Simple QR Code API

A lightweight REST API for generating and decoding QR codes.
Built with Spring Boot and exposed via Swagger UI for easy exploration.

🚀 Features

• Generate QR codes in PNG, JPEG, or Base64 format
• Customize size, foreground color, and background color
• Decode QR codes from uploaded image files or Base64 strings
• Explore endpoints via integrated Swagger UI

📖 API Documentation

Swagger UI is available at:
http://localhost:8080/swagger-ui/index.html

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🔧 Endpoints

1. Generate QR Code

GET /api/qr/generate

Parameters (query):

• data (required) → Text or URL to encode
• size (optional, default=200) → Image size in pixels
• fgColor (optional, default=#000000) → Foreground color (hex)
• bgColor (optional, default=#FFFFFF) → Background color (hex)
• format (optional, default=PNG) → Output format: PNG, JPEG, or BASE64

Responses:

• image/png or image/jpeg → QR code image
• application/json → Base64-encoded string (if format=BASE64)

Example Request (Base64 output):

    curl -X POST "http://localhost:8080/api/qr/generate?data=HelloWorld&size=300&format=BASE64"

2. Decode QR Code (File Upload)

POST /api/qr/decode
Consumes: multipart/form-data

Form Data:

• file (required) → QR code image file (.png or .jpg)

Response:

{
  "type": "string",
  "data": "string"
}

Example Request (Base64 output):

    curl -X POST "http://localhost:8080/api/qr/decode" \
    -F "file=@qrcode.png"

3. Decode QR Code (Base64 JSON)

POST /api/qr/decode
Consumes: application/json

Request Body:

{
  "image": "BASE64_ENCODED_IMAGE"
}

Example Request (Base64 output):

    curl -X POST "http://localhost:8080/api/qr/decode" \
      -H "Content-Type: application/json" \
      -d '{"image": "BASE64_ENCODED_IMAGE"}'

🛠️ Tech Stack

• Java 17+
• Spring Boot
• Swagger UI for API documentation

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The API will be available at: 👉 http://localhost:8080

Swagger UI: 👉 http://localhost:8080/swagger-ui/index.html