Generic Type applied to method parameter - avoid Type erasure

Question

public static abstract class ViewHolder<T> extends RecyclerView.ViewHolder {
    public ViewHolder(View itemView) {
        super(itemView);
    }

    public abstract void bindItem(T item);
}

Is there a way to ensure bindItem(T item) parameter T is exactly T instead of Object? (As Type erasure replaces the method parameter type T with Object since it is unbounded.)

Update - accidental Raw Type usage

This is how I ended up implementing the abstract class:

static class EventHolder extends ViewHolder {

    @Override
    public void bindItem(Object item) {

    }
}

causing the bindItem parameter type to be Object since the raw type of ViewHolder was subclassed.

---

Should have been

static class EventHolder extends ViewHolder<Event> {

    @Override
    public void bindItem(Event item) {

    }
}

Which forces the correct parameter type.

Sorry. Late night coding = stupid mistakes.

Answer 1

You can narrow down the generic type to whatever is needed, for example:

public static abstract class ViewHolder<T extends SuperItem>
   ...
}

So anywhere inside this class you will get a compile-time warning if there is an object of non-declared type.