推土机映射对象中包含的ArrayList

Question

I have an object A that contain an arrayList and I want to map it to an object B with the same structure of A.
After the mapping the arrayList of object B is null. I tried this mapping.

<mapping type="bi-directional">
    <class-a>it.firstpackage.A</class-a>
    <class-b>it.secondpackage.B</class-b>
    <field copy-by-reference="true">
        <a>collection</a>
        <b>collection</b>
        <a-hint>it.firstpackage.ListA</a-hint>
        <b-hint>it.secondpackage.ListB</b-hint>
    </field>
</mapping>

Can you tell me where I am wrong?
Thanks in advance and sorry for my english

Answer 1

You are trying to map collection by reference what tells dozer not to map subelements but copy the value as it is. But this way it cannot copy the property since they are of different types. Try removing copy-by-reference and add mapping between lista and listb if needed.