将新数据发布到远程服务器时，如何警告Android应用程序的用户？

Question

I am developing an Android application for an already existing website. When ever a user enters some data into the website (like a forum post), all the other users should be alerted about that post. Is it possible?

I think this is possible with triggers. Am I correct?

Answer 1

You can try 'Android Cloud to Device Messaging Framework' which can push messages to your android application.

http://code.google.com/android/c2dm/

Answer 2

What you search for is called "Server pushing". Your "listeners/observers", these are the mobile phones, register to a subject (in this case the server) at initialization. Then they are listening for new calls all the time (Thread). If the data on server will be refreshed, every observer gets a call. If your server is running on Java, you could use "observer pattern" for this. Maybe you could use UDP calls to notify your observers. After your observers receive the call, they "refresh" their data via an usual HTTP call. If you are running php with a database you could save the IPs of your observers into the database (when they register on the server) iterate over it, and send them an UDP call, after a form submit is executed.