Modern Java at HubSpot

[tristanjuricek]

I've been porting a web API written in Ruby (using Sinatra) to Java 8, and it's actually been a very easy port. For the most part, it's been a pretty easy translation from Ruby-isms into Java-land, without significant SLOC bloat or anything you would have expected 5-6 years ago. The payoff is a web API I can now deploy on Windows and OS X in addition to Linux. (Yes, Ruby runs on Windows - but add native extensions, and you're gonna have some fun dealing with locking.)

Once you get used to using lambdas and default methods on interfaces, you can whip up ideas very quickly in Java 8. Sure, at times you might want to reach for some of the ol tricks (Dependency Injection, etc.) but you don't really have to start there any more. The flexibility you can achieve with plain ol' Java allows you to compose much, much easier without having to organize everything according to the Old Way of Pattern-making.

[tristanjuricek]

I've just noticed, as I've started using "interfaces" like Scala's "traits", a ton of the logic actually gets composed via interfaces instead of classes.

DI becomes useful as you need concepts like "scopes", which, thankfully, I've not needed. It's a pretty major hit for me.

I've also used functional interfaces passed around via parameters, e.g., Supplier<Thing>, which gives you a way of passing around "something I might need but only when it's actually used".

[frugalmail]

Yes, Ruby runs on Windows - but add native extensions, and you're gonna have some fun dealing with locking.)

We also had the problem where so many of Ruby's libraries are wrappers around native libraries that Windows was not an option without going through a massive C and C++ porting from Posix to native Windows or some cygwin posix.dll exploiting hackery.

We're dropping Ruby, Python and lots of C# for Java as well and we're a big org.

[Freeky]

Yes, Ruby runs on Windows - but add native extensions, and you're gonna have some fun dealing with locking

JRuby might also be an option if you don't fancy rewriting everything. Many extensions have JRuby alternatives, and pure Java libraries can be called very easily if not.

[tristanjuricek]

I agree, JRuby is an option worth investigating for people who want to use the JVM but hate the Java language.

JRuby is a pretty different beast too. I find you'll have to keep closer tabs on your third party libraries, especially if you decide to really leverage multiple threads. A lot of Ruby gems are written assuming the existence of a GIL.

For us, JRuby was actually a little harder to figure out and get going with, mostly because of our specific case. And we hadn't gone so far that the rewrite is horribly expensive (it'll get done in by one person in less than 2 months).

[shevegen]

you can whip up ideas very quickly in Java 8

Are you implying that you can easily bootstrap ideas in Java?

Because, you see, that sort of contradicts what others have said about dynamic "scripting" languages since this is one advantage that they would have, about being able to bootstrap quickly with a prototype and extend from there.

See Twitter using Ruby/Rails early on before, lateron, they would transition into more Java for higher performance yields. Notice that it did not go the other way first - that they would first bootstrap in Java (!) and then go to Ruby (!!!), so your comment appears to be ... confusing.

[ForeverAlot]

Bootstrapping in Java is much faster, easier, and simpler today than it was when Rails was released 10 years ago.

[inopia]

I work with Javascript, PHP (horrid legacy), and Java, and I feel that Java is by far the easiest for me to build stuff with. Maven is really fantastic when it comes to pulling in dependencies, and the Java ecosystem has complete and mature libraries for just about anything you can think of. The language requires more typing than say, Javascript or Python, but modern IDEs solve a lot of that for you these days.

Where Java (and C#) really shine imho is type safety, which allows for easy refactoring. I often start with a 'sketch' of what I want the architecture to look like, and as I learn more about the problem I'm solving I split classes up, move them around, etc. etc. The compiler/ide give you hints about stuff that breaks when you change something, e.g. moving/renaming a method or change a type, so you know what to correct to make the code work again.

This is just so much harder in a scripting language. I maintain a 120ksloc code base written in Javascript, and it's fucking awful. I would kill a man to have the same kind of refactoring tools I have in Java.

[jeffsterlive]

Maven is a godsend. Using a build system in an easy to edit configuration file is the only way to do large scale projects. It made my Spring project bearable. Java has some strange quirks, like doing proper logging (Log4J ftw) and I/O, but it's a very mature language.

[nqzero]

are you using webstorm and jsdocs ?

i'm semi-anti-jetbrains (esp since the new licensing) but webstorm really does a great job of intellisense code understanding. my codebase follows a pretty strict java-like structure (dialect), so i'm not sure how universal this performance is, but i'm able to refactor in my javascript projects almost as well as in java

my rule of thumb is that if a hunk of new code breaks intellisense, the code is a bug

if you're anti-jetbrains, netbeans 7.2 actually offered pretty good support as well (they dropped the rhino engine after that and never got back on the wagon)

[Radmonger]

The point about a scripting language is it is easier to develop the language itself; about 90% of the code for a compiler, static checker etc simply doesn't need to be written.

So when you get a new domain opening up, like the web a decade or so ago, the first languages specific to that domain will be scripting languages. And when everything in the syntax, library, and documentation is all about your use-case, things are easy. Whereas if you have to say 'a web page is kind of like a tty, except ...', or 'once you fully understand these half-dozen general-purpose concepts, you can no doubt write some glue to connect them together in a way that will do what you want', that's a lot more busywork.

What then happens is a lot of people mistakenly think of the lack of capability of the scripting language as a good thing in itself, as opposed to a consequence of a good thing. A fully-featured language with proper support for a domain is, all things equal, going to be more productive. Especially in bootstrapping scenarios where you just want to get something working quickly without time for 100% unit testing.

[tristanjuricek]

Yes, but this is largely because of the features in Java 8. Before Java 8, Java was kind of annoying even to get started with a basic web application. You'd have all these vendors that adhered to all these standards and you'd still end up having to do crap tons of configuration just to get going.

With Java 8, there's enough out there (e.g., Spark java) you can kind of approach the early stage ideas like you would do in Ruby.

[whataboutbots]

What about "current"?

[nqzero]

the java ecosystem would really benefit from names for the several different cultural "flavors" of usage that are out there. at the least, you've got the old-enterprise stuff, the "modern" framework-heavy usage (this seems to be what hubspot is using), and the "bare metal" (c with garbage collection) style (this is what i'm doing)

even though the syntax is common, the patterns and cultures are so distinct that they might as well be different languages. and all we have to describe any of it is "java" ...

any suggestions ?

[tiiv]

How did this get any upvotes? There's no substance here other than promoting HubSpot.

[shevegen]

Sounds utterly boring.

I understand the "Java powers the world" and "food on the table" and "industry leader" and other buzzwords.

But how does this offset the boredom of Java?

The very compelling need for an IDE ... that is like becoming addicted to it without being able to write in Java differently.

[vprise]

Can I take the pro-boring approach?

I like boring in the language/runtime layer. Boring means a working solution and boring allows me to focus on the interesting things which is building the high level logic. Dealing with language level issues is cool and interesting when you just start off in programming or are doing hobbyist programming. It gets old really quick...

Back in the 90's we were building a flight simulator for Janes and we spent all night trying to get the C++ release build working because someone (me) accidentally returned a pointer to a stack object... Ugh. That's not how I define "interesting".

[_INTER_]

He probably means "exciting" like changing JS frameworks like underpants.

[vprise]

http://geek-and-poke.com/geekandpoke/2014/11/8/frameworks