Android - force network requests go through wifi instead of mobile network

Question

I have an app which connects to a hardware device Wi-Fi hotspot. It seems that Android forward requests over other networks (3G/4G for example) instead the hotspot, since my

Answer 1

Use the ConnectivityManager to get the state of the Wifi adapter and then you can check if it is connected or even available using NetworkInfo.

ConnectivityManager connManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo wifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

if (wifi.isConnected()) {
    // Continue with logic
}

In case he is not connected to wifi then don't proceed else continue you flow.

Add the following permission in you Manifest file

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

Answer 2

Per the Connecting your App to a Wi-Fi Device blog post:

To direct all the network requests from your app to an external Wi-Fi device, call ConnectivityManager#setProcessDefaultNetwork on Lollipop devices, and on Marshmallow call ConnectivityManager#bindProcessToNetwork instead, which is a direct API replacement.