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JRuby on Rails

GAO ANGSun Functional Campus Ambassadorhttp://www.gaoang.com

tomgaoang@gmail.com1

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JRuby on Rails

Introduction to Ruby

Agenda

JRuby on Netbeans

Where To Go

What is JRuby

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What is Ruby?

• Created/lead by Matz • Open Source interpreted scripting language, like

Perl, Python, Tcl, etc.• Focused on being very object oriented,

expressive, and bringing joy to programming.

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Ruby calling Java

• require ‘java’

include_class “javax.swing.JFrame”include_class “javax.swing.JButton”

frm = JFrame.new(“My frame”)btn = JButton.new(“My button”)

frm.set_size(300, 300)frm.content_pane.add(btn)frm.show

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Interactive ruby console: irbirb• This powerful tool can be used for trying out single

line commands while you are getting used to Ruby, or to run whole programs.

DEMO

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Ruby in a nutshell – RubyGems

• Ruby Gem: http://docs.rubygems.org/• Examples:

> gem list> gem install redcloth --version ">= 3.0.0"

• Using gems in your program:> require ‘rubygems’> require ‘some_gem’

DEMO

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What is Ruby on Rails

• Web Framework that makes MVC-oriented web apps easy through a template engine, ORM (ActiveRecord) ,test driven development.

• Much less complicated than J2EE solutions, but perhaps more so than PHP or Perl in cgi-bin.

• Similar Web Framework> Python (TurboGears, Django)> Perl (Maypole)> Groovy on Rails (Grails)> Ruby(Merb)

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Java and Rails

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Rails Architecture

• Rails applications are implemented using the Model-View-Controller (MVC)

• Model - ActiveRecord• View - ActionView• Controller - ActionController

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Comparison of Rails and J2EE stacks

• Tomcat servlet container• Struts Web application framework• Hibernate persistence framework

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Database Migration (Bookmarks)• db/migrate/001_create_bookmarks.rb

• class CreateBookmarks < ActiveRecord::Migration

• def self.up

• create_table :bookmarks do |t|

• t.column :url, :string

• t.column :title, :string

• end

• end

• def self.down

• drop_table :bookmarks

• end

• end

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Running the Migration

• Rake is the general purpose build tool for rails, much like make, or ant. It has many functions, one of which is to control migrations.> rake db:migrate

• Now the table has been created

• Migration in Netbeans

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What is JRuby

• 100% Java impl of Ruby• Ruby on the JVM• Pure interpreted, native threaded• Born 2001, product of many developers• Largely Ruby 1.8-compatible• Slower than Ruby...for now

http://jruby.codehaus.org/

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Why JRuby on Rails

• Java is pervasive• Java libraries are exhaustive• Many still believe Java is the “everytool”• Java webapp developers are unhappy• Rails webapp developers are happy

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Advantage of JRuby on Rails

• JRuby on Rails mostly works right now• JRuby will not be “done” until it’s fully working• ActiveRecord-JDBC opens many doors• Java EE is actually fun with Rails• More Rails is more Rails...JRuby enables!

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JRuby on Netbeans

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Netbeans 6.1 Depot Demo

DEMO

Where to go for Ruby information

• Online material:> http://www.ruby-doc.org/> http://rubyonrails.org/> Rails screencast(s)> Planet Ruby on Rails

Netbeans 6 Resources• Netbeans Product Site: http://www.netbeans.org

> Download: previews, current & past releases of IDE, plugins> Learning: tutorials, technical articles, flash demos> Community: latest news, forums, events, mailing lists

• Netbeans Wiki: http://wiki.netbeans.org/wiki/> Open-source documentation site for Netbeans.

• Planet Netbeans: http://www.planetnetbeans.org/> Aggregate for all Netbeans-related blogs

• Netbeans TV: http://www.netbeans.tv/> Connecting the diverse and worldwide community of People, Projects

and Technologies surrounding NetBeans.

Stay In Touch

• Check blog regularly : > http://blogs.sun.com/> http://www.javapassion.com/> http://blogs.sun.com/GaoAng/

• Join Java Open Source User Group > BJUG http://www.bjug.org/> BLUG http://www.beijinglug.org/

• You Can find lots of material on :> http://developers.sun.com/students/

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Resources• http://java.sun.com/

> Java 2 Platform, Standard Edition v1.4.1> java, javac, jar, jre, etc.> Online documentation and tutorials

• http://www.netbeans.org/> Docs & Support> Netbeans Tutorials & Training> Get the latest version of Netbeans

• http://developers.sun.com.cn/> The Source for Sun Developer Solutions

• http://www.sunacademic.com

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Gao AngSun Functional Campus Ambassadorhttp://www.gaoang.com

tomgaoang@gmail.com

THANK YOU

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