My most common headache during my last Spring project was:

java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener

during start of Tomcat.

Every source pointed to problems with spring.jar, so I suspected having some version conflict between my Spring libraries (eg. I used also Spring-WS in an old version). But that wasn’t real cause and I’d wasted a lot of time. The real problem was faulty Eclipse IAM plugin.

Try out some tricks I’ve described in my another article : Problems using Eclipse IAM and Maven

They really may help you.

During my last project I was involved, I used Eclipse IAM plugin for integration with Maven. It caused many problems, mainly Class not found exceptions and issues with Tomcat server.

Generally I perceived that Eclipse IAM tends to lose jars from pom.xml, what leads to unexpected, bizarre time wasting NoClassDefFoundError.

Unfortunately I hadn’t been sucessful in finding causes of my problems but I’d like to share with you my standard ‘IAM problems checklist’ 😉

If you have any problems try this (in specified order) :

1. Use refresh, then fetch source jars option from maven menu.
2. Try cleaning maven libraries, then do ‘1.’
3. After doing ‘2.’, remove your app from Tomcat, clean server, then deploy again.
4. Try removing whole server, then add it again.
5. REMOVE AND REGENERATE WHOLE WORKSPACE

Any step mentioned above is not a joke. I had really to ‘reset’ workspace a few times to make things work again.. First three steps helped me in 80% cases.

I hope my tips will save your time.