Example For JRuby

JRuby 1.0.3 was recently released and so was Rails 2.0. I decided to try JRuby 1.0.3 + Rails 2.0 and realized that a few additional steps (because of Rails 2.0) are required to get a trivial Hello World applcation up and running. Here are the steps:

1. Unzip JRuby 1.0.3.
1. Make sure to set JAVA_HOME and JRUBY_HOME.
2. Also include JAVA_HOME/bin and JRUBY_HOME/bin in PATH for convenience.
2. Install Rails 2.0 as shown below:
   
   ~/samples/jruby arungupta$ jruby -S gem install rails --include-dependencies --no-ri --no-rdoc
Bulk updating Gem source index for: http://gems.rubyforge.org
Successfully installed rails-2.0.2
Successfully installed activesupport-2.0.2
Successfully installed activerecord-2.0.2
Successfully installed actionpack-2.0.2
Successfully installed actionmailer-2.0.2
Successfully installed activeresource-2.0.2
3. Create a simple app using the following steps
1. Create a template app as:
   
   jruby -S rails --database mysql hello or jruby -S rails -d mysql hello
   
   It's important to specify --database mysql otherwise Rails 2.0 uses sqlite3 as the default database.
   
2. Add a Controller and View as:
   
cd hello
jruby script/generate controller say hello
3. Edit the controller as:
   
   vi app/controllers/say_controller.rb
   
   and add the following variable in "hello" helper method:
   
   @hello_string = ""
4. Edit the View as:
   
   vi app/views/say/hello.html.erb
   
   and add the following as last line:
   
<%= @hello_string %>
   
   Notice, the view extension is .html.erb instead of .rhtml.
4. Download, Install and Configure MySQL (additional step for Rails 2.0)
1. Mac OS comes pre-installed with MySQL in /usr/local/mysql directory. Start the server as:
   
   sudo ./bin/mysqld_safe
   
   Alternatively, you can download and install MySQL Universal server (only .dmg format, not tar.gz format as specified here).
2. Create a database as:
   
   sudo ./bin/mysqladmin create hello_development
5. Start the WEBrick server (in hello directory) as:
   
   jruby script/server

Have Nice Try... :p