Check Network Connection Using BroadcastReceiver

BroadCastSampleActivity.java

public class BroadCastSampleActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        this.registerReceiver(this.mConnReceiver,
                new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
    }
    private BroadcastReceiver mConnReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            boolean noConnectivity = intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);
            String reason = intent.getStringExtra(ConnectivityManager.EXTRA_REASON);
            boolean isFailover = intent.getBooleanExtra(ConnectivityManager.EXTRA_IS_FAILOVER, false);

            NetworkInfo currentNetworkInfo = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);
            NetworkInfo otherNetworkInfo = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager.EXTRA_OTHER_NETWORK_INFO);

            if(currentNetworkInfo.isConnected()){
                Toast.makeText(getApplicationContext(), "Connected", Toast.LENGTH_LONG).show();
            }else{
                Toast.makeText(getApplicationContext(), "Not Connected", Toast.LENGTH_LONG).show();
            }
        }
    };
}

Add uses-permission in  AndroidManifest

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

Android - How to Get activity from context

Sometimes we pass context of an activity as a parameter to some other function and later we might want the activity too. So instead of passing the activity also to that function, we can get the activity from context itself.

You can get the activity from the context by type casting the context to activity.

Activity activity = (Activity) _context;