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Understanding the Generated Code

Let’s briefly explore what the openapi-generator plugin produced and why it looks so verbose.

What’s Inside the Generated Code?​

  • Models: Java classes mirroring your OpenAPI schemas (e.g., User). These include validation annotations, serialization logic, and builder patterns.
  • API Interfaces: Spring @RestController interfaces (e.g., UsersApi) that define your endpoints and their method signatures.

Why Does It Look So Complicated?​

The generated code includes:

  • Boilerplate for OpenAPI/Spring compatibility (e.g., @Validated, @Generated annotations).
  • Validation logic (e.g., @NotNull, @Size) to enforce your contract.
  • Serialization/deserialization support (e.g., JSON ↔ Java object mapping).

Why You Shouldn’t Care (Too Much)​

  • It’s autogenerated: Treat it like a compiled dependency—you use it, not modify it.
  • Contract-first philosophy: The code exactly matches your OpenAPI spec. If you need changes, update the YAML file and regenerate.
  • Maintenance-free: The generator handles updates, so you avoid manual refactoring.

Focus on consuming the generated code, not its internals. Let the tool handle the heavy lifting!