How to validate Spring MVC @PathVariable values?

Question

For a simple RESTful JSON api implemented in Spring MVC, can I use Bean Validation (JSR-303) to validate the path variables passed into the handler method?

For example:

 @RequestMapping(value = "/number/{customerNumber}")  @ResponseBody  public ResponseObject searchByNumber(@PathVariable("customerNumber") String customerNumber) {  ...  } 

Here, I need to validate the customerNumber variables's length using Bean validation. Is this possible with Spring MVC v3.x.x? If not, what's the best approach for this type of validations?

Thanks.

Answer 1

Spring does not support @javax.validation.Valid on @PathVariable annotated parameters in handler methods. There was an Improvement request, but it is still unresolved.

Your best bet is to just do your custom validation in the handler method body or consider using org.springframework.validation.annotation.Validated as suggested in other answers.

Answer 2

You can use like this: use org.springframework.validation.annotation.Validated to valid RequestParam or PathVariable.

 *  * Variant of JSR-303's {@link javax.validation.Valid}, supporting the  * specification of validation groups. Designed for convenient use with  * Spring's JSR-303 support but not JSR-303 specific.  * 

step.1 init ValidationConfig

@Configuration public class ValidationConfig {     @Bean     public MethodValidationPostProcessor methodValidationPostProcessor() {         MethodValidationPostProcessor processor = new MethodValidationPostProcessor();         return processor;     } } 

step.2 Add @Validated to your controller handler class, Like:

@RequestMapping(value = "poo/foo") @Validated public class FooController { ... } 

step.3 Add validators to your handler method:

   @RequestMapping(value = "{id}", method = RequestMethod.DELETE)    public ResponseEntity<Foo> delete(            @PathVariable("id") @Size(min = 1) @CustomerValidator int id) throws RestException {         // do something         return new ResponseEntity(HttpStatus.OK);     } 

final step. Add exception resolver to your context:

@Component public class BindExceptionResolver implements HandlerExceptionResolver {      @Override     public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {         if (ex.getClass().equals(BindException.class)) {             BindException exception = (BindException) ex;              List<FieldError> fieldErrors = exception.getFieldErrors();             return new ModelAndView(new MappingJackson2JsonView(), buildErrorModel(request, response, fieldErrors));         }     } }