Java, Where To Start?

I'm a web developer who has design and programming experience. So, VB, ASP, PHP, Coldfusion, Perl, even C and C++ I have in my belt. I also use Dreamweaver and/or do a lot of my HTML/XHTML/JavaScript coding by hand. So, the DOM, DHTML, etc, all good to me and even OOP thinking and design I have when I code. And I even have MySQL and other databases, again, not an issue here. So, my weak point is — Java — I see so many jobs out there with J2EE, Hibernate, Eclipse, Netbeans. Beside the obvious, which is to learn Java the core language, I don't know where else to go from there. There is so much! What should I read? in what order? What software do I require? UML? Swing? I mean, what is the curriculum required for someone to say they are a solid Java developer? Even assuming I have to go through Java itself, what are the good books out there?

Comments

My opinion of what Java APIs are worth learning

[hattig]

The language itself won't be a problem if you've done C and C++, nor should OO concepts. So the difficulty is with APIs - what is worth it, and what isn't.

In terms of Java APIs (core or otherwise), I'd learn in roughly this order:

* Collections
* Reflection
* IO
* Servlets & JSPs then Struts, Tiles, Spring, etc
* JDBC, then Hibernate
* Axis (web services) and Apache HTTPClient

You don't need to learn them off by heart - I've seen people advance very slowly because they're trying to do that. It is enough to know what is what, so that when you have a problem, you know there is a solution, and where it is.

In terms of interfaces, I wouldn't bother with Swing or AWT really, until you need them. SWT ain't too bad (Eclipse uses it, and it's cross platform enough - Windows, Linux, Mac, Pocket PC, ...). Maybe you could be fancy and learn Fenggui instead! Then you could learn JOGL and write 3D games and the like.

Oh, and learn how to do Java on the command line first, use ANT to build and compile and deploy, then try Eclipse or NetBeans as an IDE. This way you'll avoid all the niceties that the IDE gives you that inhibits your initial learning.

I wouldn't bother with half of the enterprise wank, like Enterprise Beans and all that.

Groovy

[mgkimsal2]

I'd suggest starting with Groovy (http://groovy.codehaus.org/) then perhaps move in to Grails (http://grails.org). Groovy is a dynamic language that runs *on* the JVM, and can co-exist with native Java code, but requires far less boilerplate code to get anything done. If you're coming from a dynamic language background, Groovy will be a bit easier to understand.

This will allow you to get involved with Java technologies without as steep a learning curve as you'd require if you were doing it 'from scratch'. You can incorporate as much 'other' Java tech as you want as you go along, but you'll be up and running fast with Groovy.

http://michaelkimsal.com/blog/grails-for-php-developers/grails-for-php-developers-part-1 is few part series on did on Groovy and Grails for people coming to it from non-Java backgrounds. Never quite finished the series, but it's someplace to look to see if it's something to investigate further.

Good luck!

Re:I beg to disagree

[MrNaz]

Come on now. I'm getting tired of all the "I'm thinking of learning $fooCommonThing and I need Slashdot to spoon feed me Google results." type questions.

I cannot believe this made front page when there are other, rather good questions in the firehose that would result in good dialog and idea exchange, but that get rejected.

Seriously, is there some shortage on Java dicumentation out there or something? Granted, I don't know the language as I never had a need for it, but I can't trip over without falling into a pile of Java tutorials.

Here's my answer to this particular Ask Slashdot.

Re:Don't

[alex4u2nv]

I would have to agree here, as someone who knows J2EE.

I studied J2EE application development a couple years ago, when it was supposed to be the "new" next big thing.

I was already bought, and for all my term papers, in every language course that I wrote, was touting how the future was Java and J2EE.

In the real world? Its not. I would say, stick with the languages under your belt as they're the most marketable tools in the world.

My opinion was completely reversed, because in a world where opensource is aspiring and component based development is becoming cleaner and easier, the languages with most opensource software, such as C/C++, PHP, Perl, MySQL, etc will grow even faster.

Look at it this way, Php 4.x as a non object oriented language, and php 5 as a 80% object oriented language has more freely available software available for coupling than Java does.

Client/Server Development -- I would focus on the Javascript framworks, Flex, Google Gears, Adobe AIR, etc. + what you already know.

Re:managers just don't care about skill level

[thermian]

In my experience, managers don't tend to care one whole hell of a lot about the skill level of local employees when a job goes offshore. You could be the worst or the best; at the end of the week, you are still laid off so that Anand & Prasun can have your job.

Then don't work for companies like that.

Any heavily outsourced software house is screwed if its working against another which has skilled, highly motivated staff. Outsource workers have a task to do, they do it, and they cease to care. You don't get innovation that way, you just get lines of code.

Re:Don't

[Z00L00K]

Maybe, but I'll say that it's not a bad thing to be able to know Java.

There are benefits and there are drawbacks with Java, as there are with other languages. The drawback with Java is that you don't have any control over memory management, but the benefit is that it's easy to program in if you have been working with C and C++. And you will at least not suffer from some weird bugs that you can get in C or C++.

For beginners in Java I usually recommend JavaRanch.

And to develop I recommend Eclipse. It works fine and can give you instant feedback on many issues. Of course - it has some quirks too, but so does every tool.

And if you want to select a more extreme language I would recommend Erlang. It has a completely different approach than normal procedural languages, but sometimes it makes more sense.

Re:What does Java lack now?

[SuperKendall]

Java programmers have libraries for generating bytecode on the fly, but they have nowhere near the ease at which S-expressions can be thrown around.

Java is soon adding closures though. Honestly I used to do a lot of Lisp and Scheme and I always though I could represent pretty well want I wanted to do in Java, coming from those as a base - there are just different mechanics to achieve a similar design.

You have me on monads, though even there there are possibilities, and they are not that difficult (and in fact I have made heavy use in some code of exactly the technique mentioned for one project).

My criticism, therefore, lies with more with programmers who don't look beyond the language of Java,

While I agree with that at some level, I would say there are too many people that have not explored the full range of what Java itself can do and how techniques learned in different languages can be applied using a combination of Java and various libraries.