Why can't static classes have non-static methods and variables?

Question

Why can\'t static classes have non-static methods and variables when non-static classes can have static methods and variables?

What is the advantage of having static

Answer 1

Say you have a class Person that has a field name. And let's suppose, for the sake of argument, that Java did allow static methods to directly access non-static member variables. We might then specify a getName static method for our Person like so:

class Person {
  private final String name;

  public Person(String name) {
    this.name = name;
  }

  public static String getName() {
    return name;
  }
}

Now let's try using this class in an example:

public static void main(String[] args) {
  Person alice = new Person("Alice");
  Person bob = new Person("Bob");
  System.out.println("name: " + Person.getName());
}

So tell me, what on earth would we expect Person.getName() to print in this example? Alice? Bob? Null?

There's no right answer. It makes no sense, because a name is something that belongs to an individual (an instance), not the class as a whole. So clearly we cannot have a static method access non-static members because we have no way of knowing which non-static members we should be accessing.