Android : get the current location fast and once in android

I have an android application that need device current location (latitude and longitude). I'av tried some tutorial on the net and specially some solutions from stack overflow, but they doesn't work well for me. My requirement is so simple: First I need it to be fast and need the location once when I the fragment starts. Second I need it to be precious as much as possible, I mean it should use GPS first if GPS is not available then use Network provider.

For example, I'av tried this solution but it return null after 30 second, but I know there is some all the things is ok because google map and other application works well !!!

Something that almost all the answers suggest is to use getLastKnownLocation(), but I suppose it's not the current and I don't want it if it is so.

can anyone suggest me some kind of simple and fast way to get the location just ONCE ?!

thanks in advance