JAXB

JAXB | Java Architecture for XML Binding

JAXB 1.0 - JSR-31 [jcp.org]

JAXB Reference Implementation [2.x]  jaxb.java.net

JAXB Reference Implementation [1.0] jaxb.java.net/1.0

Java Tutorials - Introduction to JAXB  docs.oracle.com

JAXB binding process 

"... more about validation: A web service processing model is to be lax in reading in data and strict on writing it out." 

- [yay]

Marshalling optional elements and attributes...

"By default a JAXB (JSR-222) implementation will not marshal null values. " - somewhere on stackoverflow.com

"An attribute will only be marshalled out with an empty String value if the corresponding field/property contains a empty String value. If the value is null the attribute will not be marshalled." - somewhere on stackoverflow.com

[ERROR] Thrown by JAXB:

[ERROR] Complex type and its child element share the same name "xxx". 

Use a class customization to resolve this conflict.

JAXB Customizations With a Poorly Formed WSDL stackoverflow.com

This is an alternative to fixing a  WSDL with duplicate names 

JAX-WS - XML schema customization jax-ws.java.net

JAX-WS - WSDL Customization  jax-ws.java.net