title: how to know the value variable defined in pom.xml?
body: <p>I have some multi-module Maven project, I am looking through whole pom.xml. I am beginner for Maven project, so not have enough knowledge to understand it comprehensively. There is some variable defined in pom.xml, </p>
  
  <pre><code>&lt;dependency&gt;
  &lt;groupId&gt;${project.groupId}&lt;/groupId&gt;
  &lt;artifactId&gt;xxx&lt;/artifactId&gt;
  &lt;version&gt;${project.version}&lt;/version&gt;
  &lt;/dependency&gt;
  </code></pre>
  
  <p>I searched whole properties defined in pom.xml cause those are that I know of which variable can be defined for pom.xml.
  Does anybody know about how I can figure I what the 'project.groupId' is? Is there any files or environments I can search for?</p>