Android Q, programmatically connect to different WiFi AP for internet

Solution 1:

Try calling bindProcessToNetwork() in onAvailable() callback to regain network connectivity, it works fine for me.

Connect to network:

    WifiNetworkSpecifier.Builder builder = new WifiNetworkSpecifier.Builder();
    builder.setSsid("wifi-ap-ssid");
    builder.setWpa2Passphrase("wifi-ap-password");

    WifiNetworkSpecifier wifiNetworkSpecifier = builder.build();

    NetworkRequest.Builder networkRequestBuilder1 = new NetworkRequest.Builder();
    networkRequestBuilder1.addTransportType(NetworkCapabilities.TRANSPORT_WIFI);
    networkRequestBuilder1.setNetworkSpecifier(wifiNetworkSpecifier);

    NetworkRequest nr = networkRequestBuilder1.build();
    ConnectivityManager cm = (ConnectivityManager)
            context.getSystemService(Context.CONNECTIVITY_SERVICE);
    ConnectivityManager.NetworkCallback networkCallback = new 
        ConnectivityManager.NetworkCallback() {
        @Override
        public void onAvailable(Network network) {
            super.onAvailable(network);
            Log.d(TAG, "onAvailable:" + network);
            cm.bindProcessToNetwork(network);
        }
    });
    cm.requestNetwork(nr, networkCallback);

Disconnect from the bound network:

cm.unregisterNetworkCallback(networkCallback);

Solution 2:

WifiNetworkSuggestion API is used to suggest the user about joining an AP(System will post a notification for user to join)

Use WifiNetworkSpecifier to send your requests. Use the network object provided in onAvailable().

WifiNetworkSpecifier.Builder builder = new WifiNetworkSpecifier.Builder();
builder.setSsid("wifi-ap-ssid");
builder.setWpa2Passphrase("wifi-ap-password");

WifiNetworkSpecifier wifiNetworkSpecifier = builder.build();

NetworkRequest.Builder networkRequestBuilder = new NetworkRequest.Builder();
networkRequestBuilder1.addTransportType(NetworkCapabilities.TRANSPORT_WIFI);
networkRequestBuilder1.setNetworkSpecifier(wifiNetworkSpecifier);

NetworkRequest networkRequest = networkRequestBuilder.build();
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
cm.requestNetwork(networkRequest, networkCallback);
networkCallback = new ConnectivityManager.NetworkCallback() {
            @Override
            public void onAvailable(@NonNull Network network) {
                //Use this network object to Send request. 
                //eg - Using OkHttp library to create a service request
                 //Service is an OkHttp interface where we define docs. Please read OkHttp docs
                 Service service = null;

                 OkHttpClient.Builder okHttpBuilder = new OkHttpClient.Builder();
                okHttpBuilder.socketFactory(network.getSocketFactory());

                service = new Retrofit.Builder()                                    .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
                        .addConverterFactory(GsonConverterFactory.create(gson))
                         .client(okHttpBuilder.build())
                         .build()
                         .create(Service.class);


               Observable<Object> observable = null;
               try {
                  if (service != null) {
                     observable = service.yourRestCall();
                  }
                  Subscriber<Object> sub = new Subscriber< Object >() {
                     @Override
                     public void onError(Throwable e) {
                        //Do on error
                     }

                     @Override
                     public void onNext(Object logs) {
                        //Do on next
                     }
                  };
                 if(observable != null) {
                     observable.subscribeOn(Schedulers.io())
                                          .observeOn(AndroidSchedulers.mainThread()).subscribe(sub);
                 }

                super.onAvailable(network);
            }
        };

After you are done using the Wifi access point do

connectivityManager.unregisterNetworkCallback(networkCallback);

From Google's Issue tracker by Google's Engineer:

The network suggestions API flow requires the user to approve the app (platform posts a notification to ask user for approval). Once the app is approved, the platform will consider all networks from the app in future auto-connection attempts. But, this API does not give you guarantees on when the device will connect to your AP for provisioning. So, WifiNetworkSuggestion is not the right API surface for the provided use-case (peer to peer instant connectivity).

Using WifiNetworkSpecifier establishes a local connection to the wifi access point as mentioned above. The default network will still be cellular in this case (we don't disrupt other app's internet connectivity). The app making the request should use the multi-network API's to route their traffic over the established connection. The |Network| object provided in the onAvailable() callback for the request is the handle that app needs to use for opening sockets over that local network (Look at https://developer.android.com/reference/android/net/Network.html#bindSocket(java.net.DatagramSocket) and other such API's available in the |Network| object surface.

Hope this helps.

Solution 3:

As stated here, Android 10 made it intentionally so that the WifiNetworkSpecifier prevents actual internet connectivity. It is meant for peer to peer connections.

The WifiNetworkSuggestion API, however, provides internet connectivity and behaves similarly to the WifiNetworkSpecifier API. As long as the device is not currently connected to any Wifi network, the WifiNetworkSuggestion API will automatically connect to the specified network. The first time a device uses it, a notification will appear asking if the app can suggest networks. The user must accept this notification for the WifiNetworkSuggestion API to work.

I found that Android's provided code in the WifiNetworkSuggestion documentation had a few compile errors. Here is the code that I found to work:

final WifiNetworkSuggestion suggestion1 = new WifiNetworkSuggestion.Builder()
.setSsid("SSID here")
.setWpa2Passphrase("password here")
.setIsAppInteractionRequired(true) // Optional (Needs location permission)
.build();

// Optional extra suggesstion, you can delete this or add more
final WifiNetworkSuggestion suggestion2 = new WifiNetworkSuggestion.Builder()
.setSsid("SSID here 2")
.setWpa2Passphrase("password here 2")
.setIsAppInteractionRequired(true) // Optional (Needs location permission)
.build();

final List<WifiNetworkSuggestion> suggestionsList = new ArrayList<WifiNetworkSuggestion>();
suggestionsList.add(suggestion1);
suggestionsList.add(suggestion2); // Optional extra suggestion
final WifiManager wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
final int status = wifiManager.addNetworkSuggestions(suggestionsList);

if (status != WifiManager.STATUS_NETWORK_SUGGESTIONS_SUCCESS) {
     // Error handling
}

final IntentFilter intentFilter = new IntentFilter(WifiManager.ACTION_WIFI_NETWORK_SUGGESTION_POST_CONNECTION);

final BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
    @Override public void onReceive(Context context, Intent intent) {
        if (!intent.getAction().equals(WifiManager.ACTION_WIFI_NETWORK_SUGGESTION_POST_CONNECTION)) {
              return;
        }
        // Post connection
    }
};
getApplicationContext().registerReceiver(broadcastReceiver, intentFilter);