Added in API level 10

Summary: Constants | Methods | Inherited Methods

MifareUltralight

Kotlin |Java

public final class MifareUltralight
extends Object implements TagTechnology

java.lang.Object
↳	android.nfc.tech.MifareUltralight

Provides access to MIFARE Ultralight properties and I/O operations on a Tag.

Acquire a MifareUltralight object using get(Tag).

MIFARE Ultralight compatible tags have 4 byte pages PAGE_SIZE. The primary operations on an Ultralight tag are readPages(int) and writePage(int, byte).

The original MIFARE Ultralight consists of a 64 byte EEPROM. The first 4 pages are for the OTP area, manufacturer data, and locking bits. They are readable and some bits are writable. The final 12 pages are the user read/write area. For more information see the NXP data sheet MF0ICU1.

The MIFARE Ultralight C consists of a 192 byte EEPROM. The first 4 pages are for OTP, manufacturer data, and locking bits. The next 36 pages are the user read/write area. The next 4 pages are additional locking bits, counters and authentication configuration and are readable. The final 4 pages are for the authentication key and are not readable. For more information see the NXP data sheet MF0ICU2.

Implementation of this class on a Android NFC device is optional. If it is not implemented, then MifareUltralight will never be enumerated in Tag#getTechList. If it is enumerated, then all MifareUltralight I/O operations will be supported. In either case, NfcA will also be enumerated on the tag, because all MIFARE Ultralight tags are also NfcA tags.

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

Summary

Constants
`int`	`PAGE_SIZE` Size of a MIFARE Ultralight page in bytes
`int`	`TYPE_ULTRALIGHT` A MIFARE Ultralight tag
`int`	`TYPE_ULTRALIGHT_C` A MIFARE Ultralight C tag
`int`	`TYPE_UNKNOWN` A MIFARE Ultralight compatible tag of unknown type

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.
`static MifareUltralight`	`get(Tag tag)` Get an instance of `MifareUltralight` for the given tag.
`int`	`getMaxTransceiveLength()` Return the maximum number of bytes that can be sent with `transceive(byte)`.
`Tag`	`getTag()` Get the `Tag` object backing this `TagTechnology` object.
`int`	`getTimeout()` Get the current `transceive(byte)` timeout in milliseconds.
`int`	`getType()` Return the MIFARE Ultralight type of the tag.
`boolean`	`isConnected()` Helper to indicate if I/O operations should be possible.
`byte[]`	`readPages(int pageOffset)` Read 4 pages (16 bytes).
`void`	`setTimeout(int timeout)` Set the `transceive(byte)` timeout in milliseconds.
`byte[]`	`transceive(byte[] data)` Send raw NfcA data to a tag and receive the response.
`void`	`writePage(int pageOffset, byte[] data)` Write 1 page (4 bytes).

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.

Constants

PAGE_SIZE

Added in API level 10

public static final int PAGE_SIZE

Size of a MIFARE Ultralight page in bytes

Constant Value: 4 (0x00000004)

TYPE_ULTRALIGHT

Added in API level 10

public static final int TYPE_ULTRALIGHT

A MIFARE Ultralight tag

Constant Value: 1 (0x00000001)

TYPE_ULTRALIGHT_C

Added in API level 10

public static final int TYPE_ULTRALIGHT_C

A MIFARE Ultralight C tag

Constant Value: 2 (0x00000002)

TYPE_UNKNOWN

Added in API level 10

public static final int TYPE_UNKNOWN

A MIFARE Ultralight compatible tag of unknown type

Constant Value: -1 (0xffffffff)

Public methods

close

Added in API level 10

public void close ()

Disable I/O operations to the tag from this TagTechnology object, and release resources.

Also causes all blocked I/O operations on other thread to be canceled and return with IOException.

Requires the Manifest.permission.NFC permission.

Throws
`IOException`

connect

Added in API level 10

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`

get

Added in API level 10

public static MifareUltralight get (Tag tag)

Get an instance of MifareUltralight for the given tag.

Returns null if MifareUltralight was not enumerated in Tag#getTechList - this indicates the tag is not MIFARE Ultralight compatible, or that this Android device does not implement MIFARE Ultralight.

Does not cause any RF activity and does not block.

Parameters
`tag`	`Tag`: an MIFARE Ultralight compatible tag

Returns
`MifareUltralight`	MIFARE Ultralight object

getMaxTransceiveLength

Added in API level 14

public int getMaxTransceiveLength ()

Return the maximum number of bytes that can be sent with transceive(byte).

Returns
`int`	the maximum number of bytes that can be sent with `transceive(byte)`.

getTag

Added in API level 10

public Tag getTag ()

Get the Tag object backing this TagTechnology object.

Returns
`Tag`	the `Tag` backing this `TagTechnology` object.

getTimeout

Added in API level 14

public int getTimeout ()

Get the current transceive(byte) timeout in milliseconds.

Requires the Manifest.permission.NFC permission.

Returns
`int`	timeout value in milliseconds

Throws
`SecurityException`	if the tag object is reused after the tag has left the field

getType

Added in API level 10

public int getType ()

Return the MIFARE Ultralight type of the tag.

One of TYPE_ULTRALIGHT or TYPE_ULTRALIGHT_C or TYPE_UNKNOWN.

Depending on how the tag has been formatted, it can be impossible to accurately classify between original MIFARE Ultralight and Ultralight C. So treat this method as a hint.

Does not cause any RF activity and does not block.

Returns
`int`	the type

isConnected

Added in API level 10

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

readPages

Added in API level 10

public byte[] readPages (int pageOffset)

Read 4 pages (16 bytes).

The MIFARE Ultralight protocol always reads 4 pages at a time, to reduce the number of commands required to read an entire tag.

If a read spans past the last readable block, then the tag will return pages that have been wrapped back to the first blocks. MIFARE Ultralight tags have readable blocks 0x00 through 0x0F. So a read to block offset 0x0E would return blocks 0x0E, 0x0F, 0x00, 0x01. MIFARE Ultralight C tags have readable blocks 0x00 through 0x2B. So a read to block 0x2A would return blocks 0x2A, 0x2B, 0x00, 0x01.

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
`pageOffset`	`int`: index of first page to read, starting from 0

Returns
`byte[]`	4 pages (16 bytes)

Throws
`TagLostException`	if the tag leaves the field
`IOException`	if there is an I/O failure, or the operation is canceled

setTimeout

Added in API level 14

public void setTimeout (int timeout)

Set the transceive(byte) timeout in milliseconds.

The timeout only applies to transceive(byte) on this object, and is reset to a default value when close() is called.

Setting a longer timeout may be useful when performing transactions that require a long processing time on the tag such as key generation.

Requires the Manifest.permission.NFC permission.

Parameters
`timeout`	`int`: timeout value in milliseconds

Throws
`SecurityException`	if the tag object is reused after the tag has left the field

transceive

Added in API level 10

public byte[] transceive (byte[] data)

Send raw NfcA data to a tag and receive the response.

This is equivalent to connecting to this tag via NfcA and calling NfcA#transceive. Note that all MIFARE Classic tags are based on NfcA technology.

Use getMaxTransceiveLength() to retrieve the maximum number of bytes that can be sent with transceive(byte).

Requires the Manifest.permission.NFC permission.

Parameters
`data`	`byte`

Returns
`byte[]`

Throws
`IOException`

See also:

NfcA.transceive(byte)

writePage

Added in API level 10

public void writePage (int pageOffset, 
                byte[] data)

Write 1 page (4 bytes).

The MIFARE Ultralight protocol always writes 1 page at a time, to minimize EEPROM write cycles.

Requires the Manifest.permission.NFC permission.

Parameters
`pageOffset`	`int`: index of page to write, starting from 0
`data`	`byte`: 4 bytes to write

Throws
`TagLostException`	if the tag leaves the field
`IOException`	if there is an I/O failure, or the operation is canceled