TODOIST - Task Management Application

Documentation Link

ZAYAAN IT
DESIGN & DEVELOPED BY : ZUBAYER AHAMED
Email: zubayerahamed1990@gmail.com
Mobile : +8801748562164

Project Overview

TODOIST is a comprehensive task management application built with Spring Boot 3.5.0 and Java 17. It provides a robust platform for managing tasks, projects, workspaces, and collaborative workflows with real-time notifications and multi-user support.

System Architecture & Design

1. Architecture Pattern

• Layered Architecture: The application follows a clean layered architecture with clear separation of concerns
• MVC Pattern: Model-View-Controller pattern implementation using Spring Boot
• Repository Pattern: Data access layer abstraction using Spring Data JPA
• Service Layer Pattern: Business logic encapsulation in service classes

2. Technology Stack

Backend Technologies

• Framework: Spring Boot 3.5.0
• Language: Java 17
• Database: Microsoft SQL Server 2019
• ORM: Spring Data JPA with Hibernate
• Security: Spring Security with JWT authentication
• Build Tool: Maven
• Testing: JUnit with Spring Boot Test

Key Dependencies

• Authentication: JWT (JSON Web Tokens) with io.jsonwebtoken
• Email: Spring Boot Mail with Apache Velocity templates
• WebSocket: Spring WebSocket for real-time communication
• Push Notifications: Web Push notifications with nl.martijndwars.webpush
• Security: BCrypt password encoding, BouncyCastle cryptography
• Validation: Jakarta Validation API with Hibernate Validator
• Utilities: Lombok for boilerplate code reduction, Apache Commons Lang3

3. Project Structure & Organization

Package Structure

com.zayaanit/
├── config/                 # Configuration classes
│   ├── CORSConfig          # Cross-Origin Resource Sharing
│   ├── DataAuditorAware    # JPA auditing configuration
│   ├── SchedulerConfig     # Task scheduling configuration
│   └── WebSocketConfig     # WebSocket messaging configuration
├── enums/                  # Application enumerations
├── exception/              # Global exception handling
├── mail/                   # Email service implementation
├── model/                  # Base models and response builders
├── module/                 # Feature modules (domain-driven)
│   ├── auth/              # Authentication & authorization
│   ├── category/          # Task categorization
│   ├── documents/         # File management
│   ├── events/            # Calendar events
│   ├── notification/      # Push notifications
│   ├── projects/          # Project management
│   ├── reminder/          # Reminder system
│   ├── sections/          # Project sections
│   ├── tags/              # Task tagging
│   ├── tasks/             # Core task management
│   ├── tokens/            # JWT token management
│   ├── users/             # User management
│   ├── workflows/         # Workflow automation
│   └── workspaces/        # Multi-tenant workspaces
└── security/              # Security configuration

4. Core Domain Models

Primary Entities

• User: User account management with preferences and profiles
• Workspace: Multi-tenant workspace isolation
• Project: Project containers with layout types and settings
• Task: Core task entity with priorities, dates, and completion status
• Section: Project organization sections
• Category: Task categorization system
• Tag: Flexible tagging system for tasks
• Event: Calendar events with participants
• Document: File attachment management

Entity Relationships

• Hierarchical Structure: Workspace → Project → Section → Task
• Many-to-Many: Users ↔ Workspaces, Tasks ↔ Tags, Events ↔ Participants
• One-to-Many: Project → Tasks, Task → SubTasks
• Audit Trail: All entities extend AbstractModel for creation/modification tracking

5. Development Patterns & Best Practices

Design Patterns Implemented

• Repository Pattern: Data access abstraction with Spring Data JPA
• Service Layer Pattern: Business logic encapsulation
• DTO Pattern: Data Transfer Objects for API communication
• Builder Pattern: Entity construction using Lombok @Builder
• Template Method Pattern: Base service classes for common operations
• Observer Pattern: Event-driven notifications

Code Organization

• Modular Design: Feature-based module organization
• Separation of Concerns: Clear layer boundaries
• DRY Principle: Base classes for common functionality
• SOLID Principles: Interface segregation and dependency inversion

6. Security Implementation

Authentication & Authorization

• JWT-based Authentication: Stateless token-based security
• Role-based Access Control: User roles and permissions
• Password Security: BCrypt hashing with salt
• Session Management: Stateless session with JWT tokens

Security Features

• CORS Configuration: Cross-origin request handling
• CSRF Protection: Cross-site request forgery prevention
• Input Validation: Jakarta Validation with custom validators
• Exception Handling: Centralized security exception management

7. Real-time Features

WebSocket Implementation

• STOMP Protocol: Simple Text Oriented Messaging Protocol
• User-specific Channels: Personal notification channels
• Real-time Notifications: Instant task and event updates
• Cross-origin Support: Frontend integration support

Notification System

• Multi-channel Notifications: Email, WebSocket, and Push notifications
• Asynchronous Processing: Non-blocking notification delivery
• User Preferences: Configurable notification settings
• Template-based Emails: Velocity template engine for email formatting

8. Data Management

Database Design

• Relational Model: Normalized database structure
• Audit Trails: Automatic creation and modification tracking
• Soft Deletes: Data preservation with status flags
• Indexing Strategy: Optimized queries with proper indexing

Data Access Layer

• Spring Data JPA: Repository abstraction
• Custom Queries: Complex business logic queries
• Transaction Management: Declarative transaction handling
• Connection Pooling: Tomcat JDBC connection pooling

9. API Design

RESTful Architecture

• Resource-based URLs: Intuitive endpoint structure
• HTTP Methods: Proper verb usage (GET, POST, PUT, DELETE)
• Status Codes: Meaningful HTTP response codes
• JSON Communication: Standardized request/response format

API Features

• Validation: Request validation with Jakarta Validation
• Error Handling: Centralized exception management
• Response Standardization: Consistent response structure
• Documentation: Postman collection for API testing

10. Testing Strategy

Test Structure

• Unit Tests: Service layer testing
• Integration Tests: Controller layer testing
• Base Test Classes: Common test functionality
• Test Profiles: Environment-specific test configurations

Testing Tools

• JUnit 5: Primary testing framework
• Spring Boot Test: Integration testing support
• Mockito: Mocking framework for unit tests
• Test Containers: Database testing with containers

11. Configuration Management

Environment Configuration

• Profile-based Configuration: Development and production profiles
• External Configuration: YAML-based configuration files
• Environment Variables: Sensitive data management
• Feature Toggles: Configurable application features

Application Properties

• Database Configuration: Connection settings and pool configuration
• Security Settings: JWT secrets and token expiration
• Mail Configuration: SMTP settings and templates
• File Storage: Document and email storage paths

12. Deployment & Operations

Build Process

mvn clean install

Deployment Requirements

1. Java Runtime: JDK 17 (minimum required)
2. Database: Microsoft SQL Server 2019
3. Application Server: Apache Tomcat 9
4. Port Configuration: Default port 8081
5. File System: Document and email storage directories

Production Considerations

• Security: HTTPS configuration and secure headers
• Performance: Connection pooling and caching strategies
• Monitoring: Application health checks and metrics
• Logging: Structured logging with appropriate levels
• Backup: Database backup and recovery procedures

13. Development Workflow

Code Standards

• Lombok Integration: Reduced boilerplate code
• Validation Annotations: Declarative input validation
• Exception Handling: Centralized error management
• Logging: Structured logging with SLF4J

Development Tools

• Maven: Dependency management and build automation
• Spring Boot DevTools: Development-time enhancements
• Hot Reload: Automatic application restart during development
• Profile Management: Environment-specific configurations

14. Scalability & Performance

Performance Optimizations

• Connection Pooling: Database connection management
• Asynchronous Processing: Non-blocking operations for notifications
• Lazy Loading: Efficient entity relationship loading
• Caching Strategy: Application-level caching where appropriate

Scalability Features

• Stateless Design: Horizontal scaling capability
• Multi-tenancy: Workspace-based data isolation
• Modular Architecture: Independent module scaling
• Database Optimization: Proper indexing and query optimization

15. Future Enhancements

Potential Improvements

• Microservices Migration: Service decomposition for better scalability
• Caching Layer: Redis integration for improved performance
• API Gateway: Centralized API management
• Container Deployment: Docker containerization
• Cloud Integration: Cloud-native deployment options
• Mobile API: Dedicated mobile application support
• Analytics: Task and productivity analytics
• Integration APIs: Third-party service integrations

Conclusion

The TODOIST application demonstrates a well-architected, enterprise-grade task management system built with modern Java technologies. The modular design, comprehensive security implementation, real-time features, and scalable architecture make it suitable for both small teams and large organizations. The codebase follows industry best practices and provides a solid foundation for future enhancements and scaling requirements.