Java generics with overloading

[bxb100]

The scenario:

    public static void test1(Object... args) {

    }

    public static void test1(List<Object> args) {

    }

there are two overloading method, but when you're using

  List<Long> list1 = new ArrayList<>();
  test1(list1);

It's always using the first method test1(Object... args), but when using List<Object> list2 the executor is different, It's too wired

---

Some document identified

The example above shows why generics and arrays don't mix well together. An array is what is called reifiable type -- a type where full type information is available during run-time. It is because Java array is reifiable that the Java run-time can check what we store into the array matches the type of the array and throw an ArrayStoreException at us if there is a mismatch. Java generics, however, is not reifiable due to type erasure. Java designers have decided not to mix the two.^1

the List<?> means you can assign any type of List to it and List<Object> means you can store any type of object into it.^2

Sure, it's not the same question, but I think some conception can go to the same destination

I think the runtime compiler design to obey this:

1. List same as List<Object>
2. List<Type> list1 with generics can accept any type
3. List<Object> means just accept List<Object> or List
4. List<T> list1 calling varargs method equals new Object[]{ list1 }
5. Using test1(Collections.singletonList(x)) equals test1(new ArrayList<Object>())

---

So this is the check trick problem

[bxb100]

generics safety term like PECS

[bxb100]

public static void test1(List<Object> args) {

}

Diff with

public static void test1(List args) {

}

public static void test1(List<?> args) {

}