온라인 시험 시스템에서 시험 문제의 무작위 선택을 구현하는 Java 프로그래밍

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

public class Exam {
    private List<Question> questions;

    public Exam() {
        this.questions = new ArrayList<>();
    }

    public void addQuestion(Question question) {
        questions.add(question);
    }

    public List<Question> getQuestions() {
        return questions;
    }

    public void generateQuestions(List<Question> questionBank, int num) {
        Random random = new Random();

        // 随机生成num个不重复的下标
        List<Integer> indexes = new ArrayList<>();
        int totalQuestions = questionBank.size();
        while (indexes.size() < num) {
            int index = random.nextInt(totalQuestions);
            if (!indexes.contains(index)) {
                indexes.add(index);
            }
        }

        // 根据随机下标抽取试题
        for (int index : indexes) {
            questions.add(questionBank.get(index));
        }
    }
}

class Question {
    private int id;
    private String content;
    private List<String> options;
    private String answer;

    // 省略构造方法和getter/setter方法
}

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

public class Main {
    public static void main(String[] args) {
        List<Question> questionBank = new ArrayList<>();

        // 假设试题库中有5个试题
        questionBank.add(new Question(1, "问题1", List.of("选项1", "选项2", "选项3"), "A"));
        questionBank.add(new Question(2, "问题2", List.of("选项1", "选项2", "选项3"), "B"));
        questionBank.add(new Question(3, "问题3", List.of("选项1", "选项2", "选项3"), "C"));
        questionBank.add(new Question(4, "问题4", List.of("选项1", "选项2", "选项3"), "A"));
        questionBank.add(new Question(5, "问题5", List.of("选项1", "选项2", "选项3"), "B"));

        Exam exam = new Exam();
        exam.generateQuestions(questionBank, 3);

        List<Question> questions = exam.getQuestions();
        for (Question question : questions) {
            System.out.println("问题：" + question.getContent());
            System.out.println("选项：" + question.getOptions());
            System.out.println("答案：" + question.getAnswer());
            System.out.println();
        }
    }
}