QuestionBank.java

import java.util.ArrayList;
import java.util.List;

/**
 * PART D: Question Sourcing Integration
 * A pre-populated storage of predefined question objects.
 * Used by BankQuestionSource to fetch questions pseudo-randomly.
 */
public class QuestionBank {

    private static final List<Question> bank = new ArrayList<>();

    static {
        // Pre-populate the bank with a variety of questions
        bank.add(new MCQQuestion(
                "Which keyword is used to inherit a class in Java?",
                2, "Easy", "B"));

        bank.add(new MCQQuestion(
                "What is the time complexity of binary search?",
                2, "Medium", "C"));

        bank.add(new MCQQuestion(
                "Which data structure uses LIFO ordering?",
                2, "Easy", "A"));

        bank.add(new TrueFalseQuestion(
                "Java supports multiple inheritance through classes.",
                1, "Easy", false));

        bank.add(new TrueFalseQuestion(
                "An interface can have default methods in Java 8+.",
                1, "Medium", true));

        bank.add(new EssayQuestion(
                "Explain the SOLID principles of object-oriented design.",
                10, "Hard", 150));

        bank.add(new EssayQuestion(
                "Describe the differences between SQL and NoSQL databases.",
                10, "Hard", 200));

        bank.add(new ProgrammingQuestion(
                "Write a Java method to reverse a linked list in place.",
                20, "Hard", "Java", "next"));

        bank.add(new ProgrammingQuestion(
                "Implement a binary search algorithm in Java.",
                15, "Medium", "Java", "mid"));
    }

    /**
     * Returns the internal question list for random access.
     */
    public static List<Question> getAll() {
        return bank;
    }
}