ConnectivityManager getActiveNetworkInfo null pointer exception

Question

Sometimes I see an exception exception in the pointer in the connection manager. From the Intent service, I check the status of the network using isOnWIFI (this). An exception occurs in the line cm.getActiveNetworkInfo (). This is strange because I am checking for null until I name it. Note. Permissions are installed.

public static boolean isOnWIFI(Context context) { ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); return cm != null //here occurs NullPointerException && cm.getActiveNetworkInfo() != null && ((cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI) != null && cm.getNetworkInfo( ConnectivityManager.TYPE_WIFI).isConnected())); } 

Any thoughts why this is happening? I cannot debug it because these are just random error messages. The only solution I see is to put it in a catch try block. Thanks.

Answer 1

You checked api that they are mentioned if there are no active connections which they simply return null. I think this is a problem with ur.

http://developer.android.com/reference/android/net/ConnectivityManager.html #getActiveNetworkInfo ()

Answer 2

android_dev is right. The problem in your code comes from cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isConnected()));

Yes! you check cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI) != null before, but by calling getNetworkInfo() second time, the android receives and retrieves network information a second time, but only this time it does not encounter an active network returning zero this second time. It’s not that you called getNetworkInfo() millisecond earlier and did not get zero, which means you won’t get milliseconds after

Answer 3

 Try this. Read more here 

http://developer.android.com/training/basics/network-ops/managing.html

 public static boolean isOnWIFI(Context context) { ConnectivityManager cm = (ConnectivityManager) this.getSystemService(context.CONNECTIVITY_SERVICE); if(cm != null){ NetworkInfo networkInfo = cm.getActiveNetworkInfo(); boolean isWiFi = networkInfo.getType() == ConnectivityManager.TYPE_WIFI; // if user is connected to network if (isWifi) { return true; }else { return false; } } else{ //cm is null return false } } 

Answer 4

When I worked with services, this solved my problem. Before I just used it! info.isConnected (), but that wasn’t enough

  ConnectivityManager cm = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE); NetworkInfo info = cm.getActiveNetworkInfo(); if(info==null || !info.isConnected()) { stopSelf(); return; } 

Answer 5

getActiveNetworkInfo returns null if there is no default connection available according to documents - > getActiveNetworkInfo . What I would advise you to do is check the networks, each individually, as shown below.

 NetworkInfo WiFiInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI); NetworkInfo mobileInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE); 

then check if they are available

 if(mobileInfo != null & mobileInfo.isConnectedOrConnecting() || WiFiInfo != null & WiFiInfo.isConnectedOrConnecting()) { //do your task here } else { //show an alert dialog or something } 

Answer 6

I just created one template with such a problem, now it works well. You can try this code, I tried it on many devices and there are no problems. getActiveNetworkInfo() . Before I tried getAllNetworkInfo() , and I do not understand what is wrong, but getAllNetworkInfo() works stupidly on some devices.