Can you use a constructor in Child Activity to change Parent Activity String variable?

Question

I have a Parent Activity class that all my Child Activity classes extend from. This parent activity has a field called 'activity_Id' that is a String and defaults to be null.

In the onCreate of the Parent Activity, I need to check if that field has a value, which it would only get from the Child Activity if it does I do some other logic in the onCreate of the parent activity.

Note, that each activity has a unique 'activity_Id' that it is used to alter the other logic that is being done.

Here is the ParentActivity:

public class ParentActivity extends Activity{
    protected String activity_Id = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if(activity_Id != null)
            //DO OTHER LOGIC UNIQUE TO THIS STRING ID
    }
}

Here is the ChildActivity:

public class ChildActivity extends ParentActivity{

    public ChildActivity(){
        super();
        activity_Id = "Foo123";
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }
}

This activity_Id String is predetermined but does not match the Activities name so I can not do

this.getClass().getName()

in my ParentActivity class.

This seems like the cleanliness way BUT there seems to be some taboo around using constructors in activities so I just want to make sure I do not break anything. Or if someone can think of a cleaner way to do it?

Answer 1

This can be done with abstract class because constructor don't construct an activity directly.

Try it like this

public abstract class ParentActivity extends Activity{
    protected abstract String activityId();
    .....
}

Then in child activity override activityId() with required value. And now you can compare activityId() in ParentActivity onCreate(...) method.