Is Interface in java provide 100% abstraction or not ?

Answer 1

The interface definition states the names of the methods and their return types and argument signatures. There is no executable body for any method that is left to each class that implements the interface.

Answer 2

Interface give 100% abstraction and abstract class give 0-100% abstraction.

Answer 3

but java 8/9 has default/static/private methods, so how it's possible 100% abstraction in interface