As the envjs site http://www.envjs.com/ expired, and I want to access the doc and guides of envjs, I will setup a local envjs-site server.
First I need to download appengine java sdk with version 1.2.1, from maven repository http://mvnrepository.com/artifact/com.google.appengine/appengine-java-sdk/1.2.1, as it does not exist on google appengine official site.
Then I need to clone or download envjs-site project, and put it under /opt/webapps/
Then I need to modify the dev_appserver.sh, add
--jvm_flag=-Dappengine.user.timezone=UTC
to the java command at last line.
Run it on local:
sudo dev_appserver.sh --address=0.0.0.0 path-to-envjs-site
Done.