Preventing a Java class from being instantiated and inherited
A class can’t be both final and abstract. You can prevent instantiation by hiding the constructor, and raising an exception to prevent instantiation via reflection. That looks like this:
instance
How to create a list of objects?
Storing a list of object instances is very simple
What is the difference between an Instance and an Object?
What is the difference between an Instance and an Object? Is there a difference or not?