Backend Assignment: Dynamic PDF Generation

Build a Spring Boot Application with REST API to generate PDF using Java Template Engine.

Requirement
● REST API to accept data and generate a PDF based on the received data.
● Ability to download the above-generated PDF
● Store the above-generated PDF on the local storage and redownload it when the same data is provided instead of generating it again.
Use Java Template Engines like Thymeleaf or iText to generate the PDF and store it on the local storage which can be retrieved later. The input should have a proper schema.

Example
The request body of the API call looks something like this:

{
"seller": "XYZ Pvt. Ltd.",
"sellerGstin": "29AABBCCDD121ZD",
"sellerAddress": "New Delhi, India",
"buyer": "Vedant Computers",
"buyerGstin": "29AABBCCDD131ZD",
"buyerAddress": "New Delhi, India",
"items": [
{
"name": "Product 1",
"quantity": "12 Nos",
"rate": 123.00,
"amount": 1476.00
}
]

}

Note
● Only REST APIs are required. No UI.
● Testable on Postman / Swagger.
● Will prefer properly structured code.
● Will prefer Test Cases (TDD).