[java] When do I have to use interfaces instead of abstract classes?

From the Oracle tutorials :

Unlike interfaces, abstract classes can contain fields that are not static and final, and they can contain implemented methods. Such abstract classes are similar to interfaces, except that they provide a partial implementation, leaving it to subclasses to complete the implementation. If an abstract class contains only abstract method declarations, it should be declared as an interface instead.

Multiple interfaces can be implemented by classes anywhere in the class hierarchy, whether or not they are related to one another in any way. Think of Comparable or Cloneable, for example.

By comparison, abstract classes are most commonly subclassed to share pieces of implementation. A single abstract class is subclassed by similar classes that have a lot in common (the implemented parts of the abstract class), but also have some differences (the abstract methods).

Examples related to java

Under what circumstances can I call findViewById with an Options Menu / Action Bar item? How much should a function trust another function How to implement a simple scenario the OO way Two constructors How do I get some variable from another class in Java? this in equals method How to split a string in two and store it in a field How to do perspective fixing? String index out of range: 4 My eclipse won't open, i download the bundle pack it keeps saying error log

Examples related to oop

How to implement a simple scenario the OO way When to use 'raise NotImplementedError'? PHP: cannot declare class because the name is already in use Python class input argument Call an overridden method from super class in typescript Typescript: How to extend two classes? What's the difference between abstraction and encapsulation? An object reference is required to access a non-static member Java Multiple Inheritance Why not inherit from List<T>?

Examples related to inheritance

How to extend / inherit components? Inheritance with base class constructor with parameters Class is not abstract and does not override abstract method Why not inherit from List<T>? Can an interface extend multiple interfaces in Java? How to call Base Class's __init__ method from the child class? How should I have explained the difference between an Interface and an Abstract class? JavaScript OOP in NodeJS: how? When do I have to use interfaces instead of abstract classes? C++ calling base class constructors

Examples related to interface

Cast object to interface in TypeScript When to use Interface and Model in TypeScript / Angular Is there a way to create interfaces in ES6 / Node 4? Can a normal Class implement multiple interfaces? When to use: Java 8+ interface default method, vs. abstract method How should I have explained the difference between an Interface and an Abstract class? When do I have to use interfaces instead of abstract classes? How to extend a class in python? Interface type check with Typescript Abstract Class vs Interface in C++

Examples related to abstract-class

invalid new-expression of abstract class type Class is not abstract and does not override abstract method When to use: Java 8+ interface default method, vs. abstract method Spring can you autowire inside an abstract class? Abstract Class:-Real Time Example How should I have explained the difference between an Interface and an Abstract class? When do I have to use interfaces instead of abstract classes? Is it possible to make abstract classes in Python? Abstract Class vs Interface in C++ How do you handle a "cannot instantiate abstract class" error in C++?