UTC/GMT is :- 
2022-08-21T05:57:59.565840600Z

GregorianCalendar is :- 
Sun Aug 21 11:27:59 IST 2022

Conversion of Instant to XMLGregorianCalendar is :- 
2022-08-21T11:27:59.565+05:30

2. Convert XMLGregorianCalendar to an Instant :

  • First, create XMLGregorianCalendar object using DatatypeFactory.newInstance().newXMLGregorianCalendar(String) method
  • For conversion of XMLGregorianCalendar to an Instant,
    • First, convert XMLGregorianCalendar to GregorianCalendar using toGregorianCalendar() method
    • And then invoke toInstant() method for conversion of GregorianCalendar to an Instant
  • Converted Instant will have,
    • Date & Time & Zone/Offset parts represents current Instant date/time at GMT/UTC
  • In short, XMLGregorianCalendar -> GregorianCalendar -> Instant
  • Lets see an example for conversion of XMLGregorianCalendar to an Instant in the below illustration

ConvertXmlGregorianCalendarToInstant.java

package in.bench.resources.java8.instant.examples;

import java.time.Instant;

import javax.xml.datatype.DatatypeConfigurationException;
import javax.xml.datatype.DatatypeFactory;
import javax.xml.datatype.XMLGregorianCalendar;

public class ConvertXmlGregorianCalendarToInstant {

	public static void main(String[] args) throws DatatypeConfigurationException {

		// 1. get new instance of XMLGregorianCalendar
		XMLGregorianCalendar xmlGregorianCalendar = DatatypeFactory
				.newInstance()
				.newXMLGregorianCalendar(
						"2022-12-23T18:28:34.438+05:30"
						);
		System.out.println("XMLGregorianCalendar/Date is :- \n" 
				+ xmlGregorianCalendar);


		// 2. convert XMLGregorianCalendar to Instant
		Instant instant = xmlGregorianCalendar
				.toGregorianCalendar() // GregorianCalendar
				.toInstant(); // Instant


		// 3. print to console
		System.out.print("\nConversion of XMLGregorianCalendar to an Instant is :- \n"
				+ instant);
	}
}

Output:

XMLGregorianCalendar/Date is :- 
2022-12-23T18:28:34.438+05:30

Conversion of XMLGregorianCalendar to an Instant is :- 
2022-12-23T12:58:34.438Z

Related Articles:

References:

Happy Coding !!
Happy Learning !!

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