Add your Wi-Fi Network to Android Things

AddWifiNetwork.java

String networkSSID = "Your Network SSID here";
String networkPasskey = "YourNetworkPasswordHere";

WifiConfiguration wifiConfiguration = new WifiConfiguration();
wifiConfiguration.SSID = "\"" + networkSSID + "\"";
wifiConfiguration.preSharedKey = "\"" + networkPasskey + "\"";

WifiManager manager = (WifiManager) getSystemService(WIFI_SERVICE);
manager.addNetwork(wifiConfiguration);