• 

  invoice

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  postman-test

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  exported-excelfile

AI PDF Invoice Analyzer

AI-powered invoice processing system that extracts invoice data from PDF files using Google Gemini 2.5 Flash and stores the results in PostgreSQL.

Features

• 📄 PDF Invoice Upload
• 🤖 Gemini AI Data Extraction
• 🗄 PostgreSQL Persistence
• 📊 Excel Export
• 📦 Multi PDF Upload Support

AI PDF Invoice Analyzer

AI-powered invoice processing system built with Spring Boot, Gemini API, PostgreSQL, and Apache POI.

Features

• Upload PDF invoices
• Extract invoice data using Gemini 2.5 Flash

• Automatically identify:

  • Invoice Date
  • Seller Company Name
  • Product Description
  • Quantity
  • Unit Price
  • Total Amount

• Store extracted data in PostgreSQL

• Export invoice data to Excel (.xlsx)

• Process multiple PDF invoices in a single request

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Tech Stack

Backend

• Java 17
• Spring Boot
• Spring Data JPA
• PostgreSQL

AI

• Google Gemini 2.5 Flash API

Document Processing

• PDF Upload (MultipartFile)
• Apache POI (Excel Export)

---

Architecture

PDF Upload
    ↓
Gemini API
    ↓
Invoice Extraction
    ↓
DTO Mapping
    ↓
PostgreSQL
    ↓
Excel Export

---

API Endpoints

Upload Invoice(s)

POST /api/invoices

Request:

multipart/form-data
files: invoice1.pdf
files: invoice2.pdf

Response:

[
  {
    "invoice_date": "28.04.2026",
    "seller_company_name": "Agrol LLC",
    "items": [
      {
        "product_description": "Frozen Whole Chicken",
        "quantity": 20000,
        "unit_price": 1.40,
        "total_amount": 28000
      }
    ]
  }
]

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Get All Invoices

GET /api/invoices

---

Export Excel Report

GET /api/invoices/export

Downloads:

invoices.xlsx

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Environment Variables

Create an environment variable:

GEMINI_API_KEY=YOUR_API_KEY

application.yml:

gemini:
  api-key: ${GEMINI_API_KEY}

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Running Locally

Clone the repository:

git clone https://github.com/your-username/your-repository.git

Configure PostgreSQL.

Set your Gemini API key.

Run:

./gradlew bootRun

or

mvn spring-boot:run

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Future Improvements

• Invoice duplicate detection
• ZIP file upload support
• Invoice statistics dashboard
• Company-based filtering
• Docker support
• Swagger/OpenAPI documentation
• Batch processing with RabbitMQ
• OCR fallback support

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Author

Or Khan

Java Backend Developer Spring Boot | PostgreSQL | AI Integrations

Built With

• geminiapi
• java
• postgresql
• postman
• springboot