Combining Raw Types and Generic Methods

Here's a question, this first code listing compiles just fine (JDK 1.6 | JDK 1.7):

ArrayList<String> a = new ArrayList<String>();
String[] s = a.toArray(new String[0]);

However, if I declare the List reference as a raw type:

ArrayList a = new ArrayList();
String[] s = a.toArray(new String[0]);

I get a compiler error saying the String[] is required but Object[] was found.

This means my compiler is interpreting the generic method as returning Object[] despite of receiving a String[] as its argument.

I doubled-checked the toArray(myArray) method signature:

<T> T[] toArray(T[] a);

Therefore it is a parameterized method whose type parameter <T> has no relation whatsoever with that of the List (i.e. <E>).

I have no idea how using a raw type here affects the evaluation of parameterized methods using independent type parameters.

• Does anyone has any idea why this code does not compile?
• Does anybody knows any reference where this behavior is documented?