Check for tethering, hotspot, access point on android

activity.java

public static boolean isSharingWiFi(final WifiManager manager)
{
    try
    {
        final Method method = manager.getClass().getDeclaredMethod("isWifiApEnabled");
        method.setAccessible(true); //in the case of visibility change in future APIs
        return (Boolean) method.invoke(manager);
    }
    catch (final Throwable ignored)
    {
    }

    return false;
}

manifest.xml

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