On an iPhone project I'm using AsyncUdpSocket and AsyncSocket which I've found here.
Do you know if there is something similar for Android?
I've tried to search on google for a java verion of these classes but I haven't found any. By the way I've searched this "AsyncUdpSocket.java".
I've also found something about NIO libraries but I don't know if I can use it on Android.
I am not that familiar with Java, but since AsyncSocket is just a higher-level verison of Apple's socket API, all you need to do is create a socket in Java and receive the data. There is no "trick" the data will not be in "objective-c" so it's pretty easy to process (I created a Objc-> Python and that data was the same). Heres oracle on creating java sockets: http://docs.oracle.com/javase/tutorial/networking/sockets/index.html