Accessing Of Static Members Using Null Reference

Why static member are allowed to be accessed with class-name and a null reference?

Here's the given code.

class Employee{
public static Integer companyId = 1001; // this could be private.
public static Integer getCompanyId(){
return Employee.companyId;
}
//a setter method will be here if the companyId will be private.
}
public class TestStatic{
public static void main(String[] args){
Employee emp =null;
emp.companyId = 11111;
System.out.println(emp.getCompanyId());
}
}

In this code the static members of a class are accessible by the null reference of that class.

These can also be access by the class (Employee.companyId or Employee.getCompanyId()).

What is the difference here in both. why a null reference can access these static members.