The Java Language Specification, Third Edition

NAMES Example: Access to public and Non-public Classes 6.6.4
• The methods move, getX, and getY of the class Point are declared public
and so are available to any code that uses an object of type Point.
• The fields x and y are declared protected and are accessible outside the
package points only in subclasses of class Point, and only when they are
fields of objects that are being implemented by the code that is accessing
them.
See §6.6.7 for an example of how the protected access modifier limits access.
6.6.4 Example: Access to public and Non-public Classes
If a class lacks the public modifier, access to the class declaration is limited to
the package in which it is declared (§6.6). In the example:
package points;
public class Point {
public int x, y;
public void move(int dx, int dy) { x += dx; y += dy; }
}
class PointList {
Point next, prev;
}
two classes are declared in the compilation unit. The class Point is available outside
the package points, while the class PointList is available for access only
within the package.
Thus a compilation unit in another package can access points.Point, either
by using its fully qualified name:
package pointsUser;
class Test {
public static void main(String[] args) {
points.Point p = new points.Point();
System.out.println(p.x + " " + p.y);
}
}
or by using a single-type-import declaration (§7.5.1) that mentions the fully qualified
name, so that the simple name may be used thereafter:
package pointsUser;
import points.Point;
class Test {
public static void main(String[] args) {
Point p = new Point();
System.out.println(p.x + " " + p.y);
}}
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