NetworkOnMainThreadException: The exception that is thrown when an application attempts to perform a networking operation on its main thread.
You should call sendfeedback method on asynctask then only above code will work. As webserver is taking lot of time to response main thread becomes unresponsive. To avoid it you should call it on another thread. Hence asynctask is better.
http://android-developers.blogspot.in/2009/05/painless-threading.html
