How does Android check Internet connection?

Question

I'm interested in how Android checks internet connectivity. For example in our company's wifi the wlan-symbol turns grey, even if there is working connection for http/https/dns etc. At Home (No restrictions on Firewall) it turns blue.

Which checks are done in background? Does anybody know it in detail?

First Search!Check here : http://stackoverflow.com/questions/1783117/network-listener-android — Arash GM, Feb 18 '13 at 12:42
Guys my question was no code matter. It was a technical question, which is done by android to determine an connection as up or down — redflag237, Feb 18 '13 at 12:50
that question is probably more suitable to http://android.stackexchange.com/ then here. SO is for programming questions. Anyway, to be absolutely sure you can check the source code, it's there. But if I had to guess I would say that they ping some google server to test connection. — Budius, Feb 18 '13 at 13:30

score 0 · Answer 1 · answered Feb 18 '13 at 12:42

public final boolean isInternetOn() {

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

    if ( connec.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTED ||
            connec.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTING ||
            connec.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTING ||
            connec.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTED ) 
    {
        return true;
    } else if ( connec.getNetworkInfo(0).getState() == NetworkInfo.State.DISCONNECTED ||  
            connec.getNetworkInfo(1).getState() == NetworkInfo.State.DISCONNECTED  ) 
    {

        return false;
    }
    return false;
}//end of the Internet Connection Checking

This is what i found on related posts, too. But what is Android doing exactly? DNS resolve or any HTTP request? — redflag237, Feb 18 '13 at 12:45

score 0 · Answer 2 · answered Feb 18 '13 at 12:42

0

private boolean isNetworkConnected() {
   ConnectivityManager cm = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
     NetworkInfo ni = cm.getActiveNetworkInfo();
  if (ni == null) {
  // There are no active networks.

return false; } else return true; }

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

answered Feb 18 '13 at 12:42

Rohit

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This is what i found on related posts, too. But what is Android doing exactly? DNS resolve or any HTTP request? – redflag237 Feb 18 '13 at 12:44
what is android doing to determine if the connection is up or down? In this case, not by code. – redflag237 Feb 18 '13 at 12:46
try this NetworkInfo i = conMgr.getActiveNetworkInfo(); if (i == null) return false; if (!i.isConnected()) return false; if (!i.isAvailable()) return false; return true; – Rohit Feb 18 '13 at 12:51

score 0 · Answer 3 · answered Jul 06 '19 at 13:42

you can use this function to check network in your app:

  public boolean isConnectToInternet() {
        ConnectivityManager connectivity = (ConnectivityManager) 
        getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);
        if (connectivity != null) {
          NetworkInfo[] info = connectivity.getAllNetworkInfo();
          if (info != null)
            for (int i = 0; i < info.length; i++)
              if (info[i].getState() == NetworkInfo.State.CONNECTED) {
                return true;
              }
        }
        return false;
      }

and you must add this permission at manifest.xml:

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

How does Android check Internet connection?

3 Answers3