Pass parameter from validate to custom validator in hibernate validator

Question

I'm trying to validate a bean using custom validator. But the validator needs info that is to be passed to it from the method where validate is invoked. Is there a way to do that?

I can't pass it in initialize as it is not available at the time of bean creation.

Bean to validate

class vehicle {
   @VehicleNameValidator
   String vehicleName;
}

Annotation

@Target({ElementType.FIELD})
@Retention(RUNTIME)
@Constraint(validatedBy = VehicleNameValidatorImpl.class)
@Documented
public @interface VehicleNameValidator {
    String message() default "Invalid vehicle Name";

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

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

custom validator

public class VehicleNameValidatorImpl implements ConstraintValidator<VehicleNameValidator, String[]> {

    @Override
    public boolean isValid(String vehicleName, ConstraintValidatorContext constraintValidatorContext) {
        boolean isValid = logicmethod()//some logic here
        return isValid;
    }
}

Main method

public static void main(String[] args) {
   String whatIwantToPass = runtimelogic(args);
   vehicle veh1 = new vehicle();
   Set<ConstraintViolation<vehicle>> constraintViolations = 
   validator.validate(veh1);
}

How to I pass variable "whatIwantToPass" from main method to VehicleNameValidatorImpl.

Answer 1

In case you are using Hibernate Validator you might want to take a look at constraint validator payload. In your case it would look somewhat like this:

In your validator impl you can access the payload:

public boolean isValid(String vehicleName, ConstraintValidatorContext constraintValidatorContext) {
    boolean isValid = false;
    if ( constraintValidatorContext instanceof HibernateConstraintValidatorContext ) {
        final String payload = constraintValidatorContext
                .unwrap( HibernateConstraintValidatorContext.class )
                .getConstraintValidatorPayload( String.class );
        // do whatever you need
        isValid = logicmethod()//some logic here
    }
    return isValid;
}

And the payload can be set either on the validator factory level or per validator like this:

ValidatorFactory validatorFactory = Validation.byProvider( HibernateValidator.class )
        .configure()
        .buildValidatorFactory();

String whatIwantToPass = runtimelogic( args );

Validator validator = validatorFactory.unwrap( HibernateValidatorFactory.class )
        .usingContext()
        .constraintValidatorPayload( whatIwantToPass )
        .getValidator();

// use the validator with the constraint validator payload 
vehicle veh1 = new vehicle();
Set<ConstraintViolation<vehicle>> constraintViolations = validator.validate( veh1 );

For more detailed info check this part of documentation - Passing a payload to the constraint validator