| name | 303-frameworks-spring-boot-validation |
| description | Use when you need to design, review, or improve validation in Spring Boot applications — including Bean Validation on request DTOs, @Valid/@Validated at API boundaries, constraint groups, custom constraints, @ConfigurationProperties validation, nested DTO validation, and consistent validation error handling. This should trigger for requests such as Add validation support in Spring Boot; Review Spring Boot validation rules; Improve request validation in Spring Boot REST APIs; Add custom Bean Validation constraints in Spring Boot; Validate configuration properties in Spring Boot. Part of Plinth Toolkit |
| license | Apache-2.0 |
| metadata | {"author":"Juan Antonio Breña Moral","version":"0.18.0"} |
Spring Boot Validation Guidelines
Apply Spring Boot validation best practices at API boundaries.
What is covered in this Skill?
- Bean Validation annotations on DTOs and command models
- @Valid / @Validated on controllers and method parameters
- Validation groups for create/update workflows
- Custom constraint annotations and validators
- Consistent 400 error responses for validation failures
Scope: Apply recommendations based on the reference rules and good/bad examples.
Constraints
Before applying validation changes, ensure the project compiles. After improvements, run full verification.
- MANDATORY: Run
./mvnw compile or mvn compile before applying any change
- SAFETY: If compilation fails, stop immediately
- VERIFY: Run
./mvnw clean verify or mvn clean verify after applying improvements
- BEFORE APPLYING: Read the reference for detailed rules and examples
When to use this skill
- Add validation support in Spring Boot
- Review Spring Boot validation rules
- Improve request validation in Spring Boot REST APIs
- Add custom Bean Validation constraints in Spring Boot
- Validate configuration properties in Spring Boot
- Improve nested DTO validation in Spring Boot
Workflow
- Read reference and assess project context
Read references/303-frameworks-spring-boot-validation.md and inspect the current project setup before proposing changes.
- Gather scope and decide target improvements
Identify requested outcomes, constraints, and the minimum safe set of changes to apply.
- Apply framework-aligned changes
Implement or refactor validation-related configuration/code following the reference patterns and project conventions.
- Run verification and report results
Execute appropriate build/tests and summarize what changed, what was verified, and any follow-up actions.
Reference
For detailed guidance, examples, and constraints, see references/303-frameworks-spring-boot-validation.md.
