Question

Following on from a question on unit testing my POJO:

public class MyPojo{
    private final Object interestingData;

    MyPojo(Object data){
        interestingData = data;
    }

   //Methods etc...
}

Hibernate is populating the final field, and the package private construtor is just for unit testing. I want to give the constructor other objects to perform logic that should be mockable in tests. E.g.

public class MyPojo{
    private final Object interestingData;
    private final ILogicEngine engine;

    MyPojo(Object data, ILogicEngine engine){
        interestingData = data;
        this.engine = engine
    }

   //Methods etc...
}

What is the right/easy way to get hibernate to supply the ‘engine’ to each POJO? Spring seems overkill, since in production there will only ever been one engine, I’m only doing this for testing. Should I be injecting the ILogicEngine through the MyPojoUserType somehow? (not sure how this would work since I don’t instantiate it myself, hibernate does)

Or is this smelly, and I should keep objects representing DB data clean and wrap them to do the engines work?

Answer 1

I think we are mixing the concerns of DI and ORM here. Would it be wise to even try to use hibernate for DI purposes so that you could test things easily?
I agree with your last statement. Keep the data separate from the engine.