Interfaces and abstract classes

Difference

abstract	Interface
Only one abstract class can be inherited	There can be multiple interfaces
There can be construction methods	Can not have
Common member variable	No,
Common method	Must be abstract
The access type of an abstract method can be public,protected	Abstract methods can only be public
Contains static methods	Can not contain
Static member variables can be arbitrary	Can only public static final
Mainly in code , Implementing code reuse plays a role in the architecture design approach	, It mainly defines the communication contract between modules

The same thing
1、 Can't be instantiated
2、 The implementation class of the interface or the subclass of the abstract class Can only be instantiated after the methods in the interface or abstract class are implemented