How to install the Appengine SDK to the Maven local repository? Note that this needs to be done only once. $ mvn gae:unpack Note that you don't need to manually download any SDK. How to generate the WAR? $ mvn package $ mvn war:war Note that this must be done before running the webapp locally and before deploying it to Appengine. How to run the webapp locally? $ mvn gae:run How to deploy the webapp to Appengine? $ mvn gae:update If you have made any changes to the code or pom.xml file of demo here, you may need to run Maven commands like ```mvn clean install -U``` (especially one hierarchy above i.e at java/ folder) to resolve any dependency issues w.r.t new developement version.