Added in API level 18

Summary: Constants | Inherited Constants | Fields | Ctors | Methods | Inherited Methods

BluetoothGattCharacteristic

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Kotlin |Java

public class BluetoothGattCharacteristic
extends Object implements Parcelable

java.lang.Object
↳	android.bluetooth.BluetoothGattCharacteristic

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Represents a Bluetooth GATT Characteristic

A GATT characteristic is a basic data element used to construct a GATT service, BluetoothGattService. The characteristic contains a value as well as additional information and optional GATT descriptors, BluetoothGattDescriptor.

Summary

Constants
int	FORMAT_FLOAT Characteristic value format type float (32-bit float)
int	FORMAT_SFLOAT Characteristic value format type sfloat (16-bit float)
int	FORMAT_SINT16 Characteristic value format type sint16
int	FORMAT_SINT32 Characteristic value format type sint32
int	FORMAT_SINT8 Characteristic value format type sint8
int	FORMAT_UINT16 Characteristic value format type uint16
int	FORMAT_UINT32 Characteristic value format type uint32
int	FORMAT_UINT8 Characteristic value format type uint8
int	PERMISSION_READ Characteristic read permission
int	PERMISSION_READ_ENCRYPTED Characteristic permission: Allow encrypted read operations
int	PERMISSION_READ_ENCRYPTED_MITM Characteristic permission: Allow reading with person-in-the-middle protection
int	PERMISSION_WRITE Characteristic write permission
int	PERMISSION_WRITE_ENCRYPTED Characteristic permission: Allow encrypted writes
int	PERMISSION_WRITE_ENCRYPTED_MITM Characteristic permission: Allow encrypted writes with person-in-the-middle protection
int	PERMISSION_WRITE_SIGNED Characteristic permission: Allow signed write operations
int	PERMISSION_WRITE_SIGNED_MITM Characteristic permission: Allow signed write operations with person-in-the-middle protection
int	PROPERTY_BROADCAST Characteristic property: Characteristic is broadcastable.
int	PROPERTY_EXTENDED_PROPS Characteristic property: Characteristic has extended properties
int	PROPERTY_INDICATE Characteristic property: Characteristic supports indication
int	PROPERTY_NOTIFY Characteristic property: Characteristic supports notification
int	PROPERTY_READ Characteristic property: Characteristic is readable.
int	PROPERTY_SIGNED_WRITE Characteristic property: Characteristic supports write with signature
int	PROPERTY_WRITE Characteristic property: Characteristic can be written.
int	PROPERTY_WRITE_NO_RESPONSE Characteristic property: Characteristic can be written without response.
int	WRITE_TYPE_DEFAULT Write characteristic, requesting acknowledgement by the remote device
int	WRITE_TYPE_NO_RESPONSE Write characteristic without requiring a response by the remote device
int	WRITE_TYPE_SIGNED Write characteristic including authentication signature

Inherited constants

From interface android.os.Parcelable int CONTENTS_FILE_DESCRIPTOR Descriptor bit used with describeContents(): indicates that the Parcelable object's flattened representation includes a file descriptor. int PARCELABLE_WRITE_RETURN_VALUE Flag for use with writeToParcel(Parcel, int): 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<BluetoothGattCharacteristic>	CREATOR
protected List<BluetoothGattDescriptor>	mDescriptors List of descriptors included in this characteristic.

Public constructors
BluetoothGattCharacteristic(UUID uuid, int properties, int permissions) Create a new BluetoothGattCharacteristic.

Public methods
boolean	addDescriptor(BluetoothGattDescriptor descriptor) Adds a descriptor to this characteristic.
int	describeContents() Describe the kinds of special objects contained in this Parcelable instance's marshaled representation.
BluetoothGattDescriptor	getDescriptor(UUID uuid) Returns a descriptor with a given UUID out of the list of descriptors for this characteristic.
List<BluetoothGattDescriptor>	getDescriptors() Returns a list of descriptors for this characteristic.
Float	getFloatValue(int formatType, int offset) This method was deprecated in API level 33. Use BluetoothGatt#readCharacteristic(BluetoothGattCharacteristic) to get the characteristic value
int	getInstanceId() Returns the instance ID for this characteristic.
Integer	getIntValue(int formatType, int offset) This method was deprecated in API level 33. Use BluetoothGatt#readCharacteristic(BluetoothGattCharacteristic) to get the characteristic value
int	getPermissions() Returns the permissions for this characteristic.
int	getProperties() Returns the properties of this characteristic.
BluetoothGattService	getService() Returns the service this characteristic belongs to.
String	getStringValue(int offset) This method was deprecated in API level 33. Use BluetoothGatt#readCharacteristic(BluetoothGattCharacteristic) to get the characteristic value
UUID	getUuid() Returns the UUID of this characteristic
byte[]	getValue() This method was deprecated in API level 33. Use BluetoothGatt#readCharacteristic(BluetoothGattCharacteristic) instead
int	getWriteType() Gets the write type for this characteristic.
boolean	setValue(String value) This method was deprecated in API level 33. Pass the characteristic value directly into BluetoothGatt.writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int)
boolean	setValue(int value, int formatType, int offset) This method was deprecated in API level 33. Pass the characteristic value directly into BluetoothGatt.writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int)
boolean	setValue(byte[] value) This method was deprecated in API level 33. Pass the characteristic value directly into BluetoothGatt.writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int)
boolean	setValue(int mantissa, int exponent, int formatType, int offset) This method was deprecated in API level 33. Pass the characteristic value directly into BluetoothGatt.writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int)
void	setWriteType(int writeType) Set the write type for this characteristic Setting the write type of a characteristic determines how the BluetoothGatt.writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int) function write this characteristic.
void	writeToParcel(Parcel out, int flags) Flatten this object in to a Parcel.

Inherited methods
From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(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(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() Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
From interface android.os.Parcelable abstract int describeContents() Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. abstract void writeToParcel(Parcel dest, int flags) Flatten this object in to a Parcel.

Constants

FORMAT_FLOAT

Added in API level 18

public static final int FORMAT_FLOAT

Characteristic value format type float (32-bit float)

Constant Value: 52 (0x00000034)

FORMAT_SFLOAT

Added in API level 18

public static final int FORMAT_SFLOAT

Characteristic value format type sfloat (16-bit float)

Constant Value: 50 (0x00000032)

FORMAT_SINT16

Added in API level 18

public static final int FORMAT_SINT16

Characteristic value format type sint16

Constant Value: 34 (0x00000022)

FORMAT_SINT32

Added in API level 18

public static final int FORMAT_SINT32

Characteristic value format type sint32

Constant Value: 36 (0x00000024)

FORMAT_SINT8

Added in API level 18

public static final int FORMAT_SINT8

Characteristic value format type sint8

Constant Value: 33 (0x00000021)

FORMAT_UINT16

Added in API level 18

public static final int FORMAT_UINT16

Characteristic value format type uint16

Constant Value: 18 (0x00000012)

FORMAT_UINT32

Added in API level 18

public static final int FORMAT_UINT32

Characteristic value format type uint32

Constant Value: 20 (0x00000014)

FORMAT_UINT8

Added in API level 18

public static final int FORMAT_UINT8

Characteristic value format type uint8

Constant Value: 17 (0x00000011)

PERMISSION_READ

Added in API level 18

public static final int PERMISSION_READ

Characteristic read permission

Constant Value: 1 (0x00000001)

PERMISSION_READ_ENCRYPTED

Added in API level 18

public static final int PERMISSION_READ_ENCRYPTED

Characteristic permission: Allow encrypted read operations

Constant Value: 2 (0x00000002)

PERMISSION_READ_ENCRYPTED_MITM

Added in API level 18

public static final int PERMISSION_READ_ENCRYPTED_MITM

Characteristic permission: Allow reading with person-in-the-middle protection

Constant Value: 4 (0x00000004)

PERMISSION_WRITE

Added in API level 18

public static final int PERMISSION_WRITE

Characteristic write permission

Constant Value: 16 (0x00000010)

PERMISSION_WRITE_ENCRYPTED

Added in API level 18

public static final int PERMISSION_WRITE_ENCRYPTED

Characteristic permission: Allow encrypted writes

Constant Value: 32 (0x00000020)

PERMISSION_WRITE_ENCRYPTED_MITM

Added in API level 18

public static final int PERMISSION_WRITE_ENCRYPTED_MITM

Characteristic permission: Allow encrypted writes with person-in-the-middle protection

Constant Value: 64 (0x00000040)

PERMISSION_WRITE_SIGNED

Added in API level 18

public static final int PERMISSION_WRITE_SIGNED

Characteristic permission: Allow signed write operations

Constant Value: 128 (0x00000080)

PERMISSION_WRITE_SIGNED_MITM

Added in API level 18

public static final int PERMISSION_WRITE_SIGNED_MITM

Characteristic permission: Allow signed write operations with person-in-the-middle protection

Constant Value: 256 (0x00000100)

PROPERTY_BROADCAST

Added in API level 18

public static final int PROPERTY_BROADCAST

Characteristic property: Characteristic is broadcastable.

Constant Value: 1 (0x00000001)

PROPERTY_EXTENDED_PROPS

Added in API level 18

public static final int PROPERTY_EXTENDED_PROPS

Characteristic property: Characteristic has extended properties

Constant Value: 128 (0x00000080)

PROPERTY_INDICATE

Added in API level 18

public static final int PROPERTY_INDICATE

Characteristic property: Characteristic supports indication

Constant Value: 32 (0x00000020)

PROPERTY_NOTIFY

Added in API level 18

public static final int PROPERTY_NOTIFY

Characteristic property: Characteristic supports notification

Constant Value: 16 (0x00000010)

PROPERTY_READ

Added in API level 18

public static final int PROPERTY_READ

Characteristic property: Characteristic is readable.

Constant Value: 2 (0x00000002)

PROPERTY_SIGNED_WRITE

Added in API level 18

public static final int PROPERTY_SIGNED_WRITE

Characteristic property: Characteristic supports write with signature

Constant Value: 64 (0x00000040)

PROPERTY_WRITE

Added in API level 18

public static final int PROPERTY_WRITE

Characteristic property: Characteristic can be written.

Constant Value: 8 (0x00000008)

PROPERTY_WRITE_NO_RESPONSE

Added in API level 18

public static final int PROPERTY_WRITE_NO_RESPONSE

Characteristic property: Characteristic can be written without response.

Constant Value: 4 (0x00000004)

WRITE_TYPE_DEFAULT

Added in API level 18

public static final int WRITE_TYPE_DEFAULT

Write characteristic, requesting acknowledgement by the remote device

Constant Value: 2 (0x00000002)

WRITE_TYPE_NO_RESPONSE

Added in API level 18

public static final int WRITE_TYPE_NO_RESPONSE

Write characteristic without requiring a response by the remote device

Constant Value: 1 (0x00000001)

WRITE_TYPE_SIGNED

Added in API level 18

public static final int WRITE_TYPE_SIGNED

Write characteristic including authentication signature

Constant Value: 4 (0x00000004)

Fields

CREATOR

Added in API level 24

public static final Creator<BluetoothGattCharacteristic> CREATOR

mDescriptors

Added in API level 18

protected List<BluetoothGattDescriptor> mDescriptors

List of descriptors included in this characteristic.

Public constructors

BluetoothGattCharacteristic

Added in API level 18

public BluetoothGattCharacteristic (UUID uuid, 
                int properties, 
                int permissions)

Create a new BluetoothGattCharacteristic.

Parameters
uuid	UUID: The UUID for this characteristic
properties	int: Properties of this characteristic
permissions	int: Permissions for this characteristic

Public methods

addDescriptor

Added in API level 18

public boolean addDescriptor (BluetoothGattDescriptor descriptor)

Adds a descriptor to this characteristic.

Parameters
descriptor	BluetoothGattDescriptor: Descriptor to be added to this characteristic.

Returns
boolean	true, if the descriptor was added to the characteristic

describeContents

Added in API level 24

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), the return value of this method must include the 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

getDescriptor

Added in API level 18

public BluetoothGattDescriptor getDescriptor (UUID uuid)

Returns a descriptor with a given UUID out of the list of descriptors for this characteristic.

Parameters
uuid	UUID

Returns
BluetoothGattDescriptor	GATT descriptor object or null if no descriptor with the given UUID was found.

getDescriptors

Added in API level 18

public List<BluetoothGattDescriptor> getDescriptors ()

Returns a list of descriptors for this characteristic.

Returns
List<BluetoothGattDescriptor>	Descriptors for this characteristic

getFloatValue

Added in API level 18
Deprecated in API level 33

public Float getFloatValue (int formatType, 
                int offset)

This method was deprecated in API level 33.
Use BluetoothGatt#readCharacteristic(BluetoothGattCharacteristic) to get the characteristic value

Return the stored value of this characteristic.

See getValue() for details.

Parameters
formatType	int: The format type used to interpret the characteristic value.
offset	int: Offset at which the float value can be found.

Returns
Float	Cached value of the characteristic at a given offset or null if the requested offset exceeds the value size.

getInstanceId

Added in API level 18

public int getInstanceId ()

Returns the instance ID for this characteristic.

If a remote device offers multiple characteristics with the same UUID, the instance ID is used to distuinguish between characteristics.

Returns
int	Instance ID of this characteristic

getIntValue

Added in API level 18
Deprecated in API level 33

public Integer getIntValue (int formatType, 
                int offset)

This method was deprecated in API level 33.
Use BluetoothGatt#readCharacteristic(BluetoothGattCharacteristic) to get the characteristic value

Return the stored value of this characteristic.

The formatType parameter determines how the characteristic value is to be interpreted. For example, setting formatType to FORMAT_UINT16 specifies that the first two bytes of the characteristic value at the given offset are interpreted to generate the return value.

Parameters
formatType	int: The format type used to interpret the characteristic value.
offset	int: Offset at which the integer value can be found.

Returns
Integer	Cached value of the characteristic or null of offset exceeds value size.

getPermissions

Added in API level 18

public int getPermissions ()

Returns the permissions for this characteristic.

Returns
int	Permissions of this characteristic

getProperties

Added in API level 18

public int getProperties ()

Returns the properties of this characteristic.

The properties contain a bit mask of property flags indicating the features of this characteristic.

Returns
int	Properties of this characteristic

getService

Added in API level 18

public BluetoothGattService getService ()

Returns the service this characteristic belongs to.

Returns
BluetoothGattService	The associated service

getStringValue

Added in API level 18
Deprecated in API level 33

public String getStringValue (int offset)

This method was deprecated in API level 33.
Use BluetoothGatt#readCharacteristic(BluetoothGattCharacteristic) to get the characteristic value

Return the stored value of this characteristic.

See getValue() for details.

Parameters
offset	int: Offset at which the string value can be found.

Returns
String	Cached value of the characteristic

getUuid

Added in API level 18

public UUID getUuid ()

Returns the UUID of this characteristic

Returns
UUID	UUID of this characteristic

getValue

Added in API level 18
Deprecated in API level 33

public byte[] getValue ()

This method was deprecated in API level 33.
Use BluetoothGatt#readCharacteristic(BluetoothGattCharacteristic) instead

Get the stored value for this characteristic.

This function returns the stored value for this characteristic as retrieved by calling BluetoothGatt#readCharacteristic. The cached value of the characteristic is updated as a result of a read characteristic operation or if a characteristic update notification has been received.

Returns
byte[]	Cached value of the characteristic

getWriteType

Added in API level 18

public int getWriteType ()

Gets the write type for this characteristic.

Returns
int	Write type for this characteristic

setValue

Added in API level 18
Deprecated in API level 33

public boolean setValue (String value)

This method was deprecated in API level 33.
Pass the characteristic value directly into BluetoothGatt.writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int)

Set the locally stored value of this characteristic.

See setValue(byte[]) for details.

Parameters
value	String: New value for this characteristic

Returns
boolean	true if the locally stored value has been set

setValue

Added in API level 18
Deprecated in API level 33

public boolean setValue (int value, 
                int formatType, 
                int offset)

This method was deprecated in API level 33.
Pass the characteristic value directly into BluetoothGatt.writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int)

Set the locally stored value of this characteristic.

See setValue(byte[]) for details.

Parameters
value	int: New value for this characteristic
formatType	int: Integer format type used to transform the value parameter
offset	int: Offset at which the value should be placed

Returns
boolean	true if the locally stored value has been set

setValue

Added in API level 18
Deprecated in API level 33

public boolean setValue (byte[] value)

This method was deprecated in API level 33.
Pass the characteristic value directly into BluetoothGatt.writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int)

Updates the locally stored value of this characteristic.

This function modifies the locally stored cached value of this characteristic. To send the value to the remote device, call BluetoothGatt#writeCharacteristic to send the value to the remote device.

Parameters
value	byte: New value for this characteristic

Returns
boolean	true if the locally stored value has been set, false if the requested value could not be stored locally.

setValue

Added in API level 18
Deprecated in API level 33

public boolean setValue (int mantissa, 
                int exponent, 
                int formatType, 
                int offset)

This method was deprecated in API level 33.
Pass the characteristic value directly into BluetoothGatt.writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int)

Set the locally stored value of this characteristic.

See setValue(byte[]) for details.

Parameters
mantissa	int: Mantissa for this characteristic
exponent	int: exponent value for this characteristic
formatType	int: Float format type used to transform the value parameter
offset	int: Offset at which the value should be placed

Returns
boolean	true if the locally stored value has been set

setWriteType

Added in API level 18

public void setWriteType (int writeType)

Set the write type for this characteristic

Setting the write type of a characteristic determines how the BluetoothGatt.writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int) function write this characteristic.

Parameters
writeType	int: The write type to for this characteristic. Can be one of: WRITE_TYPE_DEFAULT, WRITE_TYPE_NO_RESPONSE or WRITE_TYPE_SIGNED.

writeToParcel

Added in API level 24

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. Value is either 0 or a combination of Parcelable.PARCELABLE_WRITE_RETURN_VALUE, and android.os.Parcelable.PARCELABLE_ELIDE_DUPLICATES