Arrays are objects, but their type is defined by the type of the contained objects. Therefore, one cannot just cast A[]
to T[]
, but each A member of the specific A[]
must be cast to a T
object. Generic example:
public static <T, A> T[] castArray(T[] target, A[] array) {
for (int i = 0; i < array.length; i++) {
target[i] = (T) array[i];
}
return target;
}
Thus, given an A[]
array:
T[] target = new T[array.Length];
target = castArray(target, array);
Java SE provides the method [Arrays.copyOf(original, newLength, newType)](<https://docs.oracle.com/javase/7/docs/api/java/util/Arrays.html#copyOf(U%5B%5D,%20int,%20java.lang.Class)>)
for this purpose:
Double[] doubles = { 1.0, 2.0, 3.0 };
Number[] numbers = Arrays.copyOf(doubles, doubles.length, Number[].class);