Java generics unchecked cast - Possible to check at runtime?

Question

// @SuppressWarnings("unchecked")
private <T> T extractResult(Continuation continuation) {
    Object result = continuation.getAttribute("result");
    return (T) result;
}

Is it (at runtime) possible to verify that result can be cast to T?

Answer 1

No. To check at runtime, you need an instance of a class, so that you can use isAssignableFrom. You don't have access to this using T due to type erasure.

Answer 2

Not within this method. All type information related to T is erased by the compiler.