Spring Boot REST @RequestParam not being Validated

Question

I have tried a number of examples from the net and cannot get Spring to validate my query string parameter. It doesn't seem execute the REGEX / fail.

package my.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import javax.validation.Valid;
import javax.validation.constraints.Pattern;

import static org.springframework.web.bind.annotation.RequestMethod.GET;

@RestController
public class MyController {

    private static final String VALIDATION_REGEX = "^[0-9]+(,[0-9]+)*$";

    @RequestMapping(value = "/my/{id}", method = GET)
    public myResonseObject getMyParams(@PathVariable("id") String id,
                                       @Valid @Pattern(regexp = VALIDATION_REGEX) 
                                       @RequestParam(value = "myparam", required = true) String myParam) {
         // Do Stuff!
    }

}

Current behaviour

PASS - /my/1?myparam=1
PASS - /my/1?myparam=1,2,3
PASS - /my/1?myparam=
PASS - /my/1?myparam=1,bob

Desired behaviour

PASS - /my/1?myparam=1
PASS - /my/1?myparam=1,2,3
FAIL - /my/1?myparam=
FAIL - /my/1?myparam=1,bob

Thanks

Answer 1

You need add @Validated to your class like this:

@RestController
@Validated
class Controller {
  // ...
}

UPDATE :

you need to configure it properly.. add this bean to your context:

@Bean
 public MethodValidationPostProcessor methodValidationPostProcessor() {
      return new MethodValidationPostProcessor();
 }

Example to handle exception :

@ControllerAdvice
@Component
public class GlobalExceptionHandler {
    @ExceptionHandler
    @ResponseBody
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    public Map handle(MethodArgumentNotValidException exception) {
        return error(exception.getBindingResult().getFieldErrors()
                .stream()
                .map(FieldError::getDefaultMessage)
                .collect(Collectors.toList()));
    }


    @ExceptionHandler
    @ResponseBody
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    public Map handle(ConstraintViolationException exception) {
        return error(exception.getConstraintViolations()
                .stream()
                .map(ConstraintViolation::getMessage)
                .collect(Collectors.toList()));
    }

    private Map error(Object message) {
        return Collections.singletonMap("error", message);
    }
}

Answer 2

You can try this

@Pattern(regexp="^[0-9]+(,[0-9]+)*$")
private static final String VALIDATION_REGEX;

(pay attention for the final modifier) or else

 @Pattern()
 private static final String VALIDATION_REGEX = "^[0-9]+(,[0-9]+)*$";

And then remove @Pattern(regexp = VALIDATION_REGEX) from your method and keep only the @Valid annotation:

public myResonseObject getMyParams(@PathVariable("id") String id, @Valid @RequestParam(value = "myparam", required = true) String myParam) {

Answer 3

You have incorrect regex

"^[0-9]+(,[0-9]+)*$"

It will never parse

1,bob

Maybe, you need:

"^\w+(,\w+)*$"

And if you need to parse also an empty line, use:

"^(\w+(,\w+)*)?$"