API channel API GAE, so yes, you can only use it in the GAE environment. If you plan to deploy your servlets to GAE, you can still use the feed API.
If you do not plan to use GAE as your server and use only GWT on the client / user side, then you can use other parameters, such as Comet (link for checking http://caucho.com/resin-3.1/examples/servlet- comet / for example). I don't know very well the other push APIs, but some searches will give you answers.
Also check out http://tomcat.apache.org/tomcat-6.0-doc/aio.html
source
share