What is the best Java OXM library?

Question

Even though I've been a developer for awhile I've been lucky enough to have avoided doing much work with XML. So now I've got a project where I've got to interact with some web services, and would like to use some kind of Object-to-XML Mapping solution.

The only one I'm aware of is JAXB. Is that the best to go with? Are there any other recommendations?

One catch - I'm stuck using Java 1.4, so I can't do anything with annotations.

Answer 1

JAXB is the best choice:

• Public API included in Java SE 6
• Binding layer for JAX-WS (Web Services)
• Binding layer for JAX-RS (Rest)
• Can preserve XML Infoset
• Multiple implementations: Metro, MOXy, JaxMe, etc

EclipseLink JAXB (MOXy) is the best implementation:

MOXy is a JAXB implementation with Extensions

MOXy has an external configuration file (based on JAXB annotations with extensions):

• http://bdoughan.blogspot.com/2010/12/extending-jaxb-representing-annotations.html
• http://wiki.eclipse.org/EclipseLink/Examples/MOXy/EclipseLink-OXM.XML

Has XPath based mapping, for deep mapping:

• http://bdoughan.blogspot.com/2010/07/xpath-based-mapping.html
• http://bdoughan.blogspot.com/2011/03/map-to-element-based-on-attribute-value.html
• http://bdoughan.blogspot.com/2010/09/xpath-based-mapping-geocode-example.html

Designed to handle ORM mapped objects, including support for bidirectional relationships:

• http://wiki.eclipse.org/EclipseLink/Examples/MOXy/JPA
• http://bdoughan.blogspot.com/2010/07/jpa-entities-to-xml-bidirectional.html

Answer 2

If you're calling a web-service with a WSDL, JAXB is absolutely the best option. Take a look at wsimport, and you're be up and running in 10 minutes.

I don't think JAXB 2.0 will be possible on Java 1.4. You may need to use Axis instead:

java -cp axis-1.4.jar;commons-logging-1.1.jar;commons-discovery-0.2.jar;jaxrpc-1.1.jar;saaj-1.1.jar;wsdl4j-1.4.jar;activation-1.1.jar;mail-1.4.jar org.apache.axis.wsdl.WSDL2Java http://someurl?WSDL

This will generate similar stubs to JAXB.

If you don't have a WSDL or XSD, you can always generate one.

Answer 3

There's XStream. I seem to remember I used that ages ago, and it was fine. Can't say I have enough experience to recommend it for or against, but it's worth checking out just as an alternative.