java force an extending class

Question

In Java, can I somehow force a class that extends an abstract class to implement its constructor with a Object as a parameter?

Something like

public          


        

Answer 1

Probably there it's not possible at compile time, but you can use reflection to check at run time if the desired constructor was declared:

public abstract class Points {

    protected Points() {
        try {

            Constructor constructor = 
                getClass().getDeclaredConstructor(Object.class);
            if (!Modifier.isPublic(constructor.getModifiers()))
                throw new NoSuchMethodError("constructor not public");

        } catch (SecurityException ex) {
            throw new RuntimeException(ex);
        } catch (NoSuchMethodException ex) {
            throw (NoSuchMethodError) new NoSuchMethodError().initCause(ex);
        }
    }
}