Java设计问题：从多个抽象类继承

Question

I have a design problem in Java. I have

• an abstract class Feature which represents features (machine learning), and
• an abstract class Normalizable which inherits from Feature and represents features which can be normalized.

A concrete feature can be an instance of either Feature or Normalizable .

I would like to introduce an abstract class called Probablity which inherits from Feature and represents features on which some sort of probability calculations can be done.

An actual feature should either be an instance of Feature (not normalizable and no probability) or it should be an instance of Normalizable , or Probability or both.

The problem now is that an actual feature cannot inherit from both Normalizable and Probability .

How can I solve this issue? I think using interfaces is not the solution because all of the mentioned classes contains implementations.

Answer 1

You can create a class NormalizablePrbability.java Use Composition and have Probability.java and Normalize.java as fields in newly created class NormalizablePrbability.java . You can extend NormalizablePrbability.java from Feature.java and override the methods and in each method you can provide the combined features of both Probability.java and Normalize.java .

Now you can have your concrete classes which can extends from Feature.java or Normalize.java or Probability.java or NormalizablePrbability.java