How to detect when WIFI Connection has been established in Android

Question

I need to detect when I have network connectivity over WIFI   What broadcast is sent to establish that a valid network connection has been made   I need to validate that a valid network connection for HTTP exists   What should I listen for and what additional tests do I need to make to know that a valid connection exists

User · Answer

You can start a wifi connection if you give the user a choice to override the normal behavior of asking each time     I choose to use three methods     public boolean isOnline       ConnectivityManager connMgr    ConnectivityManager  getSystemService Context CONNECTIVITY SERVICE    NetworkInfo networkInfo   connMgr getActiveNetworkInfo     return  networkInfo    null  amp  amp  networkInfo isConnected           This is quick check if  there is an internet connect either Wifi or CellData  From here you can choose what action you want to take  Is it in Airplane mode needs to be checked also   On a separate thread  I set a variable IpAddress to       And poll until I have a valid an ip address     WifiManager wifi    wifi    WifiManager  this getSystemService Context WIFI SERVICE     WifiInfo wifiInfo   wifi getConnectionInfo      int ipAddress   wifiInfo getIpAddress      String ip   null    ip   String format   d  d  d  d      ipAddress  amp  0xff      ipAddress  gt  gt  8  amp  0xff      ipAddress  gt  gt  16  amp  0xff      ipAddress  gt  gt  24  amp  0xff      Log e    gt  gt IP number Begin   ip     Another code snippet    If its not on turn it on  with users prior permission      if wifi isWifiEnabled    true wifi setWifiEnabled true

User · Answer

This code does not require permission at all  It is restricted only to Wi-Fi network connectivity state changes  any other network is not taken into account   The receiver is statically published in the AndroidManifest xml file and does not need to be exported as it will be invoked by the system protected broadcast  NETWORK STATE CHANGED ACTION  at every network connectivity state change    AndroidManifest    lt receiver     android name   WifiReceiver      android enabled  true      android exported  false  gt        lt intent-filter gt           lt  --protected-broadcast  Special broadcast that only the system can send-- gt           lt  --Corresponds to  android net wifi WifiManager NETWORK STATE CHANGED ACTION-- gt           lt action android name  android net wifi STATE CHANGE    gt       lt  intent-filter gt    lt  receiver gt    BroadcastReceiver class   public class WifiReceiver extends BroadcastReceiver    Override public void onReceive Context context  Intent intent        Tested  I didn t test with the WPS  Wi-Fi Protected Setup  standard    In API15  ICE CREAM SANDWICH  this method is called when the new Wi-Fi network state is   DISCONNECTED  OBTAINING IPADDR  CONNECTED or SCANNING   In API19  KITKAT  this method is called when the new Wi-Fi network state is   DISCONNECTED  twice   OBTAINING IPADDR  VERIFYING POOR LINK  CAPTIVE PORTAL CHECK  or CONNECTED    Those states can be obtained as NetworkInfo DetailedState objects by calling  the NetworkInfo object method   networkInfo getDetailedState                      NetworkInfo object associated with the Wi-Fi network         It won t be null when  android net wifi STATE CHANGE  action intent arrives              NetworkInfo networkInfo   intent getParcelableExtra WifiManager EXTRA NETWORK INFO        if  networkInfo    null  amp  amp  networkInfo isConnected                 TODO  Place the work here  like retrieving the access point s SSID                        WifiInfo object giving information about the access point we are connected to             It shouldn t be null when the new Wi-Fi network state is CONNECTED  but it got            null sometimes when connecting to a  virtualized Wi-Fi router  in API15                      WifiInfo wifiInfo   intent getParcelableExtra WifiManager EXTRA WIFI INFO           String ssid   wifiInfo getSSID                Permissions   None

User · Answer

I have two methods to detect WIFI connection receiving the application context  1 my old method public boolean isConnectedWifi1 Context context        try           ConnectivityManager connectivityManager    ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE           NetworkInfo networkInfo   connectivityManager getActiveNetworkInfo                       if  networkInfo    null                NetworkInfo   netInfo   connectivityManager getAllNetworkInfo                for  NetworkInfo ni   netInfo                    if   ni getTypeName   equalsIgnoreCase  quot WIFI quot                             amp  amp  ni isConnected                          return true                                                                       return false        catch  Exception e            Log e TAG  e getMessage               return false     2 my New method  I  m currently using this method   public boolean isConnectedWifi Context context             ConnectivityManager connectivityManager    ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE            NetworkInfo networkInfo   connectivityManager getNetworkInfo ConnectivityManager TYPE WIFI                 return networkInfo isConnected

User · Answer

To detect WIFI connection state  I have used CONNECTIVITY ACTION from ConnectivityManager class so       IntentFilter filter new IntentFilter        filter addAction ConnectivityManager CONNECTIVITY ACTION       registerReceiver receiver  filter     and from your BroadCastReceiver       if  ConnectivityManager CONNECTIVITY ACTION equals action             int networkType   intent getIntExtra                  android net ConnectivityManager EXTRA NETWORK TYPE  -1           if  ConnectivityManager TYPE WIFI    networkType                NetworkInfo networkInfo    NetworkInfo  intent                      getParcelableExtra WifiManager EXTRA NETWORK INFO               if  networkInfo    null                    if  networkInfo isConnected                              TODO  wifi is connected                   else                          TODO  wifi is not connected                                                    ps works fine for me

User · Answer

November 2020  I have dealt too much with items deprecated by Google  Finally I found a solution to my particular requirement using  quot registerNetworkCallback quot  as Google currently suggests  What I needed was a simple way to detect that my device has an IPv4 assigned in WIFI   I haven t tried other cases  my requirement was very specific  but maybe this method  without deprecated elements  will serve as a basis for other cases   Tested on APIs 23  24 and 26  physical devices  and APIs 28 and 29  emulated devices       ConnectivityManager cm                 ConnectivityManager  this getSystemService Context CONNECTIVITY SERVICE       NetworkRequest Builder builder   new NetworkRequest Builder         cm registerNetworkCallback                                   builder build                        new ConnectivityManager NetworkCallback                                                  Override                         public void onAvailable Network network                                                          Actions to take with Wifi available                                                     Override                         public void onLost Network network                                                          Actions to take with lost Wifi                                                                    Implemented inside  quot MainActivity Oncreate quot   Note  In manifest needs  quot android permission ACCESS NETWORK STATE quot

User · Answer

1  I tried Broadcast Receiver approach as well even though I know CONNECTIVITY ACTION CONNECTIVITY CHANGE is deprecated in API 28 and not recommended  Also bound to using explicit register  it listens as long as app is running   2  I also tried Firebase Dispatcher which works but not beyond app killed   3  Recommended way found is WorkManager to guarantee execution beyond process killed and internally using registerNetworkRequest    The biggest evidence in favor of  3 approach is referred by Android doc itself  Especially for apps in the background    Also here     In Android 7 0 we re removing three commonly-used implicit broadcasts     CONNECTIVITY ACTION  ACTION NEW PICTURE  and ACTION NEW VIDEO     since those can wake the background processes of multiple apps at once and strain memory and battery  If your app is receiving these  take advantage of the Android 7 0 to migrate to JobScheduler and related APIs instead    So far it works fine for us using Periodic WorkManager request   Update  I ended up writing 2 series medium post about it

User · Answer

For all those who enjoying CONNECTIVITY CHANGE broadcast  please note this is no more fired when app is in background in Android O   https   developer android com about versions o background html

User · Answer

I used this code   public class MainActivity extends Activity                              Override     protected void onCreate Bundle savedInstanceState                    super onCreate savedInstanceState                                                 Override     protected void onResume                     super onResume            IntentFilter intentFilter   new IntentFilter            intentFilter addAction WifiManager SUPPLICANT CONNECTION CHANGE ACTION           registerReceiver broadcastReceiver  intentFilter                     Override     protected void onPause                     super onPause            unregisterReceiver broadcastReceiver                  private final BroadcastReceiver broadcastReceiver   new BroadcastReceiver                      Override         public void onReceive Context context  Intent intent                            final String action   intent getAction                if  action equals WifiManager SUPPLICANT CONNECTION CHANGE ACTION                                     if  intent getBooleanExtra WifiManager EXTRA SUPPLICANT CONNECTED  false                                                wifi is enabled                                       else                                              wifi is disabled

User · Answer

You can register a BroadcastReceiver to be notified when a WiFi connection is established  or if the connection changed    Register the BroadcastReceiver   IntentFilter intentFilter   new IntentFilter    intentFilter addAction WifiManager SUPPLICANT CONNECTION CHANGE ACTION   registerReceiver broadcastReceiver  intentFilter     And then in your BroadcastReceiver do something like this    Override public void onReceive Context context  Intent intent        final String action   intent getAction        if  action equals WifiManager SUPPLICANT CONNECTION CHANGE ACTION             if  intent getBooleanExtra WifiManager EXTRA SUPPLICANT CONNECTED  false                   do stuff           else                  wifi connection was lost                     For more info  see the documentation for BroadcastReceiver and WifiManager  Of course you should check whether the device is already connected to WiFi before this   EDIT  Thanks to ban-geoengineering  here s a method to check whether the device is already connected   private boolean isConnectedViaWifi          ConnectivityManager connectivityManager    ConnectivityManager  appObj getSystemService Context CONNECTIVITY SERVICE        NetworkInfo mWifi   connectivityManager getNetworkInfo ConnectivityManager TYPE WIFI             return mWifi isConnected

User · Answer

Answer given by user  JPM and  usman are really very useful  It works fine but in my case it come in onReceive multiple time in my case 4 times so my code execute multiple time   I do some modification and make as per my requirement and now it comes only 1 time  Here is java class for Broadcast   public class WifiReceiver extends BroadcastReceiver    String TAG   getClass   getSimpleName    private Context mContext    Override public void onReceive Context context  Intent intent         mContext   context        if  intent getAction   equals ConnectivityManager CONNECTIVITY ACTION              ConnectivityManager cm    ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE           NetworkInfo networkInfo   cm getActiveNetworkInfo             if  networkInfo    null  amp  amp  networkInfo getType      ConnectivityManager TYPE WIFI  amp  amp                  networkInfo isConnected                     Wifi is connected             WifiManager wifiManager    WifiManager  context getSystemService Context WIFI SERVICE               WifiInfo wifiInfo   wifiManager getConnectionInfo                String ssid   wifiInfo getSSID                 Log e TAG    -- Wifi connected ---       SSID     ssid                         else if  intent getAction   equalsIgnoreCase WifiManager WIFI STATE CHANGED ACTION                 int wifiState   intent getIntExtra WifiManager EXTRA WIFI STATE  WifiManager WIFI STATE UNKNOWN           if  wifiState    WifiManager WIFI STATE DISABLED                        Log e TAG    ----- Wifi  Disconnected -----                            In AndroidManifest   lt receiver android name   util WifiReceiver  android enabled  true  gt           lt intent-filter gt               lt action android name  android net wifi WIFI STATE CHANGED    gt               lt action android name  android net conn CONNECTIVITY CHANGE   gt           lt  intent-filter gt       lt  receiver gt     lt uses-permission android name  android permission ACCESS WIFI STATE   gt   lt uses-permission android name  android permission ACCESS NETWORK STATE   gt

User · Answer

The best that worked for me   AndroidManifest   lt receiver android name  com AEDesign communication WifiReceiver   gt      lt intent-filter android priority  100  gt         lt action android name  android net wifi STATE CHANGE    gt      lt  intent-filter gt   lt  receiver gt    BroadcastReceiver class  public class WifiReceiver extends BroadcastReceiver        Override    public void onReceive Context context  Intent intent           NetworkInfo info   intent getParcelableExtra WifiManager EXTRA NETWORK INFO         if info    null  amp  amp  info isConnected                 Do your work               e g  To check the Network Name or other info          WifiManager wifiManager    WifiManager context getSystemService Context WIFI SERVICE           WifiInfo wifiInfo   wifiManager getConnectionInfo            String ssid   wifiInfo getSSID                     Permissions   lt uses-permission android name  android permission ACCESS WIFI STATE   gt   lt uses-permission android name  android permission ACCESS NETWORK STATE   gt

User · Answer

For me only WifiManager NETWORK STATE CHANGED ACTION works   Register a broadcast receiver   IntentFilter intentFilter   new IntentFilter    intentFilter addAction WifiManager NETWORK STATE CHANGED ACTION   registerReceiver broadcastReceiver  intentFilter     and receive    Override public void onReceive Context context  Intent intent         final String action   intent getAction         if action equals WifiManager NETWORK STATE CHANGED ACTION            NetworkInfo info   intent getParcelableExtra WifiManager EXTRA NETWORK INFO           boolean connected   info isConnected               call your method

User · Answer

Here is an example of my code  that takes into account the users preference of only allowing comms when connected to Wifi   I am calling this code from inside an IntentService before I attempt to download stuff   Note that NetworkInfo will be null if there is no network connection of any kind   private boolean canConnect         ConnectivityManager connectivityManager    ConnectivityManager  getSystemService Context CONNECTIVITY SERVICE        boolean canConnect   false      boolean wifiOnly   SharedPreferencesUtils wifiOnly         NetworkInfo networkInfo   connectivityManager getActiveNetworkInfo        if networkInfo    null                if networkInfo isConnected                          if  networkInfo getType      ConnectivityManager TYPE WIFI                     networkInfo getType      ConnectivityManager TYPE WIFI  amp  amp   wifiOnly                                 canConnect   true                                     return canConnect

User · Answer

Android O removed the possibility to receive the implicit broadcasts for a wifi state change  So if your app is closed  you ll not be able to receive them  The new WorkManager has the ability to run when your app is closed  so I ve experimented a bit with it and it seems to work quite well   Add this to your dependencies   implementation  android arch work work-runtime 1 0 0-alpha08    WifiConnectWorker kt  class WifiConnectWorker   Worker          override fun doWork    Result           Log i TAG   I think we connected to a wifi           return Result SUCCESS           MainActivity kt   class MainActivity   AppCompatActivity          override fun onCreate savedInstanceState  Bundle             super onCreate savedInstanceState          setContentView R layout main activity           val workManager   WorkManager getInstance               Add constraint to start the worker when connecting to WiFi         val request   OneTimeWorkRequest Builder WifiConnectWorker  class java               setConstraints Constraints Builder                    setRequiredNetworkType UNMETERED                   build                 build               The worker should be started  even if your app is closed         workManager beginUniqueWork  watch wifi   REPLACE  request  enqueue             Keep in mind that this was just a quick test for a one-time notification  There is more work to do to always get notified when WiFi is turned on and off    PS  When the app is force quit  the worker is not started  it seems WorkManager is canceling the requests then

[android] How to detect when WIFI Connection has been established in Android?

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