Scala - ambiguous reference to overloaded definiti

2020-08-10 19:08发布

问题:

This question already has answers here:
Closed 9 years ago.

Possible Duplicate:
How do I disambiguate in Scala between methods with vararg and without

I am currently porting part of an application to scala and it uses the Oval library. The method is question is the Validator.validate method. It has two signatures:

List<ConstraintViolation> validate(Object validatedObject)
List<ConstraintViolation> validate(Object validatedObject, String... profiles) 

The scala code looks generally like this:

def validate(toValidate: AnyRef) = {
  val validator = createValidator
  validator.validate(toValidate)
}

And the error message:

error: ambiguous reference to overloaded definition,
[INFO] both method validate in class Validator of type (x$1: Any,x$2: <repeated...>[java.lang.String])java.util.List[net.sf.oval.ConstraintViolation]
[INFO] and  method validate in class Validator of type (x$1: Any)java.util.List[net.sf.oval.ConstraintViolation]
[INFO] match argument types (AnyRef)
[INFO]       this.validator.validate(toValidate)

How can I get this be be unambiguous?

回答1:

I think that this could be a duplicate of How do I disambiguate in Scala between methods with vararg and without

Basically, it is a known java-scala-interop problem, and the only workarounds involve extra Java adapters to make accessible in Scala.



回答2:

The only way I know of is to use reflection:

val ambiguous = validator.getClass.getMethods.filter(_.getName == "validate")
val wanted = ambiguous.find(_.getParameterTypes.length == 1).get
wanted.invoke(validator, toValidate).asInstanceOf[java.util.List[ConstraintViolation]]