JRuby on Rails with Nine Lives: Running a JRuby on Rails Application on Tomcat

Configuring the Database

Next, you need to tell your JRuby on Rails app to use ActiveRecord-JDBC and what database you will be using. Within the railswartest directory, edit the config/environment.rb file and add the following just before the line containing Rails::Initializer.run do |config|:

if RUBY_PLATFORM =~ /java/
   require 'rubygems'
   gem 'ActiveRecord-JDBC'
   require 'jdbc_adapter'
end

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Figure 7: Configuring JRuby on Rails app to use ActiveRecord-JDBC

This tells Rails that, if it detects that it is running on Java (in other words, JRuby) to load the ActiveRecord-JDBC gem.

Now, configure your JDBC driver. Within the railswartest directory, edit the config/database.yml file and edit the development: and production: configurations to contain the following:

development:
   adapter: jdbc
   driver: com.mysql.jdbc.Driver
   url: jdbc:mysql://localhost:3306/railswartest
   username: <username>
   password: <password>

production:
   adapter: jdbc
   driver: com.mysql.jdbc.Driver
   url: jdbc:mysql://localhost:3306/railswartest
   username: <username>
   password: <password>

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Figure 8: Configuring the JRuby on Rails app development and production database connections

I am using a database named railswartest, which I created using the MySQL Query Browser:

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Figure 9: Creating MySQL database 'railswartest' using MySQL Query Browser