How to check internet access on Android InetAddress never times out

Question

I got a AsyncTask that is supposed to check the network access to a host name  But the doInBackground   is never timed out  Anyone have a clue   public class HostAvailabilityTask extends AsyncTask lt String  Void  Boolean gt         private Main main       public HostAvailabilityTask Main main            this main   main             protected Boolean doInBackground String    params            Main Log  doInBackground   isHostAvailable     params 0             try               return InetAddress getByName params 0   isReachable 30              catch  UnknownHostException e                e printStackTrace              catch  IOException e                e printStackTrace                      return false                    protected void onPostExecute Boolean    result            Main Log  onPostExecute               if result 0     false                main setContentView R layout splash               return                     main continueAfterHostCheck

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public boolean isOnline         boolean var   false      ConnectivityManager cm    ConnectivityManager  getSystemService Context CONNECTIVITY SERVICE       if   cm getActiveNetworkInfo      null             var   true            return var       I have done it this way  A little bit shorter and more readable I guess   Cheers   Saiyan

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Here is the optimal method for checking internet connection  What this method does is perform a series of checks  is the phone not in airplane mode  is the phone connected to a network  etc   If all the checks return true  the method will then download a file from the internet and see if the contents matches an expected value   The benefits of this method compared to other methods that ping a server to check for internet connection are    The Android runtime varies on different phones - so you may not always be able to execute those commands  as shown here  Why does ping works on some devices and not others  Pinging a server doesn t always work because of login pages re-directs on wifi networks which can give the false impression of a connection    This answer is written in Kotlin and uses the Fuel library to download a file from the internet with the methodfetchUrlAsString  but any library can be substituted as long as you make sure your HTTP request is not cached  Think of showConnectionWarning   and hideConnectionWarning   as equivalent to internet connection status   false and internet connection status   true respectively    private val networkReceiver   object   BroadcastReceiver          override fun onReceive context  Context   intent  Intent              val activeNetworkInfo    context  getSystemService Context CONNECTIVITY SERVICE  as ConnectivityManager  activeNetworkInfo          if  activeNetworkInfo    null                if  activeNetworkInfo isConnectedOrConnecting                      Launches a coroutine to fetch file asynchronously                  launch                       try                             Downloads file from url on the internet - use any library you want here                            val connectionStatus   fetchUrlAsString  lt url for file on internet gt                             check if the contents of the file is as expected                         if  connectionStatus     Connected To Database                                 hideConnectionWarning                             else                               showConnectionWarning                                                   catch  e  Exception                              Catches an exception - fetchUrlAsString only throws an exception if there is no internet                          showConnectionWarning                                                         else                   showConnectionWarning                           else               showConnectionWarning                      private suspend fun fetchUrlAsString url  String   String   suspendCoroutine   cont - gt      url httpGet   header Pair  pragma    no-cache    Pair  cache-control    no-cache    responseString         result - gt           when  result                is Result Failure - gt                    cont resumeWithException result getException                              is Result Success - gt                    cont resume result value                                     You will need the following permissions    lt uses-permission android name  android permission ACCESS NETWORK STATE    gt   lt uses-permission android name  android permission INTERNET    gt

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There s more than one way  First  shortest but Inefficient way  Network State Permission only needed   lt uses-permission android name  android permission ACCESS NETWORK STATE    gt    Then this method    public boolean activeNetwork              ConnectivityManager cm                    ConnectivityManager getSystemService Context CONNECTIVITY SERVICE            NetworkInfo activeNetwork   cm getActiveNetworkInfo            boolean isConnected   activeNetwork    null  amp  amp                  activeNetwork isConnected             return isConnected           As seen in answers ConnectivityManager is a solution  I just added it within a method this is a simplified method all use ConnectivityManager returns true if there is a network access not Internet access  means if your WiFi is connected to a router but the router has no internet it returns true  it check connection availability  Second  Efficient way  Network State and Internet Permissions needed   lt uses-permission android name  android permission ACCESS NETWORK STATE    gt   lt uses-permission android name  android permission INTERNET    gt    Then this class    public class CheckInternetAsyncTask extends AsyncTask lt Void  Integer  Boolean gt             private Context context           public CheckInternetAsyncTask Context context                this context   context                      Override         protected Boolean doInBackground Void    params                 ConnectivityManager cm                        ConnectivityManager context getSystemService Context CONNECTIVITY SERVICE                assert cm    null              NetworkInfo activeNetwork   cm getActiveNetworkInfo                boolean isConnected   activeNetwork    null  amp  amp                      activeNetwork isConnected                  if  isConnected                    try                       HttpURLConnection urlc    HttpURLConnection                               new URL  http   clients3 google com generate 204                                        openConnection                         urlc setRequestProperty  User-Agent    Android                        urlc setRequestProperty  Connection    close                        urlc setConnectTimeout 1500                       urlc connect                        if  urlc getResponseCode      204  amp  amp                              urlc getContentLength      0                          return true                     catch  IOException e                        Log e  TAG    Error checking internet connection   e                       return false                                  else                   Log d  TAG    No network available                     return false                              return null                      Override         protected void onPostExecute Boolean result                super onPostExecute result               Log d  TAG    result    result                if result                      do ur code                                    Call CheckInternetAsyncTask  new CheckInternetAsyncTask getApplicationContext    execute      Some Explanations  -    you have to check Internet on AsyncTask  otherwise it can throw android os NetworkOnMainThreadException in some cases ConnectivityManager used to check the network access if true sends request  Ping  Request send to http   clients3 google com generate 204  This well-known URL is known to return an empty page with an HTTP status 204 this is faster and more efficient than http   www google com   read this  if you have website it s preferred to put you website instead of google  only if you use it within the app Timeout can be changed range  20ms -  2000ms   1500ms is commonly used

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Here is the method I use   public boolean isNetworkAvailable final Context context        return   ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE   getActiveNetworkInfo      null      Even better  check to make sure it is  connected    public boolean isNetworkAvailable final Context context        final ConnectivityManager connectivityManager     ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE        return connectivityManager getActiveNetworkInfo      null  amp  amp  connectivityManager getActiveNetworkInfo   isConnected        Here is how to use the method   if  isNetworkAvailable context            code here   else          code     Permission needed    lt uses-permission android name  android permission ACCESS NETWORK STATE    gt    https   stackoverflow com a 16124915 950427

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Take a look at the ConnectivityManager class  You can use this class to get information on the active connections on a host  http   developer android com reference android net ConnectivityManager html  EDIT  You can use       Context getSystemService Context CONNECTIVITY SERVICE       getNetworkInfo ConnectivityManager TYPE MOBILE     or  Context getSystemService Context CONNECTIVITY SERVICE       getNetworkInfo ConnectivityManager TYPE WIFI     and parse the DetailedState enum of the returned NetworkInfo object  EDIT EDIT  To find out whether you can access a host  you can use   Context getSystemService Context CONNECTIVITY SERVICE       requestRouteToHost TYPE WIFI  int hostAddress    Obviously  I m using Context getSystemService Context CONNECTIVITY SERVICE  as a proxy to say  ConnectivityManager cm   Context getSystemService Context CONNECTIVITY SERVICE   cm yourMethodCallHere

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public static boolean isNetworkAvailable Context ctx    ConnectivityManager connMgr    ConnectivityManager ctx getSystemService Context CONNECTIVITY SERVICE   if connMgr getNetworkInfo ConnectivityManager TYPE WIFI  isConnected          connMgr getNetworkInfo ConnectivityManager TYPE MOBILE  isConnected             return true     return false        user this

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Following is the code from my Utils class   public static boolean isNetworkAvailable Context context            ConnectivityManager connectivityManager                   ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE           NetworkInfo activeNetworkInfo   connectivityManager getActiveNetworkInfo            return activeNetworkInfo    null  amp  amp  activeNetworkInfo isConnected

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check this code    it worked for me     public static void isNetworkAvailable final Handler handler  final int timeout           ask fo message  0   not connected  or  1   connected  on  handler         the answer must be send before before within the  timeout   in milliseconds       new Thread             private boolean responded   false              Override         public void run                     set  responded  to TRUE if is able to connect with google mobile  responds fast               new Thread                            Override                 public void run                         HttpGet requestForTest   new HttpGet  http   m google com                        try                           new DefaultHttpClient   execute requestForTest      can last                            responded   true                                             catch  Exception e                                                           start                 try                   int waited   0                  while  responded  amp  amp   waited  lt  timeout                         sleep 100                       if  responded                              waited    100                                                                     catch InterruptedException e        do nothing              finally                    if   responded    handler sendEmptyMessage 0                      else   handler sendEmptyMessage 1                                   start        Then  I define the handler   Handler h   new Handler          Override     public void handleMessage Message msg             if  msg what    1       code if not connected            else      code if connected                             and launch the test   isNetworkAvailable h 2000      get the answser within 2000 ms

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No need to be complex  The simplest and framework manner is to use ACCESS NETWORK STATE permission and just make a connected method  public boolean isOnline         ConnectivityManager cm            ConnectivityManager  getSystemService Context CONNECTIVITY SERVICE        return cm getActiveNetworkInfo      null  amp  amp          cm getActiveNetworkInfo   isConnectedOrConnecting        You can also use requestRouteToHost if you have a particualr host and connection type  wifi mobile  in mind   You will also need    lt uses-permission android name  android permission ACCESS NETWORK STATE    gt    in your android manifest

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public static boolean isNetworkAvailable Context context        boolean flag   checkNetworkAvailable context        if   flag            Log d      No network available                return flag      private static boolean checkNetworkAvailable Context context        ConnectivityManager connectivityManager                ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE       NetworkInfo activeNetworkInfo   connectivityManager getActiveNetworkInfo        return activeNetworkInfo    null

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The most Simplest solution would be  In most cases one will only check internet connection if he she wants to connect to the remote server so the simple and best solution would be pinging your server as following   public boolean isConnected         final String command    ping -c 1 yourExmapleDomain com       boolean isConnected   false      try           isConnected   Runtime getRuntime   exec command  waitFor      0        catch  InterruptedException e            e printStackTrace          catch  IOException e            e printStackTrace              return isConnected

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Update 29 06 2015 If you are using Xamarin Android and want to check for connectivity  you can use a Nuget package that would give you this functionality on multiple platforms  Good candidates are here and here    End of Update   The Answers above are quite good  but they are all in Java  and almost all of them check for a connectivity  In my case  I needed to have connectivity with a specific type of connection and I am developing on Xamarin Android  Moreover  I do not pass a reference to my activities Context in the Hardware layer  I use the Application Context  So here is my solution  in case somebody comes here with similar requirements  I have not done full testing though  will update the answer once I am done with my testing  using Android App  using Android Content  using Android Net   namespace Leopard Mobile Hal Android       public class AndroidNetworkHelper               public static AndroidNetworkStatus GetWifiConnectivityStatus                         return GetConnectivityStatus ConnectivityType Wifi                      public static AndroidNetworkStatus GetMobileConnectivityStatus                         return GetConnectivityStatus ConnectivityType Mobile                       region Implementation          private static AndroidNetworkStatus GetConnectivityStatus ConnectivityType connectivityType                        var connectivityManager    ConnectivityManager Application Context GetSystemService Context ConnectivityService               var wifiNetworkInfo   connectivityManager GetNetworkInfo connectivityType               var result   GetNetworkStatus wifiNetworkInfo               return result                     private static AndroidNetworkStatus GetNetworkStatus NetworkInfo wifiNetworkInfo                        var result   AndroidNetworkStatus Unknown              if  wifiNetworkInfo    null                                if  wifiNetworkInfo IsAvailable  amp  amp  wifiNetworkInfo IsConnected                                        result   AndroidNetworkStatus Connected                                    else                                       result   AndroidNetworkStatus Disconnected                                              return result                       endregion            public enum AndroidNetworkStatus               Connected          Disconnected          Unknown

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Don t forget to add this permissions to your manifest     lt uses-permission android name  android permission INTERNET    gt   lt uses-permission android name  android permission ACCESS NETWORK STATE    gt

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As Android doc suggest  after     getActiveNetworkInfo   was deprecated in Android 10  Use   NetworkCallbacks instead for apps that target Android 10  API level   29  and higher    So below is the way which we are using to check network connection Currently   val cm   context getSystemService Context CONNECTIVITY SERVICE  as ConnectivityManager val activeNetwork  NetworkInfo    cm activeNetworkInfo val isConnected  Boolean   activeNetwork  isConnectedOrConnecting    true   The new way for checking internet connection using NetworkCallbacks  Step 1       private lateinit var connectivityManager ConnectivityManager      override fun onCreate savedInstanceState  Bundle             super onCreate savedInstanceState                      connectivityManager   getSystemService Context CONNECTIVITY SERVICE  as ConnectivityManager         Step 2  Create Callback   private val callback   object   ConnectivityManager NetworkCallback         override fun onAvailable network  Network            super onAvailable network          Timber e  Network onAvailable              override fun onLost network  Network            super onLost network          Timber e  Network onLost              Step 3  Register and UnRegister CallBack   private fun registerNetworkCallback         if  Build VERSION SDK INT  gt   Build VERSION CODES N            connectivityManager registerDefaultNetworkCallback callback        else              Old way to check network connection          override fun onStop         unRegisterNetworkCallback       super onStop      private fun unRegisterNetworkCallback         connectivityManager unregisterNetworkCallback callback      Checkout update details on below link   https   developer android com training monitoring-device-state connectivity-status-type

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Use method   private fun isInternetAvailable context  Context   Boolean        context getSystemService Context CONNECTIVITY SERVICE  as ConnectivityManager  run           if  Build VERSION SDK INT  gt   Build VERSION CODES M                return this getNetworkCapabilities this activeNetwork   hasCapability                  NetworkCapabilities NET CAPABILITY INTERNET                  false           else                 Suppress  DEPRECATION               return this activeNetworkInfo  isConnected    false                      And permissions required    lt uses-permission android name  android permission ACCESS NETWORK STATE    gt

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Instead of checking WIFI connection or Mobile data connection  try hitting any hosted domain  So that  you can check whether the WIFI Mobile connection has ability to connect public Internet   The below will return if your mobile device is able to connect with the public domain provided   boolean isReachable                         boolean connected   false              String instanceURL    Your trusted domain name               Socket socket              try                   socket   new Socket                    SocketAddress socketAddress   new InetSocketAddress instanceURL  80                   socket connect socketAddress  5000                   if  socket isConnected                          connected   true                      socket close                                    catch  IOException e                    e printStackTrace                  finally                   socket   null                            return connected              Hope it will be helpful

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This is simplest and easy way to check internet connection for wifi and mobile data   public static boolean isConnected Activity  context            if   context    null                ConnectivityManager connMgr    ConnectivityManager   context getSystemService Context CONNECTIVITY SERVICE               NetworkInfo activeInfo   connMgr getActiveNetworkInfo                if  activeInfo    null  amp  amp  activeInfo isConnected                      boolean wifiConnected   activeInfo getType      ConnectivityManager TYPE WIFI                  boolean mobileConnected   activeInfo getType      ConnectivityManager TYPE MOBILE                   if  wifiConnected    mobileConnected                        Log d TAG   Wifi Connected                         return true                    else                       showAlert  context  context getString R string err no internet                        return false                                  else                   showAlert  context  context getString R string err no internet                    return false                          else               Log e TAG   networkConnectivity  Context NULL                       return false

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The other answers that use ConnectivityManager are wrong because having a network connection doesn t mean you have internet access  For example  the user might be connected to a coffee shop s WiFi portal but can t get to the internet  To check that the internet is accessible you have to try to connect to an actual server  Normally when you want to do this you have a specific server in mind that you want to connect to  so go ahead and check if you can connect to that server  Here s a simple method for checking connectivity to a server   private boolean isOnTheInternet         try           URLConnection urlConnection   new URL  http   yourserver   openConnection            urlConnection setConnectTimeout 400           urlConnection connect            return true        catch  Exception e            return false            The reason for setting the ConnectTimeout is that otherwise it defaults to the TCP timeout which can be many seconds long    Note also that Android won t let you run this on your main thread

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Using the following method to check internet connectivity  also ConnectivityManager getActiveNetworkInfo   is deprecated in API 28    Suppress  DEPRECATION   fun isNetworkConnected context  Context   Boolean       val cm   context getSystemService Context CONNECTIVITY SERVICE  as ConnectivityManager      return cm  run           if  Build VERSION SDK INT  gt   Build VERSION CODES M                cm getNetworkCapabilities cm activeNetwork   run                   when                       hasTransport NetworkCapabilities TRANSPORT WIFI  - gt  true                     hasTransport NetworkCapabilities TRANSPORT CELLULAR  - gt  true                     hasTransport NetworkCapabilities TRANSPORT ETHERNET  - gt  true                     else - gt  false                                           else               cm activeNetworkInfo  run                   when  type                        ConnectivityManager TYPE WIFI - gt  true                     ConnectivityManager TYPE MOBILE - gt  true                     else - gt  false                                                    false      Also add the following permission to the manifest   lt uses-permission android name  android permission ACCESS NETWORK STATE    gt    hasTransport NetworkCapabilities TRANSPORT ETHERNET  is used for apps developed for Android TV where TV can be directly connected to Ethernet

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Use this Kotlin Extension          Check whether network is available        param context     return Whether device is connected to Network      fun Context isNetworkAvailable    Boolean       with getSystemService Context CONNECTIVITY SERVICE  as ConnectivityManager            if  Build VERSION SDK INT  gt   Build VERSION CODES M                  Device is running on Marshmallow or later Android OS              with getNetworkCapabilities activeNetwork                     return hasTransport NetworkCapabilities TRANSPORT WIFI     hasTransport                      NetworkCapabilities TRANSPORT CELLULAR                                           else               activeNetworkInfo  let                      connected to the internet                  Suppress  DEPRECATION                   return listOf ConnectivityManager TYPE WIFI  ConnectivityManager TYPE MOBILE  contains it type                                    return false

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In kotlin   class UtilityMethods   companion object       fun isConnected activity  Activity   Boolean           val connectivityManager  ConnectivityManager                   activity getSystemService Context CONNECTIVITY SERVICE  as ConnectivityManager         return null    connectivityManager activeNetworkInfo            Invoke isConnected inside Activity class as   UtilityMethods isConnected this    Inside fragment class as   UtilityMethods isConnected activity

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Kotlin implementation       Function that uses ping  takes server name or ip as argument       return  Double MAX VALUE  if server is not reachable  Average RTT if the server is reachable      Success output example     PING 8 8 8 8  8 8 8 8  56 84  bytes of data    64 bytes from 8 8 8 8  icmp seq 1 ttl 254 time 172 ms   64 bytes from 8 8 8 8  icmp seq 2 ttl 254 time 166 ms   64 bytes from 8 8 8 8  icmp seq 3 ttl 254 time 167 ms   64 bytes from 8 8 8 8  icmp seq 4 ttl 254 time 172 ms   64 bytes from 8 8 8 8  icmp seq 5 ttl 254 time 167 ms    --- 8 8 8 8 ping statistics ---   5 packets transmitted  5 received  0  packet loss  time 4011ms   rtt min avg max mdev   166 470 169 313 172 322 2 539 ms                                         value to parse using it split      1  trim   split      0  trim   split      1  toDouble       ExperimentalStdlibApi fun pingServerAverageRtt host  String   Double        var aveRtt  Double   Double MAX VALUE      try              execute the command on the environment interface  timeout is set as 0 2 to get response faster          val pingProcess  Process   Runtime getRuntime   exec  quot  system bin ping -i 0 2 -c 5  host quot              gets the input stream to get the output of the executed command         val bufferedReader   BufferedReader InputStreamReader pingProcess inputStream            bufferedReader forEachLine               if  it isNotEmpty    amp  amp  it contains  quot min avg max mdev quot          when we get to the last line of executed ping command                 aveRtt   it split      1  trim                            split      0  trim                            split      1  toDouble                                 catch  e  IOException            e printStackTrace              return aveRtt     Usage example  val latency   pingServerAverageRtt ipString  if  latency    Double MAX VALUE           server reachable   else         server not reachable

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For me it was not a good practice to check the connection state in the Activity class  because   ConnectivityManager cm        ConnectivityManager  getSystemService Context CONNECTIVITY SERVICE     should be called there  or you need to push down your Activity instance  context  to the connection handler class to able to check the connection state there When no available connection  wifi  network  I catch the UnknownHostException exception   JSONObject jObj   null  Boolean responded   false  HttpGet requestForTest   new HttpGet  http   myserver com    try       new DefaultHttpClient   execute requestForTest       responded   true    catch  UnknownHostException e        jObj   new JSONObject        try           jObj put  answer code   1           jObj put  answer text    No available connection          catch  Exception e1         return jObj    catch  IOException e        e printStackTrace        In this way I can handle this case along with the other cases in the same class  my server always response back with a json string

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You can check internet with below code as well    public class CheckInternetConnection           public Context context   null           public CheckInternetConnection Context ctx                this context   ctx                     public boolean CheckInternet                 return isOnline                      public Boolean isOnline                          try                   if isNetAvailable context                       return true                  else                                       try                           URL url   new URL  http   www google com                            HttpURLConnection urlc    HttpURLConnection  url                                  openConnection                            urlc setRequestProperty  User-Agent    Test                            urlc setRequestProperty  Connection    close                            urlc setConnectTimeout 3000      This is time limit if the                            connection time limit                         try                               urlc connect                                Log e  TAG     urlc ----------    urlc getResponseCode                                 if  urlc getResponseCode      200                                    return true                                                         catch  Exception e                               e printStackTrace                                                    catch  MalformedURLException e1                            e1 printStackTrace                          catch  IOException e                            e printStackTrace                                                         catch  Exception e                   e printStackTrace                               return false                              public synchronized static boolean isNetAvailable Context context                 try               boolean isNetAvailable false               if   context    null                                   ConnectivityManager mgr    ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE                    if   mgr    null                                           boolean mobileNetwork   false                       boolean wifiNetwork   false                       boolean wiMaxNetwork   false                        boolean mobileNetworkConnecetd   false                       boolean wifiNetworkConnecetd   false                       boolean wiMaxNetworkConnected   false                        NetworkInfo mobileInfo   mgr getNetworkInfo ConnectivityManager TYPE MOBILE                        NetworkInfo wifiInfo   mgr getNetworkInfo ConnectivityManager TYPE WIFI                        NetworkInfo wiMaxInfo   mgr getNetworkInfo ConnectivityManager TYPE WIMAX                         if   mobileInfo    null                            mobileNetwork   mobileInfo isAvailable                                             if   wifiInfo    null                            wifiNetwork   wifiInfo isAvailable                          if wiMaxInfo    null                           wiMaxNetwork   wiMaxInfo isAvailable                          if wifiNetwork    true                           wifiNetworkConnecetd   wifiInfo isConnectedOrConnecting                         if mobileNetwork    true                           mobileNetworkConnecetd   mobileInfo isConnectedOrConnecting                         if wiMaxNetwork    true                           wiMaxNetworkConnected   wiMaxInfo isConnectedOrConnecting                          isNetAvailable     mobileNetworkConnecetd    wifiNetworkConnecetd    wiMaxNetworkConnected                                                   return isNetAvailable                catch NullPointerException e                                  return false                catch Exception e                                  return false

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This is covered in android docs http   developer android com training monitoring-device-state connectivity-monitoring html

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If you need to check for the internet connection  use this method using ping to the server   public boolean checkIntCON         try           Process ipProcess   Runtime getRuntime   exec   system bin ping -c 1 8 8 8 8            return  ipProcess waitFor      0             catch  IOException e             e printStackTrace          catch  InterruptedException e    e printStackTrace          return false      Either you can use check through using port  public boolean checkIntCON         try           Socket sock   new Socket            SocketAddress sockaddr   new InetSocketAddress  8 8 8 8   80               port will change according to protocols          sock connect sockaddr  1250           sock close             return true        catch  IOException e    return false

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If the device is in airplane mode  or presumably in other situations where there s no available network   cm getActiveNetworkInfo   will be null  so you need to add a null check   Modified  Eddie s solution  below   public boolean isOnline         ConnectivityManager cm            ConnectivityManager  getSystemService Context CONNECTIVITY SERVICE       NetworkInfo netInfo   cm getActiveNetworkInfo        return netInfo    null  amp  amp  netInfo isConnectedOrConnecting        Also add the following permission to the AndroidManifest xml    lt uses-permission android name  android permission ACCESS NETWORK STATE    gt    One other small point  if you absolutely need a network connection at the given point in time  then it might be better to use netInfo isConnected   rather than netInfo isConnectedOrConnecting   I guess this is up to the individual use-case however

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You can use this method to detect network availability-  public static boolean isDeviceOnline Context context            boolean isConnectionAvail   false          try               ConnectivityManager cm    ConnectivityManager  context                      getSystemService Context CONNECTIVITY SERVICE               NetworkInfo netInfo   cm getActiveNetworkInfo                return netInfo isConnected              catch  Exception e                e printStackTrace                      return isConnectionAvail

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Most of the answers in this thread only check if there is a connection available but do not check if that connection work  others answers are not device wide  my solution should work on every device   You can drop my code in your main activity before launching the app  it will quickly determine if there is an actual internet connectivity  if there is the dialog will be immediately dropped and the app will be launched  if not an alert will pop up saying the app needs internet connectivity to work   final AlertDialog alertDialog   new AlertDialog Builder this  create            alertDialog setTitle  Checking Connection            alertDialog setMessage  Checking               alertDialog show            new CountDownTimer 5000  1000                 Override             public void onTick long millisUntilFinished                     new Thread new Runnable                         public void run                             try                               URL url   new URL  http   web mit edu                                 HttpURLConnection connection    HttpURLConnection  url openConnection                                connection setRequestMethod  GET                                connection setConnectTimeout 5000                               isConnected   connection getResponseCode      HttpURLConnection HTTP OK                            catch  Exception e                                e printStackTrace                                                                       start                     if  isConnected    false                       alertDialog setMessage  Try       5 - millisUntilFinished 1000      of 5                       else                       alertDialog dismiss                                                 Override             public void onFinish                     if  isConnected    false                        alertDialog dismiss                        new AlertDialog Builder activity                               setTitle  No Internet                                setMessage  Please connect to Internet first                                 setPositiveButton android R string yes  new DialogInterface OnClickListener                                     public void onClick DialogInterface dialog  int which                                           kill the app                                                                                                setIcon android R drawable ic dialog alert                               show                      else                          Launch the app                                           start

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To get getActiveNetworkInfo   to work you need to add the following to the manifest    lt uses-permission android name  android permission ACCESS NETWORK STATE    gt

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Here is some modern code that uses an AsynTask to get around an issue where android crashes when you try and connect on the main thread and introduces an alert with a rinse and repeat option for the user   class TestInternet extends AsyncTask lt Void  Void  Boolean gt         Override     protected Boolean doInBackground Void    params            try               URL url   new URL  http   www google com                HttpURLConnection urlc    HttpURLConnection  url openConnection                urlc setConnectTimeout 3000               urlc connect                if  urlc getResponseCode      200                    return true                          catch  MalformedURLException e1                   TODO Auto-generated catch block             e1 printStackTrace                return false            catch  IOException e                   TODO Auto-generated catch block             e printStackTrace                return false                    return false              Override     protected void onPostExecute Boolean result            if   result       code if not connected             AlertDialog Builder builder   new AlertDialog Builder MainActivity this               builder setMessage  An internet connection is required                 builder setCancelable false                builder setPositiveButton                       TRY AGAIN                       new DialogInterface OnClickListener                             public void onClick DialogInterface dialog  int id                                dialog cancel                                new TestInternet   execute                                                                    AlertDialog alert11   builder create                alert11 show              else      code if connected             doMyStuff                             new TestInternet   execute

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You can iterate over all network connections and chek whether there is at least one available connection   public boolean isConnected         boolean connected   false       ConnectivityManager cm             ConnectivityManager  getSystemService Context CONNECTIVITY SERVICE        if  cm    null            NetworkInfo   netInfo   cm getAllNetworkInfo             for  NetworkInfo ni   netInfo                if   ni getTypeName   equalsIgnoreCase  WIFI                          ni getTypeName   equalsIgnoreCase  MOBILE                         amp  amp  ni isConnected    amp  amp  ni isAvailable                      connected   true                                      return connected

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Here is the Kotlin version I use for reachability checking   Kotlin MyReachability  object MyReachability        private val REACHABILITY SERVER    http   google com     can be any URL you want      private fun hasNetworkAvailable context  Context   Boolean           val service   Context CONNECTIVITY SERVICE         val manager   context getSystemService service  as ConnectivityManager          val network   manager  activeNetworkInfo         Log d classTag   hasNetworkAvailable     network    null             return  network    null             fun hasInternetConnected context  Context   Boolean           if  hasNetworkAvailable context                 try                   val connection   URL REACHABILITY SERVER  openConnection   as HttpURLConnection                 connection setRequestProperty  User-Agent    Test                   connection setRequestProperty  Connection    close                   connection connectTimeout   1500                 connection connect                   Log d classTag   hasInternetConnected     connection responseCode    200                     return  connection responseCode    200                catch  e  IOException                    Log e classTag   Error checking internet connection   e                          else               Log w classTag   No network available                      Log d classTag   hasInternetConnected  false           return false           You can even pass the REACHABILITY SERVER as param based on policy and restrictions  for example when you are in china you can check https   baidu com rather https   google com   Calling example   val webLoaderThread   Thread      if  MyReachability hasInternetConnected this           runOnUiThread                mWebView loadUrl LANDING SERVER     connected               else          runOnUiThread                showDialogNoNetwork      not connected                 webLoaderThread start     Android permissions  Dont forget to add these below permissions to your AndroidManifest xml   lt uses-permission android name  android permission INTERNET   gt   lt uses-permission android name  android permission ACCESS NETWORK STATE   gt

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Very important to check if we have connectivity with isAvailable   and if is possible to establish a connection with isConnected    private static ConnectivityManager manager   public static boolean isOnline Context context        ConnectivityManager connectivityManager    ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE       NetworkInfo networkInfo   connectivityManager getActiveNetworkInfo        return networkInfo    null  amp  amp  networkInfo isAvailable    amp  amp  networkInfo isConnected        and you can derterminate the type of network active WiFi    public static boolean isConnectedWifi Context context        ConnectivityManager connectivityManager    ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE       NetworkInfo networkInfo   connectivityManager getActiveNetworkInfo        return networkInfo    null  amp  amp  networkInfo getType      ConnectivityManager TYPE WIFI      or mobile M  vil    public static boolean isConnectedMobile Context context        ConnectivityManager connectivityManager    ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE       NetworkInfo networkInfo   connectivityManager getActiveNetworkInfo        return networkInfo    null  amp  amp  networkInfo getType      ConnectivityManager TYPE MOBILE      don  t forget the permissions        lt uses-permission android name  android permission ACCESS NETWORK STATE    gt      lt uses-permission android name  android permission INTERNET    gt

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It s works for me  Try it out   public void onCreate Bundle savedInstanceState        super onCreate savedInstanceState       setContentView R layout main       try           URL url   new URL  http   stackoverflow com posts 11642475 edit               URL url   new URL  http   www nofoundwebsite com              executeReq url           Toast makeText getApplicationContext     Webpage is available    Toast LENGTH SHORT  show              catch Exception e            Toast makeText getApplicationContext     oops  webpage is not available    Toast LENGTH SHORT  show             private void executeReq URL urlObject  throws IOException       HttpURLConnection conn   null      conn    HttpURLConnection  urlObject openConnection        conn setReadTimeout 30000    milliseconds     conn setConnectTimeout 3500    milliseconds     conn setRequestMethod  GET        conn setDoInput true           Start connect     conn connect        InputStream response  conn getInputStream        Log d  Response    response toString

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Im using this code instead of the InetAddress        try            URL url   new URL  http     params 0             HttpURLConnection urlc    HttpURLConnection  url openConnection            urlc setRequestProperty  User-Agent    Android Application   Z APP VERSION           urlc setRequestProperty  Connection    close            urlc setConnectTimeout 1000   30      mTimeout is in seconds         urlc connect            if  urlc getResponseCode      200                Main Log  getResponseCode    200                return new Boolean true                   catch  MalformedURLException e1               TODO Auto-generated catch block         e1 printStackTrace          catch  IOException e               TODO Auto-generated catch block         e printStackTrace

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Android provides ConnectivityManager class to know about the internet connection status  The following method will be very useful to know internet connection state   First add the INTERNET and ACCESS NETWORK STATE permission to AndroidManifest xml   lt uses-permission android name  android permission INTERNET    gt   lt uses-permission android name  android permission ACCESS NETWORK STATE    gt    Then use the below method to check if the device is connected to internet or not  This method will return true if the device is connected to internet   public boolean isInternetAvailable Context context        ConnectivityManager connectivityManager    ConnectivityManager       context getSystemService Context CONNECTIVITY SERVICE       NetworkInfo activeNetwork   connectivityManager getActiveNetworkInfo        return activeNetwork    null              amp  amp  activeNetwork isConnectedOrConnecting        Reference Link  - http   www androidtutorialshub com android-check-internet-connection-status

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This method gives you the option for a really fast method  for real time feedback  or a slower method  for one off checks that require reliability   public boolean isNetworkAvailable bool SlowButMoreReliable        bool Result   false       try           if SlowButMoreReliable               ConnectivityManager MyConnectivityManager   null              MyConnectivityManager    ConnectivityManager  getSystemService Context CONNECTIVITY SERVICE                NetworkInfo MyNetworkInfo   null              MyNetworkInfo   MyConnectivityManager getActiveNetworkInfo                 Result   MyNetworkInfo    null  amp  amp  MyNetworkInfo isConnected               else                       Runtime runtime   Runtime getRuntime                Process ipProcess   runtime exec   system bin ping -c 1 8 8 8 8                 int i   ipProcess waitFor                 Result   i   0                    catch Exception ex                  Common Exception ex     This method is one you should have that displays exceptions in your log           return Result

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Of everything I have seen so far shortest and cleanest way should be   public final static boolean isConnected  Context context           final ConnectivityManager connectivityManager              ConnectivityManager  context getSystemService  Context CONNECTIVITY SERVICE         final NetworkInfo networkInfo   connectivityManager getActiveNetworkInfo           return networkInfo    null  amp  amp  networkInfo isConnected        PS  This does not ping any host  it just checks the connectionstatus  so if your router has no internet connection and your device is connected to it this method would return true although you have no internet  For an actual test I would recommend execuding a HttpHead request  e g  to www google com  and check the status  if its 200 OK everything is fine and your device has an internet connection

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Just create the following class which checks for an internet connection   public class ConnectionStatus        private Context  context       public ConnectionStatus Context context            this  context   context             public boolean isConnectionAvailable             ConnectivityManager connectivity    ConnectivityManager   context                  getSystemService Context CONNECTIVITY SERVICE           if  connectivity    null                NetworkInfo   info   connectivity getAllNetworkInfo                if  info    null                  for  int i   0  i  lt  info length  i                        if  info i  getState      NetworkInfo State CONNECTED                            return true                                          return false            This class simply contains a method which returns the boolean value of the connection status  Therefore in simple terms  if the method finds a valid connection to the Internet  the return value is true  otherwise false if no valid connection is found   The following method in the MainActivity then calls the result from the method previously described  and prompts the user to act accordingly   public void addListenerOnWifiButton             Button btnWifi    Button findViewById R id btnWifi            iia   new ConnectionStatus getApplicationContext              isConnected   iia isConnectionAvailable            if   isConnected                btnWifi setOnClickListener new View OnClickListener                       Override                 public void onClick View v                        startActivity new Intent Settings ACTION WIFI SETTINGS                        Toast makeText getBaseContext     Please connect to a hotspot                               Toast LENGTH SHORT  show                                                        else               btnWifi setVisibility 4               warning setText  This app may use your mobile data to update events and get their details                       In the above code  if the result is false   therefore there is no internet connection  the user is taken to the Android wi-fi panel  where he is prompted to connect to a wi-fi hotspot

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It is not complex to check Android network   internet connectivity status  The below DetectConnection class will help you to check this status   import android content Context  import android net ConnectivityManager   public class DetectConnection       public static boolean checkInternetConnection Context context            ConnectivityManager con manager    ConnectivityManager  context                                  getSystemService Context CONNECTIVITY SERVICE            if  con manager getActiveNetworkInfo      null              amp  amp  con manager getActiveNetworkInfo   isAvailable                amp  amp  con manager getActiveNetworkInfo   isConnected                      return true            else               return false                      For more details visit  How to Check Android Network   Internet Connectivity Status

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I have applied the solution provided by  Levit and created function that will not call the extra Http Request   It will solve the error Unable to Resolve Host  public static boolean isInternetAvailable Context context        ConnectivityManager cm    ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE       NetworkInfo activeNetwork   cm getActiveNetworkInfo        if  activeNetwork    null  return false       switch  activeNetwork getType              case ConnectivityManager TYPE WIFI              if   activeNetwork getState      NetworkInfo State CONNECTED                        activeNetwork getState      NetworkInfo State CONNECTING   amp  amp                      isInternet                    return true              break          case ConnectivityManager TYPE MOBILE              if   activeNetwork getState      NetworkInfo State CONNECTED                        activeNetwork getState      NetworkInfo State CONNECTING   amp  amp                      isInternet                    return true              break          default              return false            return false     private static boolean isInternet          Runtime runtime   Runtime getRuntime        try           Process ipProcess   runtime exec   system bin ping -c 1 8 8 8 8            int exitValue   ipProcess waitFor            Debug i exitValue                return  exitValue    0         catch  IOException   InterruptedException e            e printStackTrace               return false      Now call it like   if   isInternetAvailable getActivity              Show message   else          Perfoem the api request

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public class Network    Context context   public Network Context context       this context   context     public boolean isOnline         ConnectivityManager cm                ConnectivityManager context getSystemService Context CONNECTIVITY SERVICE        NetworkInfo activeNetwork   cm getActiveNetworkInfo        return activeNetwork    null  amp  amp                            activeNetwork isConnectedOrConnecting

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Kotlin and coroutines  I have placed the function in a ViewModel  which has the viewModelScope  Using an observable LiveData I inform an activity about the connection  ViewModel  fun checkInternetConnection timeoutMs  Int            viewModelScope launch Dispatchers IO                try                   val socket   Socket                   val socketAddress   InetSocketAddress  quot 8 8 8 8 quot   53                   socket connect socketAddress  timeoutMs                  socket close                     connection postValue true                            catch ex  IOException                     connection postValue false                                  private val  connection   MutableLiveData lt Boolean gt     val connection  LiveData lt Boolean gt     connection  Activity  private fun checkInternetConnection          viewModel connection observe this    hasInternet - gt           if  hasInternet                   hasn t connection                     else                 has connection

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It does works for me   To verify network availability   private Boolean isNetworkAvailable     ConnectivityManager connectivityManager           ConnectivityManager  getSystemService Context CONNECTIVITY SERVICE   NetworkInfo activeNetworkInfo   connectivityManager getActiveNetworkInfo    return activeNetworkInfo    null  amp  amp  activeNetworkInfo isConnectedOrConnecting       To verify internet access   public Boolean isOnline         try           Process p1   java lang Runtime getRuntime   exec  ping -c 1 www google com            int returnVal   p1 waitFor            boolean reachable    returnVal  0           return reachable        catch  Exception e               TODO Auto-generated catch block         e printStackTrace              return false

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if isConnected                     Toast makeText getApplication    Thank you  Toast LENGTH SHORT  show                      else               AlertDialog Builder builder                       new AlertDialog Builder this  R style AppCompatAlertDialogStyle               builder setTitle  Amar Bhat                builder setMessage  Oops   You are not connected to Internet                   builder setPositiveButton  OK   null               builder setNegativeButton  Cancel   null               builder show                  Toast makeText getApplication    You are not connected  Toast LENGTH SHORT  show                    And outside the class define isConnected     public boolean isConnected            ConnectivityManager connMgr    ConnectivityManager  getSystemService Activity CONNECTIVITY SERVICE           NetworkInfo networkInfo   connMgr getActiveNetworkInfo            if  networkInfo    null  amp  amp  networkInfo isConnected                return true          else             return false            In minifest add these permission  lt uses-permission android name  android permission INTERNET    gt        lt uses-permission android name  android permission ACCESS NETWORK STATE    gt

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I have gone through all the answers and i come up with my own answer which first check whether Internet is available and if Internet is available then it check whether it is active or not   I have included all necessary method and classes to check for active Internet connection   NetworkUtils class  public class NetworkUtils        public static final int STATUS CONNECTED   0        public static boolean isInternetAvailable Context ctx           ConnectivityManager cm    ConnectivityManager ctx getSystemService Context CONNECTIVITY SERVICE           NetworkInfo activeNetwork   cm getActiveNetworkInfo            return activeNetwork    null  amp  amp  activeNetwork isConnectedOrConnecting               public static int isInternetActiveWithPing             try               Runtime runtime   Runtime getRuntime                Process process   runtime exec   system bin ping -c 1 8 8 8 8                int exitValue   process waitFor                return exitValue            catch  Exception ex                return -1                       public static boolean isInternetActiveWithInetAddress             try               InetAddress inetAddress   InetAddress getByName  www google com                return inetAddress    null  amp  amp   inetAddress toString   equals                catch  Exception ex                return false                       public static void displayInternetConnectionMessage Context ctx           Toast makeText ctx   Check Internet Connection   Toast LENGTH SHORT  show              You can check whether Internet is active using below code    private void checkInternetConnection             if  NetworkUtils isInternetAvailable this                 new Thread new Runnable                      Override                 public void run                         if  NetworkUtils isInternetActiveWithPing      NetworkUtils STATUS CONNECTED                            performNetworkingOperations                          else                           if  NetworkUtils isInternetActiveWithInetAddress                                  performNetworkingOperations                              else                               displayConnectionMessage                                                                                     start               else               displayConnectionMessage                         private void performNetworkingOperations             runOnUiThread new Runnable                  Override             public void run                     Toast makeText MainActivity this   Internet is Available   Toast LENGTH SHORT  show                                         private void displayConnectionMessage             runOnUiThread new Runnable                  Override             public void run                     NetworkUtils displayInternetConnectionMessage MainActivity this

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One important use case on mobile devices to it ensure an actual connection exists  This is a common problem when a mobile user enters a Wifi network with a  Captive Portal   in which they need to sign in  I use this blocking function in the background to ensure a connection exists         Not Thread safe  Blocking thread  Returns true if it    can connect to URL  false and exception is logged      public boolean checkConnectionHttps String url       boolean responded   false      HttpGet requestTest   new HttpGet url       HttpParams params   new BasicHttpParams        HttpConnectionParams setConnectionTimeout params  3000       HttpConnectionParams setSoTimeout params  5000       DefaultHttpClient client   new DefaultHttpClient params       try           client execute requestTest           responded   true        catch  ClientProtocolException e            Log w MainActivity TAG  Unable to connect to     url         e toString           catch  IOException e            Log w MainActivity TAG  Unable to connect to     url         e toString             e printStackTrace              return responded

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Found at and modified     from this link    In your manifest file add at least    lt uses-permission android name  android permission ACCESS NETWORK STATE    gt    You probably already have the INTERNET permission if you are accessing it  Then a boolean function that allows to test for connectivity is   private boolean checkInternetConnection         ConnectivityManager cm    ConnectivityManager  getSystemService Context CONNECTIVITY SERVICE          test for connection     if  cm getActiveNetworkInfo      null              amp  amp  cm getActiveNetworkInfo   isAvailable                amp  amp  cm getActiveNetworkInfo   isConnected              return true        else           Log v TAG   Internet Connection Not Present            return false

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public boolean isNetworkAvailable Context context        ConnectivityManager connectivityManager                ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE       NetworkInfo activeNetworkInfo   connectivityManager getActiveNetworkInfo        return activeNetworkInfo    null  amp  amp  activeNetworkInfo isConnected        Here is the permission that you need     lt uses-permission android name  android permission ACCESS NETWORK STATE   gt

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If you are using API 23 or above  you can now check whether or not internet is active using NetworkCapabilities NET CAPABILITY VALIDATED  which is backed by Google s own ping service   ConnectivityManager NetworkCallback networkCallback   new ConnectivityManager NetworkCallback          Override     public void onLost Network network               handle network lost             Override     public void onAvailable Network network            ConnectivityManager cm    ConnectivityManager  getApplicationContext   getSystemService Context CONNECTIVITY SERVICE           NetworkInfo info   cm getNetworkInfo network           boolean isConnected    info    null  amp  amp  info isConnectedOrConnecting              if  isConnected                NetworkCapabilities nc   cm getNetworkCapabilities network               if  nc    null                    boolean isInternetValid   nc hasCapability NetworkCapabilities NET CAPABILITY VALIDATED                   if  isInternetValid                           internet is valid                                                     NetworkRequest request   new NetworkRequest Builder   addCapability NetworkCapabilities NET CAPABILITY INTERNET  build    ConnectivityManager connectivityManager    ConnectivityManager  getApplicationContext   getSystemService Context CONNECTIVITY SERVICE   connectivityManager registerNetworkCallback request  networkCallback

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This code will help you find the internet is on or not   public final boolean isInternetOn             ConnectivityManager conMgr    ConnectivityManager  this con                  getSystemService Context CONNECTIVITY SERVICE           NetworkInfo info   conMgr getActiveNetworkInfo            return  info    null  amp  amp  info isConnected         Also  you should provide the following permissions   lt uses-permission android name  android permission INTERNET    gt   lt uses-permission android name  android permission ACCESS NETWORK STATE    gt

User · Answer

Its so great to have more then one way to code  Here is my example   ConnectivityManager icheck   getSystemService Context CONNECTIVITY SERVICE    TextView tv   findViewById R id textView1    boolean wifi   icheck getActiveNetworkInfo      null          if wifi            tv setText  Internet is on                 else                tv setText  Internet is off                     Good luck

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This my workaround to solve this problem and check the valid internet connection because as they said that Network info class cannot give you the expected result and it may return true when network connected but no internet  So this my COMPLETE WORKAROUND based on  Levite Answer  First you must have AsynckTask for checking Network availability and this is mine  public class Connectivity    private static final String TAG    quot Connectivity quot   private static boolean hasConnected   false  hasChecked   false  private InternetListener internetListener  private Activity activity   public Connectivity InternetListener internetListener  Activity activity        this internetListener   internetListener      this activity   activity     public void startInternetListener           CheckURL checkURL   new CheckURL activity        checkURL execute         long startTime   System currentTimeMillis         while  true            if  hasChecked  amp  amp  hasConnected                activity runOnUiThread new Runnable                      Override                 public void run                         internetListener onConnected                                                   checkURL cancel true               return                        check if time         if  System currentTimeMillis   - startTime  gt   1000                activity runOnUiThread new Runnable                      Override                 public void run                         internetListener onDisconnected                                                    checkURL cancel true               return                         return hasConnected      class CheckURL extends AsyncTask lt Void  Void  Boolean gt         private Activity activity       public CheckURL Activity activity            this activity   activity              Override     protected Boolean doInBackground Void    params            if   isNetWorkAvailable activity                 Log i TAG   quot Internet not available  quot                return false                     int timeoutMs   3000           try               Socket sock   new Socket                SocketAddress sockaddr   new InetSocketAddress  quot 8 8 8 8 quot   53               sock connect sockaddr  timeoutMs               sock close                Log i TAG   quot Internet available    quot                return true             catch  IOException e                e printStackTrace                return false                         Override     protected void onPostExecute Boolean result            hasChecked   true          hasConnected   result          super onPostExecute result            private static final String TAG    quot Connectivity quot     private static boolean isNetWorkAvailable Activity activity         ConnectivityManager connectivityManager                ConnectivityManager      activity getSystemService Activity CONNECTIVITY SERVICE       NetworkInfo networkInfo               null      if  connectivityManager    null            networkInfo       connectivityManager getNetworkInfo ConnectivityManager TYPE WIFI             boolean isConnected      boolean isWifiAvailable   false      if  networkInfo    null            isWifiAvailable   networkInfo isAvailable              boolean isWifiConnected   false      if  networkInfo    null            isWifiConnected   networkInfo isConnected              if  connectivityManager    null            networkInfo                   connectivityManager getNetworkInfo ConnectivityManager TYPE MOBILE             boolean isMobileAvailable   false      if  networkInfo    null            isMobileAvailable   networkInfo isAvailable              boolean isMobileConnected   false      if  networkInfo    null            isMobileConnected   networkInfo isConnected              isConnected    isMobileAvailable  amp  amp  isMobileConnected                  isWifiAvailable  amp  amp  isWifiConnected       return  isConnected              private static boolean isNetWorkAvailable Context context         ConnectivityManager connectivityManager                ConnectivityManager  context getSystemService Context CONNECTIVITY SERVICE       NetworkInfo networkInfo               null      if  connectivityManager    null            networkInfo   connectivityManager getNetworkInfo ConnectivityManager TYPE WIFI             boolean isConnected      boolean isWifiAvailable   false      if  networkInfo    null            isWifiAvailable   networkInfo isAvailable              boolean isWifiConnected   false      if  networkInfo    null            isWifiConnected   networkInfo isConnected              if  connectivityManager    null            networkInfo                   connectivityManager getNetworkInfo ConnectivityManager TYPE MOBILE             boolean isMobileAvailable   false      if  networkInfo    null            isMobileAvailable   networkInfo isAvailable              boolean isMobileConnected   false      if  networkInfo    null            isMobileConnected   networkInfo isConnected              isConnected    isMobileAvailable  amp  amp  isMobileConnected                  isWifiAvailable  amp  amp  isWifiConnected       return  isConnected         After that you should create another thread to start AscnkTask And listen for result with the InternetListener  public interface InternetListener   void onConnected    void onDisconnected       And the Thread that is waiting for AsynckTask result you can put it in Utility class   private static Thread thread   public static void startNetworkListener Context context  InternetListener      internetListener         if  thread    null           thread   new Thread new Runnable                  Override             public void run                     Looper prepare                    new Connectivity internetListener context  startInternetListener                                         thread start        Finally call the startNetworkListener   method and listen for result  example in activity from My Utils java class        Utils startNetworkListener this  new InternetListener              Override         public void onConnected                   do your work when internet available                       Override         public void onDisconnected                  do your work when no internet available                      Happy Coding

User · Answer

Best approach   public static boolean isOnline         try       InetAddress getByName  google com   isReachable 3        return true        catch  UnknownHostException e       return false        catch  IOException e       return false

User · Answer

Network connection   Internet access  isConnectedOrConnecting    used in most answers  checks for any network connection To know whether any of those networks have internet access  use one of the following  A  Ping a Server  easy     ICMP  public boolean isOnline         Runtime runtime   Runtime getRuntime        try           Process ipProcess   runtime exec  quot  system bin ping -c 1 8 8 8 8 quot            int     exitValue   ipProcess waitFor            return  exitValue    0             catch  IOException e             e printStackTrace          catch  InterruptedException e    e printStackTrace           return false       could run on main thread - does not work on some old devices  Galays S3  etc    it blocks a while if no internet is available  B  Connect to a Socket on the Internet  advanced     TCP HTTP DNS  depending on the port  53 DNS  80 HTTP  etc   public boolean isOnline         try           int timeoutMs   1500          Socket sock   new Socket            SocketAddress sockaddr   new InetSocketAddress  quot 8 8 8 8 quot   53            sock connect sockaddr  timeoutMs           sock close             return true        catch  IOException e    return false         very fast  either way   works on all devices  very reliable - can t run on the UI thread This works very reliably  on every device  and is very fast  It needs to run in a separate task though  e g  ScheduledExecutorService or AsyncTask   Possible Questions  Is it really fast enough  Yes  very fast  -   Is there no reliable way to check internet  other than testing something on the internet  Not as far as I know  but let me know  and I will edit my answer   What if the DNS is down  Google DNS  e g  8 8 8 8  is the largest public DNS in the world  As of 2018 it handled over a trillion queries a day  1   Let  s just say  your app would probably not be the talk of the day   Which permissions are required   lt uses-permission android name  quot android permission INTERNET quot    gt   Just internet access - surprise     Btw have you ever thought about  how some of the methods suggested here could even have a remote glue about internet access  without this permission        Extra  One-shot RxJava RxAndroid Example  Kotlin  fun hasInternetConnection    Single lt Boolean gt      return Single fromCallable       try            Connect to Google DNS to check for connection       val timeoutMs   1500       val socket   Socket         val socketAddress   InetSocketAddress  quot 8 8 8 8 quot   53             socket connect socketAddress  timeoutMs        socket close            true       catch  e  IOException          false              subscribeOn Schedulers io       observeOn AndroidSchedulers mainThread                                                                                              Usage      hasInternetConnection   subscribe   hasInternet - gt     do something      Extra  One-shot RxJava RxAndroid Example  Java  public static Single lt Boolean gt  hasInternetConnection         return Single fromCallable    - gt            try                  Connect to Google DNS to check for connection             int timeoutMs   1500              Socket socket   new Socket                InetSocketAddress socketAddress   new InetSocketAddress  quot 8 8 8 8 quot   53                socket connect socketAddress  timeoutMs               socket close                 return true            catch  IOException e                return false                   subscribeOn Schedulers io    observeOn AndroidSchedulers mainThread                                                                                               Usage      hasInternetConnection   subscribe  hasInternet  - gt            if hasInternet              else                       Extra  One-shot AsyncTask Example Caution  This shows another example of how to do the request  However  since AsyncTask is deprecated  it should be replaced by your App s thread scheduling   Kotlin Coroutines  Rx      class InternetCheck extends AsyncTask lt Void Void Boolean gt         private Consumer mConsumer      public  interface Consumer   void accept Boolean internet          public  InternetCheck Consumer consumer    mConsumer   consumer  execute            Override protected Boolean doInBackground Void    voids    try           Socket sock   new Socket            sock connect new InetSocketAddress  quot 8 8 8 8 quot   53   1500           sock close            return true        catch  IOException e    return false            Override protected void onPostExecute Boolean internet    mConsumer accept internet                                                                                               Usage      new InternetCheck internet - gt       do something with boolean response

User · Answer

I have tried with almost 5  different android approaches and found this is the best solution provided by google especially for android     try     HttpURLConnection urlConnection    HttpURLConnection     new URL  http   clients3 google com generate 204      openConnection       urlConnection setRequestProperty  User-Agent    Android      urlConnection setRequestProperty  Connection    close      urlConnection setConnectTimeout 1500     urlConnection connect      if  urlConnection getResponseCode      204  amp  amp    urlConnection getContentLength      0      Log d  Network Checker    Successfully connected to internet      return true          catch  IOException e      Log e  Network Checker    Error checking internet connection   e         It s faster   efficient and accurate than any other available solution

User · Answer

I made this code  it is the simplest and it is just a boolean  by asking if isOnline      You get if there is a connection and if it can connect to a page the status code 200  stable connection        Make sure to add the correct INTERNET and ACCESS NETWORK STATE permissions   public boolean isOnline         ConnectivityManager cm    ConnectivityManager  getSystemService Context CONNECTIVITY SERVICE       NetworkInfo netInfo   cm getActiveNetworkInfo        if  netInfo    null  amp  amp  netInfo isConnected              try               URL url   new URL  http   www google com                HttpURLConnection urlc    HttpURLConnection  url openConnection                urlc setConnectTimeout 3000               urlc connect                if  urlc getResponseCode      200                    return new Boolean true                           catch  MalformedURLException e1                   TODO Auto-generated catch block             e1 printStackTrace              catch  IOException e                   TODO Auto-generated catch block             e printStackTrace                        return false

[android] How to check internet access on Android? InetAddress never times out

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