Re: [jruby-user] JRuby pitch for Java developers?

I was a full time Java developer for over ten years (though I’m very happy that that is no longer so!).

Here are my feelings about it:

So many Java developers have never worked with a scripting language.  Using a scripting language can make automation of some tasks feasible where using Java instead would be prohibitively complex and time consuming.

Using a scripting language that runs on the JVM (JRuby, Groovy, Clojure, and others) provides easy interaction with a Java product’s code.  This can be handy for:

1) unit testing (e.g. with rspec, minitest)
2) providing an interactive shell (e.g. irb, pry) for that code.  Having an interactive shell to exercise Java code can be mind-blowing for someone whose interaction with their code has been limited to an IDE and the OS' command line.
3) RDBMS manipulation - for interacting with RDBMS’s, using JRuby and the Sequel gem can make DB interrogation and manipulation way, way simpler than in Java.
4..n) …

Ruby is a great language.  JRuby is the only Ruby implementation that can run in the same process as Java code (the JVM).  So JRuby offers the intersection of those three very valuable attributes — being a scripting language, Java interoperability, and being the highly productive language that we know and love.

Many times a project is mandated to be written in Java, but it’s really only important for the production code that the application runs; other things, such as unit tests, admin scripts, etc., can be written in another language.

I am convinced that there is a gold mine of functionality that can be added to Java dev teams using JRuby.  Unfortunately, the mindset of most Java developers seems to be rather bigoted against JRuby (just as so many Ruby developers are bigoted against Java).  So it’s a people problem (as usual) that stands between us and greater value.

Some will complain that the effort of learning another language for this is prohibitive, but my response is that if a team’s toolbelt doesn’t include any scripting languages, then the team is functioning with a hand tied behind its back.

* * *

By the way, I used to give a JRuby presentation that included addressing this question (see https://speakerdeck.com/keithrbennett/jruby-the-synergy-of-ruby-and-the-jvm).  It’s a little dated, but most of it is still accurate.

- Keith


  

On Jan 11, 2015, at 4:51 PM, Paweł Wielgus <[email protected]> wrote:

> I might not be the best case study
> but JRuby in my Java applications
> is used primarly in these situations:
> 
> 1. Querying application objects in realtime/runtime
> 2. Creating reports for users in runtime inside application (we have
> special module for this)
> 3. Using JRuby scripts for these parts of application that are very
> likely to change frequently (loading complicated data from xls files
> on runtime)
> 
> 
> --
> Pozdrawiam,
> Paweł Wielgus.
> tel: +48 604 603 546
> 
> 
> 2015-01-11 22:11 GMT+01:00 Tobias Pfeiffer <[email protected]>:
>> Hi everyone,
>> 
>> couple of months back I listened to the Ruby Rogues JRuby episode with
>> Charlie (http://devchat.tv/ruby-rogues/124-rr-jruby-with-charlie-nutter)
>> and he said that the "sales pitch" of JRuby to Java developers is very
>> different than from the one of JRuby for Ruby developers. And ever since
>> I wondered, what is the pitch for Java developers?
>> 
>> Java developers here, why do you use JRuby? Which problems does it solve
>> for you? How can we get more Java people to try out JRuby?
>> 
>> Thinking of it I can come up with the following points:
>> 
>> * write code faster/prototyping/quicker changes
>> * not type annotations everywhere
>> * easier access to powerful meta programming features
>> * superb Java integration, e.g. use libraries/other code easily
>> * integration goes so far that you can package ruby applications as .war
>> * for a tester: nicer test framework
>> 
>> That's about what I can think of - and still makes it hard to explain
>> why people shouldn't just go with languages "born" on the JVM
>> (Clojure/Groovy/Scala).
>> 
>> Ideas/Input/Pointers?
>> 
>> Cheers,
>> Tobi
>> 
>> --
>> www.pragtob.info
>> 
>> 
> 
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