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TagTechnology.java API Doc Android 5.1 API 8743 Thu Mar 12 22:22:10 GMT 2015 android.nfc.tech

TagTechnology

public interface TagTechnology implements Closeable

{@link TagTechnology} is an interface to a technology in a {@link Tag}.

Obtain a {@link 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 {@link TagTechnology} implementations provide access to these different technologies and capabilities. Some sub-classes map to technology specification (for example {@link NfcA}, {@link IsoDep}, others map to pseudo-technologies or capabilities (for example {@link Ndef}, {@link NdefFormatable}).

It is mandatory for all Android NFC devices to provide the following {@link TagTechnology} implementations.

{@link NfcA} (also known as ISO 14443-3A)
{@link NfcB} (also known as ISO 14443-3B)
{@link NfcF} (also known as JIS 6319-4)
{@link NfcV} (also known as ISO 15693)
{@link IsoDep}
{@link Ndef} on NFC Forum Type 1, Type 2, Type 3 or Type 4 compliant tags

It is optional for Android NFC devices to provide the following {@link TagTechnology} implementations. If it is not provided, the Android device will never enumerate that class via {@link Tag#getTechList}.

{@link MifareClassic}
{@link MifareUltralight}
{@link NfcBarcode}
{@link 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.

{@link TagTechnology} implementations provide methods that fall into two classes: cached getters and I/O operations.

Cached getters

These methods (usually prefixed by 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 {@link #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.

I/O operations

I/O operations may require RF activity, and may block. They have the following semantics.

{@link #connect} must be called before using any other I/O operation.
{@link #close} must be called after completing I/O operations with a {@link TagTechnology}, and it will cancel all other blocked I/O operations on other threads (including {@link #connect} with {@link IOException}.
Only one {@link TagTechnology} can be connected at a time. Other calls to {@link #connect} will return {@link IOException}.
I/O operations may block, and should never be called on the main application thread.

Note: Methods that perform I/O operations require the {@link android.Manifest.permission#NFC} permission.

Fields Summary
public static final int
NFC_A
This technology is an instance of {@link NfcA}.
Support for this technology type is mandatory.
public static final int
NFC_B
This technology is an instance of {@link NfcB}.
Support for this technology type is mandatory.
public static final int
ISO_DEP
This technology is an instance of {@link IsoDep}.
Support for this technology type is mandatory.
public static final int
NFC_F
This technology is an instance of {@link NfcF}.
Support for this technology type is mandatory.
public static final int
NFC_V
This technology is an instance of {@link NfcV}.
Support for this technology type is mandatory.
public static final int
NDEF
This technology is an instance of {@link Ndef}.
Support for this technology type is mandatory.
public static final int
NDEF_FORMATABLE
This technology is an instance of {@link NdefFormatable}.
Support for this technology type is mandatory.
public static final int
MIFARE_CLASSIC
This technology is an instance of {@link MifareClassic}.
Support for this technology type is optional. If a stack doesn't support this technology type tags using it must still be discovered and present the lower level radio interface technologies in use.
public static final int
MIFARE_ULTRALIGHT
This technology is an instance of {@link MifareUltralight}.
Support for this technology type is optional. If a stack doesn't support this technology type tags using it must still be discovered and present the lower level radio interface technologies in use.
public static final int
NFC_BARCODE
This technology is an instance of {@link NfcBarcode}.
Support for this technology type is optional. If a stack doesn't support this technology type tags using it must still be discovered and present the lower level radio interface technologies in use.
Constructors Summary
Methods Summary
public void close()
Disable I/O operations to the tag from this {@link TagTechnology} object, and release resources.
Also causes all blocked I/O operations on other thread to be canceled and return with {@link IOException}.
Requires the {@link android.Manifest.permission#NFC} permission.
see
#connect()
public void connect()
Enable I/O operations to the tag from this {@link 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 {@link IOException} by calling {@link #close} from another thread.
Only one {@link TagTechnology} object can be connected to a {@link Tag} at a time.
Applications must call {@link #close} when I/O operations are complete.
Requires the {@link android.Manifest.permission#NFC} permission.
see
#close()
throws
TagLostException if the tag leaves the field
throws
IOException if there is an I/O failure, or connect is canceled
public android.nfc.Tag getTag()
Get the {@link Tag} object backing this {@link TagTechnology} object.
return
the {@link Tag} backing this {@link TagTechnology} object.
public boolean isConnected()
Helper to indicate if I/O operations should be possible.
Returns true if {@link #connect} has completed, and {@link #close} has not been called, and the {@link Tag} is not known to be out of range.
Does not cause RF activity, and does not block.
return
true if I/O operations should be possible
public void reconnect()
Re-connect to the {@link Tag} associated with this connection. Reconnecting to a tag can be used to reset the state of the tag itself.
May cause RF activity and may block. Must not be called from the main application thread. A blocked call will be canceled with {@link IOException} by calling {@link #close} from another thread.
Requires the {@link android.Manifest.permission#NFC} permission.
see
#connect()
see
#close()
throws
TagLostException if the tag leaves the field
throws
IOException if there is an I/O failure, or connect is canceled
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