I have just wasted 1 whole day trying to debug this issues. Since I get most help from the internet, here is what I can do in return :D
I was trying to build a Spring 3.0 webapp with Tiles 2.2. Since Tiles depends on common-digester which subsequently depends on SAXParserFactory, I got stuck in a whole range of strange Weblogic behaviors.
Firstly, I got UnsupportedOperationException everytime I first access the webapp. Subsequent access is fine, but the first always encounters that exception. Hours of googling tells me that the exception is due to weblogic’s RegistrySAXParserFactory.
Lesson learnt: google with the culpit classname and method: RegistrySAXParserFactory + setXIncludeAware
Secondly, my common-digester.jar is versioned 2.0 and it called SAXParserFactory.setXIncludeAware. As stated in apache website, Tiles 2.2 requires common-digester 2.0 or higher. Yet my webapp seems to work fines with common-digester 1.8 (which does not call SAXParserFactory.setXIncludeAware).
Lesson learnt: beware of library version, especially if your server host other applications besides yours.
WLS 10.3 has a default factory named weblogic.xml.jaxp.RegistrySAXParserFactory. You can find it in the weblogic.jar
This class seems like a wrapper factory, it delegates all method calls to underlying factory. EXCEPT for 1 method: setXIncludeAware
Instead of setXIncludeAware, the method name is wrongly typed setXInludeAware (missing an ‘c’). Thus instead of overriding the method, it inherits the unimplemented version which always throws UnsupportedOperationException.
Now, to fix this problem, you can try telling the JVM to ignore Weblogic factory class and use a different one. For example, include in your server startup script:
-Djavax.xml.parsers.SAXParserFactory=com.sun.org.apache.xerces.internal.jaxp.SAXParserFactoryImpl
Or, create an lib/jaxp.properties in the JRE directory. This configuration file is in standard java.util.Properties format and contains the fully qualified name of the implementation class with the key being the system property defined above (http://download.oracle.com/javase/6/docs/api/javax/xml/parsers/SAXParserFactory.html)
Or, use WLS Filtering classloader (http://download.oracle.com/docs/cd/E13222_01/wls/docs92/programming/classloading.html#wp1097263)