Apress - Practical JRuby On Rails Web 2.0 Projects

Introduction

JRuby on Rails is an exciting technology. If you’ve picked up this book, you’ve probably realized the same thing. You might not have much experience with either Ruby or Rails, or you’ve tried both of them out and want to see why the combination of JRuby on Rails is so spectacular. Regardless of the reason, I hope this book will teach you something about some of the technologies involved, introduce you to new ways to look at problems, and help you see solutions in the intersection of languages where each one isn’t perfectly suited for a problem.

I’ve been using Java for a long time, but my heart has never been in it. I’ve always been a programming language nerd, trying out new languages like my girlfriend tries new shoes. I knew what was out there, and that Java wasn’t the end-all solution for all the problems in the world. However, the fact remained that Java was the main language used for implementing systems during most of my employment. I compensated by continuing to have fun with other languages in my spare time. About three and a half years ago, I found Ruby. I can’t exactly remember how I did that, but I started using it and liked it very much. It combined some of the more useful parts of Lisp metaprogrammability, with a Smalltalky sensibility and cleanliness, while still retaining much of Perl’s pragmatism of doing whatever works.

It took me more than two years to convince my employer to start using Ruby. As much as I’d like to attribute that to the growth of my persuasion capabilities, the real reason was much more about the rise of Rails. At the time we decided to do a Rails spike, we faced a situation with resource and time limitations and needed to create a fairly simple database-backed web application. We finally convinced everyone to do this using Rails, which proved to be a clear win. Since then, more and more development is done in Rails, and right now about half the projects developed are Ruby on Rails projects instead of Java.

However, I still felt that something was wrong. As much as I liked Ruby and Rails, there were situations in which I felt it wasn’t enough. In Java, I always felt constrained by the language. With Ruby, the situation was the inverse: the language was lovely, but important things were missing in the platform and ecosystem. In most cases this was caused by the relative newness of Ruby and Rails, but some of it came from features that make Java code more robust and well-performing.

That’s when I started looking for a combination of the features I liked best from Ruby, while still retaining some of the good parts of the Java platform. I spent some time with different Lisp implementations on Java, ending up as a committer on the Jatha project (a Common Lisp implementation), but the Lisp implementations all shared the same problem: they didn’t have Ruby’s killer apps. I liked Jatha very much, but there wasn’t enough community behind it, and not enough pressure to support major libraries.