public
interface
TagTechnology
implements
Closeable
| android.nfc.tech.TagTechnology |
 Known Indirect Subclasses
|
TagTechnology is an interface to a technology in a Tag.
Obtain a TagTechnology implementation by calling the static method get()
on the implementation class.
NFC tags are based on a number of independently developed technologies and offer a
wide range of capabilities. The
TagTechnology implementations provide access to these different
technologies and capabilities. Some sub-classes map to technology
specification (for example NfcA, IsoDep, others map to
pseudo-technologies or capabilities (for example Ndef, NdefFormatable).
It is mandatory for all Android NFC devices to provide the following
TagTechnology implementations.
Developers
NfcA (also known as ISO 14443-3A)
NfcB (also known as ISO 14443-3B)
NfcF (also known as JIS 6319-4)
NfcV (also known as ISO 15693)
IsoDep
Ndef on NFC Forum Type 1, Type 2, Type 3 or Type 4 compliant tags
TagTechnology implementations. If it is not provided, the
Android device will never enumerate that class via getTechList().
MifareClassic
MifareUltralight
NfcBarcode
NdefFormatable must only be enumerated on tags for which this Android device
is capable of formatting. Proprietary knowledge is often required to format a tag
to make it NDEF compatible.
TagTechnology implementations provide methods that fall into two classes:
cached getters and I/O operations.
get or is) return
properties of the tag, as determined at discovery time. These methods will never
block or cause RF activity, and do not require connect() to have been called.
They also never update, for example if a property is changed by an I/O operation with a tag
then the cached getter will still return the result from tag discovery time.
connect() must be called before using any other I/O operation.
close() must be called after completing I/O operations with a
TagTechnology, and it will cancel all other blocked I/O operations on other threads
(including connect() with IOException.
TagTechnology can be connected at a time. Other calls to
connect() will return IOException.
Note: Methods that perform I/O operations
require the NFC permission.
Public methods | |
|---|---|
abstract
void
|
close()
Disable I/O operations to the tag from this |
abstract
void
|
connect()
Enable I/O operations to the tag from this |
abstract
Tag
|
getTag()
Get the |
abstract
boolean
|
isConnected()
Helper to indicate if I/O operations should be possible. |
Inherited methods | |
|---|---|
From
interface
java.io.Closeable
| |
From
interface
java.lang.AutoCloseable
| |
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 NFC permission.
| Throws | |
|---|---|
IOException |
|
See also:
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 NFC permission.
| Throws | |
|---|---|
|
if the tag leaves the field |
IOException |
if there is an I/O failure, or connect is canceled |
See also:
Tag getTag ()
Get the Tag object backing this TagTechnology object.
| Returns | |
|---|---|
Tag |
the Tag backing this TagTechnology object.
|
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 |