Checking for legal RDF before reading into a model

[Monika Solanki]

Is it possible to check if the incoming data is legal RDF before reading 
into the model? I do not want my program to throw an error via 
RDFDefaultErrorHandler if the incoming data is illegal RDF. I only want 
a warning to be issued and the program should continue execution. If 
there are any  supporting examples, that would be very helpful.

Thanks,
Monika