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Naming a Package

With programmers all over the world writing classes, interfaces, enums and annotations using the Java programming language, it is likely that two programmers will use the same name for two different classes. In fact, the previous example does just that: It defines a Rectangle class when there is already a Rectangle class in the java.awt package. Yet the compiler allows both classes to have the same name. Why? Because they are in different packages, and the fully qualified name of each class includes the package name. That is, the fully qualified name of the Rectangle class in the graphics package is graphics.Rectangle, and the fully qualified name of the Rectangle class in the java.awt package is java.awt.Rectangle.

This generally works just fine unless two independent programmers use the same name for their packages. What prevents this problem? Convention.

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By Convention:  Companies use their reversed Internet domain name in their package names, like this: com.company.package. Name collisions that occur within a single company need to be handled by convention within that company, perhaps by including the region or the project name after the company name, for example, com.company.region.package.

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