BluetoothGatt

public final class BluetoothGatt
extends Object implements BluetoothProfile

java.lang.Object
   ↳ android.bluetooth.BluetoothGatt


Public API for the Bluetooth GATT Profile.

This class provides Bluetooth GATT functionality to enable communication with Bluetooth Smart or Smart Ready devices.

To connect to a remote peripheral device, create a BluetoothGattCallback and call BluetoothDevice#connectGatt to get a instance of this class. GATT capable devices can be discovered using the Bluetooth device discovery or BLE scan process.

Summary

Constants

int CONNECTION_PRIORITY_BALANCED

Connection parameter update - Use the connection parameters recommended by the Bluetooth SIG.

int CONNECTION_PRIORITY_DCK

Connection parameter update - Request the priority preferred for Digital Car Key for a lower latency connection.

int CONNECTION_PRIORITY_HIGH

Connection parameter update - Request a high priority, low latency connection.

int CONNECTION_PRIORITY_LOW_POWER

Connection parameter update - Request low power, reduced data rate connection parameters.

int GATT_CONNECTION_CONGESTED

A remote device connection is congested.

int GATT_FAILURE

A GATT operation failed, errors other than the above

int GATT_INSUFFICIENT_AUTHENTICATION

Insufficient authentication for a given operation

int GATT_INSUFFICIENT_AUTHORIZATION

Insufficient authorization for a given operation

int GATT_INSUFFICIENT_ENCRYPTION

Insufficient encryption for a given operation

int GATT_INVALID_ATTRIBUTE_LENGTH

A write operation exceeds the maximum length of the attribute

int GATT_INVALID_OFFSET

A read or write operation was requested with an invalid offset

int GATT_READ_NOT_PERMITTED

GATT read operation is not permitted

int GATT_REQUEST_NOT_SUPPORTED

The given request is not supported

int GATT_SUCCESS

A GATT operation completed successfully

int GATT_WRITE_NOT_PERMITTED

GATT write operation is not permitted

Inherited constants

Public methods

void abortReliableWrite(BluetoothDevice mDevice)

This method was deprecated in API level 19. Use abortReliableWrite()

void abortReliableWrite()

Cancels a reliable write transaction for a given device.

boolean beginReliableWrite()

Initiates a reliable write transaction for a given remote device.

void close()

Close this Bluetooth GATT client.

boolean connect()

Connect back to remote device.

void disconnect()

Disconnects an established connection, or cancels a connection attempt currently in progress.

boolean discoverServices()

Discovers services offered by a remote device as well as their characteristics and descriptors.

boolean executeReliableWrite()

Executes a reliable write transaction for a given remote device.

List<BluetoothDevice> getConnectedDevices()

This method is deprecated. Not supported - please use BluetoothManager#getConnectedDevices(int) with BluetoothProfile#GATT as argument

int getConnectionState(BluetoothDevice device)

This method is deprecated. Not supported - please use BluetoothManager#getConnectedDevices(int) with BluetoothProfile#GATT as argument

BluetoothDevice getDevice()

Return the remote bluetooth device this GATT client targets to

List<BluetoothDevice> getDevicesMatchingConnectionStates(int[] states)

This method is deprecated. Not supported - please use BluetoothManager.getDevicesMatchingConnectionStates(int, int[]) with BluetoothProfile.GATT as first argument

BluetoothGattService getService(UUID uuid)

Returns a BluetoothGattService, if the requested UUID is supported by the remote device.

List<BluetoothGattService> getServices()

Returns a list of GATT services offered by the remote device.

boolean readCharacteristic(BluetoothGattCharacteristic characteristic)

Reads the requested characteristic from the associated remote device.

boolean readDescriptor(BluetoothGattDescriptor descriptor)

Reads the value for a given descriptor from the associated remote device.

void readPhy()

Read the current transmitter PHY and receiver PHY of the connection.

boolean readRemoteRssi()

Read the RSSI for a connected remote device.

boolean requestConnectionPriority(int connectionPriority)

Request a connection parameter update.

boolean requestMtu(int mtu)

Request an MTU size used for a given connection.

boolean setCharacteristicNotification(BluetoothGattCharacteristic characteristic, boolean enable)

Enable or disable notifications/indications for a given characteristic.

void setPreferredPhy(int txPhy, int rxPhy, int phyOptions)

Set the preferred connection PHY for this app.

boolean writeCharacteristic(BluetoothGattCharacteristic characteristic)

This method was deprecated in API level 33. Use BluetoothGatt#writeCharacteristic(BluetoothGattCharacteristic, byte[], int) as this is not memory safe because it relies on a BluetoothGattCharacteristic object whose underlying fields are subject to change outside this method.

int writeCharacteristic(BluetoothGattCharacteristic characteristic, byte[] value, int writeType)

Writes a given characteristic and its values to the associated remote device.

boolean writeDescriptor(BluetoothGattDescriptor descriptor)

This method was deprecated in API level 33. Use BluetoothGatt#writeDescriptor(BluetoothGattDescriptor, byte[]) as this is not memory safe because it relies on a BluetoothGattDescriptor object whose underlying fields are subject to change outside this method.

int writeDescriptor(BluetoothGattDescriptor descriptor, byte[] value)

Write the value of a given descriptor to the associated remote device.

Inherited methods

Constants

CONNECTION_PRIORITY_BALANCED

Added in API level 21
public static final int CONNECTION_PRIORITY_BALANCED

Connection parameter update - Use the connection parameters recommended by the Bluetooth SIG. This is the default value if no connection parameter update is requested.

Constant Value: 0 (0x00000000)

CONNECTION_PRIORITY_DCK

Added in API level 34
public static final int CONNECTION_PRIORITY_DCK

Connection parameter update - Request the priority preferred for Digital Car Key for a lower latency connection. This connection parameter will consume more power than CONNECTION_PRIORITY_BALANCED, so it is recommended that apps do not use this unless it specifically fits their use case.

Constant Value: 3 (0x00000003)

CONNECTION_PRIORITY_HIGH

Added in API level 21
public static final int CONNECTION_PRIORITY_HIGH

Connection parameter update - Request a high priority, low latency connection. An application should only request high priority connection parameters to transfer large amounts of data over LE quickly. Once the transfer is complete, the application should request CONNECTION_PRIORITY_BALANCED connection parameters to reduce energy use.

Constant Value: 1 (0x00000001)

CONNECTION_PRIORITY_LOW_POWER

Added in API level 21
public static final int CONNECTION_PRIORITY_LOW_POWER

Connection parameter update - Request low power, reduced data rate connection parameters.

Constant Value: 2 (0x00000002)

GATT_CONNECTION_CONGESTED

Added in API level 21
public static final int GATT_CONNECTION_CONGESTED

A remote device connection is congested.

Constant Value: 143 (0x0000008f)

GATT_FAILURE

Added in API level 18
public static final int GATT_FAILURE

A GATT operation failed, errors other than the above

Constant Value: 257 (0x00000101)

GATT_INSUFFICIENT_AUTHENTICATION

Added in API level 18
public static final int GATT_INSUFFICIENT_AUTHENTICATION

Insufficient authentication for a given operation

Constant Value: 5 (0x00000005)

GATT_INSUFFICIENT_AUTHORIZATION

Added in API level 33
public static final int GATT_INSUFFICIENT_AUTHORIZATION

Insufficient authorization for a given operation

Constant Value: 8 (0x00000008)

GATT_INSUFFICIENT_ENCRYPTION

Added in API level 18
public static final int GATT_INSUFFICIENT_ENCRYPTION

Insufficient encryption for a given operation

Constant Value: 15 (0x0000000f)

GATT_INVALID_ATTRIBUTE_LENGTH

Added in API level 18
public static final int GATT_INVALID_ATTRIBUTE_LENGTH

A write operation exceeds the maximum length of the attribute

Constant Value: 13 (0x0000000d)

GATT_INVALID_OFFSET

Added in API level 18
public static final int GATT_INVALID_OFFSET

A read or write operation was requested with an invalid offset

Constant Value: 7 (0x00000007)

GATT_READ_NOT_PERMITTED

Added in API level 18
public static final int GATT_READ_NOT_PERMITTED

GATT read operation is not permitted

Constant Value: 2 (0x00000002)

GATT_REQUEST_NOT_SUPPORTED

Added in API level 18
public static final int GATT_REQUEST_NOT_SUPPORTED

The given request is not supported

Constant Value: 6 (0x00000006)

GATT_SUCCESS

Added in API level 18
public static final int GATT_SUCCESS

A GATT operation completed successfully

Constant Value: 0 (0x00000000)

GATT_WRITE_NOT_PERMITTED

Added in API level 18
public static final int GATT_WRITE_NOT_PERMITTED

GATT write operation is not permitted

Constant Value: 3 (0x00000003)

Public methods

abortReliableWrite

Added in API level 18
Deprecated in API level 19
public void abortReliableWrite (BluetoothDevice mDevice)

This method was deprecated in API level 19.
Use abortReliableWrite()


For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
mDevice BluetoothDevice

abortReliableWrite

Added in API level 19
public void abortReliableWrite ()

Cancels a reliable write transaction for a given device.

Calling this function will discard all queued characteristic write operations for a given remote 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.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

beginReliableWrite

Added in API level 18
public boolean beginReliableWrite ()

Initiates a reliable write transaction for a given remote device.

Once a reliable write transaction has been initiated, all calls to writeCharacteristic(BluetoothGattCharacteristic) are sent to the remote device for verification and queued up for atomic execution. The application will receive a BluetoothGattCallback#onCharacteristicWrite callback in response to every writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int) call and is responsible for verifying if the value has been transmitted accurately.

After all characteristics have been queued up and verified, executeReliableWrite() will execute all writes. If a characteristic was not written correctly, calling abortReliableWrite() will cancel the current transaction without committing any values on the remote 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.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Returns
boolean true, if the reliable write transaction has been initiated

close

Added in API level 18
public void close ()

Close this Bluetooth GATT client.

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

connect

Added in API level 18
public boolean connect ()

Connect back to remote device.

This method is used to re-connect to a remote device after the connection has been dropped. If the device is not in range, the re-connection will be triggered once the device is back in range.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Returns
boolean true, if the connection attempt was initiated successfully

disconnect

Added in API level 18
public void disconnect ()

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 Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

discoverServices

Added in API level 18
public boolean discoverServices ()

Discovers services offered by a remote device as well as their characteristics and descriptors.

This is an asynchronous operation. Once service discovery is completed, the BluetoothGattCallback.onServicesDiscovered(BluetoothGatt, int) callback is triggered. If the discovery was successful, the remote services can be retrieved using the getServices() function.
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 Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Returns
boolean true, if the remote service discovery has been started

executeReliableWrite

Added in API level 18
public boolean executeReliableWrite ()

Executes a reliable write transaction for a given remote device.

This function will commit all queued up characteristic write operations for a given remote device.

A BluetoothGattCallback#onReliableWriteCompleted callback is invoked to indicate whether the transaction has been executed correctly.
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 Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Returns
boolean true, if the request to execute the transaction has been sent

getConnectedDevices

Added in API level 18
public List<BluetoothDevice> getConnectedDevices ()

This method is deprecated.
Not supported - please use BluetoothManager#getConnectedDevices(int) with BluetoothProfile#GATT as argument

Get connected devices for this specific profile.

Return the set of devices which are in state STATE_CONNECTED

Returns
List<BluetoothDevice> List of devices. The list will be empty on error.

Throws
UnsupportedOperationException on every call

getConnectionState

Added in API level 18
public int getConnectionState (BluetoothDevice device)

This method is deprecated.
Not supported - please use BluetoothManager#getConnectedDevices(int) with BluetoothProfile#GATT as argument

Get the current connection state of the profile

Parameters
device BluetoothDevice: Remote bluetooth device.

Returns
int State of the profile connection. One of STATE_CONNECTED, STATE_CONNECTING, STATE_DISCONNECTED, STATE_DISCONNECTING Value is STATE_DISCONNECTED, STATE_CONNECTING, STATE_CONNECTED, or STATE_DISCONNECTING

Throws
UnsupportedOperationException on every call

getDevice

Added in API level 18
public BluetoothDevice getDevice ()

Return the remote bluetooth device this GATT client targets to

Returns
BluetoothDevice remote bluetooth device

getDevicesMatchingConnectionStates

Added in API level 18
public List<BluetoothDevice> getDevicesMatchingConnectionStates (int[] states)

This method is deprecated.
Not supported - please use BluetoothManager.getDevicesMatchingConnectionStates(int, int[]) with BluetoothProfile.GATT as first argument

Get a list of devices that match any of the given connection states.

If none of the devices match any of the given states, an empty list will be returned.

Parameters
states int: Array of states. States can be one of BluetoothProfile.STATE_CONNECTED, BluetoothProfile.STATE_CONNECTING, BluetoothProfile.STATE_DISCONNECTED, BluetoothProfile.STATE_DISCONNECTING,

Returns
List<BluetoothDevice> List of devices. The list will be empty on error.

Throws
UnsupportedOperationException on every call

getService

Added in API level 18
public BluetoothGattService getService (UUID uuid)

Returns a BluetoothGattService, if the requested UUID is supported by the remote device.

This function requires that service discovery has been completed for the given 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

Returns
BluetoothGattService BluetoothGattService if supported, or null if the requested service is not offered by the remote device.

getServices

Added in API level 18
public List<BluetoothGattService> getServices ()

Returns a list of GATT services offered by the remote device.

This function requires that service discovery has been completed for the given 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.

Returns
List<BluetoothGattService> List of services on the remote device. Returns an empty list if service discovery has not yet been performed.

readCharacteristic

Added in API level 18
public boolean readCharacteristic (BluetoothGattCharacteristic characteristic)

Reads the requested characteristic from the associated remote device.

This is an asynchronous operation. The result of the read operation is reported by the BluetoothGattCallback#onCharacteristicRead(BluetoothGatt, BluetoothGattCharacteristic, byte[], int) 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 Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
characteristic BluetoothGattCharacteristic: Characteristic to read from the remote device

Returns
boolean true, if the read operation was initiated successfully

readDescriptor

Added in API level 18
public boolean readDescriptor (BluetoothGattDescriptor descriptor)

Reads the value for a given descriptor from the associated remote device.

Once the read operation has been completed, the BluetoothGattCallback.onDescriptorRead(BluetoothGatt, BluetoothGattDescriptor, int) callback is triggered, signaling the result of the operation.
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 Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
descriptor BluetoothGattDescriptor: Descriptor value to read from the remote device

Returns
boolean true, if the read operation was initiated successfully

readPhy

Added in API level 26
public void readPhy ()

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

readRemoteRssi

Added in API level 18
public boolean readRemoteRssi ()

Read the RSSI for a connected remote device.

The BluetoothGattCallback#onReadRemoteRssi callback will be invoked when the RSSI value has been read.
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 Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Returns
boolean true, if the RSSI value has been requested successfully

requestConnectionPriority

Added in API level 21
public boolean requestConnectionPriority (int connectionPriority)

Request a connection parameter update.

This function will send a connection parameter update request to the remote device.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
connectionPriority int: Request a specific connection priority. Must be one of CONNECTION_PRIORITY_BALANCED, CONNECTION_PRIORITY_HIGH CONNECTION_PRIORITY_LOW_POWER, or CONNECTION_PRIORITY_DCK.

Returns
boolean

Throws
IllegalArgumentException If the parameters are outside of their specified range.

requestMtu

Added in API level 21
public boolean requestMtu (int mtu)

Request an MTU size used for a given connection. Please note that starting from Android 14, the Android Bluetooth stack requests the BLE ATT MTU to 517 bytes when the first GATT client requests an MTU, and disregards all subsequent MTU requests. Check out MTU is set to 517 for the first GATT client requesting an MTU for more information.

When performing a write request operation (write without response), the data sent is truncated to the MTU size. This function may be used to request a larger MTU size to be able to send more data at once.

A BluetoothGattCallback#onMtuChanged callback will indicate whether this operation was successful.
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 Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
mtu int

Returns
boolean true, if the new MTU value has been requested successfully

setCharacteristicNotification

Added in API level 18
public boolean setCharacteristicNotification (BluetoothGattCharacteristic characteristic, 
                boolean enable)

Enable or disable notifications/indications for a given characteristic.

Once notifications are enabled for a characteristic, a BluetoothGattCallback.onCharacteristicChanged(android.bluetooth.BluetoothGatt, android.bluetooth.BluetoothGattCharacteristic, byte[]) callback will be triggered if the remote device indicates that the given characteristic has changed.
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 Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
characteristic BluetoothGattCharacteristic: The characteristic for which to enable notifications

enable boolean: Set to true to enable notifications/indications

Returns
boolean true, if the requested notification status was set successfully

setPreferredPhy

Added in API level 26
public void setPreferredPhy (int txPhy, 
                int rxPhy, 
                int phyOptions)

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.

BluetoothGattCallback#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 Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
txPhy int: preferred transmitter PHY. Bitwise OR of any of BluetoothDevice.PHY_LE_1M_MASK, BluetoothDevice#PHY_LE_2M_MASK, and BluetoothDevice.PHY_LE_CODED_MASK.

rxPhy int: preferred receiver PHY. Bitwise OR of any of BluetoothDevice.PHY_LE_1M_MASK, BluetoothDevice#PHY_LE_2M_MASK, and 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

writeCharacteristic

Added in API level 18
Deprecated in API level 33
public boolean writeCharacteristic (BluetoothGattCharacteristic characteristic)

This method was deprecated in API level 33.
Use BluetoothGatt#writeCharacteristic(BluetoothGattCharacteristic, byte[], int) as this is not memory safe because it relies on a BluetoothGattCharacteristic object whose underlying fields are subject to change outside this method.

Writes a given characteristic and its values to the associated remote device.

Once the write operation has been completed, the BluetoothGattCallback.onCharacteristicWrite(BluetoothGatt, BluetoothGattCharacteristic, int) callback is invoked, reporting the result of the operation.
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 Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
characteristic BluetoothGattCharacteristic: Characteristic to write on the remote device

Returns
boolean true, if the write operation was initiated successfully

Throws
IllegalArgumentException if characteristic or its value are null

writeCharacteristic

Added in API level 33
public int writeCharacteristic (BluetoothGattCharacteristic characteristic, 
                byte[] value, 
                int writeType)

Writes a given characteristic and its values to the associated remote device.

Once the write operation has been completed, the BluetoothGattCallback.onCharacteristicWrite(BluetoothGatt, BluetoothGattCharacteristic, int) callback is invoked, reporting the result of the operation.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
characteristic BluetoothGattCharacteristic: Characteristic to write on the remote device This value cannot be null.

value byte: This value cannot be null.

writeType int: Value is BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT, BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE, or BluetoothGattCharacteristic.WRITE_TYPE_SIGNED

Returns
int whether the characteristic was successfully written to Value is BluetoothStatusCodes.SUCCESS, BluetoothStatusCodes.ERROR_MISSING_BLUETOOTH_CONNECT_PERMISSION, android.bluetooth.BluetoothStatusCodes.ERROR_DEVICE_NOT_CONNECTED, BluetoothStatusCodes.ERROR_PROFILE_SERVICE_NOT_BOUND, BluetoothStatusCodes.ERROR_GATT_WRITE_NOT_ALLOWED, BluetoothStatusCodes.ERROR_GATT_WRITE_REQUEST_BUSY, or BluetoothStatusCodes.ERROR_UNKNOWN

Throws
IllegalArgumentException if characteristic or value are null

writeDescriptor

Added in API level 18
Deprecated in API level 33
public boolean writeDescriptor (BluetoothGattDescriptor descriptor)

This method was deprecated in API level 33.
Use BluetoothGatt#writeDescriptor(BluetoothGattDescriptor, byte[]) as this is not memory safe because it relies on a BluetoothGattDescriptor object whose underlying fields are subject to change outside this method.

Write the value of a given descriptor to the associated remote device.

A BluetoothGattCallback#onDescriptorWrite callback is triggered to report the result of the write operation.
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 Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
descriptor BluetoothGattDescriptor: Descriptor to write to the associated remote device

Returns
boolean true, if the write operation was initiated successfully

Throws
IllegalArgumentException if descriptor or its value are null

writeDescriptor

Added in API level 33
public int writeDescriptor (BluetoothGattDescriptor descriptor, 
                byte[] value)

Write the value of a given descriptor to the associated remote device.

A BluetoothGattCallback#onDescriptorWrite callback is triggered to report the result of the write operation.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
descriptor BluetoothGattDescriptor: Descriptor to write to the associated remote device This value cannot be null.

value byte: This value cannot be null.

Returns
int true, if the write operation was initiated successfully Value is BluetoothStatusCodes.SUCCESS, BluetoothStatusCodes.ERROR_MISSING_BLUETOOTH_CONNECT_PERMISSION, android.bluetooth.BluetoothStatusCodes.ERROR_DEVICE_NOT_CONNECTED, BluetoothStatusCodes.ERROR_PROFILE_SERVICE_NOT_BOUND, BluetoothStatusCodes.ERROR_GATT_WRITE_NOT_ALLOWED, BluetoothStatusCodes.ERROR_GATT_WRITE_REQUEST_BUSY, or BluetoothStatusCodes.ERROR_UNKNOWN

Throws
IllegalArgumentException if descriptor or value are null