org.apache.commons

In the previous section, we talked about one package with the org.apache root name - the package org.apache.log4j.

The package org.apache.commons is another popular library, representing a project called Apache Commons that is maintained by open source community of programmers called Apache Software Foundation. This organization was formed from the Apache Group in 1999. The Apache Group has grown around the development of Apache HTTP Server since 1993.  The Apache HTTP Server is an open source cross-platform web server that has remained the most popular since April 1996. From a Wikipedia article:

"As of July 2016, it was estimated to serve 46% of all active websites and 43% of the top million websites. The name "Apache" was chosen from respect for the Native American Apache Nation, well known for their superior skills in warfare strategy and their inexhaustible endurance. It also makes a pun on "a patchy web server"—a server made from a series of patches—but this was not its origin" 

The Apache Commons project has three parts:

• Commons Sandbox: A workspace for Java component development; you can contribute to the open source working there
• Commons Dormant: A repository of components that are currently inactive; you can use the code there, but have to build the components yourselves since these components probably will not be released in the near future
• Commons Proper: The reusable Java components, which compose the actual library org.apache.commons

In the following subsections, we will discuss only four of Commons Proper's most popular packages:

• org.apache.commons.io
• org.apache.commons.lang
• org.apache.commons.lang3
• org.apache.commons.codec.binary

There are, however, many more packages under org.apache.commons that contain thousands of useful classes that can easily be used and can help make your code elegant and efficient.