Comments on: IoC is not just Dependency Injection

By: Sam Newman

Sam Newman — Tue, 27 Jan 2004 16:42:33 +0000

Erm, I didn’t say it wasn’t about dependency management, or that Martin Fowler said it was – a fact that the inclusion of a quote from Jeffrey Aaron Farr’s post should make clear. As such my post is just reiterating the point for people (a point I think needs to be made as until recently I didn’t fully realise it).
I think sometimes Martin can be guilty of renaming stuff for the sake of it (some would say that it just gives us a richer language, I would argue that in many cases it can just promote misunderstanding) however in this case I do agree with him.

By: Anonymous

Anonymous — Tue, 27 Jan 2004 16:26:34 +0000

Hmm, anyone who says “IoC is not about dependency management” after reading Martin Fowler’s article missed his point. Mr. Fowler is not trying to redefine IoC or rename it. Rather he is saying IoC has had a well-defined meaning for years and not until very recently when these so called “IoC containers” popped up was there any misunderstanding what IoC meant. So he is trying to give a new, specific names to the pattern these containers use so they would stop confusing the whole naming issue trying to redefine IoC to something else from its original meaning.

By: Sam Newman

Sam Newman — Tue, 27 Jan 2004 10:26:03 +0000

I’ve decided to update my original piece on this including your suggestions – I’ll try and post it today

By: Sam Newman

Sam Newman — Tue, 27 Jan 2004 10:23:19 +0000

Thanks for the clarification Juergen! You’re quite right concerning the configuration of Spring. As for providing Type 3 IoC I was unaware of this, as the last version I used was M2. Type 2 is of course required if you want to provide Configuration IoC (I am unsure if Pico can do this – if it can then it therefore follows that it also provides type 2 IoC).

As for the web framework being complex I was referring to needing to embed references in my spring config file and a separate property file etc. I think part of the problem is the system is so flexible that you can do too much, as a result it is less user friendly than configuring Struts for example.

By: Juergen Hoeller

Juergen Hoeller — Tue, 27 Jan 2004 09:00:18 +0000

Sam, I’ve noticed repeatedly that you talk about Spring as a Type 2 IoC container. While this the style that we recommend, Spring supports both Type 2 and Type 3 since 1.0 M3, aka setter injection and constructor injection (and also Type 1 via BeanFactoryAware). We even arguably offer more sophisticated constructor resolution than Pico.

Furthermore, XML is by no means the only way to create bean definitions with Spring – it is just the most popular one. You can use programmatic registration via DefaultListableBeanFactory, or load definitions from a property file via PropertiesBeanDefinitionReader.

BTW, I also noticed that you consider Spring’s web framework too hard to set up. While there is certainly a tradeoff involved in terms of flexibility versus simplicity, I wonder what gave you that impression. I would be happy to accept constructive feedback! :-)

Juergen