Java iterator over an empty collection of a parameterized type

Question

In Java, I need to return an Iterator from my method. My data comes from another object which usually can give me an iterator so I can just return that, but in some circums

Answer 1

Sorry, I figured it out. You need to use an assignment so that the compiler can figure out the parameterized type.

public Iterator iterator() {
   if (underlyingData != null) {
      return underlyingData.iterator();
   } else {
      List empty = Collections.emptyList();  // param type inference
      return empty.iterator();
   }
}