A few things have change to connect to a WiFi network in android Marshmallow.
The following code will help you...If you are using Android 6.0 or lowlevel versions...
public void connectToWifi(){
try{
WifiManager wifiManager = (WifiManager) super.getSystemService(android.content.Context.WIFI_SERVICE);
WifiConfiguration wc = new WifiConfiguration();
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
wc.SSID = "\"NETWORK_NAME\"";
wc.preSharedKey = "\"PASSWORD\"";
wc.status = WifiConfiguration.Status.ENABLED;
wc.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
wc.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
wifiManager.setWifiEnabled(true);
int netId = wifiManager.addNetwork(wc);
if (netId == -1) {
netId = getExistingNetworkId(wc.SSID);
}
wifiManager.disconnect();
wifiManager.enableNetwork(netId, true);
wifiManager.reconnect();
} catch (Exception e) {
e.printStackTrace();
}
}
private int getExistingNetworkId(String SSID) {
WifiManager wifiManager = (WifiManager) super.getSystemService(Context.WIFI_SERVICE);
List<WifiConfiguration> configuredNetworks = wifiManager.getConfiguredNetworks();
if (configuredNetworks != null) {
for (WifiConfiguration existingConfig : configuredNetworks) {
if (existingConfig.SSID.equals(SSID)) {
return existingConfig.networkId;
}
}
}
return -1;
}
And add permissions in the Manifest file
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />