This TOTD (Tip Of The Day) shows how to install Rails 2.0.x in JRuby 1.0.3 and JRuby 1.1 RC1. Then it describes how a simple Rails application can be created and deployed using WEBrick.

First, lets deal with installing Rails 2.0.x in JRuby 1.0.3 and JRuby 1.1 RC1.

Step 1: How to install Rails 2.0.x in JRuby 1.0.3 ?

• Download and Unzip JRuby 1.0.3. This creates "jruby-1.0.3" directory.
• Install Rails by giving the following command in the newly created directory:
  
  bin/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

Step 2: How to install Rails 2.0.x in JRuby 1.1RC1?

• Download and Unzip JRuby 1.1 RC1. This creates "jruby-1.1RC1" directory.
• Install Rails by giving the following command in the newly created directory:
  
  bin/jruby -S gem install rails --no-ri --no-rdoc
Updating metadata for 632 gems from http://gems.rubyforge.org
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complete
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
Successfully installed rails-2.0.2
6 gems installed

Step 3: How to create and deploy a trivial Rails app ?

Once Rails is installed in JRuby 1.x, then the steps to develop and deploy a simple application are exactly same and given below:

1. Create the application
1. Create a Rails template app by giving the following command:
   
   jruby -S rails --database mysql hello
2. Create Controller and View by giving the following command:
   
   cd hello
jruby script/generate controller say hello
3. Edit Controller by giving the following command:
   
   vi app/controllers/say_controller.rb
   
   and updating the "hello" helper method to look like:
   
   def hello
    @hello_string = "Hello from Rail 2.0.2!!"
end
4. Edit View by giving the following command:
   
   vi app/views/say/hello.html.erb
   
   and adding the following line at the end:
   
   <%= @hello_string %>
2. Rails 2.0 default is to configure a database for the application. Following Convention-over-Configuration, either the defaults can be taken in which case you need to configure the database. Or override the convention by specifying "config.frameworks -= [ :active_record, :action_mailer ]" in "config/environment.rb". Follow the steps below if you prefer configuring the database:
1. Start MySQL server by giving the following command:
   
   sudo /usr/local/mysql/bin/mysqld_safe --user root
Starting mysqld daemon with databases from /usr/local/mysql/data
2. Create development database by giving the following command:
   
   jruby -S rake db:create
3. Test the App
1. Start WEBrick, using JRuby 1.0.3, by giving the following command:
   
   jruby script/server
=> Booting WEBrick...
=> Rails application started on http://0.0.0.0:3000
=> Ctrl-C to shutdown server; call with --help for options
[2008-02-05 23:35:02] INFO  WEBrick 1.3.1
[2008-02-05 23:35:02] INFO  ruby 1.8.5 (2007-12-15) [java]
[2008-02-05 23:35:02] INFO  WEBrick::HTTPServer#start: pid=13446204 port=3000

   The application is now accessible at http://localhost:3000/say/hello. Accessing the application shows the following output in console:
   
   127.0.0.1 - - [05/Feb/2008:23:35:31 PST] "GET /say/hello HTTP/1.1" 200 89
- -> /say/hello
127.0.0.1 - - [05/Feb/2008:23:35:32 PST] "GET /say/hello HTTP/1.1" 200 89
- -> /say/hello
127.0.0.1 - - [05/Feb/2008:23:35:32 PST] "GET /say/hello HTTP/1.1" 200 89
- -> /say/hello
   
2. Start WEBrick using JRuby 1.1RC1, then the following output is shown:
   
   => Booting WEBrick...
=> Rails application started on http://0.0.0.0:3000
=> Ctrl-C to shutdown server; call with --help for options
[2008-02-05 23:37:43] INFO  WEBrick 1.3.1
[2008-02-05 23:37:43] INFO  ruby 1.8.6 (2008-01-07) [java]
[2008-02-05 23:37:43] INFO  WEBrick::HTTPServer#start: pid=2533 port=3000

   Note, that even though the application was created using JRuby 1.0.3, it can be easily invoked using JRuby 1.1RC1 because they are using the same Rails version. Accessing the application in this case shows the following output:
   
127.0.0.1 - - [05/Feb/2008:23:37:51 PST] "GET /say/hello HTTP/1.1" 200 89
- -> /say/hello

So, you built a simple Rails 2.0.2 application and deployed using JRuby 1.0.3 and JRuby 1.1 RC1.

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