Override (2)

当我们在子类中重写父类的方法的时候，子类的权限不能低于父类的权限。
比如:
class A
{
access_specifier_1 void f()
{
System.out.printf (“AAAA\n”);
}
}
class B extends A
{
access_specifier_2 void f()
{
System.out.printf (“BBBB\n”);
}
}

access_specifier_1	access_specifier_2	Result
public	public	OK
protected	public	OK
default	protected	OK
private	private	OK
public	protected	Error
default	protected	Error
private	public	Error