Question

I have looked at the Dozer’s FAQs and docs, including the SourceForge forum, but I didn’t see any good tutorial or even a simple example on how to implement a custom BeanFactory.

Everyone says, “Just implement a BeanFactory”. How exactly do you implement it?

I’ve Googled and all I see are just jars and sources of jars.

Answer 1

Here is one of my BeanFactories, I hope it helps to explain the common pattern:

public class LineBeanFactory implements BeanFactory {

    @Override
    public Object createBean(final Object source, final Class<?> sourceClass, final String targetBeanId) {

        final LineDto dto = (LineDto) source;

        return new Line(dto.getCode(), dto.getElectrified(), dto.getName());

    }

}

And the corresponding XML mapping:

<mapping>

        <class-a bean-factory="com.floyd.nav.web.ws.mapping.dozer.LineBeanFactory">com.floyd.nav.core.model.Line</class-a>
        <class-b>com.floyd.nav.web.contract.dto.LineDto</class-b>

</mapping>

This way I declare that when a new instance of Line is needed then it should create it with my BeanFactory. Here is a unit test, that can explain it:

@Test
public void Line_is_created_with_three_arg_constructor_from_LineDto() {

    final LineDto dto = createTransientLineDto();

    final Line line = (Line) this.lineBeanFactory.createBean(dto, LineDto.class, null);

    assertEquals(dto.getCode(), line.getCode());
    assertEquals(dto.getElectrified(), line.isElectrified());
    assertEquals(dto.getName(), line.getName());

}

So Object source is the source bean that is mapped, Class sourceClass is the class of the source bean (I’m ignoring it, ’cause it will always be a LineDto instance). String targetBeanId is the ID of the destination bean (too ignored).