NdefFormatable | API reference | Android Developers

public final class NdefFormatable
extends Object implements TagTechnology

Provide access to NDEF format operations on a Tag.

Acquire a NdefFormatable object using get(Tag).

Android devices with NFC must only enumerate and implement this class for tags for which it can format to NDEF.

Unfortunately the procedures to convert unformated tags to NDEF formatted tags are not specified by NFC Forum, and are not generally well-known. So there is no mandatory set of tags for which all Android devices with NFC must support NdefFormatable.

Note: Methods that perform I/O operations require the Manifest.permission.NFC permission.

Summary

Public methods
`void`	`close()` Disable I/O operations to the tag from this `TagTechnology` object, and release resources.
`void`	`connect()` Enable I/O operations to the tag from this `TagTechnology` object.
`void`	`format(NdefMessage firstMessage)` Format a tag as NDEF, and write a `NdefMessage`.
`void`	`formatReadOnly(NdefMessage firstMessage)` Formats a tag as NDEF, write a `NdefMessage`, and make read-only.
`static NdefFormatable`	`get(Tag tag)` Get an instance of `NdefFormatable` for the given tag.
`Tag`	`getTag()` Get the `Tag` object backing this `TagTechnology` object.
`boolean`	`isConnected()` Helper to indicate if I/O operations should be possible.

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.nfc.tech.TagTechnology

`abstract void`	`close()` Disable I/O operations to the tag from this `TagTechnology` object, and release resources.
`abstract void`	`connect()` Enable I/O operations to the tag from this `TagTechnology` object.
`abstract Tag`	`getTag()` Get the `Tag` object backing this `TagTechnology` object.
`abstract boolean`	`isConnected()` Helper to indicate if I/O operations should be possible.

From interface java.io.Closeable


      close()

Closes this stream and releases any system resources associated with it.

From interface java.lang.AutoCloseable


      close()

Closes this resource, relinquishing any underlying resources.

Public methods

connect

public void connect ()

Enable I/O operations to the tag from this TagTechnology object.

May cause RF activity and may block. Must not be called from the main application thread. A blocked call will be canceled with IOException by calling close() from another thread.

Only one TagTechnology object can be connected to a Tag at a time.

Applications must call close() when I/O operations are complete.

Requires the Manifest.permission.NFC permission.

Throws
`IOException`

format

public void format (NdefMessage firstMessage)

Format a tag as NDEF, and write a NdefMessage.

This is a multi-step process, an IOException is thrown if any one step fails.

The card is left in a read-write state after this operation.

This is an I/O operation and will block until complete. It must not be called from the main application thread. A blocked call will be canceled with IOException if close() is called from another thread.

Requires the Manifest.permission.NFC permission.

Parameters
`firstMessage`	`NdefMessage`: the NDEF message to write after formatting, can be null

Throws
`FormatException`	if the NDEF Message to write is malformed
`TagLostException`	if the tag leaves the field
`IOException`	if there is an I/O failure, or the operation is canceled

formatReadOnly

public void formatReadOnly (NdefMessage firstMessage)

Formats a tag as NDEF, write a NdefMessage, and make read-only.

This is a multi-step process, an IOException is thrown if any one step fails.

The card is left in a read-only state if this method returns successfully.

Requires the Manifest.permission.NFC permission.

Parameters
`firstMessage`	`NdefMessage`: the NDEF message to write after formatting

Throws
`FormatException`	if the NDEF Message to write is malformed
`TagLostException`	if the tag leaves the field
`IOException`	if there is an I/O failure, or the operation is canceled
`SecurityException`	if the tag object is reused after the tag has left the field

get

public static NdefFormatable get (Tag tag)

Get an instance of NdefFormatable for the given tag.

Does not cause any RF activity and does not block.

Returns null if NdefFormatable was not enumerated in Tag.getTechList. This indicates the tag is not NDEF formatable by this Android device.

Parameters
`tag`	`Tag`: an NDEF formatable tag

Returns
`NdefFormatable`	NDEF formatable object

isConnected

public boolean isConnected ()

Helper to indicate if I/O operations should be possible.

Returns true if connect() has completed, and close() has not been called, and the Tag is not known to be out of range.

Does not cause RF activity, and does not block.

Returns
`boolean`	true if I/O operations should be possible