In object-oriented paradigm, a virtual function or virtual method is a function or method whose behavior can be overridden within an inheriting class by a function with the same signature to provide the polymorphic behavior.
According to the definition, every non-static method in Java is by default virtual method except final and private methods. The method which cannot be inherited for polymorphic behavior is not a virtual method.
An abstract class in Java is nothing but the pure virtual method equivalent to C++.
Why do we say that a static method in Java is not a virtual method? Even if we can override the static method and consequently it may give some advantages of the polymorphism and also a static method in Java can be invoked mostly with it’s associated class name but it is also possible to invoke it using the object of it’s associated class in Java in the same way that an instance method is invoked.
You can’t override static methods. They are bound at compile-time. They are not polymorphic. Even if you try to invoke it as if it were an instance method (which IMO you shouldn’t do) it’s bound to the compile-time type of that expression, and the execution-time value is completely ignored (even if it’s null):
This behaviour can be very confusing for a reader, which is why at least some IDEs allow you to generate warnings or errors for accessing static members “through” a reference. It was a flaw in Java’s design, pure and simple – but it doesn’t make static methods virtual at all.