Guide to Spring WebFlux with YAML-Driven API Configuration

Using external configurations to define API routes, requests, and responses is a clean, flexible approach. This method separates the API contract from its implementation, enabling consistent and centralized management of API definitions.

This blog helps to build a Spring WebFlux application using YAML for API configuration instead of @PostMapping or @GetMapping.

Why YAML for API Configuration?

1. Centralized Configuration: API definitions are managed in a single place, making updates straightforward.
2. Separation of Concerns: Developers focus on logic in the controller while routes are managed externally.
3. Interoperability with OpenAPI: YAML configuration can align with OpenAPI standards for documentation and testing.

Getting Started

We’ll create a simple product management system. The API routes, HTTP methods, and request/response formats will be configured in YAML.

Project Structure Recap

Here’s how the project structure should look:

src/main/java/
└── com.example.webflux/
    ├── WebFluxApplication.java          # Main class
    ├── controller/
    │   ├──…