Calling a Java method (dealing with generics) from Scala failed

Question

I want to call this Java method (part of an API), from Scala (2.10.3):

public <R> ConvertedResult<R> to(Class<R> type,
    ResultConverter<Map<String, Object>, R> converter)

ResultConverter interface being:

public interface ResultConverter<T, R> {
    R convert(T value, Class<R> type);
}

First, I created my converter (in Scala so):

class MyVOConverter extends ResultConverter[Map[String, AnyRef], MyVO] {

    def convert(queryResult: Map[String, AnyRef], 
                `type`: Class[MyVO]): MyVO = {
       //...
    }
}

providing a type and my MyVOConverter like this, when the call is made:

myResult.to(classOf[MyVO], new MyVOConverter())

However, Scala compiler warns about this:

Type mismatch, expected: ResultConverter[Map[String, AnyRef], NotInferedR],
actual: MyVOConverter

How to deal with this case?

Answer 1

接口上的Map是java.util.Map ，但是，假设您尚未导入，则使用的是scala.collection.immutable.Map ，因此不兼容。