Checking internet connection on android

kaibuki picture kaibuki · Nov 3, 2010 · Viewed 73.6k times · Source

I have the following code for checking internet connection wifi/EDGE/GPRS/3G on my application.

the code is

public static boolean checkConn(Context ctx) {
    ConnectivityManager conMgr = (ConnectivityManager) ctx
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    if (conMgr.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTED
        || conMgr.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTING) {
        return true;
    } else if (conMgr.getNetworkInfo(0).getState()==NetworkInfo.State.DISCONNECTED
        || conMgr.getNetworkInfo(1).getState() == NetworkInfo.State.DISCONNECTED){
        return false;
    }
    return false;
}

and I am calling it like below :

if (CheckInternet.checkConn(introPage.this) == true) {
    Intent toMainPage = new Intent(introPage.this, mainPage.class);
    System.gc();
    startActivity(toMainPage);
} else if (CheckInternet.checkConn(getApplicationContext()) == false) {
    Toast.makeText(getApplicationContext(),
        "Sorry, No internet connectivity found", Toast.LENGTH_SHORT)
            .show();
}

But I am having an issue, which is that if I am connected to wifi, and I open the application, it works fine, but if I close application and turn off wifi and re-open application, it doesn't through the error of "no connection" , I need to turn off my device and then turn it on, and same case is if wifi is off, and I open application, it throws error of "no connection", and if I turn it on, still it throws the same error of "no connection", until unless I turn off and on device.

Answer

Emmanuel picture Emmanuel · Nov 3, 2010

Sometimes the active connection is not first in the list, or is inactive or in an error state. This is how I would do it:

  NetworkInfo i = conMgr.getActiveNetworkInfo();
  if (i == null)
    return false;
  if (!i.isConnected())
    return false;
  if (!i.isAvailable())
    return false;
  return true;

[EDIT 1] Don't forget to add this permission in the application manifest:

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

Does this help you?

Emmanuel