Compilation error with JDK8

[Olivier Bourgain]

I'm still trying to compile my project with java 8 (b83), I and get another
error.

Here is the simplest test case I've found which reproduce this error  :

===== Vo.java

public interface Vo {
   public Integer getId();
}


===== Service.java

public class Service {

   public static <H extends Vo> H getParentById(H vo) {
      return (H) getParent(findByPk(vo.getClass(), vo.getId()));
   }

   public static <H extends Vo> H getParent(H vo) {
      return null;
   }

   public static <H extends Vo> H findByPk(Class<H> voClass, Integer id) {
      return null;
   }
}


The error message is :

» javac src/*.java
src/Service.java:4: error: method getParent in class Service cannot be
applied to given types;
      return (H) getParent(findByPk(vo.getClass(), vo.getId()));
                 ^
  required: H#1
  found: CAP#1
  reason: cannot infer type-variable(s) H#1,H#2
    (argument mismatch; Vo cannot be converted to CAP#2)
  where H#1,H#2 are type-variables:
    H#1 extends Vo declared in method <H#1>getParent(H#1)
    H#2 extends Vo declared in method <H#2>findByPk(Class<H#2>,Integer)
  where CAP#1,CAP#2 are fresh type-variables:
    CAP#1 extends Vo from capture of ? extends Vo
    CAP#2 extends Vo from capture of ? extends Vo
1 error


The java version :
openjdk version "1.8.0-ea"
OpenJDK Runtime Environment (build
1.8.0-ea-lambda-nightly-h3797-20130325-b83-b00)
OpenJDK Server VM (build 25.0-b21, mixed mode)


Olivier Bourgain