Added in API level 9

NdefRecord


class NdefRecord : Parcelable
kotlin.Any
   ↳ android.nfc.NdefRecord

Represents an immutable NDEF Record.

NDEF (NFC Data Exchange Format) is a light-weight binary format, used to encapsulate typed data. It is specified by the NFC Forum, for transmission and storage with NFC, however it is transport agnostic.

NDEF defines messages and records. An NDEF Record contains typed data, such as MIME-type media, a URI, or a custom application payload. An NDEF Message is a container for one or more NDEF Records.

This class represents logical (complete) NDEF Records, and can not be used to represent chunked (partial) NDEF Records. However NdefMessage#NdefMessage(byte[]) can be used to parse a message containing chunked records, and will return a message with unchunked (complete) records.

A logical NDEF Record always contains a 3-bit TNF (Type Name Field) that provides high level typing for the rest of the record. The remaining fields are variable length and not always present:

  • type: detailed typing for the payload
  • id: identifier meta-data, not commonly used
  • payload: the actual payload

Helpers such as android.nfc.NdefRecord#createUri, NdefRecord#createMime and NdefRecord#createExternal are included to create well-formatted NDEF Records with correctly set tnf, type, id and payload fields, please use these helpers whenever possible.

Use the constructor NdefRecord(short,byte[],byte[],byte[]) if you know what you are doing and what to set the fields individually. Only basic validation is performed with this constructor, so it is possible to create records that do not confirm to the strict NFC Forum specifications.

The binary representation of an NDEF Record includes additional flags to indicate location with an NDEF message, provide support for chunking of NDEF records, and to pack optional fields. This class does not expose those details. To write an NDEF Record as binary you must first put it into an NdefMessage, then call NdefMessage#toByteArray().

NdefMessage and NdefRecord implementations are always available, even on Android devices that do not have NFC hardware.

NdefRecords are intended to be immutable (and thread-safe), however they may contain mutable fields. So take care not to modify mutable fields passed into constructors, or modify mutable fields obtained by getter methods, unless such modification is explicitly marked as safe.

Summary

Constants
static Short

Indicates the type field contains an absolute-URI BNF construct defined by RFC 3986.

static Short

Indicates the record is empty.

static Short

Indicates the type field contains an external type name.

static Short

Indicates the type field contains a media-type BNF construct, defined by RFC 2046.

static Short

Indicates the payload is an intermediate or final chunk of a chunked NDEF Record.

static Short

Indicates the payload type is unknown.

static Short

Indicates the type field contains a well-known RTD type name.

Inherited constants
Public constructors
NdefRecord(tnf: Short, type: ByteArray!, id: ByteArray!, payload: ByteArray!)

Construct an NDEF Record from its component fields.

Construct an NDEF Record from raw bytes.

Public methods
static NdefRecord!

Create a new Android Application Record (AAR).

static NdefRecord!
createExternal(domain: String!, type: String!, data: ByteArray!)

Create a new NDEF Record containing external (application-specific) data.

static NdefRecord!
createMime(mimeType: String!, mimeData: ByteArray!)

Create a new NDEF Record containing MIME data.

static NdefRecord!
createTextRecord(languageCode: String!, text: String!)

Create a new NDEF record containing UTF-8 text data.

static NdefRecord!
createUri(uri: Uri!)

Create a new NDEF Record containing a URI.

static NdefRecord!
createUri(uriString: String!)

Create a new NDEF Record containing a URI.

Int

Boolean
equals(other: Any?)

Returns true if the specified NDEF Record contains identical tnf, type, id and payload fields.

ByteArray!

Returns the variable length ID.

ByteArray!

Returns the variable length payload.

Short

Returns the 3-bit TNF.

ByteArray!

Returns the variable length Type field.

Int

ByteArray!

Return this NDEF Record as a byte array.

String!

Map this record to a MIME type, or return null if it cannot be mapped.

String

Uri!

Map this record to a URI, or return null if it cannot be mapped.

Unit
writeToParcel(dest: Parcel, flags: Int)

Properties
static Parcelable.Creator<NdefRecord!>

static ByteArray!

RTD Alternative Carrier type.

static ByteArray!

RTD Handover Carrier type.

static ByteArray!

RTD Handover Request type.

static ByteArray!

RTD Handover Select type.

static ByteArray!

RTD Smart Poster type.

static ByteArray!

RTD Text type.

static ByteArray!

RTD URI type.

Constants

TNF_ABSOLUTE_URI

Added in API level 9
static val TNF_ABSOLUTE_URI: Short

Indicates the type field contains an absolute-URI BNF construct defined by RFC 3986.

When creating new records prefer #createUri, since it offers more compact URI encoding (#RTD_URI allows compression of common URI prefixes).

Value: 3

See Also

    TNF_EMPTY

    Added in API level 9
    static val TNF_EMPTY: Short

    Indicates the record is empty.

    Type, id and payload fields are empty in a TNF_EMPTY record.

    Value: 0

    TNF_EXTERNAL_TYPE

    Added in API level 9
    static val TNF_EXTERNAL_TYPE: Short

    Indicates the type field contains an external type name.

    Used to encode custom payloads. When creating new records use the helper createExternal.

    The external-type RTD format is specified in NFCForum-TS-RTD_1.0.

    Note this TNF should not be used with RTD_TEXT or RTD_URI constants. Those are well known RTD constants, not external RTD constants.

    Value: 4

    See Also

    TNF_MIME_MEDIA

    Added in API level 9
    static val TNF_MIME_MEDIA: Short

    Indicates the type field contains a media-type BNF construct, defined by RFC 2046.

    Use this with MIME type names such as "image/jpeg", or using the helper createMime.

    Value: 2

    See Also

    TNF_UNCHANGED

    Added in API level 9
    static val TNF_UNCHANGED: Short

    Indicates the payload is an intermediate or final chunk of a chunked NDEF Record.

    TNF_UNCHANGED can not be used with this class since all NdefRecords are already unchunked, however they may appear in the binary format.

    Value: 6

    TNF_UNKNOWN

    Added in API level 9
    static val TNF_UNKNOWN: Short

    Indicates the payload type is unknown.

    NFC Forum explains this should be treated similarly to the "application/octet-stream" MIME type. The payload type is not explicitly encoded within the record.

    The type field is empty in an TNF_UNKNOWN record.

    Value: 5

    TNF_WELL_KNOWN

    Added in API level 9
    static val TNF_WELL_KNOWN: Short

    Indicates the type field contains a well-known RTD type name.

    Use this tnf with RTD types such as RTD_TEXT, RTD_URI.

    The RTD type name format is specified in NFCForum-TS-RTD_1.0.

    Value: 1

    Public constructors

    NdefRecord

    Added in API level 9
    NdefRecord(
        tnf: Short,
        type: ByteArray!,
        id: ByteArray!,
        payload: ByteArray!)

    Construct an NDEF Record from its component fields.

    Recommend to use helpers such as {#createUri} or {createExternal where possible, since they perform stricter validation that the record is correctly formatted as per NDEF specifications. However if you know what you are doing then this constructor offers the most flexibility.

    An NdefRecord represents a logical (complete) record, and cannot represent NDEF Record chunks.

    Basic validation of the tnf, type, id and payload is performed as per the following rules:

    • The tnf paramter must be a 3-bit value.
    • Records with a tnf of TNF_EMPTY cannot have a type, id or payload.
    • Records with a tnf of TNF_UNKNOWN or 0x07 cannot have a type.
    • Records with a tnf of TNF_UNCHANGED are not allowed since this class only represents complete (unchunked) records.
    This minimal validation is specified by NFCForum-TS-NDEF_1.0 section 3.2.6 (Type Name Format).

    If any of the above validation steps fail then IllegalArgumentException is thrown.

    Deep inspection of the type, id and payload fields is not performed, so it is possible to create NDEF Records that conform to section 3.2.6 but fail other more strict NDEF specification requirements. For example, the payload may be invalid given the tnf and type.

    To omit a type, id or payload field, set the parameter to an empty byte array or null.

    Parameters
    tnf Short: a 3-bit TNF constant
    type ByteArray!: byte array, containing zero to 255 bytes, or null
    id ByteArray!: byte array, containing zero to 255 bytes, or null
    payload ByteArray!: byte array, containing zero to (2 ** 32 - 1) bytes, or null
    Exceptions
    IllegalArugmentException if a valid record cannot be created

    NdefRecord

    Added in API level 9
    NdefRecord(data: ByteArray!)

    Deprecated: use NdefMessage#NdefMessage(byte[]) instead.

    Construct an NDEF Record from raw bytes.

    This method is deprecated, use NdefMessage#NdefMessage(byte[]) instead. This is because it does not make sense to parse a record: the NDEF binary format is only defined for a message, and the record flags MB and ME do not make sense outside of the context of an entire message.

    This implementation will attempt to parse a single record by ignoring the MB and ME flags, and otherwise following the rules of NdefMessage#NdefMessage(byte[]).

    Parameters
    data ByteArray!: raw bytes to parse
    Exceptions
    android.nfc.FormatException if the data cannot be parsed into a valid record

    Public methods

    createApplicationRecord

    Added in API level 14
    static fun createApplicationRecord(packageName: String!): NdefRecord!

    Create a new Android Application Record (AAR).

    This record indicates to other Android devices the package that should be used to handle the entire NDEF message. You can embed this record anywhere into your message to ensure that the intended package receives the message.

    When an Android device dispatches an NdefMessage containing one or more Android application records, the applications contained in those records will be the preferred target for the NfcAdapter#ACTION_NDEF_DISCOVERED intent, in the order in which they appear in the message. This dispatch behavior was first added to Android in Ice Cream Sandwich.

    If none of the applications have a are installed on the device, a Market link will be opened to the first application.

    Note that Android application records do not overrule applications that have called NfcAdapter#enableForegroundDispatch.

    Parameters
    packageName String!: Android package name
    Return
    NdefRecord! Android application NDEF record

    createExternal

    Added in API level 16
    static fun createExternal(
        domain: String!,
        type: String!,
        data: ByteArray!
    ): NdefRecord!

    Create a new NDEF Record containing external (application-specific) data.

    Use this method to encode application specific data into an NDEF Record. The data is typed by a domain name (usually your Android package name) and a domain-specific type. This data is packaged into a "NFC Forum External Type" NDEF Record.

    NFC Forum requires that the domain and type used in an external record are treated as case insensitive, however Android intent filtering is always case sensitive. So this method will force the domain and type to lower-case before creating the NDEF Record.

    The unchecked exception IllegalArgumentException will be thrown if the domain and type have serious problems, for example if either field is empty, so always catch this exception if you are passing user-generated data into this method.

    There are no such restrictions on the payload data.

    For efficiency, This method might not make an internal copy of the data byte array, so take care not to modify the data byte array while still using the returned NdefRecord. Reference specification: NFCForum-TS-RTD_1.0

    Parameters
    domain String!: domain-name of issuing organization
    type String!: domain-specific type of data
    data ByteArray!: payload as bytes
    Exceptions
    IllegalArugmentException if either domain or type are empty or invalid

    createMime

    Added in API level 16
    static fun createMime(
        mimeType: String!,
        mimeData: ByteArray!
    ): NdefRecord!

    Create a new NDEF Record containing MIME data.

    Use this method to encode MIME-typed data into an NDEF Record, such as "text/plain", or "image/jpeg".

    The mimeType parameter will be normalized with Intent#normalizeMimeType to follow Android best practices for intent filtering, for example to force lower-case. However the unchecked exception IllegalArgumentException may be thrown if the mimeType parameter has serious problems, for example if it is empty, so always catch this exception if you are passing user-generated data into this method.

    For efficiency, This method might not make an internal copy of the mimeData byte array, so take care not to modify the mimeData byte array while still using the returned NdefRecord.

    Parameters
    mimeType String!: a valid MIME type
    mimeData ByteArray!: MIME data as bytes
    Return
    NdefRecord! an NDEF Record containing the MIME-typed data
    Exceptions
    IllegalArugmentException if the mimeType is empty or invalid

    createTextRecord

    Added in API level 21
    static fun createTextRecord(
        languageCode: String!,
        text: String!
    ): NdefRecord!

    Create a new NDEF record containing UTF-8 text data.

    The caller can either specify the language code for the provided text, or otherwise the language code corresponding to the current default locale will be used. Reference specification: NFCForum-TS-RTD_Text_1.0

    Parameters
    languageCode String!: The languageCode for the record. If locale is empty or null, the language code of the current default locale will be used.
    text String!: The text to be encoded in the record. Will be represented in UTF-8 format.
    Exceptions
    java.lang.IllegalArgumentException if text is null

    createUri

    Added in API level 14
    static fun createUri(uri: Uri!): NdefRecord!

    Create a new NDEF Record containing a URI.

    Use this method to encode a URI (or URL) into an NDEF Record.

    Uses the well known URI type representation: TNF_WELL_KNOWN and RTD_URI. This is the most efficient encoding of a URI into NDEF.

    The uri parameter will be normalized with Uri#normalizeScheme to set the scheme to lower case to follow Android best practices for intent filtering. However the unchecked exception IllegalArgumentException may be thrown if the uri parameter has serious problems, for example if it is empty, so always catch this exception if you are passing user-generated data into this method.

    Reference specification: NFCForum-TS-RTD_URI_1.0

    Parameters
    uri Uri!: URI to encode.
    Return
    NdefRecord! an NDEF Record containing the URI
    Exceptions
    IllegalArugmentException if the uri is empty or invalid

    createUri

    Added in API level 14
    static fun createUri(uriString: String!): NdefRecord!

    Create a new NDEF Record containing a URI.

    Use this method to encode a URI (or URL) into an NDEF Record.

    Uses the well known URI type representation: TNF_WELL_KNOWN and RTD_URI. This is the most efficient encoding of a URI into NDEF.

    The uriString parameter will be normalized with Uri#normalizeScheme to set the scheme to lower case to follow Android best practices for intent filtering. However the unchecked exception IllegalArgumentException may be thrown if the uriString parameter has serious problems, for example if it is empty, so always catch this exception if you are passing user-generated data into this method.

    Reference specification: NFCForum-TS-RTD_URI_1.0

    Parameters
    uriString String!: string URI to encode.
    Return
    NdefRecord! an NDEF Record containing the URI
    Exceptions
    IllegalArugmentException if the uriString is empty or invalid

    describeContents

    Added in API level 9
    fun describeContents(): Int
    Return
    Int a bitmask indicating the set of special object types marshaled by this Parcelable object instance. Value is either 0 or android.os.Parcelable#CONTENTS_FILE_DESCRIPTOR

    equals

    Added in API level 9
    fun equals(other: Any?): Boolean

    Returns true if the specified NDEF Record contains identical tnf, type, id and payload fields.

    Parameters
    obj This value may be null.
    Return
    Boolean true if this object is the same as the obj argument; false otherwise.

    getId

    Added in API level 9
    fun getId(): ByteArray!

    Returns the variable length ID.

    Returns an empty byte array if this record does not have an id field.

    getPayload

    Added in API level 9
    fun getPayload(): ByteArray!

    Returns the variable length payload.

    Returns an empty byte array if this record does not have a payload field.

    getTnf

    Added in API level 9
    fun getTnf(): Short

    Returns the 3-bit TNF.

    TNF is the top-level type.

    getType

    Added in API level 9
    fun getType(): ByteArray!

    Returns the variable length Type field.

    This should be used in conjunction with the TNF field to determine the payload format.

    Returns an empty byte array if this record does not have a type field.

    hashCode

    Added in API level 9
    fun hashCode(): Int
    Return
    Int a hash code value for this object.

    toByteArray

    Added in API level 9
    Deprecated in API level 16
    fun toByteArray(): ByteArray!

    Deprecated: use NdefMessage#toByteArray() instead

    Return this NDEF Record as a byte array.

    This method is deprecated, use NdefMessage#toByteArray instead. This is because the NDEF binary format is not defined for a record outside of the context of a message: the MB and ME flags cannot be set without knowing the location inside a message.

    This implementation will attempt to serialize a single record by always setting the MB and ME flags (in other words, assume this is a single-record NDEF Message).

    toMimeType

    Added in API level 16
    fun toMimeType(): String!

    Map this record to a MIME type, or return null if it cannot be mapped.

    Currently this method considers all TNF_MIME_MEDIA records to be MIME records, as well as some TNF_WELL_KNOWN records such as RTD_TEXT. If this is a MIME record then the MIME type as string is returned, otherwise null is returned.

    This method does not perform validation that the MIME type is actually valid. It always attempts to return a string containing the type if this is a MIME record.

    The returned MIME type will by normalized to lower-case using Intent#normalizeMimeType.

    The MIME payload can be obtained using getPayload.

    Return
    String! MIME type as a string, or null if this is not a MIME record

    toString

    Added in API level 9
    fun toString(): String
    Return
    String a string representation of the object.

    toUri

    Added in API level 16
    fun toUri(): Uri!

    Map this record to a URI, or return null if it cannot be mapped.

    Currently this method considers the following to be URI records:

    If this is not a URI record by the above rules, then null is returned.

    This method does not perform validation that the URI is actually valid: it always attempts to create and return a URI if this record appears to be a URI record by the above rules.

    The returned URI will be normalized to have a lower case scheme using Uri#normalizeScheme.

    Return
    Uri! URI, or null if this is not a URI record

    writeToParcel

    Added in API level 9
    fun writeToParcel(
        dest: Parcel,
        flags: Int
    ): Unit
    Parameters
    dest 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_WRITE_RETURN_VALUE. Value is either 0 or a combination of android.os.Parcelable#PARCELABLE_WRITE_RETURN_VALUE, and android.os.Parcelable.PARCELABLE_ELIDE_DUPLICATES

    Properties

    CREATOR

    Added in API level 9
    static val CREATOR: Parcelable.Creator<NdefRecord!>

    RTD_ALTERNATIVE_CARRIER

    Added in API level 9
    static val RTD_ALTERNATIVE_CARRIER: ByteArray!

    RTD Alternative Carrier type. For use with TNF_WELL_KNOWN.

    See Also

    RTD_HANDOVER_CARRIER

    Added in API level 9
    static val RTD_HANDOVER_CARRIER: ByteArray!

    RTD Handover Carrier type. For use with TNF_WELL_KNOWN.

    See Also

    RTD_HANDOVER_REQUEST

    Added in API level 9
    static val RTD_HANDOVER_REQUEST: ByteArray!

    RTD Handover Request type. For use with TNF_WELL_KNOWN.

    See Also

    RTD_HANDOVER_SELECT

    Added in API level 9
    static val RTD_HANDOVER_SELECT: ByteArray!

    RTD Handover Select type. For use with TNF_WELL_KNOWN.

    See Also

    RTD_SMART_POSTER

    Added in API level 9
    static val RTD_SMART_POSTER: ByteArray!

    RTD Smart Poster type. For use with TNF_WELL_KNOWN.

    See Also

    RTD_TEXT

    Added in API level 9
    static val RTD_TEXT: ByteArray!

    RTD Text type. For use with TNF_WELL_KNOWN.

    See Also

    RTD_URI

    Added in API level 9
    static val RTD_URI: ByteArray!

    RTD URI type. For use with TNF_WELL_KNOWN.

    See Also