Folks,
I have an idea for a possible enhancement to JAXB which I'd like to
throw open to the floor. It would involve a new annotation type which
takes an XPath expression, and uses that expression to bind to the field
/property being annotated.
This could come in handy when binding to XML documents which are not
conveniently structured, perhaps those with too many levels of
structure, allowing you to flatten out the structure in your class model.
For example, take the following XML fragment:
<book>
<title>The Dice Man</title>
<catalog>
<isbn>0006513905</isbn>
</catalog>
</book>
Let's say that I don't want the <catalog> intermediary type, but to
flatten tht <title> and <isbn> together into the same type.
With the new annotation, I could do something like this:
public class Book {
@XmlElement
String title;
@XPath(path="catalog/isbn")
String isbn;
}
When the JAXB runtime finds the @XPath annotation, it would evaluate it
against the "current" node, i.e. the <book>, and assign the result to
the field.
This concept could be taken much further - you could have an annotated
class which cherry-picks pieces of data from deep inside the node
structure and flattens them out. The ability to mix and match this
approach with other JAXB binding constrructs would be quite powerful, I
think.
Any thoughts?
kenny