title: Maven resource filtering of json file
body: <p>In my current project I have a submodule which is using the maven exec plugin to run a test service which pulls configuration files from a location outside of the resources/testResources folders.  </p>
  
  <p>I need to use filtering to inject an environment variable into a few of the configuration files.  This is working for one of the files, a .properties file, but not for another file which is a .json.  In the latter case it simply leaves the variable in the json file.  The two files are right next to each other in the filtered directory.</p>
  
  <p>Here is the filtering snippet from the submodule:</p>
  
  <pre><code>&lt;build&gt;
    &lt;finalName&gt;${artifactId}&lt;/finalName&gt;
    &lt;testResources&gt;
      &lt;testResource&gt;
        &lt;filtering&gt;true&lt;/filtering&gt;
        &lt;directory&gt;../etc&lt;/directory&gt;
      &lt;/testResource&gt;
    &lt;/testResources&gt;
  </code></pre>
  
  <p>json file:</p>
  
  <pre><code>{ "customMappings" :
      { "tag:example.com:/vagrant/" : "file:${VAGRANT_CWD}" }
  }
  </code></pre>
  
  <p>Abbreviated project structure:</p>
  
  <ul>
  <li>project
  
  <ul>
  <li>etc
  
  <ul>
  <li>config.properties</li>
  <li>config.json</li>
  </ul></li>
  <li>submodule
  
  <ul>
  <li>pom.xml</li>
  </ul></li>
  </ul></li>
  </ul>
  
  <p>The submodule is definitely loading both files, but only filtering the .properties file.</p>
  
  <p>Is there something special about it being a json file that would prevent filtering from happening to it?  Anything that can be done about this?  </p>