yokolet's notelets

ClojureScript on Rails Asset Pipeline

2011-11-10T19:35:00.005-05:00

This post is the second part subsequent to Tilt Template for ClojureScript. Now, Tilt template for ClojureScript has worked, so the template should work with Rails asset pipeline. Though it is brief, Ruby on Rails Guides: Asset Pipeline mentions "Registering gems on Tilt enabling Sprockets to find them." So, I tried that..To make it work, I added just one simple class, which is

Tilt Template for ClojureScript

2011-11-09T20:17:00.002-05:00

As a JVM language lover, I've written code mixed with more than one language. Ruby gems from Clojure, Clojure from Ruby, or other combinations. This blog is about using ClojureScript from JRuby. ClojureScript (https://github.com/clojure/clojurescript/) is "a new compiler for Clojure that targets JavaScript." ClojureScript uses Google Closure ( don't be confused! ) for optimization. So, instead

RedBridge Presentaion Slides

2011-09-27T11:52:00.004-04:00

I'll put the links to my presentation slides together here. Since I've written slides using Rails and jQuery instead of PowerPoint or OpenOffice, my slides are not on slideshare.StrangeLoop 2011 - "Embedding Ruby and RubyGems Over RedBridge", http://redbridge-at-strangeloop2011.herokuapp.com/slideshowWhen you put the cursor on the page, forward/backward arrows will appear on both sides of a main

Sinatra on Scala

2011-09-27T11:32:00.003-04:00

I rewrote the Servlet in my former post, Sinatra on RedBridge using Scala. Below is the code:package chestnutimport java.io.{File, IOException}import java.util.{ArrayList, List}import javax.servlet.{ServletConfig, ServletException}import javax.servlet.annotation.WebServletimport javax.servlet.http.{HttpServlet, HttpServletRequest => HSReq, HttpServletResponse => HSResp}import org.jruby.embed.{

Clojure's PersistentHashMap on JRuby

2011-09-24T22:21:00.003-04:00

Clojure is an impressive language. Not just succinct syntax, Clojure has immutable data types for concurrency. Such Clojure's persistent data types might be useful in some cases in other languages. A question is whether we can use Clojure data types from JRuby. The answer is yes. Below is what I tried on irb:$ rvm jruby-1.6.4$ irbjruby-1.6.4 :001 > require 'java' => true jruby-1.6.4 :002 > $

Haml on Clojure Web App

2011-09-08T16:58:00.003-04:00

I've wrote a couple of blog posts about making RubyGems work on JVM languages over RedBridge. Clojure is among them. So far, I could successfully make simple examples with DataMapper and UUID RubyGems. This time, I tackled a Clojure web app. The Rubygems to mix in was Haml.To create a Clojure web app, I used Leiningen (https://github.com/technomancy/leiningen) and Ring (https://github.com/

Sinatra on RedBridge

2011-09-06T17:26:00.004-04:00

Trinidad (http://thinkincode.net/trinidad/), Kirk (https://github.com/strobecorp/kirk), TorqueBox (http://torquebox.org/), mizuno (https://github.com/matadon/mizuno ) and perhaps some more are out there. As you know, those hook up Rails and/or Sinatra app on Java web servers. They are all easy to use tools even for people don't have Java background. On the other hand, there are people who want to

JRuby on Heroku via Clojure

2011-07-13T19:54:00.007-04:00

The big news about "Matz to Heroku" reminded me another news from Heroku. That's "Clojure on Heroku"!!! Yes, this news was for me, a JVM language lover. JVM has started running on Heroku, which means all JVM languages run on Heroku via Clojure. When I heard the news, I thought I should have tried that. So, today, I actually tried to run JRuby from Clojure. Happily, JRuby easily ran on Heroku.I

Extending JRuby, Compile and Jar Java Extension Code

2011-06-01T09:56:00.005-04:00

I wrote about how to extend JRuby by Java in my blog post, Extending JRuby. At that time, I didn't compile Java code since Eclipse performed that automatically. To jar Java code, I used jar command and made an archive manually. However, this is definitely not nice. In general, Java people use maven or ant to package Java code into a single jar. Although maven and ant are among choices to package

Rubinius on JRuby … ?

2011-05-15T22:55:00.007-04:00

Of course, compiled Rubinius binary, *.rbc, file doesn’t work on JRuby. This post is about JRuby’s rubinius branch. I’m not sure how may people are aware that, but JRuby does have a rubinius branch. As far as I looked at that branch, it is not to be merged into master, at least, in near future. Maybe it is headius’ pet project at this moment, and is implemented as a JRuby extension. Yes, it is a

Extending JRuby

2011-05-02T23:20:00.008-04:00

As pure Java Nokogiri does, we can extend JRuby writing a library backed by Java API. Other than Nokogiri, Weakling (https://github.com/headius/weakling), Warbler(https://github.com/nicksieger/warbler), JSON(https://github.com/flori/json) and more are examples of JRuby extension by Java. If you use google code search with a keyword, "BasicLibraryService," you'll find some more gems. This

Attempt to get Nokogiri work on Android

2011-04-25T21:20:00.003-04:00

ConclusionAs a result, Nokogiri was loaded on Android successfully but didn't work on it. When I tried to parse XML document, I got tons of errors something like:W/dalvikvm( 374): Unable to resolve superclass of Lorg/apache/xerces/dom/DeferredDocumentImpl; (2008)W/dalvikvm( 374): Link of class 'Lorg/apache/xerces/dom/DeferredDocumentImpl;' failedI'm pretty sure this sort of error messages

Nokogiri on Google App Engine

2011-04-14T16:55:00.008-04:00

Nokogiri 1.5.0 is on its way right now. Sure, it should be soonish. This version is also the first release of pure Java Nokogiri. We call it *pure Java*, but the name might not express itself precisely. Since it is written half Ruby and half Java, so *pure JRuby* (pragdave called so) would be the best name. This pure JRuby version implements methods, which are implemented in C, using xerces,

RedBrdige's Sharing Variables, How It Works

2011-03-03T22:06:00.027-05:00

RedBridge's sharing variables feature is convenient to let objects back and forth between Java and Ruby. The feature makes things easy but might be hard to understand a bit. The idea of sharing variables itself is simple. On Java side, all variables to share are saved in an internal map. When Ruby code is parsed/evaluated, all variables in the map are injected to Ruby runtime. All variables (

Rails on RedBridge, Scaffolded App to Work

2011-02-27T20:33:00.008-05:00

In my blog post, "The second step to Rails on RedBridge", I used Rails simple controller and showed how it could get run on Servlet. That was easy since there was no interaction with a Web browser. That controller just returned a result to the browser. That's it. So, Rails didn't need much information to work. However, a controller-only application isn't common. People start using Rails from

Using Rails from Scala

2011-02-15T16:50:00.002-05:00

Using Rails from Scala? Yes, it is possible if you use RailsCrossing (https://github.com/yokolet/RailsCrossing). This is a following chapter of my previous blog post, The second step to Rails on RadBridge. As I wrote "I'll try Rails from Scala next." at the end of that blog post, I tried it today. How did it go? It worked just fine. Here's how I used Rails from Scala.1. Preparation of Java web

The second step to Rails on RedBridge

2011-02-14T14:13:00.003-05:00

This is the second attempt to make Rails work on RedBrdige (JRuby embedding API). I believe Rails on RedBridge got closer to a real application. The first attempt is also in this blog, A small step to Rails on RedBridge. The blog post had some impact on a few people who want to control Rails (or Sinatra) from Java. The example there successfully showed how we could wake Rails up from Java Servlet

Embedding API refinements for JRuby 1.6.0RC1

2011-01-12T21:25:00.004-05:00

TThe biggest release ever --- JRuby 1.6.0RC1 has been released on Jan. 10, 2011. Headius wrote a blog about this biggest-ever release, JRuby 1.6.0 RC1 Released. Ruby 1.9 compatibility, performance improvement, built-in graph profiler, and more. How about embedding API (RedBridge)? In the release note (http://jruby.org/2011/01/10/jruby-1-6-0-rc1.html), you'll find a line mentioned about RedBridge,

Gems in a Jar with RedBridge

2010-10-22T11:28:00.004-04:00

Using JRuby embed API (RedBridge), it is easy to use Ruby gems from Java. However, packaging might not be simple, so people occasionally struggle to create a "portable" package. Being portable is important for a Java app. All stuffs of the Java app should be packaged in a jar archive, which should work on another PC, or even different OS. This is the good side of Java. This blog illustrates one

pure Java Nokogiri - XSLT extension function -

2010-10-11T16:10:00.002-04:00

Here's a memo of pure Java Nokogiri about an implementation of XSLT extension function. In short, I concluded pure Java version is unable to support Nokogiri style XSLT extension function. I've tried possible ways to make it happen, but for an inevitable reason, I settled to this conclusion. However, in future, this part might be reconsidered when XML libraries and APIs are replaced to others.

New featues of embedding API for JRuby 1.6

2010-09-20T12:11:00.007-04:00

This month, a lot of work for JRuby's embedding API (RedBridge) has been done. Mainly, bug fixing. While I was fixing bugs, I eventually landed to add a new feature and change the area of sharing variables. These will be in JRuby 1.6. Currently, snapshot is available at http://ci.jruby.org/snapshots/ if you want to test it. I believe the changes are good to use Ruby more naturally, but those

My Presentation at JRubyKaigi 2010

2010-09-04T23:01:00.005-04:00

I spoke at JRubyKaigi 2010 about JRuby embed API (RedBridge). Since attendees were almost all Japanese, I spoke in Japanese. However, my slide was written using simple English words, so that even non-Japanese speanker could understand what's going on. Don't worry about the Language of my slide.Now, you can see my slide at http://servletgarden-point.appspot.com/slideshow. As the url shows, my

Cucumber on RedBridge

2010-07-15T13:52:00.005-04:00

With JRuby's RedBridge, Ruby applications get started from Java. For example Cucumber, does. Let's see how Cucumber runs in Java code.Firstly, people use Cucumber like this:jruby -S cucumber addition.feature"cucumber" is installed in $JRUBY_HOME/bin directory and looks like a command. But "cucumber" is a Ruby script, so "cucumber" can be evaluated using JRuby Embed, RedBridge, API. How about "

Clojure uses DataMapper

2010-07-12T17:23:00.007-04:00

Clojure is one of the JVM languages. People know this fact well. Also, people know well JRuby is among JVM languages. On the JVM languages, many people have used Java APIs from Clojure or Ruby code. But, we can do more since the JVM languages are able to communicate each other. The communication is done over the API exposed to Java such as JSR223. This means libraries and tools for a particular

A Small Step to Rails on RedBridge

2010-05-04T21:32:00.012-04:00

When RedBridge (JRuby Embed) was released included in JRuby 1.4.0RC1 for the first time ever, I wrote“'Rails on Red Bridge' will be my exciting challenge" in my blog, What's the embedding API of JRuby 1.4.0RC1?. Since then, RedBridge had many improvements and bug fixes, so I tackled the issue this week. As a result, it went good. I could successfully made a small step to Rials on RedBridge.

Finally, pure Java Nokgiri worked on Google App Engine

2010-04-23T17:36:00.008-04:00

Pure Java version of Nokogiri is on the way to its very first version. It is "pure Java," not backed by libxml2, so people will expect that Nokogiri works on Google App Engine. In fact, Nokogiri on GAE is one of the purposes of Java port. Then... does it really work? Yes, it does! I could manage to get it work on GAE. However, it took pretty longer time than I thought, so I'm going to write down

RedBridge, what are new and improved in JRuby 1.5.0RC1

2010-04-16T17:00:00.011-04:00

As you may know, Tom Enebo announced the release of JRuby 1.5.0RC1 on Apr. 15 saying "aged like a fine wine." @headius tweated "Over 1250 commits for JRuby 1.5, our largest amount of work ever for any individual release." Also, RedBridge is. RedBridge has been improved since last release based on user inputs. It's API had many changes to become more useful and organized API. Although I've already

JRuby Embed (Red Bridge) Update: termination and skipping sharing variables

2010-02-25T16:32:00.005-05:00

Hers' recent update of RedBridge. Performance got much better, but the change on termination might affect your code. If you expect at_exit blocks to be executed automatically, you need to add termination.By the recent change, Embed Core, JSR223, and BSF, all three implementations had changes in their behaviors of evaluation and method invocation. Termination is no longer executed automatically.

Rava - pure Ruby JavaVM

2010-02-11T12:34:00.002-05:00

Since JRuby 1.4.0, become_java! method has been available to use to create a real Java class from Ruby class. This new feature always reminds me "Rava," which was written by Koichi Sasada(Ko1) back in 2002. Ko1 is, of course, famous Ruby committer and the author of YARV. When the days that Ruby was infamous while Java was thriving, Ko1 wrote Rava. Although I could not make it work, I think the

Hacking JRuby - add all Hash methods to Map

2010-02-05T14:48:00.004-05:00

I recently filed JRUBY-4528, whose patch adds all Ruby's Hash methods to a java.util.Map type object. Applying the patch, I confirmed that I could use "add_ruby_methods" method on Map type object, then, Hash methods for Map object. This would be useful especially for embedding API users since they often want to share Map object between Java and Ruby, back and forth.What's the problem of current

JRuby Embed (Red Bridge) Gotchas: on jirb

2010-02-02T13:29:00.007-05:00

I haven't used like that before, but there are people who want to use JRuby Embed API on jirb. I fixed a bug, http://jira.codehaus.org/browse/JRUBY-4521, and tried what I could do on jirb.At first, I instantiated ScriptingContainer and checked what initial parameters were set.irb(main):001:0> require 'java'=> trueirb(main):002:0> container = org.jruby.embed.ScriptingContainer.new=>

JRuby Embed (Red Bridge) Update: configuration and global runtime

2010-01-19T15:43:00.004-05:00

Here're recent updates of JRuby Embed (Red Bridge). Since I wrote about updates last time, Red Bridge's API has been changed a lot around configuration. Although this would directly affect to users' code, new API is easier to use and more stable. For example, setting jruby home directory has been changed from the fist to second one below:[JRuby 1.4.0]ScriptingContainer container = new

JRuby Embed (Red Bridge) Gotchas: FILE

2009-11-27T13:56:00.003-05:00

About a month ago, I wrote __FILE__ didn't work when Ruby code was loaded from classpath in the thread, Load path issues inside jar / external app. Tracking jruby down with a debugger, I found out one solution. It was a combination of setting a feasible current directory and using File.expand_path.Here's a test code:# file_check.rb [Birch]puts "__FILE__: #{__FILE__}"puts "dirname: #{File.dirname(

JRuby Embed (Red Bridge) Update: global vars, loading java, and more

2009-11-25T09:28:00.002-05:00

During these weeks, I made a couple of changes on Red Bridge (JRuby Embed), which would improve performance a bit and reduce problems caused by global variables. This change is available from 161d0fe in master (1.5.0.dev).Firstly, I changed an internal implementation of sharing global variables. Red Bridge injects all variables in a variable map just before the evaluation, and tries to retrieve

A Japanese Teenage Boy Improved Ruby 1.9 Performance Up to 63%

2009-11-04T21:40:00.005-05:00

Japanese online magazine, @IT Jibun Senryaku Lab. (information site for IT engineers to educate and/or develop oneself), published an interview with a Japanese teenage boy, Masahiro Kanai, who improved the performance of several methods in Ruby 1.9. He is the age of high school freshman (the third grade of junior high school in Japanese school system). The article (written in Japanese) is

JRuby Embed (Red Bridge) Update

2009-11-02T09:21:00.002-05:00

Since my last post about JRuby Embed (Red Bridge), it has been vastly changed. JRuby Embed codebase has been merged into JRuby! JRuby 1.5.0 will have Red Bridge inside in its both binary and source archives. Along with this, JRuby Embed wiki pages also have been merged into JRuby's wiki, Embedding JRuby section.Now, JRuby Embed project is almost in end-of-life period. I'll soon close jruby-embed

What's the embedding API of JRuby 1.4.0RC1?

2009-10-05T13:49:00.002-04:00

JRuby 1.4.0RC1 has been released on Oct. 2 and was a big release. JRuby had a lot of bug fixes and new features. Among them, JRuby Embed (aka Red Bridge) was there. The name, Red Bridge, means a bridge from Java to Ruby and, of course, the bridge has a color of ruby. However, many people would have thought, “What’s the new embedding API?” when they saw Tom’s announce. In this blog post, I ‘m

Splitting jruby-complete.jar up for Google App Engine

2009-09-06T16:35:00.003-04:00

When we write a web application using JRuby, we need jruby-complete.jar included in a war to use builtin libraries. The builtin libraries are supposed to be located under jruby.home, so the jruby.home system property is expected to be set correctly. However, we need an alternative to set the property since setting jruby.home on the web application doesn't make sense. The answer is

Finally yaml worked on Google App Engine

2009-09-02T18:32:00.004-04:00

In my previous post, I wrote about my struggle over an application on Google App Engine that uses JRuby's builtin library, yaml. I found the reason of the error at JRUBY-3892. Builtin library needs jruby.home environment variable to be set correctly, and it should be done in jruby-complete.jar. But, jruby-complete.jar built from old JRuby 1.4.0dev had a somewhat broken path. Since the issue has

Yaml doesn't work on Google App Engine

2009-08-29T22:22:00.002-04:00

While I was testing JRuby Embed API on Google App Engine, I encountered this awkward problem. Yaml never worked on GAE. Exactly the same Servlet successfully worked on GlassFish. Servlet and Ruby codes were:# yaml_snippet.rbrequire 'yaml'content = YAML::load @textdef format element case element when String: print "

#{element}

" when Array: print "

" element.each do |child|

NekoBean Fall Version

2009-08-26T19:30:00.003-04:00

NetBeans' mascot, NekoBean, is enjoying cool air in fall surrounded by colored foliage.More at:http://nekobean.net/2009/08/post-18.html.

JRuby Embed API Update: Servlet Examples

2009-08-25T15:09:00.003-04:00

I added Servlet Examples section in JRuby Embed API Wiki. Right now, just three examples are in that section. (I'll add more examples later.) Those are:HelloWorldServletSimple "Hello World" example, but helpful to get started.GreetingServletTwo methods written in Ruby are called from Servlet.SortableServletJava interface is implemented in two ways in Ruby.I tested these Servlets on Google App

RedBridge and JRuby Embed API update

2009-08-15T21:47:00.005-04:00

I updated both JRuby Embed API and RedBridge and the latest version is, now, 0.0.1.1. By this update, three types of local variable behaviors were added in light of the discussion, http://www.nabble.com/Call-for-discussion-about-embed-API-tc24528478.html. Before the update of Embed API and RedBridge, Ruby's local variables always survived over the multiple evaluations. Thus, local variables used

RedBridge Update: JRubyScriptEngineManager

2009-08-07T17:12:00.002-04:00

Today, I added two classes, JRubyScriptEngineManager and ServiceFinder, to RedBridge (JSR 223 JRuby engine). ServiceFinder is used from JRubyScriptEngineManager, and not for users. This update will be helpful especially for OS X users. Now, RedBridge works on both JDK 1.5 and 1.6 on OS X Java Update 4. Since its first release, RedBridge hasn't had JRubyScriptEngineManager mainly because of

Start Over: JSR 223 JRuby engine on OSGi container

2009-07-28T16:28:00.002-04:00

I got a comment from Neil Bartlett about my previous post. Yes, it was hard for OSGi people to understand what's wrong with it. Originally, my blog entry was to answer the question, "how can I create an osgi bundle using maven which uses jruby-engine to execute a jruby script?" So, I pasted entire pom.xml on it. As Neil commented, I should have pasted MANIFEST.MFs that all bundles used. This is

What's the ideal way to get JSR223 work on OSGi?

2009-07-27T12:56:00.003-04:00

After I wrote the entry, JSR 223 JRuby Engine won't work on OSGi platform, a workaround and an opposition to the workaround were posted to jruby-users ml, which is archived http://www.nabble.com/running-jruby-in-an-osgi-container-td24379565.html. The workaround Hasan found out worked well. But, Tommy opposed because the workaround would cause a tangle of references on some conainter that has

The design and implementation of Ruby M17N - Translation

2009-07-17T15:29:00.029-04:00

This is a translation of the article posted to Rubyist Magazine vol. 0025 published on Februrary, 2009. The original article is written in Japanese by Yui Naruse. The article is not new, so, probably, many poeple might have read this article via an online translation service. However, the article is really long and is not easy to understand even in my first language. To learn Ruby's M17N and

JSR 223 JRuby Engine won't work on OSGi platform

2009-07-08T20:44:00.002-04:00

I've been googling and seeking to find how I can run an application using JSR 223 JRuby Engine on OSGi platform. I could figure out some workarounds that fit JRuby Engine in OSGi world, but still get an error. When I ran a snippet on Apache Felix, I got "org.jruby.exceptions.RaiseException: library `java' could not be loaded: java.lang.ClassNotFoundException: org.jruby.javasupport.Java." This

Translation of a Panel Discussion about Ruby 1.9.1

2009-07-01T18:27:00.006-04:00

Japan Ruby Users Group (http://jp.rubyist.net) publishes an online magazine, Rubyist Magazine, a.k.a., RUBIMA. RUBIMA has some regular topics such as Getting Started, RUBIMA golf, or Ruby News, and featured topics. The latest issue released on June 30, 2009 (http://jp.rubyist.net/magazine/?0026) reported five RegionalRubyKaigis held in Japan from December, 2008 to March, 2009. Among them, the

JRuby Embed API

2009-05-20T23:25:00.005-04:00

Recently, I've been working to implement JRuby Embed API. This API is located in the middle layer between JRuby and an embeded application such as JSR 223. I designed this API based on JSR 223 and made it to suit existing JRuby API as much as possible. In addition, I added local, instance, global variables and constant sharing mehcanism, which has been a wishlist for long time.Today, I put API

Hatred of a Japanese car

2009-04-17T11:03:00.003-04:00

In these days, temperature is going up, the Sun light is getting brighter, and flowers has started blooming. Finally, spring has came to Michigan. I think I should have a seasonal exchange of my car tires as soon as possible. Putting stuffs aside and taking tires out from a back of a garage, I realized a long straight nail had stuck through the right rear tire. I remembered the tire presure alarm

Recent update of JRuby engine

2008-11-03T12:52:00.005-05:00

Recently, I updated CVS repo of JSR 223 JRuby engine to fix issue 39 and 40 filed in the issue tracker. Issue 39 was i18n related bug. To determine a character encoding for Writer type instances, I have put sun.jnu.encoding before file.encoding. However, I knew that some platforms had different values in thier sun.jnu.encoding property from file.encoding by the bug report. Since I don't have such

The sound of PyPy

2008-10-29T20:57:00.002-04:00

PyPy is, of course, an implementation of Python, but its sound is a bit embarrasing for Japaense to refer to in public. The sound is the same as the one of breasts in an informal way of mentioning them, especially babies' words. If someone pronounced PyPy by Japanese accent, other people might imagine breasts although they knew he or she talked about a computer languange. Japanese surely know it

Why did my browser display "??????" ?

2008-10-28T13:06:00.008-04:00

In the previous post, I wrote about some of Java’s i18n mechanisms especially when Java programs are compiled, plus read/write files. These are (1), (2), (3), illustrated in Figure 1, and we could do everything in a Java way. However, when we think about (6), (7), we need to know how communications between web containers and web browsers are going on in addition to Java’s i18n. All of you may

Why did I get "??????" ?

2008-10-16T10:16:00.005-04:00

Recently, I saw two i18n related questions about JSR 223 scripting engine for JRuby. Reading those questions, I thought they confused how to handle non-ASCII Strings in a Java way. Java’s i18n mechanism is not so complicated, but it has several ways of encoding and decoding characters to/from Unicode. As many Java programmers know, Java VM has arrays of Unicode code points to express characters

JRuby's unicode regular expression

2008-09-04T21:58:00.002-04:00

In my previous post, I worte about JRuby's unicode regular expression, Joni, didn't work like Ruby's even though both engines were Oniguruma. But, the truth is ... Joni dares be off the flag that enables unicode regular expression syntax described in Oniguruma's document "since unicode tables would make jruby distribiustion a bit more boilerplate (lopex)". Lopex, who is an implementor of joni,

Ruby 1.9's Unicode Regular Expression

2008-09-03T15:22:00.005-04:00

Ruby 1.9 has greatly improved its M17N features. Unicode regular expressions would be among the most improved ones. Ruby 1.9 uses Oniguruma for its regular expression engine and enables regular expressions by unicode codepoints or property names as described in Oniguruma's document at http://www.geocities.jp/kosako3/oniguruma/doc/RE.txt.When I tested some unicode regular expressions by ruby 1.9.0

Invocable#getInterface with two interfaces

2008-04-28T22:11:00.002-04:00

I wonder that even though multiple Java interfaces are mixed in and implemented by Ruby, whether only one invocation of getInterface method would be enough or not. To figure out what would happen, I wrote two interfaces below:package mountainash;public interface FlowerAttribute { String getName(); String getColor(); double getPrice();}package mountainash;public interface Flowers {

JRuby engine for JDK 1.5

2008-04-18T08:25:00.002-04:00

I've released JSR 223 JRuby engine for JDK 1.5 the other day. New release includes JRubyScirptEngineManager class, which is alternative to javax.script.ScriptEngineManager for JDK 1.5 users. However, newly added class was not necessary for JDK 1.5 users. NetBeans tricked me.When I tested JRuby engine on JDK 1.5, I could not avoid version mismatch error caused by some archives compiled on JDK 1.6.

Tips for JRuby engine: Sites to learn about scripting API

2008-04-07T09:42:00.002-04:00

For the eighth post of "Tips for JRuby engine" series I've written in this blog, I'll introduce useful sites to learn about JSR 223 scripting API.SpecificationJSR 223: Scripting for the Java Platform http://www.jcp.org/en/jsr/detail?id=223Reference Implementationscripting project home https://scripting.dev.java.net/Documents @ sun.comScripting for the Java Platform http://java.sun.com/developer/

Tips for JRuby engine: Compilable and CompiledScript usage

2008-04-07T07:58:00.006-04:00

This is the seventh post of "Tips for JRuby engine" series I've written in this blog and shows how to use Compilable interface and CompiledScript class defined in JSR 223 scripting API, and why they are useful. These two APIs are used when programmers want to just parse scripts without evaluating them. Once the script has been parsed, programmers can evaluate it continuously as many times as they

Tips for JRuby engine: servlet meets JRuby engine

2008-04-05T22:10:00.006-04:00

This is the sixth post of "Tips for JRuby engine" series I've written in this blog and shows how to get started writing servlet code using JSR 223 scripting API. Scripting API are smoothly mixed into other APIs since it is a part of standard Java APIs. Using JSR 223 scripting and Servlet APIs, we can make web applications more easily and delightfully thanks to the power of dynamic languages.

Tips for JRuby engine: getInterface() usage

2008-04-01T21:54:00.004-04:00

This is the fifth post of "Tips for JRuby engine" series I've written in this blog and shows how to use javax.script.Invocable#getInterface() method defined in JSR 223 APIs. This method is used when Ruby scripts provide implementations of Java defined interfaces. In other words, JSR 223 API allows us to write interfaces only in Java and implement them by Ruby. A programmer can discover

Tips for JRuby engine: invokeMethod usage

2008-03-30T21:03:00.010-04:00

This is the fourth post of "Tips for JRuby engine" series I've written in this blog and shows how to use javax.script.Invocable#invokeMethod() method defined in JSR 223 APIs. The idea to invoke Ruby's methods from Java is identical to the one described in the former post. It would greatly help you to understand about arguments and retuen values of invokeMethod() method.As I explained in the

Tips for JRuby engine: how to invoke Ruby's methods

2008-03-09T14:42:00.019-04:00

This is the third post of "Tips for JRuby engine" series I've written in this blog. This post is focused on how Java can invoke Ruby defined methods. Users of JRuby engine might want to have Ruby as their first language to process complicated issues and use Ruby's methods in Java. Or, they already have a bunch of methods written in Ruby and feel happy if those methods are also available to reuse

Tips for JRuby engine: how to share objects mutually

2008-03-08T18:01:00.024-05:00

This is the second tips for JRuby engine in addition to the first one. In this post, I'll show you how to share the same instances in both Java and Ruby, in other words, referring Java-created objects in Ruby, and contrarily, Ruby-created objects in Java.To refer the same instances in both languages, a global variable is a key concept. If a coder have experienced Ruby programming, he or she must

Tips for JRuby engine: how to get engine's instance

2008-03-06T21:13:00.008-05:00

Writing a code by using scripting API introduced in JDK 6 might be enjoyable because it enables us to use both dynamic languages and Java at a time, smoothly. Moreover, it enables to mix multiple dynamic languages without writing any Java code. For example, Rhino can execute Ruby code over scripting API. However, documents are few, unfortunately, and users often confuse how to use the API. In

JRuby 1.1 RC3 is about to release

2008-03-06T20:56:00.002-05:00

A few days have passed since the version name 1.1RC3 disappeared from issue jira of JRuby. And, Charles Nutter posed what would be showstoppers for final RC verison, RC3 to jruby-dev ml. So, we could know JRuby 1.1RC3 is about to released in a couple of days.How about JRuby engine? As far as I tested JRuby engine by using trunk version, JRuby engine should not need any bug fixes to catch up with

Download site just for JRuby engine

2008-03-05T21:07:00.002-05:00

Today, I created the download site just for JRuby eninge at scripting.dev.java.net. I've thought this kind of site should have existed since I updated JRuby engine for JRuby 1.1RC1. As for current release style of the scripting project, only one binary archive of each dynamic language is ready to download. This style might have been enough before and easy to release a bunch of engines for

JSR223 JRuby engine update

2008-03-03T13:27:00.002-05:00

I fixed one more bug to make JRuby engine work on JRuby 1.1RC2 yesterday, so I updated CVS today. Now, the latest version in CVS repo is compliant to JRuby 1.1RC2.I figured out that another bug was caused by newly added org.jruby.util.io.ChannelStream class to JRuby. ChannelStream has a sync member which is set to be false by default and flushes the output buffer only when the sync's value is

bug fixing for JSR223 JRuby engine

2008-02-28T15:26:00.002-05:00

I started debuggig JSR223 JRuby engine to make this work on JRuby 1.1RC2. Right now, JRuby engine in CVS, the latest version, is compliant to JRuby 1.1RC1 only. Since some internal APIs that JRuby engine uses has changed in JRuby 1.1 RC2, the engine doesn't work correctly.Today, I fixed an easy bug related to GlobalVariables. Again, GlobalVariables. Many bugs of JRuby engine have found in its own

Exam of Certified Programmer for Ruby in English will start in April

2008-01-28T09:57:00.000-05:00

Ruby Association has operated the exam to certify a programmer for Ruby three times since October, 2007. The association has organized the paper based exam only in Japanese and at two cities in Japan so far; however, the exam will be improved vastly from January. According to the article reported about extension of the exam on January 22, 2008, Prometric is responsible to the exam (Press Release

Matz objected to the article about PHP's string processing

2008-01-26T15:32:00.000-05:00

Note: Here's my version of translation without any permission nor consent of an original author. This is done just for my English training. But I'm happy if this is a good source to know what's going on in Japanese community.In his blog (http://www.rubyist.net/~matz/20080125.html), Matz, the creator of Ruby, objected to the on-line article that explained about PHP's string processing. Matz quoted

ActiveRecord Migration: how to write and the results

2007-08-29T14:56:00.000-04:00

Recently, I started learning Ruby on Rails which is getting more and more popular than a Java based web application framework. Ideas and cultures are quite different from those of Java, so I have struggled to understand them. What I figured out first was that Ruby on Rails programming is tightly coupled to database tables. Creating a table in a database is the first step of every programming. To

Four Days on Rails by NetBeans

2007-06-12T14:53:00.001-04:00

Recently, I have been intent on learning (J)Ruby on Rails. Many books are in bookstores, and so many tutorials are on the Internet. I had a bit hard time what was the good one to start learning. Wondering around the Internet, I found "Four Days on Rails"(http://rails.homelinux.org/) is one of the best tutorials though it is a little bit old. It is based on a command line interface and older

Using JRuby 1.0 on NetBeans

2007-06-11T22:54:00.000-04:00

Congratulations on JRuby 1.0 release! Right after the release, I successfully updated JRuby of my NetBeans. Here's what I did.Install JDK 1.6.0 or later. Ubuntu(and probably other Linux) users *must* use JDK 1.6.0(never use 1.6.0_01) to avoid the problem that some dialog windows of NetBeans don't open.Download a JRuby 1.0 binary version of archive from http://jruby.codehaus.org/ and extract

Guice made a good start in Japan

2007-03-18T19:58:00.000-04:00

A DI container Guice, which is written in Java and released from Google, has fascinated Japanese Java programmers since its 1.0 release in March 8, 2007. Everyday, they write blogs about Guice and shows how much they are zealous to explore Guice. It is clear that Guice made a good start in Japan. I'll introduce what they have written in their blogs.Many bloggers refer to the online magazine

A complement to the example of Guice struts plugin

2007-03-15T22:28:00.000-04:00

A Struts plugin provided by Guice has been my big concern because Sturts is used for web applications commonly. This would be one of the most attractive features in Guice. Today, I tried the counter example included in source code directory and explained in the user's guide. However, it was not easy to get the example to work. The explanation in the user's guide covers princepal parts but is not

Simple comparison with the two DI containers, Seasar and Guice

2007-03-13T17:17:00.000-04:00

Lightweight DI container, Guice 1.0 has been released. This news draws remarkable attention of Japanese Java developers who use DI container in their products. While Seasar(http://www.seasar.org/en/), which has been developed by Japanese Java programmers, is a de fact DI container and is used broadly in Japan. To study how I can write a code using Guice, I rewrote the example introduced in

Jar Archive setting of NetBeans Ruby Pack

2007-03-08T15:06:00.000-05:00

Recently, NetBeans Ruby Pack has been released, so I tried it immediately. It's very sweat and exciting except one problem. How can I set a classpath to a jdbc diver jar archive? I googled again and again putting various key words in the box, which ended up vain efforts. Instead keep searching, I looked carefully each directory related to NetBeans because JUnit tests seem to work in Ruby on Rails

Still now, Jini and JavaSpaces are sluggish in Japan

2007-02-09T21:40:00.000-05:00

When I wrote about JavaSpaces a few days ago, I got the comment which pointed out my out-of-date knowledge. The real cases based on JavaSpaces (or Jini) have worked already, though my awareness was opposite. I should have researched American Web sites. Now, I know JavaSpaces and Jini have been improving steadily. On the contrary, the situation in Japan remains the same that I wrote in my blog

Is XUL obscure? That's OK.

2007-02-07T17:28:00.000-05:00

The article of XUL appeared on XML.com this February. It's a very recent article, which is a bit strange. I mean it is the least likely appearing one. As the writer describes XUL as "a little-known use," it is obscure technology. I like XUL, and feel happy to support it; however, I admit XUL application has been slowed its development speed for more than a couple of years except products from

Does JavaSpaces have a possibility to become major?

2007-02-06T19:48:00.000-05:00

I found an article about JavaSpaces in TheServerSide.com a couple of days ago. I remembered this name well. I had worked for it for about a year before JINI was released. Since it was almost ten years ago, I'm interested in today's situation.In this article, the writer explains about the definition and the feature of JavaSpaces. In addition, he introduces a small example with describing how to

The answer for what is Web 2.0

2007-02-05T14:36:00.000-05:00

I had wondered what is the definition of Web 2.0 for more than a year. Recently, the word, "Web 2.0," has often appeared in articles about Web applications. None of these articles helped me to figure out the definition of Web 2.0. Web applications, which were introduced as Web 2.0, didn't look innovative though those were useful and attractive. Yesterday, I found the entry in Martin Fowler's

Cars bumped on a snowy road

2007-01-24T21:26:00.000-05:00

Today, snow accumulated in Michigan. Especially, snow fall in the evening was extreme, so roads were covered by snow and very slippery. When I was heading toward the swimming pool, I saw two cars bumped about 20 feet ahead of me. One car was waiting a chance to turn left; another car was to turn right to enter into a mall. Suddenly, the car turning left changed its direction and hit the car.

Revived Old Note PC

2007-01-23T14:56:00.000-05:00

Recently, I revived my old Note PC. Newly installed OS is FreeBSD 6.2R, which is the only one choice to revive this PC. This PC, released in 1998, has only a 96M-memory(which is a max size) and an 8G-disk. Besides, it is unable to boot by CD-ROM, so I really needed FD bootable OS. I prefered to install some recent easy-to-install and easy-to-use Linux, but Ubuntu, Fedore Core, Gentoo,,, all of

Why so many build problems?

2006-12-04T20:52:00.000-05:00

Reacently, I read e-mail posted to Geronimo-dev ML. One of the most frequent topics is build problem amid Geronimo developers. Why does a build problem occur so often?The larger the program grows, the more developers updates individually, frequently. Getting caught up the totally newest Geronimo might be a hard job for the developers. Geronimo-dev ML readers would know developers' frustration.

Is your answer yes or no?

2006-02-23T19:26:00.000-05:00

The answer for Yes/No questions sometimes puzzle me a lot because the answer for a negative question is opposite to Japanese one. I mean Japanese answer is like this "Yes, I didn't do that." I always try to avoid mistaking, but I have answered in Japanese style many times. Therefore, I often confuse other people and in some case, I'm misunderstood. Recently, I stay away saying just "yes" or "no",

When is it?

2006-02-10T15:32:00.001-05:00

If you got message, "Let's meet in the evening," what time do you think it is? According to LONGMAN ADVANCED AMERICAN DICTIONARY, the word "evening" means the late part of the day between about 6:00 and the time when most people go to bed. However, most Japanese think that evening is between about 4:00pm and 6:00pm, and after 7:00pm is the night. Also, the idea about the morning is different. In

What do they do?

2006-02-06T21:57:00.000-05:00

What do they do? This quesition has come into my mind so many times. I live in a suburb of Detroit with my family. All of my family member are naturally Japanese. Once I come back to my house, there is Japan even if I live in the U.S. Besides, I don't have any American friends. Therefore, sometime, I do something different. Yesterday was February 7th. I went to a fitness club as usual. The

What's this blog for?

2006-02-06T21:21:00.000-05:00

My life in the U.S. started accidentally on the end of March, 2005. I wasn't a person who were willing to come to the U.S. I have studeid English for my job, so I could speak English a little when I arrived here. However, everthing is different from Tokyo where I have lived for about ten years. I have had so many troubles and questions.Now, I learn English as a ESL(English as a Second Lanugage)