Develop Reference

Android app to dynamically turn on/off a wifi hotspot

I want to control wifi hotspot dynamically in my Android app project. I have tired Reflection (which will not work in Android Oreo and later versions), startLocalOnyNetwork (but I want specific SSID and PASSWORD, which is not possible to configure it).
Then I rooted my phone, Is it possible if the device is rooted ?
Expecting an api to turn on/off wifi hotspot with specific SSID and PASSWORD or use the previous one.
Any possibilities or workarounds ?
Thanks in advance.

To turn on Wifi Hotspot, need some permissions
<uses-permission android:name="android.permission.WRITE_SETTINGS"
tools:ignore="ProtectedPermissions" />
and the permission should be dynamically granted by user
In apps advanced settings -> Modify system settings
/**
* This enables tethering using the ssid/password defined in Settings App>Hotspot & tethering
* Does not require app to have system/privileged access
* Credit: Vishal Sharma - https://stackoverflow.com/a/52219887
*/
public boolean startTethering() {
File outputDir = mContext.getCodeCacheDir();
Object proxy;
try {
proxy = ProxyBuilder.forClass(OnStartTetheringCallbackClass())
.dexCache(outputDir).handler(new InvocationHandler() {
#Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
return null;
}
}).build();
} catch (Exception e) {
Log.e(TAG, "Error in enableTethering ProxyBuilder");
e.printStackTrace();
return false;
}
Method method = null;
try {
method = mConnectivityManager.getClass().getDeclaredMethod("startTethering", int.class, boolean.class, OnStartTetheringCallbackClass(), Handler.class);
if (method == null) {
Log.e(TAG, "startTetheringMethod is null");
} else {
method.invoke(mConnectivityManager, ConnectivityManager.TYPE_MOBILE, false, proxy, null);
Log.d(TAG, "startTethering invoked");
}
return true;
} catch (Exception e) {
Log.e(TAG, "Error in enableTethering");
e.printStackTrace();
}
return false;
}
public void stopTethering() {
try {
Method method = mConnectivityManager.getClass().getDeclaredMethod("stopTethering", int.class);
if (method == null) {
Log.e(TAG, "stopTetheringMethod is null");
} else {
method.invoke(mConnectivityManager, ConnectivityManager.TYPE_MOBILE);
Log.d(TAG, "stopTethering invoked");
}
} catch (Exception e) {
Log.e(TAG, "stopTethering error: " + e.toString());
e.printStackTrace();
}
}
Use above methods to turn on/off Wifi Hotspot with SSID and password defined in the settings.
private int AP_STATE_DISABLED = 11;
private int AP_STATE_ENABLING = 12;
private int AP_STATE_ENABLED = 13;
private int AP_STATE_ERROR = 14;
/**
* #return status hot spot enabled or not
*/
public boolean isHotSpotEnabled(Context context) {
Method method = null;
int actualState = 0;
try {
WifiManager mWifiManager = (WifiManager) context.getApplicationContext().getSystemService(Context.WIFI_SERVICE);
method = mWifiManager.getClass().getDeclaredMethod("getWifiApState");
method.setAccessible(true);
actualState = (Integer) method.invoke(mWifiManager, (Object[]) null);
if (actualState == AP_STATE_ENABLING ||actualState == AP_STATE_ENABLED) {
return true;
}
} catch (IllegalArgumentException | NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
Above method can be used to get the current state of hotspot

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

I know how to turn on/off wifi hot spot using reflection in android using below method.
private static boolean changeWifiHotspotState(Context context,boolean enable) {
try {
WifiManager manager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
Method method = manager.getClass().getDeclaredMethod("setWifiApEnabled", WifiConfiguration.class,
Boolean.TYPE);
method.setAccessible(true);
WifiConfiguration configuration = enable ? getWifiApConfiguration(manager) : null;
boolean isSuccess = (Boolean) method.invoke(manager, configuration, enable);
return isSuccess;
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
But the above method is not working Android 8.0(Oreo).
When I execute above method in Android 8.0, I am getting below statement in logcat.
com.gck.dummy W/WifiManager: com.gck.dummy attempted call to setWifiApEnabled: enabled = true
Is there any other way to on/off hotspot on android 8.0

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.

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

As per Jon suggestion, I got another way to enable WifiHotSpot in Android Oreo and above.
public boolean enableTetheringNew(MyTetheringCallback callback) {
File outputDir = mContext.getCodeCacheDir();
try {
proxy = ProxyBuilder.forClass(classOnStartTetheringCallback())
.dexCache(outputDir).handler(new InvocationHandler() {
#Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
switch (method.getName()) {
case "onTetheringStarted":
callback.onTetheringStarted();
break;
case "onTetheringFailed":
callback.onTetheringFailed();
break;
default:
ProxyBuilder.callSuper(proxy, method, args);
}
return null;
}
}).build();
} catch (IOException e) {
e.printStackTrace();
}
ConnectivityManager manager = (ConnectivityManager) mContext.getApplicationContext().getSystemService(ConnectivityManager.class);
Method method = null;
try {
method = manager.getClass().getDeclaredMethod("startTethering", int.class, boolean.class, classOnStartTetheringCallback(), Handler.class);
if (method == null) {
Log.e(TAG, "startTetheringMethod is null");
} else {
method.invoke(manager, TETHERING_WIFI, false, proxy, null);
}
return true;
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
return false;
}
private Class classOnStartTetheringCallback() {
try {
return Class.forName("android.net.ConnectivityManager$OnStartTetheringCallback");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
return null;
}

How to programmatically pair and connect a HID bluetooth device(Bluetooth Keyboard) on Android

I am able to pair a bluetooth keyboard but not able to connect so as to make it an input device.
I went through the documentation provided at developer site - http://developer.android.com/guide/topics/connectivity/bluetooth.html#Profiles
It says that the Android Bluetooth API provides implementations for the following Bluetooth profiles but you can implement the interface BluetoothProfile to write your own classes to support a particular Bluetooth profile.
Headset
A2DP
Health Device
There is no documentation how to implement BluetoothProfile for HID bluetooth device(Keyboard)
Android has itself implemented bluetooth connection for HID devices but those API's are hidden. I tried reflection to use them too. I do not get any error but keyboard does not get connected as input device. This is what i have done -
private void connect(final BluetoothDevice bluetoothDevice) {
if(bluetoothDevice.getBluetoothClass().getDeviceClass() == 1344){
final BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
BluetoothProfile.ServiceListener mProfileListener = new BluetoothProfile.ServiceListener() {
#Override
public void onServiceConnected(int profile, BluetoothProfile proxy) {
Log.i("btclass", profile + "");
if (profile == getInputDeviceHiddenConstant()) {
Class instance = null;
try {
//instance = Class.forName("android.bluetooth.IBluetoothInputDevice");
instance = Class.forName("android.bluetooth.BluetoothInputDevice");
Method connect = instance.getDeclaredMethod("connect", BluetoothDevice.class);
Object value = connect.invoke(proxy, bluetoothDevice);
Log.e("btclass", value.toString());
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
}
#Override
public void onServiceDisconnected(int profile) {
}
};
mBluetoothAdapter.getProfileProxy(this, mProfileListener,getInputDeviceHiddenConstant());
}
}
public static int getInputDeviceHiddenConstant() {
Class<BluetoothProfile> clazz = BluetoothProfile.class;
for (Field f : clazz.getFields()) {
int mod = f.getModifiers();
if (Modifier.isStatic(mod) && Modifier.isPublic(mod) && Modifier.isFinal(mod)) {
try {
if (f.getName().equals("INPUT_DEVICE")) {
return f.getInt(null);
}
} catch (Exception e) {
Log.e("", e.toString(), e);
}
}
}
return -1;
}

Due to security reasons, it is not possible for third party applications to connect to a bluetooth keyboard as the application can be a keylogger. So it can be only done manually by the user.

Here is the code I used on Android Marshmallow (6.0).. To get an L2CAP connection started (Needed for HID)
public static BluetoothSocket createL2CAPBluetoothSocket(String address, int psm){
return createBluetoothSocket(BluetoothSocket.TYPE_L2CAP, -1, false,false, address, psm);
}
// method for creating a bluetooth client socket
private static BluetoothSocket createBluetoothSocket(int type, int fd, boolean auth, boolean encrypt, String address, int port){
Log.e(TAG, "Creating socket with " + address + ":" + port);
try {
Constructor<BluetoothSocket> constructor = BluetoothSocket.class.getDeclaredConstructor(
int.class, int.class,boolean.class,boolean.class,String.class, int.class);
constructor.setAccessible(true);
BluetoothSocket clientSocket = (BluetoothSocket) constructor.newInstance(type,fd,auth,encrypt,address,port);
return clientSocket;
}catch (Exception e) {
e.printStackTrace();
}
return null;
}
public Boolean connect(View v) {
try {
// TODO: Check bluetooth enabled
mDevice = getController();
if (mDevice != null) {
Log.e(TAG, "Controller is paired");
// Create socket
mSocket = createL2CAPBluetoothSocket(mDevice.getAddress(), 0x1124);
if (mSocket != null) {
if (!mSocket.isConnected()) {
mSocket.connect();
}
Log.e(TAG, "Socket successfully created");
ConnectedThread mConnectedThread = new ConnectedThread(mSocket);
mConnectedThread.run();
}
} else {
showToast("Controller is not connected");
}
return true;
} catch (Exception e) {
e.printStackTrace();
if (e instanceof IOException){
// handle this exception type
} else {
// We didn't expect this one. What could it be? Let's log it, and let it bubble up the hierarchy.
}
return false;
}
}
private BluetoothDevice getController() {
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
for (BluetoothDevice device : pairedDevices) {
if (device.getName().equals("Wireless Controller")) // Change to match DS4 - node name
{
Log.d(TAG, "Found device named: " + device.getName());
return device;
}
}
}
return null;
}
It can still have problems creating the Service, and you need to set the correct L2CAP PSAM for the device, but hope it can help..

set bluetooth authentication PIN when listening from adapter

I'm making an app that needs to connect with a bluetooth device and get data from it... that device is set as master, so I needed to implement a Thread, where I listenUsingRfcommWithServiceRecord and wait for a connection from it:
public AcceptThread(Context context, String serverName, UUID myUUID) {
this.context = context;
BluetoothServerSocket tmp = null;
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
try {
// MY_UUID is the app's UUID string, also used by the client code
tmp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(serverName, myUUID);
} catch (IOException e) { }
mmServerSocket = tmp;
}
Then on run I run the code socket = mmServerSocket.accept(5000) to wait until it starts pairing with the device:
public void run() {
BluetoothSocket socket = null;
while (true) {
try {
socket = mmServerSocket.accept(5000);
} catch (IOException e) {
Log.e(TAG,"IOException: " + e);
}
// If a connection was accepted
if (socket != null) {
// Manage the connection
ManageConnectedSocket manageConnectedSocket = new ManageConnectedSocket(socket);
manageConnectedSocket.run();
try {
mmServerSocket.close();
} catch (IOException e) {
Log.e(TAG, "IOException: " + e);
}
break;
}
}
}
The Device asks for an authentication PIN, and I need to have an automatic procedure... for that I though of implementing a broadcast receiver to know when the device is asked to par with another device:
IntentFilter filter = new IntentFilter(ACTION_PAIRING_REQUEST);
context.registerReceiver(mPairReceiver, filter);
and receive it:
private final BroadcastReceiver mPairReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (ACTION_PAIRING_REQUEST.equals(action)) {
Log.e(TAG,"ACTION_PAIRING_REQUEST");
setBluetoothPairingPin(device);
}
}
};
In my setBluetoothPairingPin method I receive a BluetoothDevice object :
public void setBluetoothPairingPin(BluetoothDevice device) {
byte[] pinBytes = convertPinToBytes("0000");
try {
Log.e(TAG, "Try to set the PIN");
Method m = device.getClass().getMethod("setPin", byte[].class);
m.invoke(device, pinBytes);
Log.e(TAG, "Success to add the PIN.");
try {
device.getClass().getMethod("setPairingConfirmation", boolean.class).invoke(device, false);
Log.e(TAG, "Success to setPairingConfirmation.");
} catch (Exception e) {
// TODO Auto-generated catch block
Log.e(TAG, e.getMessage());
e.printStackTrace();
}
} catch (Exception e) {
Log.e(TAG, e.getMessage());
e.printStackTrace();
}
}
The problem is that I can't know when my socket receives information, and consecutively, can't know what is my BluetoothDevice to set Pairing Pin before it's connected...
Can someone help me on how to surpass this? Or is there other way to put the pin authentication when I'm listenning from BluetoothServerSocket?
If I'm not explaining correctly, please let me know...
Thanks in advance

With the help from this and this, I was able to make work for me...
My confusion was with the method setBluetoothPairingPin that I couldn't understand that the ACTION_PAIRING_REQUEST is actually called when the device is being starting to pairing, and that is when the PIN is asked from the user... so invoking BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);, and changing a bit of the set pairing method I manage to make it work...
Here's my final code:
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (ACTION_PAIRING_REQUEST.equals(action)) {
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
String PIN = "0000";
byte[] pin = new byte[0];
try {
pin = (byte[]) BluetoothDevice.class.getMethod("convertPinToBytes", String.class).invoke(BluetoothDevice.class, PIN);
BluetoothDevice.class.getMethod("setPin", byte[].class).invoke(device, pin);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
}
}
}

Start / stop built-in Wi-Fi / USB tethering from code?

How can I start or stop the built-in tethering in Android 2.2 from my application?

There is a non-public Tethering API in the ConnectivityManager. As shown above you can use reflection to access it. I tried this on a number of Android 2.2 phones, and it works on all of them (my HTC turns on tethering but does NOT show this in the status bar..., so check from the other end). Below is some rough code which emits debugging stuff and turns on tethering on usb0.
ConnectivityManager cman = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
Method[] methods = cman.getClass().getDeclaredMethods();
for (Method method : methods) {
if (method.getName().equals("getTetherableIfaces")) {
try {
String[] ifaces = (String[]) method.invoke(cman);
for (String iface : ifaces) {
Log.d("TETHER", "Tether available on " + iface);
}
} catch (Exception e) {
e.printStackTrace();
}
}
if (method.getName().equals("isTetheringSupported")) {
try {
boolean supported = (Boolean) method.invoke(cman);
Log.d("TETHER", "Tether is supported: " + (supported ? "yes" : "no"));
} catch (Exception e) {
e.printStackTrace();
}
}
if (method.getName().equals("tether")) {
Log.d("TETHER", "Starting tether usb0");
try {
int result = (Integer) method.invoke(cman, "usb0");
Log.d("TETHER", "Tether usb0 result: " + result);
} catch (Exception e) {
e.printStackTrace();
}
}
}
Please note: this code requires the following permissions to work:
android.permission.ACCESS_NETWORK_STATE
android.permission.CHANGE_NETWORK_STATE

I answered this question here. In short, it is possible, here is the code:
private void setWifiTetheringEnabled(boolean enable) {
WifiManager wifiManager = (WifiManager) getSystemService(WIFI_SERVICE);
Method[] methods = wifiManager.getClass().getDeclaredMethods();
for (Method method : methods) {
if (method.getName().equals("setWifiApEnabled")) {
try {
method.invoke(wifiManager, null, enable);
} catch (Exception ex) {
}
break;
}
}
}
Your app should have the following permission:
android.permission.CHANGE_WIFI_STATE

There are no public APIs in the Android SDK for managing the tethering -- sorry!

I used the code from Android How to turn on hotspot in Android Programmatically! and I enable the portable hotspot for android 4.2. Here's the code.
WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
// TODO Auto-generated method stub
WifiConfiguration wifi_configuration = null;
wifiManager.setWifiEnabled(false);
try
{
//USE REFLECTION TO GET METHOD "SetWifiAPEnabled"
Method method=wifiManager.getClass().getMethod("setWifiApEnabled", WifiConfiguration.class, boolean.class);
method.invoke(wifiManager, wifi_configuration, true);
}
catch (NoSuchMethodException e){
// TODO Auto-generated catch block
e.printStackTrace();
}catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}