Question

Hi I’m implementing a given design in java. Basically I have an abstract class which is called base and I have a number of concrete classes which are extending Base and implementing an interface from a different package. Each concrete class will be implementing a different interface. Now these interfaces contain both event-based and non event-based method signatures in them. My question here is; I’m only expected to implement non-event based methods in my concrete classes, however because of the implements keyword java forces me to insert an auto generated method body, which is basically return null. They might be implementing those event based methods later on but not at the moment. What would be an appropriate way to let the API user know that these methods do not contain an implementation. Here are my thoughts;

1. Use deprecated keyword
2. Create an exception class and throw that exception inside of the method and let the API user handle it.

I do not have the option of making changes to the existing architecture. Any idea really appreciated. Thank you.

Answer 1

According to Oracle, the reasons to deprecate an API include

• It is insecure, buggy, or highly inefficient
• It is going away in a future release
• It encourages bad coding practices

neither of which actually fits your case.

Personally, I would favor throwing an UnsupportedOperationException which is already provided by the Standard Library in order to

indicate that the requested operation is not supported.

To me, this sounds more like what you actually want.