Sravani D.

Abstraction is the Methodology. Abstraction means hiding the things, that can be either data or implementation or complexity or anything. So that how you are achieving abstraction means through Encapsulation, Abstract classes or Interfaces. Encapsulation means "minimizing inter-dependencies among separately-written modules by defining strict external interfaces". That means when we giving data as private and to access that data we are providing getters and setters so that we can access that data. By doing like this you are not preventing the data you are controlling the data if you want to give permission to update or insert then only you can provide setter otherwise you can provide only getter and any validations like age can be only positive we can't give negative but int can accept both like these controlling you can give it in setter methods. This is Encapsulation.

No. It is not possible to instantiate the abstract class because abstract class means incomplete class. Usually the class is a design pattern so in normal way we can't create real object for incomplete design so that we can't create software object for incomplete class. And some will feel that using anonymous inner classes we are indirectly creating object for abstract class but at that situation the compiler will provide some name to extended class so that it will create object for that class not for abstract class.