Androidアプリ開発で端末のネットワーク接続状態の確認方法_ブログ_zanmai.net

コードの抜粋：
接続しているかの確認メソッド：

public static boolean isConnected(Context context){
	ConnectivityManager cm = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
	NetworkInfo ni = cm.getActiveNetworkInfo();
	if( ni != null ){
		return cm.getActiveNetworkInfo().isConnected();
        }
	return false;
}

接続しているネットワークの種類（１）：

public static NetworkStatus getConnectedState( Context context ){
	ConnectivityManager cm = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
	NetworkStatus status = NetworkStatus.OFF;
	NetworkInfo info = cm.getActiveNetworkInfo();

	if ( info != null ){
		if ( info.isConnected() ){
			status = info.getType();
		}
	}
	return status;
}

接続しているネットワークの種類（2）：

public static NetworkStatus getConnectedState( Context context ){
ConnectivityManager cm = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
 NetworkStatus status = NetworkStatus.OFF;
   
 NetworkInfo info = cm.getActiveNetworkInfo();
   
 if ( info != null )
 {
  if ( info.isConnected() )
         {
   switch ( info.getType() )
   {
   case ConnectivityManager.TYPE_WIFI: // Wifi
           status = NetworkStatus.WIFI;
    break;
   case ConnectivityManager.TYPE_MOBILE_DUN: // Mobile 3G
   case ConnectivityManager.TYPE_MOBILE_HIPRI:
   case ConnectivityManager.TYPE_MOBILE_MMS:
   case ConnectivityManager.TYPE_MOBILE_SUPL:
   case ConnectivityManager.TYPE_MOBILE:
    status = NetworkStatus.MOBILE;
    break;
   case ConnectivityManager.TYPE_BLUETOOTH: // Bluetooth
    status = NetworkStatus.BLUETOOTH;
    break;
   case ConnectivityManager.TYPE_ETHERNET:  // Ethernet
    status = NetworkStatus.ETHERNET;
    break;
   }
  }
 }
 return status;
}