Check real internet connection

Question

In my application I need to check whether device is connected to Internet. I tried using ConnectivityManager but it doesn't give a 100% precise result. For instance, I might have a wi-fi connection but still don't have access to internet resources. In my case I've got to open a VPN connection, after I've connected to via wi-fi, in order to get real access to Internet. So the approach with ConnectivityManager doesn't work.

So, regarding the above - should I write a manual http request in order to ensure or there's another way ?

Here's some code I'm using

ConnectivityManager cm =  (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        return cm.getActiveNetworkInfo() != null && cm.getActiveNetworkInfo().isConnected() && cm.getActiveNetworkInfo().isAvailable();

Best way to catch exception if the internet connection is failed. — Gorets, Jun 19 '12 at 08:21

score 3 · Answer 1 · answered Jun 19 '12 at 08:18

Yes, you are correct, to check that you can reach the internet you need to test that explicitly. If you need HTTP access you can try connecting to the host you later on want to connect to.

You should however use the connection method that you intend to use later on. HTTP can work but not FTP. So if you need FTP access you should test it.

If you also want to get the external IP you can use this method:

public static InetAddress getExternalIp() throws IOException {
    URL url = new URL("http://automation.whatismyip.com/n09230945.asp");
    URLConnection connection = url.openConnection();
    connection.addRequestProperty("Protocol", "Http/1.1");
    connection.addRequestProperty("Connection", "keep-alive");
    connection.addRequestProperty("Keep-Alive", "1000");
    connection.addRequestProperty("User-Agent", "Web-Agent");

    Scanner s = new Scanner(connection.getInputStream());
    try {
        return InetAddress.getByName(s.nextLine());
    } finally {
        s.close();
    }
}

If you successfully got an IP address back from this method, you can connect via HTTP to that.

I agree with dacwe. From my experience, checking if you can reach the internet is really the only way that works reliably. — Dude, Jun 19 '12 at 08:22

user370305 · Accepted Answer · 2023-03-29T05:24:24.200

Instead of checking every time for internet connection, I think setting ConnectionTimeout to HTTPRequest its the best way.

try
  {

   HttpGet request = new HttpGet(url));
   HttpParams httpParameters = new BasicHttpParams();
   // Set the timeout in milliseconds until a connection is established.
   // The default value is zero, that means the timeout is not used. 
   int timeoutConnection = 60000;
   HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
   // Set the default socket timeout (SO_TIMEOUT) 
   // in milliseconds which is the timeout for waiting for data.
   int timeoutSocket = 60000;
   HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
   // create object of DefaultHttpClient    
   DefaultHttpClient httpClient = new DefaultHttpClient(httpParameters);
   request.addHeader("Content-Type", "application/json");
   HttpResponse response = httpClient.execute(request);
   // get response entity
   HttpEntity entity = response.getEntity();
   // convert entity response to string

     if (entity != null)
      {
         result = EntityUtils.toString(entity);
      }

   }
 catch (SocketException e)
  {
     return "-222" + e.toString();
  }
 catch (Exception e)
  {
     return "-333" + e.toString();
  }

I like that approach but can't get it working. When I set both timeouts to 5000 application hangs for quite a long. Are you sure it's working ? — user1462299, Jun 19 '12 at 09:52
Yes, In my all application when I have a webservice request using Http I have the same code, for ConnectionTimeOut... Also its standard way to make HttpRequest. — user370305, Jun 19 '12 at 09:56

score 0 · Answer 3 · answered Jun 19 '12 at 08:24

Try this,

     private boolean checkInternetConnection() {
     try {

            ConnectivityManager nInfo = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
            nInfo.getActiveNetworkInfo().isConnectedOrConnecting(); 

            ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo netInfo = cm.getActiveNetworkInfo();
            if (netInfo != null && netInfo.isConnectedOrConnecting()) { 
                return true;
            } else { 
                return false; }

        } catch (Exception e) {
            return false;
        }
    }

It working perfectly for me...

Hope it helps

this method only allows you to check whether you are connected or connecting to a network.. but that does not mean that you are connected to Internet — ColdFire, Jul 11 '12 at 14:01

score 0 · Answer 4 · answered Jun 19 '12 at 08:25

Try with this,

NetworkInfo ActiveNetwork;
String Isconnected="";
ConnectivityManager connectivitymanager;
connectivitymanager=(ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
Connection con=new Connection();
try
{           
    ActiveNetwork=connectivitymanager.getActiveNetworkInfo();
    Isconnected="true";                 
}
catch(Exception error)
{
    IsConnected="false";
}

score 0 · Answer 5 · edited Sep 22 '12 at 02:48

try this

private void MyCheckinternet() {
        // TODO Auto-generated method stub
        ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
            if(connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED || 
                    connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED) {
                //we are connected to a network
                connected = true;
            }
            else
            {
                connected = false;
    }
}

Check real internet connection

5 Answers5

Linked