Test for internet connection in Android

Question

I have seen all the answers here about network connectivity and they are very good. The only issue is the next use-case.

If the phone is connected to a wifi network but the router lost connection to the internet. so I thought about writing this addition to the code given around SO:

/** Google public DNS service IP address **/
public static final String GOOGLE = "http://8.8.8.8"; 

public static boolean isConnected(Context context) {
    ConnectivityManager cm = (ConnectivityManager) context
        .getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo info = cm.getActiveNetworkInfo();
    if (info == null) {
        return false;
    }
    if (info.isConnected()) {
        try {
            InetAddress addr = InetAddress.getByName(GOOGLE);
            return addr.isReachable(10000);
        } catch (UnknownHostException e) {
            Log.wtf("Utils", e);
        } catch (IOException e) {
            Log.wtf("Utils", e);
        }
        return false;
    } else
        return false;
    }
}

The only issue with this is that it runs on the main thread, or to state more correctly, it crashes for running on main-thread.

If I'll run it in a separate thread, it will return before getting a valid answer from the server.

Any thoughts on how to test for internet connection (as apposed to network connection)?

Answer 1

You have to split your logic to Before checking connectivity and after checking connectivity

Then by using Handler and background thread you can test for connectivity like this:

private static void onConnectivityCheckFinish(boolean result){

}
 public static void isConnected(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context
        .getSystemService(Context.CONNECTIVITY_SERVICE);
     NetworkInfo info = cm.getActiveNetworkInfo();
        if (info == null) {

            onConnectivityCheckFinish(false);
        }
 if (info.isConnected()) {
        final Handler handler = new Handler(

        );
        new Thread(){
            @Override
            public void run(){
                     try {
                        InetAddress addr = InetAddress.getByName(GOOGLE);
                        final boolean result = addr.isReachable(10000);
                        handler.post(new Runnable(){
                            @Override
                            public void run(){
                                onConnectivityCheckFinish(result);
                            }
                        });
                     } catch (Exception e) {
                        Log.wtf("Utils", e);
                        handler.post(new Runnable(){

                                @Override
                                public void run(){
                                    onConnectivityCheckFinish(false);
                            }

                        });



            }
        }
        }.start();

onConnectivityCheckFinish(false);}
 else {
     onConnectivityCheckFinish(false);
 }
}