Dozer mapping JodaTime property not working as expected

Question

I am using Dozer to map between a Document class to DocumentManagementBean class, both of my own making. Both have a property, with getters and setters, of Joda DateTime type, c

Answer 1

You probably don't need it anymore, but Dozer provides the chance to copy an object by reference, at least with the latest version (now, this version is 5.4.0). Copying by reference is what you are looking for.

<field copy-by-reference="true">
  <a>copyByReference</a>
  <b>copyByReferencePrime</b>
</field>

Documentation: http://dozer.sourceforge.net/documentation/copybyreference.html

Answer 2

Set a copy-by-reference global property in your xml file

    <copy-by-references>
        <copy-by-reference>
            org.joda.time.LocalDate
        </copy-by-reference>
        <copy-by-reference>
            org.joda.time.LocalDateTime
        </copy-by-reference>
    </copy-by-references>

Answer 3

I think the root cause is that DateTime is immutable, so the deep copy cannot be done (see https://github.com/DozerMapper/dozer/issues/216).

That's why you have to use a converter or copy it by reference.

Answer 4

It is possible to do it but you will have to add some configuration:

<field>
  <a set-method="placeValue" get-method="buildValue">value</a>
  <b>value</b>  
</field>

Here is more information: http://dozer.sourceforge.net/documentation/custommethods.html

Dos some one knows how to do tins with annotations?

Answer 5

The basic problem is that Dozer creates a new blank instance of DateTime, via new DateTime(), and thats how you end up with the current date/time instead of the original one. There might be multiple solutions, I usually went with a customconverter, globally defined:

    <converter type="de.kba.resper.customconverter.DateTimeCustomConverter">
        <class-a>org.joda.time.DateTime</class-a>
        <class-b>org.joda.time.DateTime</class-b>
    </converter>

and

public class DateTimeCustomConverter extends DozerConverter<DateTime, DateTime> {

    public DateTimeCustomConverter() {
        super(DateTime.class, DateTime.class);
    }

    @Override
    public DateTime convertTo(final DateTime source, final DateTime destination) {

        if (source == null) {
            return null;
        }

        return new DateTime(source);
    }

    @Override
    public DateTime convertFrom(final DateTime source, final DateTime destination) {

        if (source == null) {
            return null;
        }

        return new DateTime(source);
        }

}

It may overdo it, though :)