Programmer's Guide to Java™ Certification, A: A Comprehensive Primer, Second Edition

4.6. Packages

A package in Java is an encapsulation mechanism that can be used to group related classes, interfaces, and subpackages.

Figure 4.3 shows an example of a package hierarchy, comprising of a package called wizard that contains two other packages: pandorasBox and spells. The package pandorasBox has a class called Clown that implements an interface called Magic, also found in the same package. In addition, the package pandorasBox has a class called LovePotion and a subpackage called artifacts containing a class called Ailment. The package spells has two classes: Baldness and LovePotion. The class Baldness is a subclass of class Ailment found in the subpackage artifacts in the package pandorasBox.

Figure 4.3. Package Hierarchy

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