Node JS + Socket IO
http://socket.io/blog/native-socket-io-and-android/
http://khoapham.vn/KhoaPhamTraining/nodejs/snippet/Socket-IO-Realtime-Web-App-Development.pdf
http://khoapham.vn/KhoaPhamTraining/nodejs/snippet/
//Notice
ZALO is server code folder
RealTimechat is Android code project.
You need to install NodeJS: nodejs.org && git-scm.com.
added code on 10/12/2105