This sample displays what's going on in your app. It dumps the environment and lots more.
See the Google App Engine standard environment documentation for more detailed instructions.
Use either:
gcloud initgcloud auth application-default login
$ mvn appengine:run
$ mvn appengine:deploy
$ gradle appengineRun
If you do not have gradle installed, you can run using ./gradlew appengineRun.
$ gradle appengineDeploy
If you do not have gradle installed, you can deploy using ./gradlew appengineDeploy.