Formal Validation with @Validation

This page is mainly meant as a overview or presentation around the introduction of formal input validation using @Validation as introduced by #23754.

Formal Input Validation

• context-less (static context)
• no state
• no data related validation (just the input itself)
• no semantic validation

Typical examples

• property is required, e.g. name
• number must be be positive, e.g. page
• text must match a pattern, e.g. a UID
• set of properties must be defined together, e.g. cc+co => coc

What is @Validation?

@Validation is a declarative Java-API for (a subset of) JSON-schema

🥳 we can extract JSON-schema conform JSON and include it in our OpenAPI documentation to inform clients about expectations that is both human and machine readable

It follows: If input is formally wrong, the caller made an avoidable mistake => BadRequestException