The Java API for XML Registries (JAXR) is a Java client API for accessing both UDDI (Version 2 only) and ebXML registries. It is part of the J2EE 1.4 specification.
The JAXR API comprises the Java 2 Platform, Enterprise Edition (J2EE) packages javax.xml.registry and javax.xml.registry.infomodel. There is J2EE API documentation at http://java.sun.com/webservices/reference/api/index.html. More information about JAXR, including the JAXR Version 1.0 specification, is at http://java.sun.com/xml/jaxr/index.jsp.
The current JAXR specification (Version 1.0) defines a JAXR provider as an implementation of the JAXR API. Generally, a JAXR provider can be a JAXR provider for UDDI, a JAXR provider for ebXML, or a pluggable provider that supports both UDDI and ebXML. The JAXR provider for UDDI is a provider for UDDI only.
A JAXR provider for UDDI accesses a UDDI registry using the UDDI Version 2 SOAP APIs only. The UDDI registry for UDDI Version 3 in this version of WebSphere Application Server supports the UDDI Version 1, 2 and 3 SOAP APIs. Therefore you can use the JAXR provider for UDDI to access this registry. You can also use the JAXR provider to access the UDDI registry for UDDI Version 2 in WebSphere Application Server Version 5.x.
To work with the UDDI Version 3 SOAP APIs, use the UDDI Version 3 Client for Java; you cannot use JAXR.
The JAXR specification defines two capability profiles, capability level 0 and capability level 1. The JAXR API documentation categorizes each JAXR method as either level 0 or level 1. Generally, a JAXR provider for UDDI has capability level 0 and supports all level 0 methods, while A JAXR provider for ebXML has capability level 1 and supports all level 0 and level 1 methods. The JAXR provider for UDDI is a capability level 0 provider, and supports only level 0 methods.