resources/templates/HelloWorld/root/src/webapp/appengine-web.xml.ftl

<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
    <application>${appId}</application>
    <version>1</version>
    <threadsafe>true</threadsafe>

    <system-properties>
        <property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/>
    </system-properties>
</appengine-web-app>