~/code/scratch/array: cat ArrayFactory.java 
public interface ArrayFactory<T> {
  T[] create(int count);
}

 ~/code/scratch/array: cat ScalaArrayFactory.scala 
class ScalaArrayFactory[T: Manifest] extends ArrayFactory[T] {
  def create(count: Int) = Array.ofDim[T](count)
}

 ~/code/scratch/array: scalac -d out ArrayFactory.java ScalaArrayFactory.scala  ~/code/scratch/array: 
 ~/code/scratch/array: javac -d out ArrayFactory.java && scalac -d out -classpath out ScalaArrayFactory.scala 
ScalaArrayFactory.scala:2: error: type mismatch;
 found   : Array[T]
 required: Array[T with java.lang.Object]
  def create(count: Int) = Array.ofDim[T](count)
                                         ^
one error found
Scala compiler version 2.8.1.final -- Copyright 2002-2010, LAMP/EPFL

 ~/code/scratch/array: scalac29 -version
Scala compiler version 2.9.0.r24423-b20110309020116 -- Copyright 2002-2011, LAMP/EPFL
 ~/code/scratch/array: javac -d out ArrayFactory.java && scalac29 -d out -classpath out ScalaArrayFactory.scala 
ScalaArrayFactory.scala:2: error: type mismatch;
 found   : Array[T]
 required: Array[T with java.lang.Object]
Note: T >: T with java.lang.Object, but class Array is invariant in type T.
You may wish to investigate a wildcard type such as `_ >: T with java.lang.Object`. (SLS 3.2.10)
  def create(count: Int) = Array.ofDim[T](count)
                                         ^
one error found
 ~/code/scratch/array: scalac29 -d out ArrayFactory.java ScalaArrayFactory.scala 
 ~/code/scratch/array: