# Class NdefRecord

java.lang.Object
com.codename1.nfc.NdefRecord

public final class NdefRecord extends Object

A single NDEF (NFC Data Exchange Format) record. An NDEF tag carries one `NdefMessage` which contains one or more `NdefRecord`s.

Most apps construct records via the typed factories: `createText(String, String)` for human-readable text, `createUri(String)` for URIs (the most common payload -- launches the associated app on the device), [#createMime(String, byte[])] for binary MIME payloads, and `createApplicationRecord(String)` for the special Android Application Record (AAR) that pins a tag to a specific package.

The low-level constructor [#NdefRecord(byte, byte[], byte[], byte[])] is available for vendor / external-type records.

Records are immutable -- modify them by building a new instance.

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final byte`
  `TNF_ABSOLUTE_URI`
  TNF -- type is an absolute URI.
  `static final byte`
  `TNF_EMPTY`
  TNF (Type Name Format) -- record contains no payload.
  `static final byte`
  `TNF_EXTERNAL_TYPE`
  TNF -- external type, namespaced as `domain:type` (e.g. `android.com:pkg`).
  `static final byte`
  `TNF_MIME_MEDIA`
  TNF -- type is a MIME media type (RFC 2046).
  `static final byte`
  `TNF_UNCHANGED`
  TNF -- continuation of a chunked record (rare).
  `static final byte`
  `TNF_UNKNOWN`
  TNF -- record is unknown / unparsed.
  `static final byte`
  `TNF_WELL_KNOWN`
  TNF -- type is one of the NFC Forum well-known types (e.g. `T`, `U`, `Sp`).

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `NdefRecord(byte tnf, byte[] type, byte[] id, byte[] payload)`
  Constructs a record from its raw NDEF fields.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `static NdefRecord`
  `createApplicationRecord(String packageName)`
  Builds an Android Application Record (AAR).
  `static NdefRecord`
  `createExternal(String domain, String type, byte[] payload)`
  Builds an external-type record (TNF = `TNF_EXTERNAL_TYPE`).
  `static NdefRecord`
  `createMime(String mimeType, byte[] payload)`
  Builds a MIME media record (TNF = `TNF_MIME_MEDIA`).
  `static NdefRecord`
  `createText(String languageCode, String text)`
  Builds a well-known TEXT (`T`) record per NFC Forum RTD-Text 1.0.
  `static NdefRecord`
  `createUri(String uri)`
  Builds a well-known URI (`U`) record.
  `byte[]`
  `getId()`
  Raw record id.
  `byte[]`
  `getPayload()`
  Raw payload bytes.
  `String`
  `getTextPayload()`
  Convenience: decodes a `createText(String, String)` payload back to its text content.
  `byte`
  `getTnf()`
  One of the `TNF_*` constants.
  `byte[]`
  `getType()`
  Raw type field.
  `String`
  `getUriPayload()`
  Convenience: decodes a `createUri(String)` payload back to its full URI (re-expanding the leading prefix code).
  `static byte[]`
  `rtdAndroidApp()`
  RTD for Android Application Record (external type `android.com:pkg`).
  `static byte[]`
  `rtdSmartPoster()`
  RTD for SmartPoster (URI + title).
  `static byte[]`
  `rtdText()`
  Record Type Definition (RTD) for well-known text records.
  `static byte[]`
  `rtdUri()`
  RTD for well-known URI records.

  ### Methods inherited from class Object

  `clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Field Details

  - ### TNF_EMPTY

    public static final byte TNF_EMPTY
    TNF (Type Name Format) -- record contains no payload.
    See Also:
      - Constant Field Values

  - ### TNF_WELL_KNOWN

    public static final byte TNF_WELL_KNOWN
    TNF -- type is one of the NFC Forum well-known types (e.g. `T`, `U`, `Sp`). See `rtdText()`, `rtdUri()`.
    See Also:
      - Constant Field Values

  - ### TNF_MIME_MEDIA

    public static final byte TNF_MIME_MEDIA
    TNF -- type is a MIME media type (RFC 2046).
    See Also:
      - Constant Field Values

  - ### TNF_ABSOLUTE_URI

    public static final byte TNF_ABSOLUTE_URI
    TNF -- type is an absolute URI.
    See Also:
      - Constant Field Values

  - ### TNF_EXTERNAL_TYPE

    public static final byte TNF_EXTERNAL_TYPE
    TNF -- external type, namespaced as `domain:type` (e.g. `android.com:pkg`).
    See Also:
      - Constant Field Values

  - ### TNF_UNKNOWN

    public static final byte TNF_UNKNOWN
    TNF -- record is unknown / unparsed.
    See Also:
      - Constant Field Values

  - ### TNF_UNCHANGED

    public static final byte TNF_UNCHANGED
    TNF -- continuation of a chunked record (rare).
    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### NdefRecord

    public NdefRecord(byte tnf, byte[] type, byte[] id, byte[] payload)

    Constructs a record from its raw NDEF fields. Most callers should prefer one of the typed factories below.

    ###### Parameters

    - `tnf`: one of the `TNF_*` constants
    - `type`: type field; meaning depends on `tnf` (RTD value, MIME type string bytes, ...). Must not be `null` -- pass an empty array for `TNF_EMPTY` / `TNF_UNKNOWN`
    - `id`: optional record id; pass an empty array if unused
    - `payload`: record payload; must not be `null`

- ## Method Details

  - ### rtdText

    public static byte[] rtdText()
    Record Type Definition (RTD) for well-known text records. Returns a defensive copy so callers cannot mutate the shared constant.

  - ### rtdUri

    public static byte[] rtdUri()
    RTD for well-known URI records.

  - ### rtdSmartPoster

    public static byte[] rtdSmartPoster()
    RTD for SmartPoster (URI + title).

  - ### rtdAndroidApp

    public static byte[] rtdAndroidApp()
    RTD for Android Application Record (external type `android.com:pkg`).

  - ### getTnf

    public byte getTnf()
    One of the `TNF_*` constants.

  - ### getType

    public byte[] getType()
    Raw type field. Defensively copied -- mutating the returned array does not affect the record.

  - ### getId

    public byte[] getId()
    Raw record id. Empty when no id was assigned.

  - ### getPayload

    public byte[] getPayload()
    Raw payload bytes. Defensively copied.

  - ### createText

    public static NdefRecord createText(String languageCode, String text)

    Builds a well-known TEXT (`T`) record per NFC Forum RTD-Text 1.0. The text is UTF-8 encoded; the BCP-47 language tag (e.g. `"en"`, `"ja"`) goes in the leading status byte block.

    ###### Parameters

    - `languageCode`: BCP-47 language tag, `null` defaults to `"en"`. Must be ASCII and at most 63 bytes long
    - `text`: the text payload, UTF-8 (the spec also allows UTF-16; this factory always writes UTF-8)

  - ### createUri

    public static NdefRecord createUri(String uri)
    Builds a well-known URI (`U`) record. Common URI prefixes (`http://www.`, `https://www.`, `tel:`, `mailto:`, ...) are replaced with the one-byte abbreviation codes defined in NFC Forum RTD-URI 1.0 to save tag space.

  - ### createMime

    public static NdefRecord createMime(String mimeType, byte[] payload)
    Builds a MIME media record (TNF = `TNF_MIME_MEDIA`). Use for binary payloads -- images, small structured data, application/vnd.*.

  - ### createExternal

    public static NdefRecord createExternal(String domain, String type, byte[] payload)

    Builds an external-type record (TNF = `TNF_EXTERNAL_TYPE`). The `domain:type` string is encoded as ASCII and stored in the type field; the payload is passed through verbatim.

    External types are the recommended way to ship custom data on a tag without colliding with NFC Forum well-known types.

  - ### createApplicationRecord

    public static NdefRecord createApplicationRecord(String packageName)

    Builds an Android Application Record (AAR). When a tag carrying an AAR is tapped on Android, the OS launches the named package instead of offering the user a chooser. Honoured only on Android -- iOS ignores AARs.

    ###### Parameters

    - `packageName`: e.g. `"com.example.app"`

  - ### getTextPayload

    public String getTextPayload()
    Convenience: decodes a `createText(String, String)` payload back to its text content. Returns `null` if the record is not a well-known text record.

  - ### getUriPayload

    public String getUriPayload()
    Convenience: decodes a `createUri(String)` payload back to its full URI (re-expanding the leading prefix code). Returns `null` if the record is not a recognised URI record.