From: steve.drach@... (Steve Drach)
Date: 2004-06-20T02:48:18+09:00
Subject: Re: JRuby: How does one keep Java objects as Java objects so they can be used in method calls?

>  Well one way is to create a 'java_alias' ala:
>
>java_alias :JFile, :File
>
>  then use 'JFile.new "/etc/blah"'

Ok, I think I understand.  It's because the constant File was already
defined to be the org.jruby.RubyFile class.  Is that correct?  And
java_alias just deals with Java constants?  Is that why alias wouldn't
work, since it would have aliased the RubyFile to JFile?  It's all
a little subtle for me.

In any case, it seems to work, and both File and SAXBuilder are
the correctly scoped type (symbol?) now.  However it now fails
mysteriously, not telling me which method is missing:

jruby-0.7.0/bin/jruby.sh test.rb
Foo::SAXBuilder
Foo::JFile
Exception in thread "main" java.lang.NoSuchMethodError
at org.jruby.javasupport.JavaSupport.createRaiseException(JavaSupport.java:83)

The new code is:

require 'java'

class Foo
  include_package 'java.io'
  include_package 'org.jdom'
  include_package 'org.jdom.input'

  java_alias :JFile, :File

  attr_reader :d

  def initialize
    sb = SAXBuilder.new
    p sb.class
    f = JFile.new "/home/drach/schema/modeler/build.xml"
    p f.class
    @d = sb.build f
  end
end

foo = Foo.new