CHEKZAM

1. Introduction

1.1 Project Description

• CHEKZAM is an online learning platform that provides a centralized space for teachers to manage classes and for students to access materials and assessments.
• It standardizes online class organization, reduces technical barriers, and improves teacher–student interaction.
• The system follows an e-classroom model with separate spaces for tests, member management, and activity tracking.

1.2 Project Objectives

• Help teachers easily create and manage online classes.
• Provide multiple-choice testing with automatic grading.
• Support student management and allow flexible joining or leaving of classes.

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2. Tech Stack

• Backend: Spring Boot (Spring Web, Spring Data JPA, Spring Security, OAuth2 Resource Server (JWT), Lombok, MySQL Connector/J)
• Frontend: ReactJS (react-dom, react-router-dom, react-bootstrap, react-icons, react-toastify)
• Database: MySQL

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3. Analysis and Design

3.1 Specification

3.1.1 Actors

• Admin: Manages and monitors the entire system, including user management.
• Teacher: Creates and manages classes and assignments, and guides students.
• Student: Joins classes, completes assignments, and tracks personal progress.
• (Before role assignment, all users are general users.)

3.1.2 System Functions

• General Users: Register, log in, and update personal information.
• Admin: Create, update, and delete user accounts.
• Teacher: Manage classes (create, edit, delete, add/remove students) and assignments (create, assign, track results).
• Student: Join/leave classes, complete assignments, and view submission history.

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3.2 Entity & Database Model

3.2.1 Entities

• User
• Classroom
• Assignment
• Question
• Answer
• Submission
• ClassroomStudents (junction)
• AssignmentClassrooms (junction)
• AssignmentQuestions (junction)
• SubmissionAnswers (junction)

3.2.2 Relationships

Relationship	Type
User – Classroom	N–N
User – Assignment	1–N
Assignment – Classroom	N–N
Assignment – Question	N–N
Question – Answer	1–N
Submission – AssignmentClassrooms	N–1
Submission – Answer	N–N

3.2.3 Database

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4. Project Structure

4.1 Backend Architecture

The backend is modularized for scalability, maintainability, and clear separation of concerns.

• common/: Shared components
• module/: Feature-based modules

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4.1.1 Common Module (common/)

Folder/File	Responsibility	Key Components
configuration/	System configuration	SecurityConfig, CustomJwtDecoder, AdminConfig
exception/	Error handling	ApplicationException, GlobalExceptionHandler
message/	Message codes	ExceptionMessageCode, SuccessMessageCode
util/	Utilities	IdGenerator, JwtUtil, PaginationUtil
ApiResponse	API response format	Standardized response structure
Endpoint	API endpoints	Centralized route definitions

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4.1.2 Feature Modules (module/)

Design Principles

• Feature-based structure

• Each module includes:

  • Controller
  • Service
  • Repository
  • Entity & DTO
  • Optional: mapper, enum

• N-N relationships are separated into dedicated modules (SRP compliant)

Modules

Module	Description
user/	User management
auth/	Authentication & JWT
classroom/	Classroom management
classroom_student/	Student–classroom relationship
assignment/	Assignment management
assignment_classroom/	Assignment–classroom mapping
assignment_question/	Assignment–question mapping
question/	Question management
answer/	Answer management
submission/	Submission & grading
submission_answer/	Submission details

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5. Demo Screenshots

5.1 Landing Page

5.2 Teacher

Classroom

Assignment

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5.3 Student

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5.4 Admin

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5.5 User Profile