How to turn on/off wifi hotspot programmatically in Android 8.0 (Oreo)

Finally I got the solution. Android 8.0, they provided public api to turn on/off hotspot. WifiManager

Below is the code to turn on hotspot

private WifiManager.LocalOnlyHotspotReservation mReservation;

@RequiresApi(api = Build.VERSION_CODES.O)
private void turnOnHotspot() {
    WifiManager manager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);

    manager.startLocalOnlyHotspot(new WifiManager.LocalOnlyHotspotCallback() {

        @Override
        public void onStarted(WifiManager.LocalOnlyHotspotReservation reservation) {
            super.onStarted(reservation);
            Log.d(TAG, "Wifi Hotspot is on now");
            mReservation = reservation;
        }

        @Override
        public void onStopped() {
            super.onStopped();
            Log.d(TAG, "onStopped: ");
        }

        @Override
        public void onFailed(int reason) {
            super.onFailed(reason);
            Log.d(TAG, "onFailed: ");
        }
    }, new Handler());
}

private void turnOffHotspot() {
    if (mReservation != null) {
        mReservation.close();
    }
}

onStarted(WifiManager.LocalOnlyHotspotReservation reservation) method will be called if hotspot is turned on.. Using WifiManager.LocalOnlyHotspotReservation reference you call close() method to turn off hotspot.

Note: To turn on hotspot, the Location(GPS) should be enabled in the device. Otherwise, it will throw SecurityException

I thought the LocalOnlyHotspot route was the way to, but as @edsappfactory.com said in the comments - it only gives closed network, no internet access.

In Oreo hot-spotting/tethering moved to ConnectionManager, and its annotated @SystemApi, so (nominally) inaccessible.

As part of something else I was doing, I made an app and put it on github here. It uses reflection to get at the function and DexMaker to generate a subclass of ConnectionManager.OnStartTetheringCallback (which is also inaccessible).

Think it all works okay - bit rough around the edges, so please feel free to make better!

Relevant bits of code are in:

• MyOreoWifiManager and;
• CallbackMaker

I lost patience trying to get my DexMaker-generated callback to fire the MyOnStartTetheringCallback so all that code is in disarray and commented out.