DO NOT REPLY [Bug 15589] New: - Performance improvement ideas wrt loading JAXP Factories and DTMManager

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http://nagoya.apache.org/bugzilla/show_bug.cgi?id=15589

Performance improvement ideas wrt loading JAXP Factories and DTMManager

           Summary: Performance improvement ideas wrt loading JAXP Factories
                    and DTMManager
           Product: XalanJ2
           Version: CurrentCVS
          Platform: Other
        OS/Version: Other
            Status: NEW
          Severity: Normal
          Priority: Other
         Component: Xalan
        AssignedTo: xalan-dev@xml.apache.org
        ReportedBy: ilene@ca.ibm.com


We should go through the code and determine if we are calling newInstance() more
than necessary (for SAXParserFactory and DocumentBuilderFactory) on a single 
Transformer object.  Each call can be expensive if jars are searched for the 
implementation class.  Can we cache these classes anywhere?

I also have questions about the factory finder code for DTMManager 
implementations:

* Shouldn't we update this code to be consistent with the latest updates to the 
factory finder routines in JAXP code (from xml-commons)?

* Why are we searching in jaxp.properties for the name of the DTMManager 
implementation?  Would this really be an appropriate place for a user to set 
this property?

* Xerces has a xerces specific properties file (xerces.properties)that it looks 
for in a JDK installation (to avoid going through the classpath search.)  See 
org.apache.xerces.util.ObjectFactory.  Should we have a similar file for Xalan?