Re: Java subclasses in Ruby

> First, I build a trivial java class with a setup method and a util method
> which simply prints a string.  In addition, I add a method that simply calls
> this instance's setup method:
> public class JavaClass {
>   public void setup() {
>     util("JavaClass: setup called.");
>   }
>   public void util(String s) {
>     System.out.println(s);
>   }
>   public void callSetup() {
>     this.setup();
>   }
> }
>
> I then build a java subclass overriding setup(), and include a main which
> lets me test it.  The test creates an instance of JavaClass and an instance
> of the subclass.  It then calls setup directly, and indirectly via
> callSetup:
> public class JavaSubClass extends JavaClass {
>     public void setup() {
>       util("JavaSubClass: setup called.");
>     }
>     public static void main(String[] args) {
>       JavaClass jc = new JavaClass();
>       jc.setup();
>       jc.callSetup();
>       System.out.println("");
>       JavaSubClass jsc = new JavaSubClass();
>       jsc.setup();
>       jsc.callSetup();
>     }
> }
>
> When I run it, I get what you'd expect:
> owen|~/src/jruby[1110]: java JavaSubClass
> JavaClass: setup called.
> JavaClass: setup called.
>
> JavaSubClass: setup called.
> JavaSubClass: setup called.
>
> Next for the JRuby test:
> require 'java'
> include_class "JavaClass"
>
> javaClass = JavaClass.new
> javaClass.setup()
> javaClass.callSetup()
>
> class RubyClass < JavaClass
>   def setup()
>     util('RubyClass: setup called')
>   end
> end
>
> puts
> rubyClass = RubyClass.new
> rubyClass.setup()
> rubyClass.callSetup()
>
> .. which works just fine:
> owen|~/src/jruby[1111]: jruby testjava.rb
> JavaClass: setup called.
> JavaClass: setup called.
>
> RubyClass: setup called
> RubyClass: setup called