Java: design interface to force implementations to override toString

Question

I\'m developing an SPI and would like to define a Reportable interface such that any implementations must override toString() to something that is

Answer 1

No, you can't do this. I'd suggest you choose a different method name, e.g.

public interface Reportable
{
    String createReport();
}

That will force implementations to write an appropriate method. toString() is already somewhat vague in its intention - whether it's for debug representations, user-visible representations (at which point you need to ask yourself about locales etc). Adding another meaning doesn't seem like a good idea to me.