Rubyists Dream of
Eclectic Java
Leveraging Enterprise Java for Ruby fu
Vishnu Gopal
www.vish.in

Me
• Born and brought up a Keralite. Mallu.
• Worked in the Mobile VAS sector
• Founded Torque: www.torque.co.in
• Uzanto & SlideShare: www.slideshare.net
• Me: www.vish.in

Ruby
• New kid on the block (?)
• Dynamic programming, meta-programming
• Less is more, succinct code
• Riding the Rails wave
• Ruby (MRI) is Slow(er)

Java
• Most popular programming language
• Rich toolset, GUI tools, editors, RAD IDEs
• Enterprise support and adoption
• Community and Libraries
• Java is OpenSource
• Cumbersome, heavy language, strict typing

JVM
• A tried and true Virtual
Machine
• JSR 223: Scripting for the
Java Platform
• Java 6 increased
performance!
• SUN

Java + Ruby
• JVM is cool, Java has tools
• Ruby brings elegance
• Any solution must:
• Preserve Ruby’s ability to reflect on itself
• Not sacrifice Java performance and toolset
• Be an elegant bridge

Java + Ruby = JRuby
• Ruby interpreter written in 100% Java
• Walks, talks and quacks like Ruby
• Almost all of the Ruby Standard Library has
been ported
• Even runs Rails! (with warnings)

Interlude One
JRuby v/s Ruby

Rails on JRuby
• You can use Camping/JRuby well
• Ruby hype is mostly Rails
• JRuby running Rails is a huge milestone
• Not there yet, but good progress
• Simple web applications run well
• SQLite adapter isn’t supported

SlideShare on JRuby
• Complicated app
• 90K+ of Ruby Code
• Plugins, homegrown extensions
• Memcached libraries, fragment caching,
backgroundrb
• Ported over in 3 hours of work
• Around 40% functionally complete

Interlude Two
SlideShare on JRuby

Slideshare/JRuby
Workarounds
• script/console (in dev mode) worked
without a hitch
• script/server had problems
• Resolved by:
• removed @@instance variables
• removed flash notices
• removed OutputCompression plugin

Future
• JVM is cool, Java toolset scene is cooler
• Netbeans/Ruby/tools integration
• Dynamically add in Java modules to Rails
applications
• Glassfish and autodeploy as WARs
• Get Rails adoption into the enterprise

Finis
Questions?
www.slideshare.net/vishnu

Alternatives to JRuby
• Scripting Language:
• JPython
• Grails & Groovy
• Other Java cool stuff:
• Google Web Toolkit