[castor-user] Improving Performance with XML (Marshalling and UnMarshalling)

[Carey, Tom]

I was browsing through the site and noticed the following link under Best Practices (http://www.castor.org/xml-best-practice.html).  It mentions that if you reuse a ClassDescriptorResolver, it'll help improve performance.  I followed the sample code and came up with the following method:

 

    private static ClassDescriptorResolver getClassDescriptorResolver(String mapFileName, Mapping mapping) throws MappingException
    {
        ClassDescriptorResolver classDescriptorResolver = (ClassDescriptorResolver)s_classDescriptorResolvers.get(mapFileName);
        if (classDescriptorResolver == null)
        {
            classDescriptorResolver = ClassDescriptorResolverFactory.createClassDescriptorResolver(BindingType.XML);
            MappingUnmarshaller mappingUnmarshaller = new MappingUnmarshaller();
            XMLMappingLoader mappingLoader = (XMLMappingLoader)mappingUnmarshaller.getMappingLoader(mapping, BindingType.XML);
            classDescriptorResolver.setMappingLoader(mappingLoader);
        }
        return classDescriptorResolver;
    }

Something to note first on the code.  This is minor.  I had to cast the instance returned from mappingUnmarshaller.getMappingLoader(..) because classDescriptorResolver.setMappingLoader(.) expects a XMLMappingLoader.   Wondering why the set method isn't using the MappingLoader interface.  Then I wouldn't have to cast after calling mappingUnmarshaller.getMappingLoader().

 

Now to the errors I encountered.  Under v1.0.1, I get the following compiler errors:
   cannot access class org.castor.mapping.BindingType, file ... not found

   cannot access class org.castor.mapping.MappingUnmarshaller, file ... not found

   cannot access class org.exolab.castor.xml.ClassDescriptorResolverFactory, file ... not found

 

When I attempted to upgrade to v1.0.4, I received the following compiler errors:
  (Source code):  Marshaller marshaller.setResolver(getClassDescriptorResolver(mapFileName, mapping));

  Error(70,28): method setResolver(org.exolab.castor.xml.ClassDescriptorResolver) not found in class org.exolab.castor.xml.Marshaller

 

  (Source code):  Unmarshaller unmarshaller.setResolver(getClassDescriptorResolver(mapFileName, mapping));

  Error(114,26): method setResolver(org.exolab.castor.xml.ClassDescriptorResolver) not found in class org.exolab.castor.xml.Unmarshaller

 

Would like to use this bit of code to improve performance.  Do you have any suggestions?

 

Also, if I didn't have a mapping file, would creating an empty mapping instance work?  Something like:

  XMLMappingLoader mappingLoader = (XMLMappingLoader)mappingUnmarshaller.getMappingLoader(new Mapping(), BindingType.XML);

Thanks,

Tom