[jbosscache-dev] Configuration Related Changes and Notes

[Jason T. Greene]

I committed the following changes:
---------------------------------
- Switched to JBossEntityResolver to support automatic schema discovery
- Updated schema to use urn:jboss:jbosscache-core:config:3.0 namespace
- Corrected simple type pattern for locking scheme
- Modified parser and configs to use the namespace
- Added root element checking to prevent NPEs

I ran these through the full testsuite with no failures, however a 
recent commit I had to merge appears to have broken a number of tests 
(with or without my changes).

Some outstanding issues:
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- Schema validation failures just log errors. Shouldn't they abort 
startup? The XML parsing code seems to assume validation was performed 
and successful since it doesn't do much itself
- XmlParsingConfigurationRegistry does not use a proper schema!
- LegacyConfigurationTest is testing the new configuration format 
instead of the legacy one
- We need to decide on case sensitivity and correct either the schema 
(as I did for locking scheme), or update the xslt to lower/upper case 
everything
- Not sure what to do about the jgroups section. Right now the configs 
put it in the cache namespace, which is not really correct. However 
since we don't have a jgroups namespace, I didnt bother qualifying. The 
only other option would be to add xmlns="" to the outer jgroups element. 
In any case the parser accepts them in any namespace

JAXB
----
IMO, we should think about using JAXB for this in the future. It is 
*much* more accurate than hand rolled parsing code, and it's a lot 
easier to maintain. It also has very good error handling (you don't even 
need to do full schema validation with it). While it does require a jar 
under JDK5, it is part of JDK6, so if we added a another dep it would 
only be temporary.

-- 
Jason T. Greene
JBoss, a division of Red Hat