There are six types of properties that you can use within a Maven application POM file:
Built-in properties
Project properties
Local settings
Environment variables
Java system properties
Custom properties
It is always recommended that you use properties, instead of hardcoding values in application POM files. Let''s look at a few examples.
Let's take the application POM file inside the Apache Axis2 distribution module, available at http://svn.apache.org/repos/asf/axis/axis2/java/core/trunk/modules/distribution/pom.xml. This defines all the artifacts created in the Axis2 project that need to be included in the final distribution. All the artifacts share the same groupId tag as well as the version tag of the distribution module. This is a common scenario in most of the multi-module Maven projects.
Most of the modules (if not all) share the same groupId tag and the version tag:
<dependencies>
<dependency>
<groupId>org.apache.axis2</groupId>
<artifactId...