This is checking static data in the ConnectivityService. It doesn't leave the device, but it will leave your process. These calls don't do any network activity and could be done on your UI thread.
Note that this check is not a promise that your request will complete - we can lose contact at any time. Given that, it's probably worth calling once before you start a complex/expensive sequence, but not really worth calling throughout. Calling isConnected does not warm up the radio - only network traffic will do that. R On Mon, Jul 23, 2012 at 1:07 PM, Nathan <[email protected]> wrote: > I wanted to ask a practical question about checking for network > connection, which is probably a simple question. I am sure this is an easy > question. > > I'm looking at this: > > http://developer.android.com/training/basics/network-ops/connecting.html > > "Before your app attempts to connect to the network, it should check to > see whether a network connection is available using > getActiveNetworkInfo()<http://developer.android.com/reference/android/net/ConnectivityManager.html#getActiveNetworkInfo%28%29> > and > isConnected()<http://developer.android.com/reference/android/net/NetworkInfo.html#isConnected%28%29> > ." > > This is in context of doing 10s of networks calls on multiple threads to > retrieve small files (about 20K) over http. > > In practice, is there any cost for making this call? Does it initiate a > network operation or stay on the device? What percentage of the time is it > actually wrong? Would it be actually faster to see if one of my http > operations gets a sockettimeoutexception or a connectiontimeoutexception? > > Based on that webpage, it calls isConnected() on a UI thread, just before > explaining that "network operations can involve unpredictable delays" and > should be done. Does that mean that isConnected() is a short and > predictable delay, or should I not read that much into it? > > In one of the battery life classes at I/O, they talked about how the 3G > radio takes a bit to warm up, and that you might as well do a bunch of > network traffic while it is warm (paraphrasing a bit). Does simply calling > isConnected() warm up that radio? > > Nathan > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
