I am trying to use a factory pattern to create a QuestionTypeFactory where the instantiated classes will be like MultipleChoice, TrueFalseQuestion etc.

The factory code looks something like this

class QuestionFactory {
    public enum QuestionType {
        TrueFalse,
        MultipleChoice,
        Essay
    }

public static Question createQuestion(QuestionType quesType) {
    switch (quesType) {
        case TrueFalse:
            return new TrueFalseQuestion();
        case MultipleChoice:
            return new MultipleChoiceQuestion();
        case Essay:
            return new EssayQuestion();
    }
    throw new IllegalArgumentException("Not recognized.");
}
}

This works ok for now. If I want to add another question type I will need to modify the factory class and I do not want to do that.

How can I set it up so that each question class registers itself with the Factory so that when I add a new question type, I do not have to change the code for the factory? I am a bit new to java and am not sure how to do this.