spring mvc & hibernate validator: valid json

Question

I'd like to check if my input parameter is a valid json. it can be anything: map, string, number etc. is there some ready to use hibernate validator for this?

to make it more clear, i'm looking for something similar to, for example, @Email. Is there any annotation like @Json?

Answer 1

No Json validator as such, but you can wire a custom validator

public class Customer {

    @Size(min=2, max=30) 
    private String name;

    @NotEmpty @Email
    private String email;

    @JsonValid
    private String  json;

}

@Documented
@Constraint(validatedBy = JsonValidator.class)
@Target( { ElementType.METHOD, ElementType.FIELD })
@Retention(RetentionPolicy.RUNTIME)
public @interface JsonValid {


    String message() default "{JsonValid}";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

}

public class JsonValidator implements ConstraintValidator < JsonValid, String > {

 @Override
 public void initialize(JsonValid value) {}

 @Override
 public boolean isValid(String json, ConstraintValidatorContext ctx) {

  ObjectMapper mapper = new ObjectMapper();
  ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
  Validator validator = factory.getValidator();

  //validate with your request object
  SimpleFooRequest request = mapper.readValue(
   json, SimpleFooRequest.class);
  Set < ConstraintViolation < SimpleFooRequest >> violations = validator.validate(request);

  return  violations.size() > 0;
 }

}