🔸 TL;DR
▪️ I pushed a tiny Spring Boot endpoint that validates request bodies with networknt JSON Schema.
▪️ Send a POST with JSON → the lib checks it against a schema → on failure you get a clear list of offending fields/constraints.
🔸 WHAT’S NEW
▪️ A /api/promo/validate endpoint + a service that wraps networknt to validate payloads.
▪️ Clean responses: "status":"OK" when valid, or "status":"INVALID" with a field-by-field error list when not.
🔸 WHY USE A JSON VALIDATOR (NETWORKNT)?
▪️ Contracts, not guesses: enforce types, required fields, ranges, and formats at the edge.
▪️ Actionable errors: returns precise paths (e.g., $.internalLinksNumber) and violated rules.
▪️ Fail fast & safer code: guard your domain layer from bad inputs.
▪️ Portable & standard: uses JSON Schema (an open spec), easy to share across teams/services.
▪️ Low friction: drop-in for Spring Boot; great performance, robust ecosystem.
🔸 WHAT IS JSON SCHEMA?
▪️ A declarative contract for JSON: describes shape, types, constraints (e.g., minimum, minLength, enum, pattern).
▪️ Think OpenAPI for payloads: machine-readable rules that tooling can validate, document, and test against.
🔸 HOW THE LIFECYCLE WORKS
▪️ HTTP POST: client sends JSON to /api/promo/validate.
▪️ Validation step: controller passes the payload to a service that runs networknt JSON Schema validation.
▪️ Fail path: if rules are violated, the API returns 400 with a list of exact fields and reasons (e.g., “charactersCount must be ≥ 3001”).
▪️ Success path: returns 200 with "status":"OK" when the payload matches the schema.
🔸 TAKEAWAYS
▪️ Schema-first APIs reduce ambiguity and bugs.
▪️ Better DX: clients get clear, actionable validation messages.
▪️ Safer backends: reject bad data before business logic runs.
▪️ Composable: evolve rules centrally by updating the schema.
🔸 TRY IT
▪️ Clone → run Spring Boot → POST to /api/promo/validate with your JSON (valid/invalid) and check the responses.
▪️ Repo & code: https://github.com/vinny59200/checkJSON
#Java #Spring #SpringBoot #API #JSON #JSONSchema #Validation #NetworkNT #Backend #CleanArchitecture #DeveloperExperience #OpenSource
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