Added in API level 18

BluetoothGattServer

---

Kotlin |Java

class BluetoothGattServer : BluetoothProfile

kotlin.Any
↳	android.bluetooth.BluetoothGattServer

Public API for the Bluetooth GATT Profile server role.

This class provides Bluetooth GATT server role functionality, allowing applications to create Bluetooth Smart services and characteristics.

BluetoothGattServer is a proxy object for controlling the Bluetooth Service via IPC. Use BluetoothManager#openGattServer to get an instance of this class.

Summary

Inherited constants

From class BluetoothProfile Int A2DP A2DP profile. Int CSIP_SET_COORDINATOR Coordinated Set Identification Profile set coordinator String EXTRA_PREVIOUS_STATE Extra for the connection state intents of the individual profiles. This extra represents the previous connection state of the profile of the Bluetooth device. String EXTRA_STATE Extra for the connection state intents of the individual profiles. This extra represents the current connection state of the profile of the Bluetooth device. Int GATT GATT Int GATT_SERVER GATT_SERVER Int HAP_CLIENT Int HEADSET Headset and Handsfree profile Int HEALTH Health Profile Int HEARING_AID Hearing Aid Device Int HID_DEVICE HID Device Int LE_AUDIO LE Audio Device Int SAP Int STATE_CONNECTED The profile is in connected state Int STATE_CONNECTING The profile is in connecting state Int STATE_DISCONNECTED The profile is in disconnected state Int STATE_DISCONNECTING The profile is in disconnecting state

Public methods
Boolean	addService(service: BluetoothGattService!) Add a service to the list of services to be hosted.
Unit	cancelConnection(device: BluetoothDevice!) Disconnects an established connection, or cancels a connection attempt currently in progress.
Unit	clearServices() Remove all services from the list of provided services.
Unit	close() Close this GATT server instance.
Boolean	connect(device: BluetoothDevice!, autoConnect: Boolean) Initiate a connection to a Bluetooth GATT capable device.
MutableList<BluetoothDevice!>!	getConnectedDevices() Not supported - please use BluetoothManager#getConnectedDevices(int) with android.bluetooth.BluetoothProfile#GATT as argument
Int	getConnectionState(device: BluetoothDevice!) Not supported - please use BluetoothManager#getConnectedDevices(int) with android.bluetooth.BluetoothProfile#GATT as argument
MutableList<BluetoothDevice!>!	getDevicesMatchingConnectionStates(states: IntArray!) Not supported - please use BluetoothManager#getDevicesMatchingConnectionStates(int, with BluetoothProfile#GATT as first argument
BluetoothGattService!	getService(uuid: UUID!) Returns a BluetoothGattService from the list of services offered by this device.
MutableList<BluetoothGattService!>!	getServices() Returns a list of GATT services offered by this device.
Boolean	notifyCharacteristicChanged(device: BluetoothDevice!, characteristic: BluetoothGattCharacteristic!, confirm: Boolean) Send a notification or indication that a local characteristic has been updated.
Int	notifyCharacteristicChanged(device: BluetoothDevice, characteristic: BluetoothGattCharacteristic, confirm: Boolean, value: ByteArray) Send a notification or indication that a local characteristic has been updated.
Unit	readPhy(device: BluetoothDevice!) Read the current transmitter PHY and receiver PHY of the connection.
Boolean	removeService(service: BluetoothGattService!) Removes a service from the list of services to be provided.
Boolean	sendResponse(device: BluetoothDevice!, requestId: Int, status: Int, offset: Int, value: ByteArray!) Send a response to a read or write request to a remote device.
Unit	setPreferredPhy(device: BluetoothDevice!, txPhy: Int, rxPhy: Int, phyOptions: Int) Set the preferred connection PHY for this app.

Public methods

addService

Added in API level 18

fun addService(service: BluetoothGattService!): Boolean

Add a service to the list of services to be hosted.

Once a service has been added to the list, the service and its included characteristics will be provided by the local device.

If the local device has already exposed services when this function is called, a service update notification will be sent to all clients.

The BluetoothGattServerCallback#onServiceAdded callback will indicate whether this service has been added successfully. Do not add another service before this callback.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_CONNECT

Parameters
service	BluetoothGattService!: Service to be added to the list of services provided by this device.

Return
Boolean	true, if the request to add service has been initiated

cancelConnection

Added in API level 18

fun cancelConnection(device: BluetoothDevice!): Unit

Disconnects an established connection, or cancels a connection attempt currently in progress.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_CONNECT

Parameters
device	BluetoothDevice!: Remote device

clearServices

Added in API level 18

fun clearServices(): Unit

Remove all services from the list of provided services.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_CONNECT

close

Added in API level 18

fun close(): Unit

Close this GATT server instance.

Application should call this method as early as possible after it is done with this GATT server.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_CONNECT

connect

Added in API level 18

fun connect(
    device: BluetoothDevice!, 
    autoConnect: Boolean
): Boolean

Initiate a connection to a Bluetooth GATT capable device.

The connection may not be established right away, but will be completed when the remote device is available. A BluetoothGattServerCallback#onConnectionStateChange callback will be invoked when the connection state changes as a result of this function.

The autoConnect parameter determines whether to actively connect to the remote device, or rather passively scan and finalize the connection when the remote device is in range/available. Generally, the first ever connection to a device should be direct (autoConnect set to false) and subsequent connections to known devices should be invoked with the autoConnect parameter set to true.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_CONNECT

Parameters
autoConnect	Boolean: Whether to directly connect to the remote device (false) or to automatically connect as soon as the remote device becomes available (true).

Return
Boolean	true, if the connection attempt was initiated successfully

getConnectedDevices

Added in API level 18

fun getConnectedDevices(): MutableList<BluetoothDevice!>!

Not supported - please use BluetoothManager#getConnectedDevices(int) with android.bluetooth.BluetoothProfile#GATT as argument

Return
MutableList<BluetoothDevice!>!	List of devices. The list will be empty on error.

Exceptions
java.lang.UnsupportedOperationException	on every call

getConnectionState

Added in API level 18

fun getConnectionState(device: BluetoothDevice!): Int

Not supported - please use BluetoothManager#getConnectedDevices(int) with android.bluetooth.BluetoothProfile#GATT as argument

Parameters
device	BluetoothDevice!: Remote bluetooth device.

Return
Int	State of the profile connection. One of STATE_CONNECTED, STATE_CONNECTING, STATE_DISCONNECTED, STATE_DISCONNECTING Value is android.bluetooth.BluetoothProfile#STATE_DISCONNECTED, android.bluetooth.BluetoothProfile#STATE_CONNECTING, android.bluetooth.BluetoothProfile#STATE_CONNECTED, or android.bluetooth.BluetoothProfile#STATE_DISCONNECTING

Exceptions
java.lang.UnsupportedOperationException	on every call

getDevicesMatchingConnectionStates

Added in API level 18

fun getDevicesMatchingConnectionStates(states: IntArray!): MutableList<BluetoothDevice!>!

Not supported - please use BluetoothManager#getDevicesMatchingConnectionStates(int, with BluetoothProfile#GATT as first argument

Parameters
states	IntArray!: Array of states. States can be one of STATE_CONNECTED, STATE_CONNECTING, STATE_DISCONNECTED, STATE_DISCONNECTING,

Return
MutableList<BluetoothDevice!>!	List of devices. The list will be empty on error.

Exceptions
java.lang.UnsupportedOperationException	on every call

getService

Added in API level 18

fun getService(uuid: UUID!): BluetoothGattService!

Returns a BluetoothGattService from the list of services offered by this device.

If multiple instances of the same service (as identified by UUID) exist, the first instance of the service is returned.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.

Parameters
uuid	UUID!: UUID of the requested service

Return
BluetoothGattService!	BluetoothGattService if supported, or null if the requested service is not offered by this device.

getServices

Added in API level 18

fun getServices(): MutableList<BluetoothGattService!>!

Returns a list of GATT services offered by this device.

An application must call addService to add a service to the list of services offered by this device.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.

Return
MutableList<BluetoothGattService!>!	List of services. Returns an empty list if no services have been added yet.

notifyCharacteristicChanged

Added in API level 18
Deprecated in API level 33

fun notifyCharacteristicChanged(
    device: BluetoothDevice!, 
    characteristic: BluetoothGattCharacteristic!, 
    confirm: Boolean
): Boolean

Deprecated: Use BluetoothGattServer#notifyCharacteristicChanged(BluetoothDevice, as this is not memory safe.

Send a notification or indication that a local characteristic has been updated.

A notification or indication is sent to the remote device to signal that the characteristic has been updated. This function should be invoked for every client that requests notifications/indications by writing to the "Client Configuration" descriptor for the given characteristic.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_CONNECT

Parameters
device	BluetoothDevice!: The remote device to receive the notification/indication
characteristic	BluetoothGattCharacteristic!: The local characteristic that has been updated
confirm	Boolean: true to request confirmation from the client (indication), false to send a notification

Return
Boolean	true, if the notification has been triggered successfully

Exceptions
java.lang.IllegalArgumentException	if the characteristic value or service is null

notifyCharacteristicChanged

Added in API level 33

fun notifyCharacteristicChanged(
    device: BluetoothDevice, 
    characteristic: BluetoothGattCharacteristic, 
    confirm: Boolean, 
    value: ByteArray
): Int

Send a notification or indication that a local characteristic has been updated.

A notification or indication is sent to the remote device to signal that the characteristic has been updated. This function should be invoked for every client that requests notifications/indications by writing to the "Client Configuration" descriptor for the given characteristic.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_CONNECT

Parameters
device	BluetoothDevice: the remote device to receive the notification/indication This value cannot be null.
characteristic	BluetoothGattCharacteristic: the local characteristic that has been updated This value cannot be null.
confirm	Boolean: true to request confirmation from the client (indication) or false to send a notification
value	ByteArray: the characteristic value This value cannot be null.

Return
Int	whether the notification has been triggered successfully Value is android.bluetooth.BluetoothStatusCodes#SUCCESS, android.bluetooth.BluetoothStatusCodes#ERROR_MISSING_BLUETOOTH_CONNECT_PERMISSION, android.bluetooth.BluetoothStatusCodes.ERROR_DEVICE_NOT_CONNECTED, android.bluetooth.BluetoothStatusCodes#ERROR_PROFILE_SERVICE_NOT_BOUND, or android.bluetooth.BluetoothStatusCodes#ERROR_UNKNOWN

Exceptions
java.lang.IllegalArgumentException	if the characteristic value or service is null

readPhy

Added in API level 26

fun readPhy(device: BluetoothDevice!): Unit

Read the current transmitter PHY and receiver PHY of the connection. The values are returned in BluetoothGattServerCallback#onPhyRead
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_CONNECT

Parameters
device	BluetoothDevice!: The remote device to send this response to

removeService

Added in API level 18

fun removeService(service: BluetoothGattService!): Boolean

Removes a service from the list of services to be provided.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_CONNECT

Parameters
service	BluetoothGattService!: Service to be removed.

Return
Boolean	true, if the service has been removed

sendResponse

Added in API level 18

fun sendResponse(
    device: BluetoothDevice!, 
    requestId: Int, 
    status: Int, 
    offset: Int, 
    value: ByteArray!
): Boolean

Send a response to a read or write request to a remote device.

This function must be invoked in when a remote read/write request is received by one of these callback methods:

• BluetoothGattServerCallback#onCharacteristicReadRequest
• BluetoothGattServerCallback#onCharacteristicWriteRequest
• BluetoothGattServerCallback#onDescriptorReadRequest
• BluetoothGattServerCallback#onDescriptorWriteRequest

For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_CONNECT

Parameters
device	BluetoothDevice!: The remote device to send this response to
requestId	Int: The ID of the request that was received with the callback
status	Int: The status of the request to be sent to the remote devices
offset	Int: Value offset for partial read/write response
value	ByteArray!: The value of the attribute that was read/written (optional)

setPreferredPhy

Added in API level 26

fun setPreferredPhy(
    device: BluetoothDevice!, 
    txPhy: Int, 
    rxPhy: Int, 
    phyOptions: Int
): Unit

Set the preferred connection PHY for this app. Please note that this is just a recommendation, whether the PHY change will happen depends on other applications preferences, local and remote controller capabilities. Controller can override these settings.

BluetoothGattServerCallback#onPhyUpdate will be triggered as a result of this call, even if no PHY change happens. It is also triggered when remote device updates the PHY.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_CONNECT

Parameters
device	BluetoothDevice!: The remote device to send this response to
txPhy	Int: preferred transmitter PHY. Bitwise OR of any of android.bluetooth.BluetoothDevice#PHY_LE_1M_MASK, BluetoothDevice#PHY_LE_2M_MASK, and android.bluetooth.BluetoothDevice#PHY_LE_CODED_MASK.
rxPhy	Int: preferred receiver PHY. Bitwise OR of any of android.bluetooth.BluetoothDevice#PHY_LE_1M_MASK, BluetoothDevice#PHY_LE_2M_MASK, and android.bluetooth.BluetoothDevice#PHY_LE_CODED_MASK.
phyOptions	Int: preferred coding to use when transmitting on the LE Coded PHY. Can be one of BluetoothDevice#PHY_OPTION_NO_PREFERRED, BluetoothDevice#PHY_OPTION_S2 or BluetoothDevice#PHY_OPTION_S8