JRuby 1.0.3 + Rails 2.0 Hello World - Additional Steps Required

JRuby 1.0.3 was href="http://docs.codehaus.org/display/JRUBY/2007/12/15/JRuby+1.0.3+Released">recently
released and so was href="http://weblog.rubyonrails.org/2007/12/7/rails-2-0-it-s-done">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 href="http://dist.codehaus.org/jruby/jruby-bin-1.0.3.zip">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<br>
   Bulk updating Gem source index for: http://gems.rubyforge.org<br>
   Successfully installed rails-2.0.2<br>
   Successfully installed activesupport-2.0.2<br>
   Successfully installed activerecord-2.0.2<br>
   Successfully installed actionpack-2.0.2<br>
   Successfully installed actionmailer-2.0.2<br>
   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 href="http://weblog.rubyonrails.org/2007/12/17/rails-2-0-2-some-new-defaults-and-a-few-fixes">sqlite3
   as the default database.
   
2. Add a Controller and View as:
   
   

   <br>
   cd hello<br>
   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:
   
   

   <br>
   &lt;%= @hello_string %&gt;

   
   
   
   
   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 href="http://dev.mysql.com/get/Downloads/MySQL-5.0/mysql-5.0.45-osx10.4-i686.dmg/from/pick">MySQL
   Universal server (only .dmg format, not tar.gz format as
   specified href="http://dev.mysql.com/doc/refman/5.0/en/mac-os-x-installation.html">here).
2. Create a database as:
   
   
   
   sudo ./bin/mysqladmin create hello_development
5. Start the WEBrick server (in hello directory) as:
   
   
   
   jruby script/server

That's it, now your trivial Hello World
application is deployed using JRuby 1.0.3 + Rails 2.0 and displays the
output in a browser window as:

<img style="width: 526px; height: 253px;"
 alt="JRuby 1.0.3 + Rails 2.0 Hello World"
 src="http://blogs.sun.com/arungupta/resource/images/jruby103-rails2-helloworld.png">