In my android application, i need to do push notification so, i searched for that and i found Google Cloud Messaging at android guide, step by step procedure.
In Writing the Android Application
Step 3: Write the my_app_package.GCMIntentService class
i need to create GCMIntentService class extended from GCMBaseIntentService and i need to implement abstract methods(onRegistered,onUnregistered,etc) in GCMBaseIntentService and in onRegistered method i should send the regid to your server so it can use it to send messages to device.
I got Cordova GCM Push Notifications Plugin for Android example from here
2) how to develop client and server for push notification using Google cloud messaging
check following link for Android Push notification With server code= http://www.androidhive.info/2012/10/android-push-notifications-using-google-cloud-messaging-gcm-php-and-mysql/