Tuesday, March 22, 2011

The New XML Stack in JDK 7

In the summary of new JDK 7 features, one of the categories is called Web and its major subcategory is Update the XML Stack. This support is available as of Milestone 12 (M12 AKA "Developer Preview" AKA "beta release") and is described as "Upgrade the JAXP, JAXB, and JAX-WS APIs to the most recent stable versions." In this post, I look at the versions of JAXP, JAXB, and JAX-WS associated with JDK 7 preview release (build 1.7.0-ea-b134).

In the article Better JPA, Better JAXB, and Better Annotations Processing with Java SE 6, I wrote about some of the advantages of Java SE 6 having JAXB 2.0 baked into it. It is not uncommon for future versions of Java to include newer versions of dependent libraries and JDK 7 updates JAXB from JAXB 2.1.10 (version since Java SE 6 Update 14) to JAXB 2.2.3 as shown in the next screen snapshot.

As the above screen snapshot shows, the xjc compiler is an easy command-line approach to determining the version of JAXB associated with a particular Java distribution (assuming that xjc is not on the path from a different location). The schemagen tool can also be used to determine the JAXB version.

It is similarly easy to determine the version of JAX-WS APIs supported in the Java SE 7 release by asking associated command line tools for their versions. The following screen snapshot demonstrates doing this with the tools wsgen and wsimport.

As indicated in the above screen snapshot, the JDK 1.7.0 b134 release has JAX-WS 2.2.2 associated with it (JAXB 2.1.6 was associated with Java 6 as of Java SE 6 Update 14).

I don't know of an equivalent method to those shown above to determine from the command line what version of JAXP is included with a particular Java distribution. Fortunately, the JDK 7 Documentation includes the JAXP page that states that "the Java Platform, Standard Edition version 7.0 includes JAXP 1.4" and explains that "JAXP 1.4 is a maintenance release of JAXP 1.3 with support for the Streaming API for XML (StAX)."

I expect that the anticipated Release Notes for JDK 7 will formally and conveniently list the versions of these XML-related products included with the JDK distribution.


Sandeep said...

Thanks for the information


Martijn Verburg said...

I'm still finding that dropping out to Groovy (with its builders) or Scala (XML is treated as a first class citizen) is a better solution for XML processing. I'm really hoping that Java the language can take some ideas from there for a future release.

Dustin said...


I couldn't agree more with you about the better support for XML in the alternative JVM languages. Groovy's excellent builder/parser/slurper XML support may be the thing I miss most when using Java that I wish to myself was so easily done in Java.