Product API - Spring Boot REST Application

Project Overview

This is a RESTful Product Management API built using Java and Spring Boot.

The application supports:

• Full CRUD operations for Products
• JWT-based Authentication
• Role-based Authorization
• MySQL Database integration
• Swagger API documentation
• Docker & Docker Compose setup
• Unit Testing with JUnit & Mockito

This project was developed as a backend assignment for interview selection.

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Tech Stack

• Java 17
• Spring Boot 3
• Spring Data JPA (Hibernate)
• MySQL
• Spring Security
• JWT Authentication
• Swagger (Springdoc OpenAPI)
• JUnit 5 & Mockito
• Docker & Docker Compose
• Maven

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Project Structure

src/main/java/com/lucky/productapi

• config → Security & configuration classes
• controller → REST Controllers
• service → Business logic
• repository → JPA Repositories
• entity → JPA Entities
• dto → Request DTOs
• security → JWT & Security classes
• exception → Global Exception Handling

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Authentication Flow (JWT)

1. User logs in using /api/v1/auth/login
2. If credentials are valid:
   • JWT token is generated
3. Token must be sent in request header:

Authorization: Bearer your_jwt_token

4. Protected endpoints require valid token

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API Endpoints

Authentication

Method	Endpoint	Description
POST	/api/v1/auth/login	Login & get JWT
POST	/api/v1/auth/register	Register new user

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Products

Method	Endpoint	Description
GET	/api/v1/products	Get all products (Pagination supported)
GET	/api/v1/products/{id}	Get product by ID
POST	/api/v1/products	Create product
PUT	/api/v1/products/{id}	Update product
DELETE	/api/v1/products/{id}	Delete product

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Database Schema

Product Table

• id (Primary Key)
• product_name
• created_by
• created_on
• modified_by
• modified_on

Item Table

• id (Primary Key)
• product_id (Foreign Key)
• quantity

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Testing

Unit tests implemented using:

• JUnit 5
• Mockito

To run tests:

mvn test

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Running the Application

Run Locally

mvn clean install
mvn spring-boot:run

Application runs on:

http://localhost:8081

Swagger UI:

http://localhost:8081/swagger-ui/index.html

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Run Using Docker

Build and start containers:

docker compose up --build

This will start:

• MySQL container
• Spring Boot application container

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Pagination Support

Example:

GET /api/v1/products?page=0&size=5

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Security Implementation

• Stateless Authentication
• JWT-based access control
• Custom JWT filter
• Role-based authorization
• Password encryption using BCrypt

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Design Decisions

• Simple layered architecture (Controller → Service → Repository)
• Basic JWT implementation suitable for beginner-level understanding
• Audit fields (createdBy, createdOn) handled during product creation
• Global exception handling for consistent error responses
• Dockerized for easy deployment

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Assumptions

• This project focuses on backend REST API implementation.
• Architecture kept simple and beginner-friendly.
• Advanced enterprise-level optimizations intentionally avoided.

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Author

Laxman Kale Java Backend Developer (Fresher)