Good and not so good reasons to learn Java (or any other language)[part 2]

So this is basically the second part of "Good and not so good reasons to learn Java".

And here I will discuss the good reasons to learn Java. Some of them...
I decided to split this in two posts. The next one will be published in a few days.

If you know me a bit, you probably know that I do not like Java particularly. In fact I found out that the essential problem is with Java being presented as something modern or "superior". It is not. However, it did something very good in the software environment (a part from electing over-engineering as a form of art): many technology that were outside the mainstream and was dubbed slow (garbage collector) are now widely accepted and that is partly because of Java. This is no reason to learn Java, though.

Moreover, my opinion is that Java is not a good first language. It is not a good second language either. However, after learning a high level language like Python or Ruby, a couple of functional languages (maybe Clojure and Haskell or Scheme and Scala) and something lower level, such as C, well... learning Java it could be a very good idea.

Lots of interesting stuff runs on the JVM

Yes... I'm talking about Clojure and Scala. And perhaps JRuby too. Sometimes understanding the underlying platform helps understanding some design choices. Moreover, there is stuff (e.g., in Clojure) that has not yet a fully clojurized variant and we have to use Java stuff.

Knowing Java is a plus, of course.

Lots of interesting books deal with Java

I'm not talking here about the wonderful Effective Java or Java Puzzles. They are great Java books, of course. And some suggestions may also apply to other languages. Still, if you are not interested into Java, you may miss them.

No, I'm talking about other great books...

• Clean Code and Agile Software Development
• xUnit Test Patterns
• Analysis Patterns
• Refactoring
• Patterns of Enterprise Application Architecture
• Head First Design Patterns
• Functional Programming for Java Developers
• ...
• Here the list could be really long...

Some of them are not entirely in Java and some have non-Java alternatives. Still reading Java is a huge plus in reading those books. I believe part of the reason is that:

Java is like a common-denominator object oriented language


Forget the Java platform. Consider just the language. Essentially Java is really a common-denominator of other object oriented language. Other languages typically offer more. Are more dynamic, offer more powerful type-systems, more expressive constructs.

Just thing about the OOP building blocks. Here we are talking about the mis-interpreted OOP as a matter of types vs. a matter of messages. That is what most people think about when referring to OOP. Unfortunately, as I said.

Java has those. But does not have much more. If you want to design OO stuff, Java gives you the building block, but does not stand above offering higher level construct. Think about Python or Ruby or Lisp... their OO facilities are so superior (plus they typically offer stuff outside the OOP model -- well, Lisp is so much more than an OO language...) that you are probably going to design stuff differently. Probably you are not going to over-engineer stuff.

Modifications are cheap. Abstractions are easy. And of course you can go outside the OO model when it makes sense.

On the other hand in Java you cannot. You can just get back at a procedural level, which is clearly inferior. The best thing you can do in Java is try to be as OO as possible: other choices usually do not pay.

As a consequence:

1. Java is a great language to expose those "ill-conceived OOP" concepts that are used in every other language where ill-conceived OOP techniques are used.
2. Java is a great language to truly learn to program like an object-oriented zealot

Please notice that I consider the latter a very good thing. It is a very good exercise that lets you understand the merits and the drawbacks of the paradigm. Probably when you think that something really sucks in Java, you hit a limit of OOP in a static language. Other languages may make that easier, but the wall is still there.

Java is good to learn "good OOP" too

Yes! As I already said there is a lot of smart people working with Java. They have already discovered and taught how to do "good" OOP in Java. You should learn it too.

Then, when using a different language things could only be easier. Some of the techniques you learned may be useless, because the language offers better abstractions. Still you will have a pretty clear understanding of what such abstractions are doing and perhaps you may develop a feeling for when not to use them.

As a matter of fact, too much magic is bad, even if it may seem cool. While sticking too much to simple things may actually complicate the design in the long run (meta-programming leads to code that you do not write and that is the only kind of code that needs no debugging or testing or maintenance, as it does not exist), too much magic has the same effect at the opposite position of the spectrum.

Avoid writing Java in other languages

If you know Java, at a certain point you may discover you would be writing much the same code if you were using Java. If the language you are using is C++, you probably have done something wise: chosen a restricted subset of C++ and used that one (than we may argue if you actually left out good stuff).

However, if you are using Python or Ruby, or, worse, Clojure, then you are writing awful code. $x code is not meant to be structured like Java. If it does, you are not using the language well. This is basically a side effect of "Java is like a common-denominator object oriented language".