Java: Find out whether function was called with varargs or array

Question

Is there a way to find out whether a Java function (or a constructor) that takes varargs was actually called with varargs or with an array?

Say I have the following:

Answer 1

The only way to know is to parse the code. This is because varargs is basicaly a compile time feature and doesn't change how the program runs.

If in doubt, I would always copy the array. Unless you know this will be a performance issue.

BTW: You can do the following.

MyCompositeObjects(MyObjects o1, MyObjects... objects) {

MyCompositeObjects(MyObjects[] objects) {

However, this likely to do the opposite of what you want.

Another option is to use a static factory.

private MyCompositeObjects(MyObjects[] objects) {
   this.objects = objects;
}

MyCompositeObjects create(MyObjects... objects) {
    return new MyCompositeObjects(objects.close());
}

MyCompositeObjects createNotCopied(MyObjects... objects) {
    return new MyCompositeObjects(objects, false);
}

Use the more cumbersome method name for the less safe version. This means if a method is chosen without much thought, the safe version is more likely to be used.