Summary
Spring technology has what might be called a cost of entry—it's a little bit hard to get started with it. The examples that are bundled with the distributions help, but I've experienced difficulties in getting fairly basic things working. However, it's worth persisting with the effort, because Spring has many powerful concepts and facilities. I've been lucky in having worked on some commercial Spring-based software products.
It's pretty certain that IoC is here to stay, so I strongly recommend learning about it. In this article, I've only really scratched the surface of Spring web services development. Application contexts are an important part of the Spring approach—especially given that contexts facilitate several desirable design patterns.
Because SOAP is the underlying protocol for web services, it's essential that you have access to a product such as SOAPUI. The latter also provides an API for sending and receiving SOAP messages programmatically.
Application contexts represent a powerful IoC abstraction. They're also the Spring-recommended mechanism for defining collaborators and other injected entities. With a little effort, it's possible to define your application contexts and incorporate this important technology into your own work.