NAMES

Example: Access to

public

 and Non 

public

 Classes

6.6.4

and:

package points;

public class Point {

protected int x, y;

public void move(int dx, int dy) { x += dx; y += dy; }

public int getX() { return x; }

public int getY() { return y; }

}

which declare two class types in the package

points

:

The class type

PointVec

 is not

public

 and not part of the

public

 interface

of the package

points

, but rather can be used only by other classes in the

package.

The class type

Point

 is declared

public

 and is available to other packages. It

is part of the

public

 interface of the package

points

.

The methods

move

,

getX

, and

getY

 of the class

Point

 are declared

public

and so are available to any Java 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 out 

side 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:

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