Hello Robert, Below is the stack trace that I see when system catches the exception:
Not sure if you had any chance glancing at my sample code on original email, and see if anything obviously wrong there? I/System.out(12738): java.lang.NullPointerException I/System.out(12738): at android.content.ContextWrapper.registerReceiver(ContextWrapper.java:341) I/System.out(12738): at com.mycompany.ScsService.ScsService.<init>(ScsService.java:50) I/System.out(12738): at java.lang.Class.newInstanceImpl(Native Method) I/System.out(12738): at java.lang.Class.newInstance(Class.java:1319) I/System.out(12738): at android.app.ActivityThread.handleCreateService(ActivityThread.java:2234) I/System.out(12738): at android.app.ActivityThread.access$1600(ActivityThread.java:123) I/System.out(12738): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1201) I/System.out(12738): at android.os.Handler.dispatchMessage(Handler.java:99) I/System.out(12738): at android.os.Looper.loop(Looper.java:137) I/System.out(12738): at android.app.ActivityThread.main(ActivityThread.java:4424) I/System.out(12738): at java.lang.reflect.Method.invokeNative(Native Method) I/System.out(12738): at java.lang.reflect.Method.invoke(Method.java:511) I/System.out(12738): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) I/System.out(12738): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) I/System.out(12738): at dalvik.system.NativeStart.main(Native Method) -Subodh On Wed, Oct 3, 2012 at 7:39 AM, Robert Greenwalt <[email protected]> wrote: > Checking network types explicitly like this is bad - what happens if the > device is connected through a bluetooth tether or via ethernet adapter? > > You could use getActiveNetworkInfo() and check it's connection, but this is > still polling. If you need to get notified when a connection comes or goes > (have something to do on next connect, for example) The CONNECTIVITY_ACTION > broadcast intent is the way to go. Note that this can be chatty - there are > several secondary networks that currently cause this broadcast that you may > have to weed out. You should use getActiveNetworkInfo in your handler to > find the state that applies to you. > > Can you post the stack trace of the NPE? > > R > > > On Wed, Oct 3, 2012 at 5:46 AM, Rahul Kaushik <[email protected]> > wrote: >> >> hi subodh >> >> try this >> >> package com.FranConnectMobile; >> >> import java.io.BufferedReader; >> import java.io.InputStreamReader; >> import java.net.URL; >> import android.app.Activity; >> import android.content.Context; >> import android.net.ConnectivityManager; >> >> >> >> >> public class chkInternet extends Activity >> { >> public boolean isInternetAvailable(Context context){ >> ConnectivityManager connec = (ConnectivityManager) >> context.getSystemService(Context.CONNECTIVITY_SERVICE); >> android.net.NetworkInfo wifi = >> connec.getNetworkInfo(ConnectivityManager.TYPE_WIFI); >> android.net.NetworkInfo mobile = >> connec.getNetworkInfo(ConnectivityManager.TYPE_MOBILE); >> >> if(wifi.isConnected() || mobile.isConnected()){ >> // Check for web site >> try{ >> // Create a URL for the desired page >> URL url = new URL("http://www.google.com";); >> // Read all the text returned by the server >> BufferedReader in = new BufferedReader(new >> InputStreamReader(url.openStream())); >> in.close(); >> return true; >> } catch (Exception e) { >> return false; >> } >> } >> >> return false; >> } >> >> } >> >> TX >> RK >> >> On Wed, Oct 3, 2012 at 6:08 PM, Subodh Nijsure <[email protected]> >> wrote: >>> >>> Hello, >>> >>> I am trying to implement a service that is supposed to download stuff >>> from a cloud service. So I want this service to be notified whenever >>> phone/tablet looses network connectivity. >>> >>> >>> So I implemented code that looks like this: >>> >>> receiver = new ConnectivityReceiver(); >>> filter = new IntentFilter(); >>> >>> filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION); >>> try { >>> Intent i = registerReceiver(receiver, >>> filter); >>> } >>> catch (Exception e) { >>> .... >>> } >>> However when I have this code in a class that extends a Service >>> registerReciver always throws a NullPointerException. >>> >>> However the same code in a class that extends an activity does not throw >>> such an exception. I have attached my manifest file and the full code for >>> the service template. Would appreciate any pointers as to why this works in >>> activity and not in a service. >>> >>> Or is there any better way for a service that run in the background to >>> know when device looses/gains (IP) network connectivity? >>> >>> Regards, >>> -Subodh >>> >>> -- >>> 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 > > > -- > 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
