[JAVA] About "Dependency Injection" and "Inheritance" that are easy to understand when remembered together

Introduction

I'm Matsushita from Dream Hanks. This time, I will explain about "Dependency Injection" and "extends".

Summary of serialized articles

What are "Dependency Injection" and "Inheritance"?

What is Dependency Injection?

By creating other classes or interface objects in the class you want to implement Something that allows you to use methods of other classes.

What is extends

Assuming that the implemented class is a subclass (child class), inherit the superclass (parent class) (extends) To be able to use the methods of the parent class by doing

** In short, both want to be able to use the methods of other classes in the Java class they want to implement. ** ** Besides, "constructor injection", "setter / getter injection"