Question

So I made a mistake.

When originally writing a signature for an API, I created something like this:

public JellyBeanResult getJellyBeanReport();

Now, it turns out that I would like to re-use the more specific JellyBeanResult object because of its functionality, but it would be confusing to have other functions return a type named for a different process. There are a couple of ways to fix this that I can think of. I could re-name the return type to something more generic:

public GenericResult getJellyBeanReport();
public GenericResult getChocolateBarReport();

but that would break any code that is using the API. I could create a new, more accuratly named class that extends SpecificResult that more closely fits the new function:

public class ChocolateBarResult extends JellyBeanResult{};

public JellyBeanResult getJellyBeanReport();
public ChocolateBarResult getChocolateBarReport();

But this is really, really ugly and the problem still sticks around if I want to to use the return type again down the road. How can I clean up these signatures to make them less confusing without breaking any code that is using them?

Answer 1

Move the core functionality from JellyBeanResult to GenericResult and have JellyBeanResult extend GenericResult:

public class JellyBeanResult extends GenericResult {}

public JellyBeanResult getJellyBeanReport();
public GenericResult getChocolateBarReport();

or if you want to be completely consistent:

public class JellyBeanResult extends GenericResult {}
public class ChocolateBarResult extends GenericResult {}

public JellyBeanResult getJellyBeanReport();
public ChocolateBarResult getChocolateBarReport();