Automatically Generating an ObjectFactory

[zhi]

Before I dive into the post proper, I'd just like to extend my appreciation for all the support I've got from these forums so far. Benoit and marc, I have taken your advice and stipped down my application to the bare minimum.

I'm still stuck on streaming and am examining the demoj\Ice\invoke example.

One thing I do not understand is how the ObjectFactory methods were generated in the C.java class:

private static class __F extends Ice.LocalObjectImpl implements Ice.ObjectFactory
    {
	public Ice.Object
	create(String type)
	{
	    assert(type.equals(ice_staticId()));
	    return new C();
	}

    }
    private static Ice.ObjectFactory _factory = new __F();

    public static Ice.ObjectFactory
    ice_factory()
    {
	return _factory;
    }

My Slice definition is very simple:

module Streaming {
	class KodkodModel {
		void solve();
	};

	interface KodkodModelReceiver {
		void receiveKodkodModel(KodkodModel k);
	};
};

However my generated class does not have those ObjectFactory methods and it is the cause of this exception:

identity: kodkodmodelreceiverobject
facet:
operation: receiveKodkodModel
Ice.NoObjectFactoryException
    reason = "class sliced to Ice.Object, which is abstract"
    type = "::Streaming::KodkodModel"

Thanks!

[mes]

Hi,

The Slice compilers can only generate object factories for concrete classes. Since your class defines an operation, it is considered abstract. The application is responsible for defining a concrete subclass that implements the operations. Since the Slice compiler has no way of knowing what the name of that subclass might be, it's impossible for the compiler to generate a factory. Therefore, you must also define a subclass of ObjectFactory and register it with the communicator. Take a look at the example in demo/Ice/value for more details.

Take care,
- Mark