使用XSLT将一个JAXB对象转换为另一个JAXB对象

Question

I found this question, which helped me a bit, but not enough: Transform From one JAXB object to another using XSLT template

What I have is this:

• A source JAXB Object
• A class for my target JAXB Object
• A path to the XSLT I want to use to transform my original object to my target object

What I'm trying is this:

/**
 * Transforms one JAXB object into another with XSLT
 * @param src The source object to transform
 * @param xsltPath Path to the XSLT file to use for transformation
 * @return The transformed object
 */
public static <T, U> U transformObject(final T src, final String xsltPath) {
    // Transform the JAXB object to another JAXB object with XSLT, it's magic!

    // Marshal the original JAXBObject to a DOMResult
    DOMResult domRes = Marshaller.marshalObject(src);

    // Do something here 
    SAXTransformerFactory tf = (SAXTransformerFactory) TransformerFactory.newInstance();
    StreamSource xsltSrc = new StreamSource(xsltPath);
    TransformerHandler th = tf.newTransformerHandler(xsltSrc);
    th.setResult(domRes);
}

At this point, I'm puzzled. How do I obtain my transformed Document? From that point, unmarshalling it back to a JAXB object shouldn't be too hard, I think.

As far as I know, there's no way to do this without marshalling, right?

UPDATE

Here is a full working example, using Saxon specifically as my XSLT's are using XSLT 2.0:

    /**
     * Transforms one JAXB object into another with an XSLT Source
     * 
     * @param src
     *            The source (JAXB)object to transform
     * @param xsltSrc
     *            Source of the XSLT to use for transformation
     * @return The transformed (JAXB)object
     */
    @SuppressWarnings("unchecked")
    public static <T, U> U transformObject(final T src, final Source xsltSrc, final Class<U> clazz) {
        try {
            final JAXBSource jxSrc = new JAXBSource(JAXBContext.newInstance(src.getClass()), src);
            final TransformerFactory tf = new net.sf.saxon.TransformerFactoryImpl();
            final Transformer t = tf.newTransformer(xsltSrc);
            final JAXBResult jxRes = new JAXBResult(JAXBContext.newInstance(clazz));
            t.transform(jxSrc, jxRes);
            final U res = (U) jxRes.getResult();

            return res;

        } catch (JAXBException | TransformerException e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }

You can instantiate the xsltSrc through Source xsltSrc = new StreamSource(new File(...));

Answer 1

You could use JAXBSource and JAXBResult directly with your transformation.

JAXBSource source = new JAXBSource(marshaller, src);
JAXBResult result = new JAXBResult(jaxbContext);
transformer.transform(source, result);
Object result = result.getResult();

For More Information

You can find an example of using JAXB with the javax.xml.transform APIs on my blog:

• http://blog.bdoughan.com/2012/11/using-jaxb-with-xslt-to-produce-html.html