← Spring Boot learning pathSpring Boot · Module 5 of 10
Validation and error handling
Validate input and return clean error responses.
📖 Key ideas
- Add spring-boot-starter-validation.
- Annotate fields: @NotBlank, @Email, @Size(min=8).
- Use @Valid @RequestBody to trigger validation.
- Handle MethodArgumentNotValidException in @RestControllerAdvice.
- Return consistent error JSON with status codes.
💡 Real-life example: Validation is a quality-check counter at a factory: faulty parts are rejected with a note explaining why.
@ValidTriggers bean validation
@NotBlankString must have text
@ControllerAdviceGlobal exception handling
ProblemDetailStandard error response format