[Yanel-dev] Stax libs within Java 1.6 and why can't we use them

[Guillaume Déflache]

Michael Wechner schrieb:
> Hi

Hi!


> IIRC we override the stax libs within common/endorsed in particular for 
> Java 1.6, but it is not clear
> to me why we don't actually use the ones which are part Java 1.6?

The whole point of this is that the libraries actually shipped with the 
JRE may be much older than the versions you would like to use, or that 
other libraries need as dependencies.
For example the Xalan provided with Java 1.4 stayed old and buggy for a 
long time, and if you wanted a reasonable version you had to override it.
Also it allows to make sure that not updated JREs (e.g. 1.4.0 compared 
to 1.4.2) can still work by forcing them to use newer libraries.

Now for StAX and Java 6 using very recent versions may indeed not matter 
so much, and we may even be currently overriding with an older version 
that the one that is shipped with the latest JRE 6 updates!

Also according to 
http://java.sun.com/javase/6/docs/technotes/guides/standards/ we 
probably should override StAX using the complete JAXP JAR: "these 
technologies may be overridden only by providing a *complete* and newer 
implementation of the Standalone Technology" [emphasis mine].

Finally I  am not sure how to tell Maven that the JRE provides some 
versions of otherwise standalone libraries like xalan-2.*.jar, 
xerces-2*.jar, jsr173.jar, stax-api.jar and that it should neither 
download them nor include them in the compile and runtime classpaths.

HTH,
    Guillaume