Type Mismatch

dadams07

I have a class defined as follows:

public class MultiFacilitySearchDataProvider <T extends Facility & MilepostValue & Copyable<T>>

The class has this method:

protected T getFacility(final FacilityInstance instance) {

    final MultiFacilitySearchDAO dao = new MultiFacilitySearchDAO(instance);

    ENM.execute(dao);

   return dao.getResultModel();  // Compile error here

}

The DAO method called above looks like this:

public MultiFacilitySearchModel getResultModel() {

    return resultModel;

}

And MultiFacilitySearchModel is defined as follows:

public class MultiFacilitySearchModel implements Copyable<MultiFacilitySearchModel>, Facility,

     Serializable, MilepostValue, MenuDisplayValues

The problem is that the line return dao.getResultModel() generates a compile error "Type mismatch: cannot convert from MultiFacilitySearchModel to T". I don't understand why I'm getting this error, since MultiFacilitySearchModel implements the three interfaces specified for the generic type T. What am I missing?

jschellSomeoneStoleMyAlias

getFacility() returns a T.

That means the return value must return a T or something derived from T.

Something that extends/implements the same a T is not the same thing.