IBM Version 5 manual Java Architecture for XML Binding Jaxb, Cocoon

2.10 Java Architecture for XML Binding (JAXB)

The Java Architecture for XML Binding provides an API and tools that automate the mapping between XML documents and Java objects. These are available as an early access release. The public version of the JAXB specifications and a pre-release version of the reference implementation will be available by the third quarter 2002. The final draft is scheduled to be published in the forth quarter of the same year.

The JAXB API compiles an XML Schema into Java classes. The Java classes handle all the details of XML parsing and formatting. The generated classes ensure that the constraints expressed in the DTD are enforced in the methods and Java technology language data types. The early access release only works on DTD, but later versions are being produced to support other schemes.

The classes generated by JAXB perform at a greater efficiency than the SAX and DOM parsers, because the classes are more customized than the generic parsers. The generated application validates structure and content with the help of the Java classes. The structure and content validation classes perform better than the SAX, because the derived classes are precompiled. Unlike the DOM parser, it does not need to create the whole tree. The content tree created is specific to one schema, and the classes do not need any redundant tree-manipulation functionality.

The JAXB expert group is now working on the new specification. Among the features are:

￿Support for a subset of W3C XML Schema and XML namespaces

￿More flexible unmarshalling and marshalling functionality

￿Enhanced validation capabilities, such as allowing validation to be turned on for development purposes, and turned off for deployment.

To understand JAXB in depth, visit Java Architecture for XML Binding (JAXB) at Java.sun.com:

http://www.java.sun.com/xml/jaxb/

2.11 Cocoon

Cocoon provides an XML publishing framework that is designed around the SAX API. It can interact with common data sources, including files, relational databases, and XML databases. The content delivery can be customized to different devices such as HTML, WML, RTF, PDF and others. Its main aim is to provide a platform for building applications with distinct separation between content, logic, and presentation.

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