How do I validate a #QueryParam? - spring

Question

I've got a simple REST resource which accepts a couple of query parameters. I'd like to validate one of these parameters, and came across ConstraintValidator for this purpose. The REST resource expects the query param territoryId to be a UUID, so I'd like to validate that it indeed is a valid UUID.
I've created an #IsValidUUID annotation, and a corresponding IsValidUUIDValidator (which is a ConstraintValidator). With what I have now, nothing gets validated and getSuggestions accepts anything I throw at it. So clearly I'm doing something wrong.
What am I doing wrong?
The REST resource now looks like this :
#Component
#Path("/search")
public class SearchResource extends AbstractResource {
#GET
#Path("/suggestions")
#Produces(MediaType.APPLICATION_XML)
public Response getSuggestions(
#QueryParam("phrase") List<String> phrases,
#IsValidUUID #QueryParam("territoryId") String territoryId) {
[...]
}
}
IsValidUUID
#Target({ElementType.TYPE, ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER})
#Retention(RetentionPolicy.RUNTIME)
#Documented
#Constraint(validatedBy = {IsValidUUIDValidator.class})
public #interface IsValidUUID {
String message() default "Invalid UUID";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
IsValidUUIDValidator
public class IsValidUUIDValidator implements ConstraintValidator<IsValidUUID, String> {
#Override
public void initialize(IsValidUUID constraintAnnotation) {
}
#Override
public boolean isValid(String value, ConstraintValidatorContext context) {
if (value == null) {
return true;
}
try {
UUID.fromString(value);
return true;
} catch (Exception e) {
context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate("The provided UUID is not valid")
.addConstraintViolation();
return false;
}
}
}

Answer 1

You need to set the supported targets on IsValidUUID, using the following annotation.
#SupportedValidationTarget(ValidationTarget.ANNOTATED_ELEMENT)
or
#SupportedValidationTarget(ValidationTarget.PARAMETERS)
Edit:
Sorry, I wasn't able to make it work either on a RequestParam directly. However, if you can, try creating a POJO that you can bind your request parameters to and annotate the binding field with your constraint instead. This worked for me.
public class MyModel {
#IsValidUUID
private String territoryId;
public String getTerritoryId() {
return territoryId;
}
public void setTerritoryId(String territoryId) {
this.territoryId = territoryId;
}
}
#GET
#Path("/suggestions")
#Produces(MediaType.APPLICATION_XML)
public Response getSuggestions(
#QueryParam("phrase") List<String> phrases,
#Valid #ModelAttribute MyModel myModel) {
[...]
}