Enthuware

Would it be possible to override doPut to receive and process file as asked in the question?

Yes, it is probably possible but it is certainly not something that "you would use", which is what the question asks. For the purpose of the exam, doPost is the right answer.

HTH,
Paul.

What is the advantage of using doPost instead of doPut in this case?

It is not about advantage. It is about how the protocol is designed. HTTP protocol specifies that PUT is used to associate a resource with a URL while POST is used to process data sent by the browser. One can, of course, write a client/server pair that does just the opposite and it would work but that is not the point here.

HTH,
Paul,

Thank you for your explanation!