is subpackage considered as same package?

[adam Lui]

consider the following code:

package world;
 
public class HelloWorld extends world.moon.HelloMoon{
  public static void main(String[] args) {
    world.moon.HelloMoon wm = new world.moon.HelloMoon();
   System.out.println("Hello World");
   System.out.println(wm.x); ------------->access a subpackage variable x
  }
  
  
}

package world.moon;
 
public class HelloMoon {
  private String holeName = "rabbit hole";
  public int x = 3; //-------------->line 1, public or default?
  
  public String getHoleName() {
    return holeName;
  }
  
  public void setHoleName(String holeName) {
    this.holeName = holeName;
  }
}

so here we have a subclass access a superclass instance, which are both in the "root" package world,
if i get rid of public at line 1, the compiler complaints.
is it because of subpackage is not considered as same package, or something else is wrong in the code?


just one more thing,
if i use
import world.moon;
in the world class,
why does it not work?
[ November 05, 2007: Message edited by: adam lui ]

[Kelvin Chenhao Lim]

Hi Adam,

There's no such thing as a subpackage in Java. For all intents and purposes, "world" and "world.moon" are completely different packages. This is a bit non-intuitive because the .class files are stored hierarchically in the file system... but they don't in fact share a "subpackage" relationship in Java.