Difference between an abstract class and Interface is as
Interface implicitly abstract
Keyword abstract is required for abstract method, can include normal methods as well.
Interface variables are by default final
Abstract class can contain both final and non final variables
Interface can only be Implemented where as an Abstract class need to be “extends” ed.
It is good to Design By Interface.
A Java class can implement multiple interfaces but it can extend only one abstract class.
an interface can extend another interface, but any class can extend an abstract class.
An interface cannot provide any code, just the signature.
Abstract class can provide complete, default code and/or just the details that have to be overridden.
Abstract class can have constructor but interface can not have constructor.
Abstract class constructor run when one of its subclass constructor execute.
Interface is loosely coupled where as abstract class is tightly coupled.