@imran khan idea of using another thread is the right one. From HoneyComb and above, you can't do any networking operation inside the UI Thread. The UI Thread is the thread responsible for displaying views and receiving touch events and it must be free for this, not blocked by a long running operation. (Otherwise you got an ANR on Android).
But it's actually not a very good idea to use an AsyncTask for long running operations like a network Request. The AsyncTask javadocs even states they have been designed for short runnning operations...
The best approach is to use a service for that. I encourage you to read this infographics from the RoboSpice library and use RoboSpice, it will ease creating a service with networking and will make it easier for your to parse your json content using Spring Android.