As mentioned I stumbled over a few things while writing my first NamespaceHandler for Spring.

My very first experiments looked as if Spring simply was ignoring my namespace and I ended up having the XML parser complain about not finding my schema definition. It seemed to be some kind of infrastructural problem and not a code problem, so I tried to get the simple dateformat example from the docs working.

Unfortunately the example doesn't work without changes since the four different places you have to specify the XML Namespace URI or XSD location use two different root URIs ( and Bug reported.

After some futzing around I realized that my XSD file wasn't ending up on Spring's CLASSPATH and thus Spring didn't find it. I would have expected Spring to complain if I specify a location mapping in META-INF/spring.schemas that it cannot resolve. Unfortunately it fails silently.

Writing the NamespaceHandler is really simple, as is writing a BeanDefinitionParser, at least if you don't need to do fancy things.

Not being familiar with Spring's internals I kept looking around the BeanDefinitionBuilder class for a way to provide an id for the bean under construction. Maybe I should have looked closer or the documentation isn't that obvious. If you extend AbstractBeanDefinitionParser (maybe indirectly) you set the bean's id by overriding resolveId.

Up to here I was extending AbstractSingleBeanDefinitionParser because it did all the things I needed.

Next step: I want to define a bean that has a parent bean. Searching through BeanDefinitionBuilder's API docs lead to the childBeanDefinition factory method, which clearly is the way to go. Unfortunately AbstractSingleBeanDefinitionParser hasn't been designed for my use case so I ended up writing my own AbstractBeanDefinitionParser subclass that is almost identical to AbstractSingleBeanDefinitionParser but adds another protected getParentName(Element) method that will lead to the creation of a child bean if it returns non-null (and neither getBeanClass nor getBeanClassName return non-null).

If anybody is interested in the code, you can find it here - Apache License 2.0.

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