Invoice Spring Boot Application

This is a Spring Boot application for managing invoices and products, generating PDF invoices, and emailing them to customers. It uses PostgreSQL for data storage and integrates with Gmail SMTP for sending emails.

👉 You can test the API using Postman, or check out the frontend dashboard built with Next.js:

• 🔗 GitHub (Frontend): https://github.com/badrinarayanms/invoiceer-frontend
• 🌐 Live Demo: https://invoiceer-frontend.vercel.app
• 🚀 Deployed Backend: https://invoiceer-o31i.onrender.com

🚀 Deployment

The backend was:

• ✅ Dockerized: The Spring Boot JAR was packaged inside a Docker image
• ☁️ Hosted on Render using a containerized deployment (Docker image pushed to Docker Hub)

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Features

• Product CRUD operations
• Invoice creation with multiple items
• PDF invoice generation using iText 7
• Emailing invoices as PDF attachments
• RESTful API with CORS support for frontend integration

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API Endpoints

🔹 Products

Method	Endpoint	Description
GET	/products	Get all products
GET	/products/{id}	Get a specific product by ID
POST	/products	Add a new product
PUT	/products/{id}	Update a product by ID
DELETE	/products/{id}	Delete a product by ID

⚠️ Deleting a product that's used in invoices will return a 409 Conflict error to prevent data loss.

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📥 JSON Format for POST or PUT /products

 json
{
  "name": "Wireless Mouse",
  "price": 1299.99
}
 

🔹 Invoices

Method	Endpoint	Description
GET	/invoices	Get all invoices
GET	/invoices/{id}	Get a specific invoice by ID
POST	/invoice	Create an invoice with line items. PDF is generated and emailed to customer

✅ While creating an invoice, you must pass an array of items containing the product ID and quantity.

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📥 JSON Format for JSON Format for POST /invoice

 json
{
  "customerName": "John Doe",
  "customerEmail": "john@example.com",
  "items": [
    {
      "product": { "id": 1 },
      "quantity": 2
    },
    {
      "product": { "id": 3 },
      "quantity": 1
    }
  ]
}

 

Technologies Used

• Spring Boot
• Spring Data JPA
• Spring Mail
• PostgreSQL
• iText 7 (PDF generation)
• Lombok

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Getting Started

Prerequisites

• Java 17+
• Maven
• PostgreSQL database

Configuration

Set environment variables or update src/main/resources/application.properties:

DB_URL=jdbc:postgresql://localhost:5432/invoice_db
DB_USER=your_db_user
DB_PASSWORD=your_db_password
FRONTEND_URL=http://localhost:3000
MAIL_GMAIL=your_gmail_address@gmail.com
MAIL_APPPASS=your_gmail_app_password