Why do JDBC 4.0 Wrapper methods requires an interface be passed?
I wanted to unwrap a WebSphere DataSource to the underlying SQL Server DataSource so I can call the getSendStringParametersAsUnicode() method. The unwrap failed because there is no interface for the SQLServerDataSource, only a class. The JavaDoc for the unwrap() and isWrapperFor() methods clearly state an interface is required to be passed. I communicated with Microsoft and they said they clearly wanted the Microsoft JDBC classes to unwrappable.
What is the reason an interface is being required here?
Message was edited by: wesclark