ah yes, I hadn't considered the beans-to-xml side of this.
oh well :)
Kohsuke Kawaguchi wrote:
>
> This works really nicely if all you need to do is to read data into Java
> beans. It's kinda like Apache Digester meets annotation.
>
> But this is much harder to do for read/write systems like JAXB, partly
> because XPath is not reversible. Consider:
>
> class Foo {
> @XPath("count(item[@number='x'])")
> int x;
>
> @XPath(".//_at_id")
> String id;
> }
>
> And it gets even harder if we need to generate a schema for it.
>
> If all we want is to collapse deep element wrappers into one class, then
> giving it "XPath" as the name would send wrong impression to people, I
> think.
>
>
> Kenny MacLeod wrote:
>> 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?
>
>