NfcAdapter

ACTION_ADAPTER_STATE_CHANGED

public static final String ACTION_ADAPTER_STATE_CHANGED

Broadcast Action: The state of the local NFC adapter has been changed.

For example, NFC has been turned on or off.

Always contains the extra field EXTRA_ADAPTER_STATE

Constant Value: "android.nfc.action.ADAPTER_STATE_CHANGED"

ACTION_CHANGE_TAG_INTENT_PREFERENCE

public static final String ACTION_CHANGE_TAG_INTENT_PREFERENCE

Activity action: Bring up the settings page that allows the user to enable or disable tag intent reception for apps.

This will direct user to the settings page shows a list that asks users whether they want to allow or disallow the package to start an activity when a tag is discovered.

Constant Value: "android.nfc.action.CHANGE_TAG_INTENT_PREFERENCE"

ACTION_NDEF_DISCOVERED

public static final String ACTION_NDEF_DISCOVERED

Intent to start an activity when a tag with NDEF payload is discovered.

The system inspects the first NdefRecord in the first NdefMessage and looks for a URI, SmartPoster, or MIME record. If a URI or SmartPoster record is found the intent will contain the URI in its data field. If a MIME record is found the intent will contain the MIME type in its type field. This allows activities to register IntentFilters targeting specific content on tags. Activities should register the most specific intent filters possible to avoid the activity chooser dialog, which can disrupt the interaction with the tag as the user interacts with the screen.

If the tag has an NDEF payload this intent is started before ACTION_TECH_DISCOVERED. If any activities respond to this intent neither ACTION_TECH_DISCOVERED or ACTION_TAG_DISCOVERED will be started.

The MIME type or data URI of this intent are normalized before dispatch - so that MIME, URI scheme and URI host are always lower-case.

Constant Value: "android.nfc.action.NDEF_DISCOVERED"

ACTION_PREFERRED_PAYMENT_CHANGED

public static final String ACTION_PREFERRED_PAYMENT_CHANGED

Broadcast Action: Intent to notify if the preferred payment service changed.

This intent will only be sent to the application has requested permission for Manifest.permission.NFC_PREFERRED_PAYMENT_INFO and if the application has the necessary access to Secure Element which witnessed the particular event.
Requires Manifest.permission.NFC_PREFERRED_PAYMENT_INFO

Constant Value: "android.nfc.action.PREFERRED_PAYMENT_CHANGED"

ACTION_TAG_DISCOVERED

public static final String ACTION_TAG_DISCOVERED

Intent to start an activity when a tag is discovered.

This intent will not be started when a tag is discovered if any activities respond to ACTION_NDEF_DISCOVERED or ACTION_TECH_DISCOVERED for the current tag.

Constant Value: "android.nfc.action.TAG_DISCOVERED"

ACTION_TECH_DISCOVERED

public static final String ACTION_TECH_DISCOVERED

Intent to start an activity when a tag is discovered and activities are registered for the specific technologies on the tag.

To receive this intent an activity must include an intent filter for this action and specify the desired tech types in a manifest meta-data entry. Here is an example manfiest entry:

 <activity android:name=".nfc.TechFilter" android:label="NFC/TechFilter">
     <!-- Add a technology filter -->
     <intent-filter>
         <action android:name="android.nfc.action.TECH_DISCOVERED" />
     </intent-filter>

     <meta-data android:name="android.nfc.action.TECH_DISCOVERED"
         android:resource="@xml/filter_nfc"
     />
 </activity>

The meta-data XML file should contain one or more tech-list entries each consisting or one or more tech entries. The tech entries refer to the qualified class name implementing the technology, for example "android.nfc.tech.NfcA".

A tag matches if any of the tech-list sets is a subset of Tag.getTechList(). Each of the tech-lists is considered independently and the activity is considered a match is any single tech-list matches the tag that was discovered. This provides AND and OR semantics for filtering desired techs. Here is an example that will match any tag using NfcF or any tag using NfcA, MifareClassic, and Ndef:

 <resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
     <!-- capture anything using NfcF -->
     <tech-list>
         <tech>android.nfc.tech.NfcF</tech>
     </tech-list>

     <!-- OR -->

     <!-- capture all MIFARE Classics with NDEF payloads -->
     <tech-list>
         <tech>android.nfc.tech.NfcA</tech>
         <tech>android.nfc.tech.MifareClassic</tech>
         <tech>android.nfc.tech.Ndef</tech>
     </tech-list>
 </resources>

This intent is started after ACTION_NDEF_DISCOVERED and before ACTION_TAG_DISCOVERED. If any activities respond to ACTION_NDEF_DISCOVERED this intent will not be started. If any activities respond to this intent ACTION_TAG_DISCOVERED will not be started.

Constant Value: "android.nfc.action.TECH_DISCOVERED"

ACTION_TRANSACTION_DETECTED

public static final String ACTION_TRANSACTION_DETECTED

Broadcast Action: Intent to notify an application that a transaction event has occurred on the Secure Element.

This intent will only be sent if the application has requested permission for Manifest.permission.NFC_TRANSACTION_EVENT and if the application has the necessary access to Secure Element which witnessed the particular event.
Requires Manifest.permission.NFC_TRANSACTION_EVENT

Constant Value: "android.nfc.action.TRANSACTION_DETECTED"

EXTRA_ADAPTER_STATE

public static final String EXTRA_ADAPTER_STATE

Used as an int extra field in ACTION_ADAPTER_STATE_CHANGED intents to request the current power state. Possible values are: STATE_OFF, STATE_TURNING_ON, STATE_ON, STATE_TURNING_OFF,

Constant Value: "android.nfc.extra.ADAPTER_STATE"

EXTRA_AID

public static final String EXTRA_AID

Mandatory byte[] extra field in ACTION_TRANSACTION_DETECTED

Constant Value: "android.nfc.extra.AID"

EXTRA_DATA

public static final String EXTRA_DATA

Optional byte[] extra field in ACTION_TRANSACTION_DETECTED

Constant Value: "android.nfc.extra.DATA"

EXTRA_ID

public static final String EXTRA_ID

Optional extra containing a byte array containing the ID of the discovered tag for the ACTION_NDEF_DISCOVERED, ACTION_TECH_DISCOVERED, and ACTION_TAG_DISCOVERED intents.

Constant Value: "android.nfc.extra.ID"

EXTRA_NDEF_MESSAGES

public static final String EXTRA_NDEF_MESSAGES

Extra containing an array of NdefMessage present on the discovered tag.

This extra is mandatory for ACTION_NDEF_DISCOVERED intents, and optional for ACTION_TECH_DISCOVERED, and ACTION_TAG_DISCOVERED intents.

When this extra is present there will always be at least one NdefMessage element. Most NDEF tags have only one NDEF message, but we use an array for future compatibility.

Constant Value: "android.nfc.extra.NDEF_MESSAGES"

EXTRA_PREFERRED_PAYMENT_CHANGED_REASON

public static final String EXTRA_PREFERRED_PAYMENT_CHANGED_REASON

Mandatory String extra field in ACTION_PREFERRED_PAYMENT_CHANGED Indicates the condition when trigger this event. Possible values are: PREFERRED_PAYMENT_LOADED, PREFERRED_PAYMENT_CHANGED, PREFERRED_PAYMENT_UPDATED,

Constant Value: "android.nfc.extra.PREFERRED_PAYMENT_CHANGED_REASON"

EXTRA_READER_PRESENCE_CHECK_DELAY

public static final String EXTRA_READER_PRESENCE_CHECK_DELAY

Int Extra for use with enableReaderMode(android.app.Activity, android.nfc.NfcAdapter.ReaderCallback, int, android.os.Bundle).

Setting this integer extra allows the calling application to specify the delay that the platform will use for performing presence checks on any discovered tag.

Constant Value: "presence"

EXTRA_SECURE_ELEMENT_NAME

public static final String EXTRA_SECURE_ELEMENT_NAME

Mandatory String extra field in ACTION_TRANSACTION_DETECTED Indicates the Secure Element on which the transaction occurred. eSE1...eSEn for Embedded Secure Elements, SIM1...SIMn for UICC/EUICC, etc.

Constant Value: "android.nfc.extra.SECURE_ELEMENT_NAME"

EXTRA_TAG

public static final String EXTRA_TAG

Mandatory extra containing the Tag that was discovered for the ACTION_NDEF_DISCOVERED, ACTION_TECH_DISCOVERED, and ACTION_TAG_DISCOVERED intents.

Constant Value: "android.nfc.extra.TAG"

FLAG_LISTEN_DISABLE

public static final int FLAG_LISTEN_DISABLE

Flags for use with setDiscoveryTechnology(android.app.Activity, int, int).

Setting this flag disables listening.

Constant Value: 0 (0x00000000)

FLAG_LISTEN_KEEP

public static final int FLAG_LISTEN_KEEP

Flags for use with setDiscoveryTechnology(android.app.Activity, int, int).

Setting this flag makes listening to be set to the current stored default technology configuration.

Constant Value: -2147483648 (0x80000000)

FLAG_LISTEN_NFC_PASSIVE_A

public static final int FLAG_LISTEN_NFC_PASSIVE_A

Flag for use with setDiscoveryTechnology(android.app.Activity, int, int).

Setting this flag enables listening for Nfc-A technology.

Constant Value: 1 (0x00000001)

FLAG_LISTEN_NFC_PASSIVE_B

public static final int FLAG_LISTEN_NFC_PASSIVE_B

Flag for use with setDiscoveryTechnology(android.app.Activity, int, int).

Setting this flag enables listening for Nfc-B technology.

Constant Value: 2 (0x00000002)

FLAG_LISTEN_NFC_PASSIVE_F

public static final int FLAG_LISTEN_NFC_PASSIVE_F

Flag for use with setDiscoveryTechnology(android.app.Activity, int, int).

Setting this flag enables listening for Nfc-F technology.

Constant Value: 4 (0x00000004)

FLAG_READER_DISABLE

public static final int FLAG_READER_DISABLE

Flags for use with setDiscoveryTechnology(android.app.Activity, int, int).

Setting this flag disables polling.

Constant Value: 0 (0x00000000)

FLAG_READER_KEEP

public static final int FLAG_READER_KEEP

Flags for use with setDiscoveryTechnology(android.app.Activity, int, int).

Setting this flag makes polling to be set to the current stored default technology configuration.

Constant Value: -2147483648 (0x80000000)

FLAG_READER_NFC_A

public static final int FLAG_READER_NFC_A

Flag for use with enableReaderMode(android.app.Activity, android.nfc.NfcAdapter.ReaderCallback, int, android.os.Bundle).

Setting this flag enables polling for Nfc-A technology.

Constant Value: 1 (0x00000001)

FLAG_READER_NFC_B

public static final int FLAG_READER_NFC_B

Flag for use with enableReaderMode(android.app.Activity, android.nfc.NfcAdapter.ReaderCallback, int, android.os.Bundle).

Setting this flag enables polling for Nfc-B technology.

Constant Value: 2 (0x00000002)

FLAG_READER_NFC_BARCODE

public static final int FLAG_READER_NFC_BARCODE

Flag for use with enableReaderMode(android.app.Activity, android.nfc.NfcAdapter.ReaderCallback, int, android.os.Bundle).

Setting this flag enables polling for NfcBarcode technology.

Constant Value: 16 (0x00000010)

FLAG_READER_NFC_F

public static final int FLAG_READER_NFC_F

Flag for use with enableReaderMode(android.app.Activity, android.nfc.NfcAdapter.ReaderCallback, int, android.os.Bundle).

Setting this flag enables polling for Nfc-F technology.

Constant Value: 4 (0x00000004)

FLAG_READER_NFC_V

public static final int FLAG_READER_NFC_V

Flag for use with enableReaderMode(android.app.Activity, android.nfc.NfcAdapter.ReaderCallback, int, android.os.Bundle).

Setting this flag enables polling for Nfc-V (ISO15693) technology.

Constant Value: 8 (0x00000008)

FLAG_READER_NO_PLATFORM_SOUNDS

public static final int FLAG_READER_NO_PLATFORM_SOUNDS

Flag for use with enableReaderMode(android.app.Activity, android.nfc.NfcAdapter.ReaderCallback, int, android.os.Bundle).

Setting this flag allows the caller to prevent the platform from playing sounds when it discovers a tag.

Constant Value: 256 (0x00000100)

FLAG_READER_SKIP_NDEF_CHECK

public static final int FLAG_READER_SKIP_NDEF_CHECK

Flag for use with enableReaderMode(android.app.Activity, android.nfc.NfcAdapter.ReaderCallback, int, android.os.Bundle).

Setting this flag allows the caller to prevent the platform from performing an NDEF check on the tags it finds.

Constant Value: 128 (0x00000080)

PREFERRED_PAYMENT_CHANGED

public static final int PREFERRED_PAYMENT_CHANGED

User selected another payment application as the preferred payment.

Constant Value: 2 (0x00000002)

PREFERRED_PAYMENT_LOADED

public static final int PREFERRED_PAYMENT_LOADED

Nfc is enabled and the preferred payment aids are registered.

Constant Value: 1 (0x00000001)

PREFERRED_PAYMENT_UPDATED

public static final int PREFERRED_PAYMENT_UPDATED

Current preferred payment has issued an update (registered/unregistered new aids or has been updated itself).

Constant Value: 3 (0x00000003)

STATE_OFF

public static final int STATE_OFF

Constant Value: 1 (0x00000001)

STATE_ON

public static final int STATE_ON

Constant Value: 3 (0x00000003)

STATE_TURNING_OFF

public static final int STATE_TURNING_OFF

Constant Value: 4 (0x00000004)

STATE_TURNING_ON

public static final int STATE_TURNING_ON

Constant Value: 2 (0x00000002)

disable

public boolean disable ()

Disable NFC hardware.

No NFC features will work after this call, and the hardware will not perform or respond to any NFC communication.

This call is asynchronous. Listen for ACTION_ADAPTER_STATE_CHANGED broadcasts to find out when the operation is complete.

This API is only allowed to be called by system apps or apps which are Device Owner or Profile Owner.

If this returns true, then either NFC is already off, or a ACTION_ADAPTER_STATE_CHANGED broadcast will be sent to indicate a state transition. If this returns false, then there is some problem that prevents an attempt to turn NFC off.
Requires Manifest.permission.WRITE_SECURE_SETTINGS

disableForegroundDispatch

public void disableForegroundDispatch (Activity activity)

Disable foreground dispatch to the given activity.

After calling enableForegroundDispatch(Activity, PendingIntent, IntentFilter, String), an activity must call this method before its Activity.onPause callback completes.

This method must be called from the main thread.

Requires the Manifest.permission.NFC permission.

disableReaderMode

public void disableReaderMode (Activity activity)

Restore the NFC adapter to normal mode of operation: supporting peer-to-peer (Android Beam), card emulation, and polling for all supported tag technologies.

enable

public boolean enable ()

Enable NFC hardware.

This call is asynchronous. Listen for ACTION_ADAPTER_STATE_CHANGED broadcasts to find out when the operation is complete.

This API is only allowed to be called by system apps or apps which are Device Owner or Profile Owner.

If this returns true, then either NFC is already on, or a ACTION_ADAPTER_STATE_CHANGED broadcast will be sent to indicate a state transition. If this returns false, then there is some problem that prevents an attempt to turn NFC on (for example we are in airplane mode and NFC is not toggleable in airplane mode on this platform).
Requires Manifest.permission.WRITE_SECURE_SETTINGS

enableForegroundDispatch

public void enableForegroundDispatch (Activity activity, 
                PendingIntent intent, 
                IntentFilter[] filters, 
                String[][] techLists)

Enable foreground dispatch to the given Activity.

This will give priority to the foreground activity when dispatching a discovered Tag to an application.

If any IntentFilters are provided to this method they are used to match dispatch Intents for both the NfcAdapter.ACTION_NDEF_DISCOVERED and NfcAdapter.ACTION_TAG_DISCOVERED. Since NfcAdapter.ACTION_TECH_DISCOVERED relies on meta data outside of the IntentFilter matching for that dispatch Intent is handled by passing in the tech lists separately. Each first level entry in the tech list represents an array of technologies that must all be present to match. If any of the first level sets match then the dispatch is routed through the given PendingIntent. In other words, the second level is ANDed together and the first level entries are ORed together.

If you pass null for both the filters and techLists parameters that acts a wild card and will cause the foreground activity to receive all tags via the NfcAdapter.ACTION_TAG_DISCOVERED intent.

This method must be called from the main thread, and only when the activity is in the foreground (resumed). Also, activities must call disableForegroundDispatch(Activity) before the completion of their Activity.onPause callback to disable foreground dispatch after it has been enabled.

Requires the Manifest.permission.NFC permission.

enableReaderMode

public void enableReaderMode (Activity activity, 
                NfcAdapter.ReaderCallback callback, 
                int flags, 
                Bundle extras)

Limit the NFC controller to reader mode while this Activity is in the foreground.

In this mode the NFC controller will only act as an NFC tag reader/writer, thus disabling any peer-to-peer (Android Beam) and card-emulation modes of the NFC adapter on this device.

Use FLAG_READER_SKIP_NDEF_CHECK to prevent the platform from performing any NDEF checks in reader mode. Note that this will prevent the Ndef tag technology from being enumerated on the tag, and that NDEF-based tag dispatch will not be functional.

For interacting with tags that are emulated on another Android device using Android's host-based card-emulation, the recommended flags are FLAG_READER_NFC_A and FLAG_READER_SKIP_NDEF_CHECK.

getDefaultAdapter

public static NfcAdapter getDefaultAdapter (Context context)

Helper to get the default NFC Adapter.

Most Android devices will only have one NFC Adapter (NFC Controller).

This helper is the equivalent of:

 NfcManager manager = (NfcManager) context.getSystemService(Context.NFC_SERVICE);
 NfcAdapter adapter = manager.getDefaultAdapter();

getNfcAntennaInfo

public NfcAntennaInfo getNfcAntennaInfo ()

Returns information regarding Nfc antennas on the device such as their relative positioning on the device.

ignore

public boolean ignore (Tag tag, 
                int debounceMs, 
                NfcAdapter.OnTagRemovedListener tagRemovedListener, 
                Handler handler)

Signals that you are no longer interested in communicating with an NFC tag for as long as it remains in range. All future attempted communication to this tag will fail with ERROR(/IOException). The NFC controller will be put in a low-power polling mode, allowing the device to save power in cases where it's "attached" to a tag all the time (e.g. a tag in car dock). Additionally the debounceMs parameter allows you to specify for how long the tag needs to have gone out of range, before it will be dispatched again. Note: the NFC controller typically polls at a pretty slow interval (100 - 500 ms). This means that if the tag repeatedly goes in and out of range (for example, in case of a flaky connection), and the controller happens to poll every time the tag is out of range, it *will* re-dispatch the tag after debounceMs, despite the tag having been "in range" during the interval. Note 2: if a tag with another UID is detected after this API is called, its effect will be cancelled; if this tag shows up before the amount of time specified in debounceMs, it will be dispatched again. Note 3: some tags have a random UID, in which case this API won't work reliably.

isEnabled

public boolean isEnabled ()

Return true if this NFC Adapter has any features enabled.

If this method returns false, the NFC hardware is guaranteed not to generate or respond to any NFC communication over its NFC radio.

Applications can use this to check if NFC is enabled. Applications can request Settings UI allowing the user to toggle NFC using:

startActivity(new Intent(Settings.ACTION_NFC_SETTINGS))

isExitFramesSupported

public boolean isExitFramesSupported ()

Returns whether the device supports exit frames or not. Exit frames allow device firmware to handle the transition out of observe mode for certain auto-transacting polling loop filters . Polling loop filters set by the default wallet role holder (RoleManager.ROLE_WALLET) will be prioritized for use with exit frames.

isObserveModeEnabled

public boolean isObserveModeEnabled ()

Returns whether Observe Mode is currently enabled or not.

isObserveModeSupported

public boolean isObserveModeSupported ()

Returns whether the device supports observe mode or not. When observe mode is enabled, the NFC hardware will listen to NFC readers, but not respond to them. While enabled, observed polling frames will be sent to the APDU service (see setObserveModeEnabled(boolean). When observe mode is disabled (or if it's not supported), the NFC hardware will automatically respond to the reader and proceed with the transaction.

isPowerSavingModeEnabled

public boolean isPowerSavingModeEnabled ()

Returns whether power-saving mode is currently enabled or not.

isPowerSavingModeSupported

public boolean isPowerSavingModeSupported ()

Returns whether the device supports power-saving mode or not.

isReaderOptionEnabled

public boolean isReaderOptionEnabled ()

Checks NFC Reader option feature is enabled.

isReaderOptionSupported

public boolean isReaderOptionSupported ()

Checks if the device supports NFC Reader option functionality.

isSecureNfcEnabled

public boolean isSecureNfcEnabled ()

Checks Secure NFC feature is enabled.

isSecureNfcSupported

public boolean isSecureNfcSupported ()

Checks if the device supports Secure NFC functionality.

isTagIntentAllowed

public boolean isTagIntentAllowed ()

Checks whether the user has disabled the calling app from receiving NFC tag intents.

This method checks whether the caller package name is either not present in the user disabled list or is explicitly allowed by the user.

isTagIntentAppPreferenceSupported

public boolean isTagIntentAppPreferenceSupported ()

Checks if the device supports Tag Intent App Preference functionality. When supported, ACTION_NDEF_DISCOVERED, ACTION_TECH_DISCOVERED or ACTION_TAG_DISCOVERED will not be dispatched to an Activity if ERROR(/isTagIntentAllowed) returns false.

resetDiscoveryTechnology

public void resetDiscoveryTechnology (Activity activity)

Restore the poll/listen technologies of NFC controller to its default state, which were changed by setDiscoveryTechnology(android.app.Activity, int, int)

setDiscoveryTechnology

public void setDiscoveryTechnology (Activity activity, 
                int pollTechnology, 
                int listenTechnology)

Set the NFC controller to enable specific poll/listen technologies, as specified in parameters, while this Activity is in the foreground. Use FLAG_READER_KEEP to keep current polling technology. Use FLAG_LISTEN_KEEP to keep current listenig technology. (if the _KEEP flag is specified the other technology flags shouldn't be set and are quietly ignored otherwise). Use FLAG_READER_DISABLE to disable polling. Use FLAG_LISTEN_DISABLE to disable listening. Also refer to resetDiscoveryTechnology(android.app.Activity) to restore these changes.

                    Poll                    Listen
  Passive A         0x01   (NFC_A)           0x01  (NFC_PASSIVE_A)
  Passive B         0x02   (NFC_B)           0x02  (NFC_PASSIVE_B)
  Passive F         0x04   (NFC_F)           0x04  (NFC_PASSIVE_F)
  ISO 15693         0x08   (NFC_V)             -
  Kovio             0x10   (NFC_BARCODE)       -
 

Example usage in an Activity that requires to disable poll, keep current listen technologies:

 protected void onResume() {
     mNfcAdapter = NfcAdapter.getDefaultAdapter(getApplicationContext());
     mNfcAdapter.setDiscoveryTechnology(this,
         NfcAdapter.FLAG_READER_DISABLE, NfcAdapter.FLAG_LISTEN_KEEP);
 }

setObserveModeEnabled

public boolean setObserveModeEnabled (boolean enabled)

Controls whether the NFC adapter will allow transactions to proceed or be in observe mode and simply observe and notify the APDU service of polling loop frames. See isObserveModeSupported() for a description of observe mode. Only the package of the currently preferred service (the service set as preferred by the current foreground application via CardEmulation.setPreferredService(Activity, android.content.ComponentName) or the current Default Wallet Role Holder RoleManager.ROLE_WALLET), otherwise a call to this method will fail and return false.

setPowerSavingMode

public void setPowerSavingMode (boolean enabled)

Sets whether or not the NFC chip should be in power-saving mode next time it is disabled with NfcAdapter.disable(). If the chip is already disabled, power-saving mode will take effect immediately.

This mode puts the NFC chip in a very low power mode, but not fully turned off. This mode limits communication between the NFC chip and the host processor to conserve power, although the exact implementation may depend on the device's underlying hardware. Other NFC APIs are disabled while this mode is active.
Requires ERROR(/android.Manifest.permission#NFC_SET_CONTROLLER_ALWAYS_ON)