Thursday, January 31, 2008


The rest of the quickstart demo went pretty smoothly. Not surprising, considering that it was largely a matter of typing (or copy and pasting) sample code into real files.

But now the fun begins: problems. The truth is that you don't understand how a technology or combination of technologies works until you've had to fix them when they're supposed to work.

So, first problem: Exception stack trace in my Tomcat log. I am not going to drop the entire stack trace into the blog at this point, but let me describe how I'm handling this. First, I skimmed the stack trace looking for references to code that I know to be mine. In this case there are no "quickstart." files anywhere in the stack trace, so I know it's not my Java code. Now, here are the first few lines of the stack trace:

SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanDefinitionStoreException: Unexpected exception parsing XML document from ServletContext resource [/WEB-INF/applicationContext.xml]; nested exception is java.lang.NoSuchMethodError: org.springframework.beans.factory.xml.ParserContext.registerBeanComponent(Lorg/springframework/beans/factory/parsing/BeanComponentDefinition;)V
Caused by: java.lang.NoSuchMethodError: org.springframework.beans.factory.xml.ParserContext.registerBeanComponent(Lorg/springframework/beans/factory/parsing/BeanComponentDefinition;)V
at org.springframework.transaction.config.AnnotationDrivenBeanDefinitionParser$AopAutoProxyConfigurer.configureAutoProxyCreator(
at org.springframework.transaction.config.AnnotationDrivenBeanDefinitionParser.parse(

The most obvious problem appears to be an error parsing applicationContext.xml. Probably I have a typo in there somewhere. However, I can't find one after glancing over the file for five minutes and that is almost certainly enough time for now. So I'm going to do something annoying. I typed this one in by hand and probably fat-fingered something. So I'm going to copy-and-paste the file contents from the demo and see if that makes the problem go away. If it doesn't then I'll have to use my brain and nobody wants that.

That doesn't make the problem go away! Crap. Time to do some Google searches on the exception messages.

And Matt Raible comes through again. Dude is rapidly becoming my hero. A thread on the AppFuse mailing list suggests that there might be collisions between various Spring jars. I'm reorganizing my build path, let's see how this works.

...nope. OK, time to review my build path, make sure I have everything I need. Yes, this would have been a good time to have used Maven, I know.

Hey, it turns out that I ignored a bunch of Hibernate jars earlier -- specifically the Hibernate Annotations and Hibernate Entity Manager jars. I'll grab them now. And that doesn't solve the problem either. Same error.

Clean, refresh, delete the deployment, rebuild, redeploy... and it's a whole new suite of errors! But these are more comprehensible. They can go in another post.

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