Maven variables substitution in resource files during maven build

POM Resource directive
In the project pom.xml, enclosed within the build section, is a resource declaration which switches on variable substitution of configuration text files during maven build. Where

• enabling filtering will turn on variable substitution of application properties
• specified resource directory need not (and preferably not) be part of the source classpath, because the <resource> directive will have maven build process recreate the files in the specified directory into the run-time packaging classpath.

<build>
  .....   
  <resources>
    <resource>
      <directory>appbase</directory>
      <filtering>true</filtering>
    </resource>
  </resources>
  
  ..... 
  
</build>

Variable substitution can also use pom objects and implicit maven properties. e.g.,

• ${project.name}
• ${project.version}
• ${project.packaging}
• ${project.build.sourceDirectory}
• ${project.build.scriptSourceDirectory}
• ${project.build.directory}
• ${project.baseUri} 
• ${env.PATH}
• ${env.HOME}
• ${env.JAVA_HOME}
• ${env.M2_HOME}

A more complete list is documented in the following link:

http://books.sonatype.com/mvnref-book/reference/resource-filtering-sect-properties.html