How to create an object knowing the name of its class?

Question

Java

How can you implement the creation of objects knowing which * .java is in the folder? Let me explain: there is a folder in which there are different *.java, they are inherited from a common abstract class. (Made in order to expand the functionality in the future). You need to know the name of the class so that you can create an object based on it.

Answer 1

Object object = Class.forName(className).getConstructor().newInstance();

Answer 2

cat:
parameters:
int size;
int age;
methods:
lickeggs();
enrage the host();
We create our personal library consisting of one class.
We connect it to the project.
So it doesn't roll?
Or I didn't understand the question?
PS Just create a library from one class. Well, or from several.