Описание тега maven-jar-plugin

The Maven Jar Plugin provides the capability to build and sign jars. This is one of the most common plugins used in Maven.

If the packaging of your project is set to jar, this plugin is executed whenever it passes the package phase, according to default Maven bindings.

Goals Overview

From the official documentation:

• jar:jar create a jar file for your project sources.
• jar:test-jar create a jar file for your project test classes.

Check the official usage page for a first look at this plugin.