Question

I am new to Android and want to use MQTT as a push notifier for Android from Server.
I have read about MQTT but I do not understand it very well. If anyone has used this library, please tell me what I have to do to start using it.

I have a Java Server (running on Windows) and lots of Clients (Android phones on which my app will be installed). My server will send messages to all or some specific clients at any time.

What are my basic requirements? Is there:

1. server requirement?
2. some sort of registration?
3. Library to include in Android?
4. identifier for Android device ? (as C2DM require Google account for each device)

Answer 1

You need:

1. an MQTT broker which runs on the server side. This could be something like the mosquitto broker which is Open Source.
2. an MQTT client library which you include in your Android app, enabling your app to connect, subscribe, and publish messages. There are a number of Java options listed at http://mqtt.org/software
3. to come up with a way of uniquely identifying users or devices, and then use that as a topic so that you can individually publish a message to one device.

Dale Lane has written a nice guide on this (http://www.dalelane.co.uk/blog/?p=1599) and there is also a good set of resources about MQTT (https://github.com/mqtt/mqtt.github.io/wiki)