Why making generic instance is possible and generic array doesn't by using new-operator in JAVA

Question

class Sample<T> {
    T[] arr = new T[5];

As I know, new-operator must know the type of T in compile time, so the above code makes an error.

class Sample<T> {
    ArrayList<T> list = new ArrayList<T>();

I think new-operator in this code also doesn't know the type of T in compile time.
So, at the same context, I think this code should make an error, but it doesn't.

I don't know why. Please help.