Null URI versus empty string URI - are they equivalent?

[Andy Grove <gr...@roguewave.com>]

I've raised a JIRA (SDO-203) against the specification for this issue
but I thought it would useful to get a view from Tuscany on this as it
affects both Java and C++.

The specification does not currently state whether a null URI has the
same semantics as an empty string URI. There are specific references on
pages 19, 43, 50, and 105 of the Java 2.1 specification to null URIs. 

The SDO for C++ 2.1 API no longer allows null URIs to be used due to a
move from char* to std::string& in method signatures so if null and
empty-string URIs are not equivalent this will cause compatibility /
interoperability issues between Java and C++.

To express this is code, are the following calls equivalent?

TypeHelper.INSTANCE.defineOpenContentProperty( null, "myProperty" );
TypeHelper.INSTANCE.defineOpenContentProperty( "", "myProperty" );

Thanks,

Andy.