Todo-List-Application
📝 Todo List Application
A lightweight Spring Boot web application designed to demonstrate clean backend architecture,
Dockerized deployment, and both Low-Level (LLD) and High-Level (HLD) system design principles.
Built with Java 17, Maven, and Docker, it provides a command-based web UI for managing tasks interactively — directly in your browser.
🌐 Live Demo Video
🚀 Access the live app here (Render Free Tier):
https://todo-list-app-49q5.onrender.com/
🧩 About Deployment
• The application runs inside a Docker container hosted on Render Cloud.
• Render automatically pulls the latest image from the GitHub repository and builds it using a multi-stage Dockerfile (Maven build → JDK runtime).
• The backend is a Spring Boot service serving both the REST API and the interactive web terminal UI built with HTML + JavaScript.
• This deployment demonstrates a production-like environment on Render’s free tier (no manual server setup).
💻 Runtime Details
• Container base: eclipse-temurin:17-jdk-jammy
• Port exposed: 8080
• Auto-deployed from: Render
• Hosted endpoint: https://todo-list-app-49q5.onrender.com/
🧠 Key Features Live
• Interactive command-line style UI in browser
• Persistent REST endpoints for add, edit, delete, sort tasks
• Deployed using Spring Boot + Docker + Render CI workflow
🚀 Tech Stack
- Java 17 — Core application logic
- Spring Boot 3 — Backend framework
- Maven — Dependency management and build tool
- HTML + Vanilla JavaScript — Lightweight terminal-style web UI
- Docker — Containerized deployment
- System Design — Documentation for both LLD and HLD
⚙️ Features
- Add, edit, delete, toggle, and sort tasks
- Input validation for names and deadlines (
DD-MM-YYYYformat) - Command-style browser UI (
add|name=...|deadline=...) - In-memory task management (no database needed)
- Global exception handling and clean API design
- Ready-to-run with Docker multi-stage build
🧱 Project Structure
Todo-List-Application/
│
├── Dockerfile # Docker multi-stage build configuration
├── pom.xml # Maven build & dependency configuration
├── README.md # Project documentation
│
├── src/
│ └── main/
│ ├── java/
│ │ └── io/
│ │ └── yourname/
│ │ └── todo/
│ │ ├── WebApplication.java # Spring Boot entry point
│ │ ├── TodoController.java # REST endpoints for all commands
│ │ ├── TodoService.java # Core business logic
│ │ ├── TodoItem.java # Model class representing a task
│ │ ├── CreateTodoRequest.java # DTO for creating new tasks
│ │ ├── UpdateTodoRequest.java # DTO for updating existing tasks
│ │ └── GlobalExceptionHandler.java # Unified exception handling
│ │
│ └── resources/
│ └── static/
│ └── index.html # Browser-based terminal UI
│
├── System Design/ # Design documents & architecture artifacts
│ ├── src/
│ │ ├── Commands.txt # Example commands for testing UI
│ │ ├── LLD.jpeg # Low-Level Design diagram
│ │ ├── Low Level Design For ToDo List.jpeg # Extended LLD reference
│ │ └── TodoListApplication # Design project file (optional)
🐳 Run with Docker
# Build Docker image
docker build -t todo-list-app:latest .
# Run container
docker run -p 8080:8080 todo-list-app:latest
Visit 👉 http://localhost:8080 to interact with the terminal-style UI.
🧭 System Design
Includes both Low-Level Design (LLD) and High-Level Design (HLD) documentation:
• LLD: Internal class structure (TodoController, TodoService, DTOs, model)
• HLD: System architecture showing backend, frontend, and Docker runtime layers
• Visualized using Eraser.io Flowchart Generator for clear architecture mapping.
🎯 Learning Objectives
This project was created for hands-on exploration of:
• Spring Boot REST API development
• Dockerized builds and deployment pipelines
• Applying LLD & HLD principles to real projects
• Clean code structure and modular design
🧠 Author & Project Links
👤 Somesh Diwan
💻 GitHub Repo: SomeshDiwan/Todo-List-Application
🐳 Docker Image: someshdiwan/todo-list-app
🏁 License
This project is released under the MIT License.