Abstract classes can’t be instantiated, you need to use a concrete implementation. Same as in regular java, if you try to instantiate an abstract class, it tells you to implement the abstract methods within. When you do, an anonymous class is created. It’s not an instatiation of the abstract class, but a new subclass of that abstract class.
Spring will look for classes which extend your base class, being Report1 and Report2, Spring sees it has multiple classes which match the requirements and doesn’t know which one to choose. thus you get the error that there are multiple matching beans.
You can fix this by making an “adapter” basicly create a concrete class which extends your base-class, implements the abstract methods, but doesn’t do anything them. Then you can autowire that implementation and test against it. However your abstract class should allready be tested due to the fact you are testing report 1 and 2. If errors still occur with your base class, it means logic you don’t use is causing bugs, which is a bad practice anyway. also with a test coveage tool you could spot unused code that way.