I am new to Spring and planning to start learning Spring from next monday after i finish off Struts2.
I made a search on this forum to search for best book to start learning Spring.
a. read Spring documentation
b. read Spring in Action book 2nd edition covering Spring 2 version
c. read Spring in Action book 3nd edition covering Spring 3 version
Now i am not make up mind for two points
a. Which version should i start studying Spring as i have heard that Spring 2 and Spring 3 have significant number of changes.
b. Currently how many % of Spring projects are using which version of Spring (Spring 1 OR Spring 2 OR Spring 3)?
c. do we have any book which more like an Step by Step guide to start building Spring application?
Note on books - Spring in Action 3rd edition hasn't been released yet - there is an early access version available through the publisher, but it is not complete.
a.) The biggest changes for Spring 3 are annotation based configuration. Spring 2.5 code will still run in Spring 3. I'd download Spring 3 and use it, but as for learning materials - don't worry too much about Spring 2.5 vs. Spring 3 - the biggest difference will probably be doing all configuration through XML instead of annotations - and you still need to know how to do XML based configuration anyway. There are bigger changes in Spring MVC - the web framework - in Spring 3 it's now all annotation based, Spring 2.5 used a hierarchy of controller classes.
b.) Not sure - I'd guess most products still being developed would upgrade to Spring 3 though... like I said in a. - Spring 3 will still run Spring 2.5 code. I can't think of a good reason for new development to prefer an older version of Spring (the only reason I can think of is if if you were targeting a pre-1.5 JDK - no annotation support).