How can i check whether an android device is connected to the web?

Question

How would i know whether my device is connected the web or not? How can i detect connectivity? Any sample code?

Possible duplicate of [Android check internet connection](http://stackoverflow.com/questions/9570237/android-check-internet-connection) — Sobhan Moradi, Feb 09 '17 at 12:10

score 54 · Accepted Answer · edited Oct 23 '12 at 08:48

54

First, you need permission to know whether the device is connected to the web or not. This needs to be in your manifest, in the <manifest> element:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

Next, you need to get a reference to the ConnectivityManager:

ConnectivityManager cm = (ConnectivityManager) Context.getSystemService(Context.CONNECTIVITY_SERVICE);

From there you need to obtain a NetworkInfo object. For most, this will mean using ConnectivityManager. getActiveNetworkInfo():

NetworkInfo ni = cm.getActiveNetworkInfo();
if (ni == null) {
    // There are no active networks.
    return false;
}

From there, you just need to use one of NetworkInfo's methods to determine if the device is connected to the internet:

boolean isConnected = ni.isConnected();

edited Oct 23 '12 at 08:48

wojciii

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answered May 07 '10 at 15:44

Dan Lew

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3

I get a null pointer exception at this statement:boolean isConnected = ni.isConnected(); Why? – Muhammad Maqsoodur Rehman May 18 '10 at 10:08
3

@Maxood, it means that there are no active networks. In other words, the device is not connected to the web. I'll change the code. – Tyler Collier Oct 21 '11 at 03:01
It only check the network. Not internet. When I tested connecting with a hotspot which doesn't contain mobile data, it return true and my app crashed. – Zin Win Htet Apr 29 '16 at 08:16

score 6 · Answer 2 · edited Jan 20 '15 at 16:52

First, you need permission to know whether the device is connected to the web or not. This needs to be in your manifest, in the element:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

then

ConnectivityManager connec = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);

if (connec != null && (
    (connec.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED) || 
    (connec.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED))) { 

        //You are connected, do something online.

} else if (connec != null && (
    (connec.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.DISCONNECTED) ||
    (connec.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.DISCONNECTED ))) {            

        //Not connected.    
        Toast.makeText(getApplicationContext(), "You must be connected to the internet", Toast.LENGTH_LONG).show();

}

score 4 · Answer 3 · answered Apr 24 '15 at 02:56

Add this permission in your AppManifest.xml file:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

The method to check if network is available or not:

boolean isNetworkAvailable() {
  ConnectivityManager cm = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);

  NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
  boolean isConnected = activeNetwork != null && activeNetwork.isConnectedOrConnecting();
  return isConnected;
}

Source

score 0 · Answer 4 · answered May 07 '10 at 15:17

0

http://developer.android.com/reference/android/net/ConnectivityManager.html - CONNECTIVITY_ACTION

answered May 07 '10 at 15:17

Alex Volovoy

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How can i check whether an android device is connected to the web?

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