# BluetoothGattDescriptor Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Constants](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#constants) \| [Inherited Constants](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#inhconstants) \| [Fields](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#lfields) \| [Ctors](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#pubctors) \| [Methods](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#inhmethods) # BluetoothGattDescriptor *** ** * ** *** [Kotlin](https://developer.android.com/reference/kotlin/android/bluetooth/BluetoothGattDescriptor "View this page in Kotlin") \|Java ` public class BluetoothGattDescriptor ` ` extends `[Object](https://developer.android.com/reference/java/lang/Object)` ` ` implements `[Parcelable](https://developer.android.com/reference/android/os/Parcelable)` ` |---|-------------------------------------------| | [java.lang.Object](https://developer.android.com/reference/java/lang/Object) || | ↳ | android.bluetooth.BluetoothGattDescriptor |
*** ** * ** *** Represents a Bluetooth GATT Descriptor GATT Descriptors contain additional information and attributes of a GATT characteristic, [BluetoothGattCharacteristic](https://developer.android.com/reference/android/bluetooth/BluetoothGattCharacteristic). They can be used to describe the characteristic's features or to control certain behaviours of the characteristic. ## Summary | ### Constants || |-------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | `int` | [PERMISSION_READ](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#PERMISSION_READ) Descriptor read permission | | `int` | [PERMISSION_READ_ENCRYPTED](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#PERMISSION_READ_ENCRYPTED) Descriptor permission: Allow encrypted read operations | | `int` | [PERMISSION_READ_ENCRYPTED_MITM](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#PERMISSION_READ_ENCRYPTED_MITM) Descriptor permission: Allow reading with person-in-the-middle protection | | `int` | [PERMISSION_WRITE](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#PERMISSION_WRITE) Descriptor write permission | | `int` | [PERMISSION_WRITE_ENCRYPTED](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#PERMISSION_WRITE_ENCRYPTED) Descriptor permission: Allow encrypted writes | | `int` | [PERMISSION_WRITE_ENCRYPTED_MITM](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#PERMISSION_WRITE_ENCRYPTED_MITM) Descriptor permission: Allow encrypted writes with person-in-the-middle protection | | `int` | [PERMISSION_WRITE_SIGNED](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#PERMISSION_WRITE_SIGNED) Descriptor permission: Allow signed write operations | | `int` | [PERMISSION_WRITE_SIGNED_MITM](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#PERMISSION_WRITE_SIGNED_MITM) Descriptor permission: Allow signed write operations with person-in-the-middle protection | | ### Inherited constants | |----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | From interface [android.os.Parcelable](https://developer.android.com/reference/android/os/Parcelable) |-------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | `int` | [CONTENTS_FILE_DESCRIPTOR](https://developer.android.com/reference/android/os/Parcelable#CONTENTS_FILE_DESCRIPTOR) Descriptor bit used with [describeContents()](https://developer.android.com/reference/android/os/Parcelable#describeContents()): indicates that the Parcelable object's flattened representation includes a file descriptor. | | `int` | [PARCELABLE_WRITE_RETURN_VALUE](https://developer.android.com/reference/android/os/Parcelable#PARCELABLE_WRITE_RETURN_VALUE) Flag for use with [writeToParcel(Parcel, int)](https://developer.android.com/reference/android/os/Parcelable#writeToParcel(android.os.Parcel,%20int)): the object being written is a return value, that is the result of a function such as "`Parcelable someFunction()`", "`void someFunction(out Parcelable)`", or "`void someFunction(inout Parcelable)`". | | | ### Fields || |---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` public static final `[Creator](https://developer.android.com/reference/android/os/Parcelable.Creator)`<`[BluetoothGattDescriptor](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor)`>` | [CREATOR](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#CREATOR) | | ` public static final byte[]` | [DISABLE_NOTIFICATION_VALUE](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#DISABLE_NOTIFICATION_VALUE) Value used to disable notifications or indications | | ` public static final byte[]` | [ENABLE_INDICATION_VALUE](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#ENABLE_INDICATION_VALUE) Value used to enable indication for a client configuration descriptor | | ` public static final byte[]` | [ENABLE_NOTIFICATION_VALUE](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#ENABLE_NOTIFICATION_VALUE) Value used to enable notification for a client configuration descriptor | | ### Public constructors || |-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---| | ` `[BluetoothGattDescriptor](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#BluetoothGattDescriptor(java.util.UUID,%20int))`(`[UUID](https://developer.android.com/reference/java/util/UUID)` uuid, int permissions) ` Create a new BluetoothGattDescriptor. | | ### Public methods || |-------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` int` | ` `[describeContents](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#describeContents())`() ` Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. | | ` `[BluetoothGattCharacteristic](https://developer.android.com/reference/android/bluetooth/BluetoothGattCharacteristic) | ` `[getCharacteristic](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#getCharacteristic())`() ` Returns the characteristic this descriptor belongs to. | | ` int` | ` `[getPermissions](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#getPermissions())`() ` Returns the permissions for this descriptor. | | ` `[UUID](https://developer.android.com/reference/java/util/UUID) | ` `[getUuid](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#getUuid())`() ` Returns the UUID of this descriptor. | | ` byte[]` | ` `[getValue](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#getValue())`() ` *This method was deprecated in API level 33. Use [BluetoothGatt.readDescriptor(BluetoothGattDescriptor)](https://developer.android.com/reference/android/bluetooth/BluetoothGatt#readDescriptor(android.bluetooth.BluetoothGattDescriptor)) instead* | | ` boolean` | ` `[setValue](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#setValue(byte[]))`(byte[] value) ` *This method was deprecated in API level 33. Pass the descriptor value directly into [BluetoothGatt.writeDescriptor(android.bluetooth.BluetoothGattDescriptor, byte[])](https://developer.android.com/reference/android/bluetooth/BluetoothGatt#writeDescriptor(android.bluetooth.BluetoothGattDescriptor,%20byte[]))* | | ` void` | ` `[writeToParcel](https://developer.android.com/reference/android/bluetooth/BluetoothGattDescriptor#writeToParcel(android.os.Parcel,%20int))`(`[Parcel](https://developer.android.com/reference/android/os/Parcel)` out, int flags) ` Flatten this object in to a Parcel. | | ### Inherited methods | |-----------------------|---| | From class ` `[java.lang.Object](https://developer.android.com/reference/java/lang/Object)` ` |--------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` `[Object](https://developer.android.com/reference/java/lang/Object) | ` `[clone](https://developer.android.com/reference/java/lang/Object#clone())`() ` Creates and returns a copy of this object. | | ` boolean` | ` `[equals](https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object))`(`[Object](https://developer.android.com/reference/java/lang/Object)` obj) ` Indicates whether some other object is "equal to" this one. | | ` void` | ` `[finalize](https://developer.android.com/reference/java/lang/Object#finalize())`() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | | ` final `[Class](https://developer.android.com/reference/java/lang/Class)`` | ` `[getClass](https://developer.android.com/reference/java/lang/Object#getClass())`() ` Returns the runtime class of this `Object`. | | ` int` | ` `[hashCode](https://developer.android.com/reference/java/lang/Object#hashCode())`() ` Returns a hash code value for the object. | | ` final void` | ` `[notify](https://developer.android.com/reference/java/lang/Object#notify())`() ` Wakes up a single thread that is waiting on this object's monitor. | | ` final void` | ` `[notifyAll](https://developer.android.com/reference/java/lang/Object#notifyAll())`() ` Wakes up all threads that are waiting on this object's monitor. | | ` `[String](https://developer.android.com/reference/java/lang/String) | ` `[toString](https://developer.android.com/reference/java/lang/Object#toString())`() ` Returns a string representation of the object. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long,%20int))`(long timeoutMillis, int nanos) ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long))`(long timeoutMillis) ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait())`() ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*. | || | From interface ` `[android.os.Parcelable](https://developer.android.com/reference/android/os/Parcelable)` ` |------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` abstract int` | ` `[describeContents](https://developer.android.com/reference/android/os/Parcelable#describeContents())`() ` Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. | | ` abstract void` | ` `[writeToParcel](https://developer.android.com/reference/android/os/Parcelable#writeToParcel(android.os.Parcel,%20int))`(`[Parcel](https://developer.android.com/reference/android/os/Parcel)` dest, int flags) ` Flatten this object in to a Parcel. | || ## Constants ### PERMISSION_READ Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int PERMISSION_READ ``` Descriptor read permission
Constant Value: 1 (0x00000001) ### PERMISSION_READ_ENCRYPTED Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int PERMISSION_READ_ENCRYPTED ``` Descriptor permission: Allow encrypted read operations
Constant Value: 2 (0x00000002) ### PERMISSION_READ_ENCRYPTED_MITM Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int PERMISSION_READ_ENCRYPTED_MITM ``` Descriptor permission: Allow reading with person-in-the-middle protection
Constant Value: 4 (0x00000004) ### PERMISSION_WRITE Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int PERMISSION_WRITE ``` Descriptor write permission
Constant Value: 16 (0x00000010) ### PERMISSION_WRITE_ENCRYPTED Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int PERMISSION_WRITE_ENCRYPTED ``` Descriptor permission: Allow encrypted writes
Constant Value: 32 (0x00000020) ### PERMISSION_WRITE_ENCRYPTED_MITM Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int PERMISSION_WRITE_ENCRYPTED_MITM ``` Descriptor permission: Allow encrypted writes with person-in-the-middle protection
Constant Value: 64 (0x00000040) ### PERMISSION_WRITE_SIGNED Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int PERMISSION_WRITE_SIGNED ``` Descriptor permission: Allow signed write operations
Constant Value: 128 (0x00000080) ### PERMISSION_WRITE_SIGNED_MITM Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int PERMISSION_WRITE_SIGNED_MITM ``` Descriptor permission: Allow signed write operations with person-in-the-middle protection
Constant Value: 256 (0x00000100) ## Fields ### CREATOR Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final Creator CREATOR ```

### DISABLE_NOTIFICATION_VALUE Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final byte[] DISABLE_NOTIFICATION_VALUE ``` Value used to disable notifications or indications
### ENABLE_INDICATION_VALUE Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final byte[] ENABLE_INDICATION_VALUE ``` Value used to enable indication for a client configuration descriptor
### ENABLE_NOTIFICATION_VALUE Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final byte[] ENABLE_NOTIFICATION_VALUE ``` Value used to enable notification for a client configuration descriptor
## Public constructors ### BluetoothGattDescriptor Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public BluetoothGattDescriptor (UUID uuid, int permissions) ``` Create a new BluetoothGattDescriptor.
| Parameters || |---------------|-----------------------------------------------| | `uuid` | `UUID`: The UUID for this descriptor
| | `permissions` | `int`: Permissions for this descriptor
| ## Public methods ### describeContents Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int describeContents () ``` Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. For example, if the object will include a file descriptor in the output of [writeToParcel(android.os.Parcel, int)](https://developer.android.com/reference/android/os/Parcelable#writeToParcel(android.os.Parcel,%20int)), the return value of this method must include the [CONTENTS_FILE_DESCRIPTOR](https://developer.android.com/reference/android/os/Parcelable#CONTENTS_FILE_DESCRIPTOR) bit.
| Returns || |-------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | `int` | a bitmask indicating the set of special object types marshaled by this Parcelable object instance. Value is either `0` or [CONTENTS_FILE_DESCRIPTOR](https://developer.android.com/reference/android/os/Parcelable#CONTENTS_FILE_DESCRIPTOR)
| ### getCharacteristic Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public BluetoothGattCharacteristic getCharacteristic () ``` Returns the characteristic this descriptor belongs to.
| Returns || |----------------------------------------------------------------------------------------------------------------------|----------------------------| | [BluetoothGattCharacteristic](https://developer.android.com/reference/android/bluetooth/BluetoothGattCharacteristic) | The characteristic.
| ### getPermissions Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int getPermissions () ``` Returns the permissions for this descriptor.
| Returns || |-------|---------------------------------------| | `int` | Permissions of this descriptor
| ### getUuid Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public UUID getUuid () ``` Returns the UUID of this descriptor.
| Returns || |----------------------------------------------------------------|--------------------------------| | [UUID](https://developer.android.com/reference/java/util/UUID) | UUID of this descriptor
| ### getValue Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Deprecated in [API level 33](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public byte[] getValue () ``` **This method was deprecated in API level 33.** Use [BluetoothGatt.readDescriptor(BluetoothGattDescriptor)](https://developer.android.com/reference/android/bluetooth/BluetoothGatt#readDescriptor(android.bluetooth.BluetoothGattDescriptor)) instead Returns the stored value for this descriptor This function returns the stored value for this descriptor as retrieved by calling [BluetoothGatt.readDescriptor(BluetoothGattDescriptor)](https://developer.android.com/reference/android/bluetooth/BluetoothGatt#readDescriptor(android.bluetooth.BluetoothGattDescriptor)). The cached value of the descriptor is updated as a result of a descriptor read operation.
| Returns || |----------|---------------------------------------| | `byte[]` | Cached value of the descriptor
| ### setValue Added in [API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Deprecated in [API level 33](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public boolean setValue (byte[] value) ``` **This method was deprecated in API level 33.** Pass the descriptor value directly into [BluetoothGatt.writeDescriptor(android.bluetooth.BluetoothGattDescriptor, byte[])](https://developer.android.com/reference/android/bluetooth/BluetoothGatt#writeDescriptor(android.bluetooth.BluetoothGattDescriptor,%20byte[])) Updates the locally stored value of this descriptor. This function modifies the locally stored cached value of this descriptor. To send the value to the remote device, call [BluetoothGatt.writeDescriptor](https://developer.android.com/reference/android/bluetooth/BluetoothGatt#writeDescriptor(android.bluetooth.BluetoothGattDescriptor)) to send the value to the remote device.
| Parameters || |---------|----------------------------------------------| | `value` | `byte`: New value for this descriptor
| | Returns || |-----------|-----------------------------------------------------------------------------------------------------------------| | `boolean` | true if the locally stored value has been set, false if the requested value could not be stored locally.
| ### writeToParcel Added in [API level 24](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public void writeToParcel (Parcel out, int flags) ``` Flatten this object in to a Parcel.
| Parameters || |---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | `out` | `Parcel`: The Parcel in which the object should be written. This value cannot be `null`.
| | `flags` | `int`: Additional flags about how the object should be written. May be 0 or [Parcelable.PARCELABLE_WRITE_RETURN_VALUE](https://developer.android.com/reference/android/os/Parcelable#PARCELABLE_WRITE_RETURN_VALUE). Value is either `0` or a combination of [Parcelable.PARCELABLE_WRITE_RETURN_VALUE](https://developer.android.com/reference/android/os/Parcelable#PARCELABLE_WRITE_RETURN_VALUE), and android.os.Parcelable.PARCELABLE_ELIDE_DUPLICATES
|