Java 7 runtime support on App Engine standard was deprecated on December 13, 2017 and will be shut down entirely on January 16, 2019. It is replaced by the Java 8 Runtime Environment.

Samples for the Java 8 runtime can be found here.

This sample demonstrates how to use the Pusher on Google App Engine. Pusher enables you to create public / private channels with presence information for real time messaging. This application demonstrates presence channels in Pusher using chat rooms. All users joining the chat room are authenticated using the /authorize endpoint. All users currently in the chat room receive updates of users joining / leaving the room. Java HTTP library is used for publishing messages to the channel and the JS Websocket library is used for subscribing.

Install the Google Cloud SDK and run:

   gcloud init

If this is your first time creating an App engine application:

   gcloud app create

• Create a Pusher application and note down the app_id, app_key, app_secret and the cluster.
• Update appengine-web.xml with these credentials.

   mvn clean appengine:run

Access http://localhost:8080 via the browser, login and join the chat room. The chat window will contain a link you can use to join the room as a different user in another browser. You should now be able to view both the users within the chat application window and send messages to one another.

• Deploy the application to the project

       mvn clean appengine:deploy
  
  

  Access https://YOUR_PROJECT_ID.appspot.com