test.scala:7 error: type mismatch;
 found   : Foo
 required: java.rmi.Remote
  val obj = UnicastRemoteObject.exportObject(new Foo)
                                             ^
one error found

import java.rmi.server.UnicastRemoteObject;
class Foo implements java.rmi.Remote {
    int foo() { return 0; }
}
public class test {
    public static void main(String[] args) throws Exception {
        Object obj = UnicastRemoteObject.exportObject(new Foo());
    }
}