jruby and you

JRuby and YouHiro AsariEngine Yard

Wednesday, October 26, 11

HistorySeptember 10, 2001

Source: Wikipedia


Project Status

• Current stable release: 1.6.5 (Oct 25, 2011)

• Rails 3.1-compatible


What’s next in 1.7?

• JSR 292 (a.k.a. invokedynamic) support

• Improved Ruby 1.9 support


http://jcp.org/en/jsr/detail?id=292

http://jcp.org/en/jsr/detail?id=292

What’s in it for Javaprogrammers?

• REPL

• Testing frameworks

• Fun


What’s in it for Rubyists?

• Real threads

• No more GIL

• Mature garbage collector

• Easy deployment


Try JRubyhttp://jruby.org/tryjruby


http://jruby.org/tryjruby

http://jruby.org/tryjruby

Getting JRuby

wget http://bit.ly/jruby_bin_165 | \tar xzvf -

export PATH=$PATH:$PWD/jruby-1.6.5/bin


jruby -S irbWednesday, October 26, 11

Java Integration

require 'java'


Loading JAR

require 'example.jar'


Importing Java Class

StringBuffer = java.lang.StringBuffersb = StringBuffer.new "foo"


java_import

java_import java.lang.StringBufferjava_import 'java.lang.StringBuffer'


java.lang.System.currentTimeMillisjava.lang.System.current_time_millis

Static methods


Static Fields

java_import java.util.logging.Loggerjava_import java.util.loggin.Level

Logger.global.log Level::SEVERE, "…"


Constructor

URL.new 'http://engineyard.com'URL.new 'http', 'engineyard.com', '/'


#given# void setPrice(int):car.setPrice(2000)car.price = 2000

# int getPrice()car.price

Instance methods


Explicit Coercion

measurement = 5measurement.to_java


Overloaded methods

public class C { public static String method(String s) { return "String"; } public static String method(long l) { return "long"; }}


Overloaded methods

obj = C.newobj.method("foo") # => "String"obj.method(5) # => "long"


Overloaded methods

public class C { public String method(int i) { return "int"; } public String method(long l) { return "long"; }}


Overloaded methods

obj = C.newobj.method(5) # => "long"obj.method(5.to_java(Java::int))obj.java_send :method, [Java::int], 5


Java Interfaces

callable = java.util.concurrent.Executors.callable do puts "foo"end

callable.call


Complex Example with Akka

Java source: http://bit.ly/lTClmr

Ruby source: https://gist.github.com/1013227

http://www.engineyard.com/blog/2011/using-java-from-ruby-with-jruby-irb/


http://bit.ly/lTClmr

http://bit.ly/lTClmr

https://gist.github.com/1013227

https://gist.github.com/1013227





GUI

Redcar

http://redcareditor.com/




Grafting Rails into Spring MVC


Pet Clinic

• Example database-backed web app for Spring framework


App

Requests

/vets/ Java/Spring

JRuby

/rack/


Adding Routediff --git a/src/main/webapp/WEB-INF/jsp/vets.jsp b/src/main/webapp/WEB-INF/jsp/vets.jspindex cff2154..0d99817 100644--- a/src/main/webapp/WEB-INF/jsp/vets.jsp+++ b/src/main/webapp/WEB-INF/jsp/vets.jsp@@ -23,7 +23,7 @@ <table class="table-buttons"> <tr> <td>- <a href="<spring:url value="/vets.xml" htmlEscape="true" />">View as XML</a>+ <a href="<spring:url value="/rack/vets.xml" htmlEscape="true" />">View as XML</a> </td> </tr> </table>


Cucumber

• http://cukes.info

• Testing framework for describing software behavior in plain English


http://cukes.info

http://cukes.info

CucumberFeature: Pets

Scenario: Edit Pet Given I am on the owners search page And I press "Find Owners" And I follow "George Franklin" And I follow "Edit Pet" When I fill in "Name" with "Leoni" And press "Update Pet" Then I should see "Leoni"


Cucumber testStand by while Tomcat finishes booting...Using the default profile...............................................................F-.............

(::) failed steps (::)

expected: /xml/, got: "text/html;charset=utf-8" (using =~)Diff:@@ -1,2 +1,2 @@-/xml/+text/html;charset=utf-8 (RSpec::Expectations::ExpectationNotMetError)org/jruby/RubyProc.java:268:in `call'./features/step_definitions/xml_json_steps.rb:12:in `(root)':in `/^I should see an XML document$/'features/vets.feature:6:in `Then I should see an XML document'

Failing Scenarios:cucumber features/vets.feature:3 # Scenario: View vets as XML

13 scenarios (1 failed, 12 passed)75 steps (1 failed, 1 skipped, 73 passed)0m7.709srake aborted!Cucumber failed


diff --git a/pom.xml b/pom.xmlindex 9e22f83..0810701 100644--- a/pom.xml+++ b/pom.xml@@ -211,6 +211,18 @@ <scope>provided</scope> </dependency> + + <dependency>+ <groupId>org.jruby</groupId>+ <artifactId>jruby-complete</artifactId>+ <version>1.6.0</version>+ </dependency>+ <dependency>+ <groupId>org.jruby.rack</groupId>+ <artifactId>jruby-rack</artifactId>+ <version>1.0.8</version>+ </dependency>+  <dependency> <groupId>org.junit</groupId>

diff --git a/src/main/webapp/WEB-INF/web.xml b/src/main/webapp/WEB-INF/web.xmlindex 8d02684..60ed6cb 100644--- a/src/main/webapp/WEB-INF/web.xml+++ b/src/main/webapp/WEB-INF/web.xml@@ -87,6 +87,21 @@ <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener>++ <listener>+ <listener-class>org.jruby.rack.RackServletContextListener</listener-class>+ </listener>++ <servlet>+ <servlet-name>rack</servlet-name>+ <servlet-class>org.jruby.rack.RackServlet</servlet-class>+ </servlet>++ <servlet-mapping>+ <servlet-name>rack</servlet-name>+ <url-pattern>/rack/*</url-pattern>+ </servlet-mapping>+ <!-- Defines the 'default' servlet (usually for service static resources).


http://web.context.ContextLoaderListener

http://web.context.ContextLoaderListener

diff --git a/src/main/webapp/WEB-INF/lib/app.rb b/src/main/webapp/WEB-INF/lib/app.rbindex 6ab5b3c..4398fb4 100644--- a/src/main/webapp/WEB-INF/lib/app.rb+++ b/src/main/webapp/WEB-INF/lib/app.rb@@ -1,6 +1,33 @@ require 'builder' require 'erb'+require 'spring_helpers'++helpers do+ include Spring+end get '/rack/' do '<h1>Sinatra</h1>' end++get '/rack/vets.xml' do+ content_type 'application/vnd.petclinic+xml'+ builder do |xml|+ xml.instruct!+ xml.vets do+ clinic.vets.each do |vet|+ xml.vetList do+ xml.id vet.id+ xml.firstName vet.firstName+ xml.lastName vet.lastName+ vet.specialties.each do |spec|+ xml.specialties do+ xml.id spec.id+ xml.name spec.name+ end+ end+ end+ end+ end+ end+end


App

/vets /owners/ /owners/1/pets

Requests

Java/Spring

/vets/ JRuby


diff --git a/src/main/webapp/WEB-INF/web.xml b/src/main/webapp/WEB-INF/web.xmlindex 60ed6cb..f64b34d 100644--- a/src/main/webapp/WEB-INF/web.xml+++ b/src/main/webapp/WEB-INF/web.xml@@ -92,16 +92,6 @@ <listener-class>org.jruby.rack.RackServletContextListener</listener-class> </listener> - <servlet>- <servlet-name>rack</servlet-name>- <servlet-class>org.jruby.rack.RackServlet</servlet-class>- </servlet>-- <servlet-mapping>- <servlet-name>rack</servlet-name>- <url-pattern>/rack/*</url-pattern>- </servlet-mapping>- <!-- Defines the 'default' servlet (usually for service static resources).@@ -162,6 +152,16 @@ <url-pattern>/</url-pattern> </servlet-mapping> + <filter>+ <filter-name>RackFilter</filter-name>+ <filter-class>org.jruby.rack.RubyFirstRackFilter</filter-class>+ </filter>++ <filter-mapping>+ <filter-name>RackFilter</filter-name>+ <url-pattern>/*</url-pattern>+ </filter-mapping>+ <filter> <filter-name>httpMethodFilter</filter-name> <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>


http://web.filter.HiddenHttpMethodFilter

http://web.filter.HiddenHttpMethodFilter

The Book

http://pragprog.com/book/jruby/using-jruby

25% off for one week only: http://bit.ly/vd4Mhj






http://bit.ly/vd4Mhj

http://bit.ly/vd4Mhj

Engine Yard

500 free hourshttp://engineyard.com


http://engineyard.com

http://engineyard.com

Questions?Twitter @hiro_asari

G+ http://gplus.to/hiroasariLinkedIn http://linkedin.com/in/hiroasari

[email protected]@engineyard.com

http://github.com/banzaiman

http://www.flickr.com/photos/42033648@N00/372887164


http://gplus.to/hiroasari

http://gplus.to/hiroasari

http://linkedin.com/in/hiroasari

http://linkedin.com/in/hiroasari

mailto:[email protected]








jruby and you

Technology

edit pet

charsetutf

java

xml

http

jruby

rack

diff