Question: If both mothods are synchronized, is there a risk for thread-safty?
Since this is an interview question, I will assume that it is
testing something very specific. I am guessing it is targeting whether the candidate understands what is happening under-the-covers when a method is sychronized.
Basically, when you synchronize a method (that is not static), it will use the "this" object of that method as the synchronization lock. No other synchronization method or block that uses the same object will be able to execute in parallel.
A static method does not have access to a "this" object. Instead, it uses the "class" object of the class which the method is part of.
I am assuming that the candidate needs to understand that these are two different object, and hence, it is not thread safe.
Henry