Use of Java [Interfaces / Abstract classes]
6853
Interface vs Abstract Class (general OO)
85865
Optional Methods in Java Interface
27078
When do Java generics require  instead of  and is there any downside of switching?
18899
What is the use of marker interfaces in Java?
23198
Why explicit interface implementation?
119211
property type or class using reflection
85201
"Cannot create an instance of the abstract class or interface" C# error message
75499
Determine if a Class implements a interface in Java
55202
Why doesn't an interface work but an abstract class does with a generic class constraint?
33115
Interface naming in Java
114817
How to find all the classes which implement a given interface?
112406
Abstract types versus type parameters
153259
What is the use of creating a constructor for an abstract class in Java?
96666
Does JavaScript have the interface type (such as Java's 'interface')?
5983
Why Java needs Serializable interface?
65730
implicit super-interface in Java?
150519
When should you use a local class in Java?