What is difference between varagrs using (int...i) and (Integer...i)

When I run this code with two different varargs (Integer...i) and (int...i), the output of code with (Integer...i) displayed warning message and the other was run correctly. But I cannot understand the different between them.

public static void test(Integer...i) {

    System.out.println("int array");
}

public static void main(String[] args) {
    test(null);
}

When run this code, warnings message display like that.

File.java:11: warning: non-varargs call of varargs method with inexact argument type for last parameter;
    test(null);
         ^cast to Integer for a varargs call

But when I change varargs (Integer...i) to(int...i), code was run perfectly.

public static void test(int...i) {

    System.out.println("int array");
}

public static void main(String[] args) {
    test(null);
}

And output display is:

int array