Java를 사용하여 온라인 시험 시스템의 시간 제한 기능을 개발하는 방법

public class ExamTimeLimit {
    private LocalDateTime startTime;
    private LocalDateTime endTime;
    private int duration; // 考试时长（单位：分钟）

    // 构造方法
    public ExamTimeLimit(LocalDateTime startTime, int duration) {
        this.startTime = startTime;
        this.duration = duration;
        this.endTime = startTime.plusMinutes(duration);
    }

    // 判断是否在考试时间范围内
    public boolean isWithinTimeLimit() {
        LocalDateTime now = LocalDateTime.now();
        return now.isAfter(startTime) && now.isBefore(endTime);
    }
}

public class ExamService {
    public static boolean isWithinTimeLimit(ExamTimeLimit examTimeLimit) {
        return examTimeLimit.isWithinTimeLimit();
    }
}

@WebServlet("/submit")
public class SubmitServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 获取考试时间限制
        ExamTimeLimit examTimeLimit = ExamTimeLimitDao.getExamTimeLimit();

        // 判断是否在考试时间范围内
        if (!ExamService.isWithinTimeLimit(examTimeLimit)) {
            // 超出时间，强制提交
            submitAnswers(request, response);
            return;
        }

        // 其他业务逻辑处理
        // ...
    }

    private void submitAnswers(HttpServletRequest request, HttpServletResponse response) {
        // 提交答卷的逻辑
        // ...
    }
}

public class ExamTimeLimitDao {
    public static ExamTimeLimit getExamTimeLimit() {
        LocalDateTime startTime = LocalDateTime.of(2022, Month.JANUARY, 1, 9, 0); // 设置考试开始时间
        int duration = 120; // 设置考试时长（单位：分钟）

        return new ExamTimeLimit(startTime, duration);
    }
}