JRuby with Spring DM

[stephanos]

Hi,

I'm trying to run a JRuby script with Spring DM and run into problems.

Java Base class

package org.codingkata.unit.api; 

public abstract class BaseKataSolution { 
    abstract String reply(); 
}

JRuby Class

class MyKata 
  include org.codingkata.unit.api.BaseKataSolution 

  def reply 
    return "hello world" 
  end 
end

Spring Beans context

[...] 
   <osgi:service 
           ref="kataSolution" 
           interface="org.codingkata.unit.api.BaseKataSolution"/> 
   [...]

So far so clear - the JRuby class inherits the 'BaseKataSolution' class. In Spring I configure this as the interface (cglib is present, in the java and groovy version everything works flawlessly).

But when I try to run a test which loads the JRuby class, it results in:
Exported service object does not implement the given interface: class org.codingkata.unit.MyKata is not assignable to interface org.codingkata.unit.api.BaseKataSolution.

Then I tried to look at the classes in detail by using a decompiler:

Decompiled Groovy version

public class MyKata extends BaseKataSolution
  implements GroovyObject 
{ 
  public MyKata() 
  { 
    MyKata this; 
    [...] 
  } 

  public String reply() 
  { 
    for (CallSite[] arrayOfCallSite = $getCallSiteArray(); ; return ((String)ScriptBytecodeAdapter.castToType("hello world", $get$$class$java$lang$String()))); 
  } 
  [...] 
}

Decompiled JRuby version

public class MyKata extends AbstractScript
{ 
  private final Class $class = Class.forName("org.codingkata.unit.MyKata"); 

  public MyKata() 
  { 
    [...] 
  } 

  @JRubyMethod(name="reply", frame=true, required=0, optional=0, rest=-1) 
  public static IRubyObject method__1$RUBY$reply(MyKata paramMyKata, ThreadContext paramThreadContext, IRubyObject paramIRubyObject, Block paramBlock) { Ruby localRuby = paramThreadContext.getRuntime(); IRubyObject localIRubyObject = localRuby.getNil(); setPosition(paramThreadContext, 5); return paramMyKata.getString1(localRuby); 
  } 

  [...] 
}

Obviously Groovy directly inherits the base class while JRuby does not. Bummer. I opened a discussion in the JRuby mailing list if this is the desired behavior.

Still, I'm wondering if there is anything I can do to make it work with Spring DM - because I expect most of the JSR223 languages to act like JRuby.

Any ideas?

Cheers,
stephanos

[stephanos]

Somebody in the JRuby board proposed a Proxy - but I can't think of how to combine this with Spring DM on the one side and a dynamic JSR 223 script on the other.

Do you? Or is that not a good approach?

Cheers,
stephanos

[Costin Leau]

You could avoid this problem by using a ServiceFactory which allows one to register a factory rather then the object directly.