Seeking advice for a self-teaching programme of new Java techs

Question

Hello,
after a few years of technically poor projects (I learnt a lot in terms of process, quality, and non-Java technologies, by the way), I'd like to catch up with mainstream Java development.
I am preparing a programme to learn a few technologies I have missed over the past years. I plan to develop a couple of utilities (simple CRUD apps) on my spare time, gradually including bits and bits of the bricks I want to grasp.
I need some advice though to make this learning effective.
My first priority is to invest in reusable knowledge, so I will stick to "standard" bricks, and will aim mostly at off-the-shelf tools that work out of the box
(for example, I don't want to spend hours to fix a DB install&configuration issue, as I know I will probably never be paid for that kind of job).
Specifically, the technologies I plan to embrace are:
* Java SE 5 and 6
* jUnit 4
* Spring
* EJB 3 & JPA
* Web UIs
Here are the points where you might help me:
* JDK 1.5 vs 1.6
No real doubt here, the biggest language gap was introduced by 1.5. If I'm correct, 1.6 essentially brings new APIs; as long as those APIs are not my primary target (I'll try them only after I've completed my first round of catch-up :o), I am not missing much language-wise, am I correct?
I could also jump directly to 1.6, ignoring its new APIs, and concentrate on
1.5 language features, but the risk is stability (losing time with a 1.6 beta bug).
* jUnit 4
Nothing special, except I have practically read nothing about it on these forums (contrast this with TSS, where there are regular threads disputing the relative merits of jUnit vs TestNG).
Is v4.0 a non-event? It seems to bring some niceties (mark test components using annotations), but how much comfort did it bring to those of you who have used it over jUnit 3.8.1?
* Spring
Leaving aside that it's on my must-do list, I actually wonder which version I should try?
I also feel I should try it first on a non-EJB app, to avoid mixing concerns. I will skip the JDBC wrapping API though, as I already have a lot to do with other persistance APIs.
Any feedback?
* EJB3/JPA
(I formerly worked with generation 2.1 of the EE specs)
1) The biggest issue here is to find a reliable EJB3 container.
* I've heard JBoss is EJB3-ready, but I don't think it's certified yet.
* Project GlassFish (Sun-driven open-source JEE5 container) is still in the making
* Sun SASP9 is, well, released, but I don't know how much of JEE it supports, and haven't investigated into the licensing details yet
Any feedback on what you're using as a JEE5 container?
2) As far as EJB vs JPA goes, I also have the plan to use the persistence API
outside of EJB (likely, I will develop the same simple CRUD app twice,
once as a Webapp and once as as Swing app, both over the same DB schema).
But maybe this is pointless, as the entity annotations and API are agnostic; have you experienced some difference that deserve thorough learning?
3) Obviously I will need a DB. If the EJB container includes one, fine, at least for the EJB part, otherwise I'll need to install and configure one, that will need to run on a desktop PC on MS WIndows, and preferrably include a handy SQL client console for manual verification.
I know enough of SQL to build even a sub-optimal application schema. However I know nothing of a DB administration, and I don't want to invest in that direction.
Any advice as to a simple off-the-shelf free DB that runs on Windows?
* Web UIs
The dilmena here is two-fold:
1) In term of "view" technology, I hesitate between plain JSP and JSF
If I understand correctly, JSF is a specification for reusable view components.
My local job market leaves me no oportunity to be a UI component developer, whereas I am more likely to someday be tasked to integrate 3rd-party UI components into a business project.
Is my surface understanding of JSF correct? In this case, how much of JSF should I know if I don't have to develop JSF components?
2) In terms of controller, as part of my Spring learning, I'll probably have a look into Spring MVC.
My question is, how much of the servlet/JSP API does springMVC show/hide?
Is it a good idea to use springMVC to learn servlets and JSPs, or should I stick to manual servlet+JSP?
I should add that I've worked with servlets/JSPs formerly (as of J2EE 2 or 3),
I only need to dig new servlet/JSP features.

Answer 1

Jim_Found wrote:
okay, so normally you would write the following if-elseif block in order to achieve this
if (MessageType.TYPE_A.equals(myMessageType)) {
// do this
} else if (MessageType.TYPE_B.equals(myMessageType)) {
// do that
} else if ...
but, if you use <this design pattern> and create this <class>, you can suppress the above block to
CoolClass coolObj = new CoolClass();
coolObj.doMagic(myMessage);Funny enough inside the doMagic() method would be something along the lines of
if (MessageType.TYPE_A.equals(myMessageType)) {
// do this
} else if (MessageType.TYPE_B.equals(myMessageType)) {
// do that
} else if ...Mel