Spring validator fails looking up value of class level constraint - spring

Question

I'm getting an error with JSR 303 class level validation and spring and I'd like to know if I am setting things up in the correct way.
I'm using validation in spring (4.2.6.RELEASE) using hibernate-validator (5.2.4.Final) with a typical setup inside a spring controller like:
#RequestMapping(value = "/{id}", method = RequestMethod.PUT)
public SomeDto update(#PathVariable Integer id, #Valid #RequestBody SomeDto someDto) {
...
return someDto;
}
This works fine with most setups, but when the target of the validation includes a set of objects that are annotated with a Class level validation the SpringValidatorAdaptor fails when trying to lookup the original value
The following code illustrates the problem:
Target class to validate:
public class Base {
#Valid
Set<MyClass> myClassSet = new HashSet<>();
public Set<MyClass> getMyClassSet() {
return myClassSet;
}
Class with class level validation annotation:
#CheckMyClass
public class MyClass {
String a;
String b;
public MyClass(final String a, final String b) {
this.a = a;
this.b = b;
}
}
Constraint:
#Target({ TYPE, ANNOTATION_TYPE })
#Retention(RUNTIME)
#Constraint(validatedBy = CheckMyClassValidator.class)
#Documented
public #interface CheckMyClass {
String message() default "Invalid class";
Class<?>[] groups() default { };
Class<? extends Payload>[] payload() default { };
}
Validator:
public class CheckMyClassValidator implements ConstraintValidator<CheckMyClass, MyClass> {
#Override
public void initialize(final CheckMyClass constraintAnnotation) {
}
#Override
public boolean isValid(final MyClass value, final ConstraintValidatorContext context) {
return false; // want it to fail for testing purposes
}
}
Test class:
#SpringBootApplication
public class SpringValidationTest {
#Bean
public org.springframework.validation.Validator validator() {
return new org.springframework.validation.beanvalidation.LocalValidatorFactoryBean();
}
private void doStandardValidation() {
Base base = createBase();
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
Set<ConstraintViolation<Base>> violations = validator.validate(base);
for (ConstraintViolation<?> violation : violations) {
System.out.println(violation.getMessage());
}
}
private Base createBase() {
Base base = new Base();
base.getMyClassSet().add(new MyClass("a1", "b1"));
// base.getMyClassSet().add(new MyClass("a2", "b2"));
return base;
}
#PostConstruct
private void doSpringValidation() {
Base base = createBase();
org.springframework.validation.Validator validator = validator();
DataBinder binder = new DataBinder(base);
binder.setValidator(validator);
binder.validate();
BindingResult results = binder.getBindingResult();
for (ObjectError error : results.getAllErrors()) {
System.out.println(error.getDefaultMessage());
}
}
public static void main(String[] args) {
(new SpringValidationTest()).doStandardValidation();
System.out.println();
ApplicationContext applicationContext = SpringApplication.run(SpringValidationTest.class);
}
}
The standard validation works fine, but when it is wrapped by the spring validator (as in the typical controller setup) it ends up with an exception (as below) trying to lookup the value of the property:
Caused by: java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) ~[na:1.8.0_45]
at java.lang.Integer.parseInt(Integer.java:592) ~[na:1.8.0_45]
at java.lang.Integer.parseInt(Integer.java:615) ~[na:1.8.0_45]
at org.springframework.beans.AbstractNestablePropertyAccessor.getPropertyValue(AbstractNestablePropertyAccessor.java:657) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE]
... 37 common frames omitted