I got my SCJP and I am very comfortable with Java. But that definitely ain't good enough in this fast moving world. When I see a job requirement, it starts with "Java developer" as the title and then digresses into the candidate requiring experience in different areas. One of those omnipresent (among several skills like Struts, JUnit, Hibernate, EJB, J2EE...etc.) is Spring.
I don't have much of an idea of what Spring is. I tried to Google it a few times, but got no satisfactory learning material on that that provides a simple working example I could understand for Spring. How far is Spring removed from Java? Besides POJ what are the other pre-requisites for learning Spring?
Where could I get started for a good learning material for Spring? It would be greate if there is a simple "Hello world" example that I could compile, execute etc. Are there any good books? I would love if there is a Head first book for Spring. Does anyone know?
There are countless tutorials, from beginning to advanced--just search.
The idea of a "hello, world" is a bit... misleading, because Spring has many modules--but you probably mean a simple dependency injection/inversion of control example, since that's what's at Spring's heart.
As far as books go, I think Spring in Action is pretty good, but have also used a couple of the Apress books. But at this stage, I'd imagine the Spring tutorials, even just running the examples that come with the distribution or following the Spring documentation, would be enough to get started.