下面列出了怎么用android.nfc.tech.Ndef的API类实例代码及写法，或者点击链接到github查看源代码。
private static HashMap<String, Integer> getTechStringToCodeMap() {
HashMap<String, Integer> techStringToCodeMap = new HashMap<String, Integer>();
techStringToCodeMap.put(IsoDep.class.getName(), TagTechnology.ISO_DEP);
techStringToCodeMap.put(MifareClassic.class.getName(), TagTechnology.MIFARE_CLASSIC);
techStringToCodeMap.put(MifareUltralight.class.getName(), TagTechnology.MIFARE_ULTRALIGHT);
techStringToCodeMap.put(Ndef.class.getName(), TagTechnology.NDEF);
techStringToCodeMap.put(NdefFormatable.class.getName(), TagTechnology.NDEF_FORMATABLE);
techStringToCodeMap.put(NfcA.class.getName(), TagTechnology.NFC_A);
techStringToCodeMap.put(NfcB.class.getName(), TagTechnology.NFC_B);
techStringToCodeMap.put(NfcF.class.getName(), TagTechnology.NFC_F);
techStringToCodeMap.put(NfcV.class.getName(), TagTechnology.NFC_V);
techStringToCodeMap.put(NfcBarcode.class.getName(), TagTechnology.NFC_BARCODE);
return techStringToCodeMap;
}
/**
* 写入标签
*
* @param message
* @param tag
* @return
*/
public static boolean writeTag(NdefMessage message, Tag tag) {
int size = message.toByteArray().length;
try {
Ndef ndef = Ndef.get(tag);
if (ndef != null) {
ndef.connect();
if (!ndef.isWritable()) {
return false;
}
if (ndef.getMaxSize() < size) {
return false;
}
ndef.writeNdefMessage(message);
return true;
}
} catch (Exception e) {
}
return false;
}
private void writeToNfc(Ndef ndef, String message){
mTvMessage.setText(getString(R.string.message_write_progress));
if (ndef != null) {
try {
ndef.connect();
NdefRecord mimeRecord = NdefRecord.createMime("text/plain", message.getBytes(Charset.forName("US-ASCII")));
ndef.writeNdefMessage(new NdefMessage(mimeRecord));
ndef.close();
//Write Successful
mTvMessage.setText(getString(R.string.message_write_success));
} catch (IOException | FormatException e) {
e.printStackTrace();
mTvMessage.setText(getString(R.string.message_write_error));
} finally {
mProgress.setVisibility(View.GONE);
}
}
}
@Override
protected void onNewIntent(Intent intent) {
Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
Log.d(TAG, "onNewIntent: "+intent.getAction());
if(tag != null) {
Toast.makeText(this, getString(R.string.message_tag_detected), Toast.LENGTH_SHORT).show();
Ndef ndef = Ndef.get(tag);
if (isDialogDisplayed) {
if (isWrite) {
String messageToWrite = mEtMessage.getText().toString();
mNfcWriteFragment = (NFCWriteFragment) getFragmentManager().findFragmentByTag(NFCWriteFragment.TAG);
mNfcWriteFragment.onNfcDetected(ndef,messageToWrite);
} else {
mNfcReadFragment = (NFCReadFragment)getFragmentManager().findFragmentByTag(NFCReadFragment.TAG);
mNfcReadFragment.onNfcDetected(ndef);
}
}
}
}
/**
* Writes an NdefMessage to a NFC tag
*/
public static void writeTag(NdefMessage message, Tag tag) throws Exception {
int size = message.toByteArray().length;
Ndef ndef = Ndef.get(tag);
if (ndef != null) {
ndef.connect();
if (!ndef.isWritable()) {
throw new NfcTagNotWritableException();
}
if (ndef.getMaxSize() < size) {
throw new NfcTagInsufficientMemoryException(ndef.getMaxSize(), size);
}
ndef.writeNdefMessage(message);
} else {
NdefFormatable format = NdefFormatable.get(tag);
if (format != null) {
format.connect();
format.format(message);
} else {
throw new IllegalArgumentException("Ndef format is NULL");
}
}
}
/**
* Parses nfc tag and extracts otp credential from it
* @param tag an NDEF compatible tag
* @return OTP data
* @throws ParseTagException if tag has no NDEF Tag Technology or there is no YK OTP payload
*/
public static @NonNull String parseTag(Tag tag) throws ParseTagException {
Ndef ndef = Ndef.get(tag);
if (ndef == null) {
throw new ParseTagException("Tag is not NDEF formatted");
}
NdefMessage message;
try {
ndef.connect();
message = ndef.getNdefMessage();
} catch (FormatException | IOException e) {
message = ndef.getCachedNdefMessage();
} finally {
try {
ndef.close();
} catch (IOException ignore) {
}
}
if (message == null) {
throw new ParseTagException("Couldn't read ndef message");
}
String parsedData = parseNdefMessage(message);
if (parsedData != null) {
return parsedData;
}
throw new ParseTagException("Tag doesn't have YK OTP payload");
}
/**
* 写数据
*
* @param ndefMessage 创建好的NDEF文本数据
* @param tag 标签
* @return
*/
public static boolean writeTag(NdefMessage ndefMessage, Tag tag) {
try {
Ndef ndef = Ndef.get(tag);
ndef.connect();
ndef.writeNdefMessage(ndefMessage);
return true;
} catch (Exception e) {
}
return false;
}
@Override
public void onNewIntent(Intent intent) {
//获取Tag对象
Tag detectedTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
//获取Ndef的实例
Ndef ndef = Ndef.get(detectedTag);
mTagText = ndef.getType() + "\n max size:" + ndef.getMaxSize() + " bytes\n\n";
readNfcTag(intent);
mNfcText.setText(mTagText);
}
@Override
public void onNewIntent(Intent intent) {
//1.获取Tag对象
Tag detectedTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
//2.获取Ndef的实例
Ndef ndef = Ndef.get(detectedTag);
mTagText = ndef.getType() + "\nmaxsize:" + ndef.getMaxSize() + "bytes\n\n";
readNfcTag(intent);
mNfcText.setText(mTagText);
}
void writeNdef(Ndef ndef, Uri uri) throws IOException, FormatException {
NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
if (nfcAdapter == null) return; // no NFC support here
NdefRecord recordNFC = NdefRecord.createUri(uri);
NdefMessage message = new NdefMessage(recordNFC);
ndef.connect();
int tagSize = ndef.getMaxSize();
int msgSize = message.getByteArrayLength();
Timber.d("tagSize=%d, msgSIze=%d, uriSize=%d", tagSize, msgSize, uri.toString().length());
if (tagSize < msgSize)
throw new IllegalArgumentException(getString(R.string.nfc_tag_size, tagSize, msgSize));
ndef.writeNdefMessage(message);
}
public static WifiConfiguration readTag(Tag tag) {
Ndef ndef = Ndef.get(tag);
if (ndef == null) {
Log.d(TAG, "NDEF not supported");
return null;
}
NdefMessage ndefMessage = ndef.getCachedNdefMessage();
if (ndefMessage == null) {
Log.d(TAG, "ndefMessage is null");
return null;
}
return NfcUtils.parse(ndefMessage);
}
private void readFromNFC(Ndef ndef) {
try {
ndef.connect();
NdefMessage ndefMessage = ndef.getNdefMessage();
String message = new String(ndefMessage.getRecords()[0].getPayload());
Log.d(TAG, "readFromNFC: "+message);
mTvMessage.setText(message);
ndef.close();
} catch (IOException | FormatException e) {
e.printStackTrace();
}
}
/**
* Ndef の情報を読み込みます.
*
* @param tag タグ
* @param tagInfo 情報を格納するクラス
* @throws FormatException NFCタグのフォーマットが不正な場合に発生
*/
private void readNdef(final Tag tag, final TagInfo tagInfo) throws FormatException {
try {
Ndef ndef = Ndef.get(tag);
ndef.connect();
readNdefMessage(ndef.getNdefMessage(), tagInfo.getList());
} catch (IOException e) {
// ignore.
}
}
/**
* Factory method that creates NfcTagHandler for a given NFC Tag.
*
* @param tag @see android.nfc.Tag
* @return NfcTagHandler or null when unsupported Tag is provided.
*/
public static NfcTagHandler create(Tag tag) {
if (tag == null) return null;
Ndef ndef = Ndef.get(tag);
if (ndef != null) return new NfcTagHandler(ndef, new NdefHandler(ndef));
NdefFormatable formattable = NdefFormatable.get(tag);
if (formattable != null) {
return new NfcTagHandler(formattable, new NdefFormattableHandler(formattable));
}
return null;
}
private void readTagFromIntent(Intent intent) {
if (intent != null){
String action = intent.getAction();
/*if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(action)) {
uidRead = true;
String uid = ByteArrayToHexString(intent.getByteArrayExtra(NfcAdapter.EXTRA_ID));
onTagReadListener.onUidRead(uid);
}*/
if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) {
tagRead = true;
// get NDEF tag details
Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
if (tag != null) {
Ndef ndefTag = Ndef.get(tag);
//int tagSize = ndefTag.getMaxSize(); // tag size
tagIsWritable = ndefTag.isWritable(); // is tag writable?
//String tagType = ndefTag.getType(); // tag type
Parcelable[] rawMessages = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
if (rawMessages != null) {
NdefRecord[] records = ((NdefMessage) rawMessages[0]).getRecords();
String text = ndefRecordToString(records[0]);
onTagReadListener.onTagRead(text);
}
}
}
}
}
/**
* Initializes which intents and NfcTechnologies to filter for
*/
private void initFields() {
pendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
mIntentFilters = new IntentFilter[]{new IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED)};
mTechLists = new String[][]{new String[]{Ndef.class.getName()},
new String[]{NdefFormatable.class.getName()}};
}
/**
* {@inheritDoc}
*/
@Override
public boolean writeToNdefAndMakeReadonly(NdefMessage message, Ndef ndef) throws ReadOnlyTagException, InsufficientCapacityException, FormatException {
setReadOnly(true);
boolean result = writeToNdef(message, ndef);
setReadOnly(false);
return result;
}
@Override
public boolean writeToTag(NdefMessage message, Tag tag) throws FormatException, ReadOnlyTagException, InsufficientCapacityException {
Ndef ndef = Ndef.get(tag);
NdefFormatable formatable = NdefFormatable.get(tag);
boolean result;
if (readOnly) {
result = writeToNdefAndMakeReadonly(message, ndef) || writeToNdefFormatableAndMakeReadonly(message, formatable);
} else {
result = writeToNdef(message, ndef) || writeToNdefFormatable(message, formatable);
}
readOnly = false;
return result;
}
private String[] generateTechStringList(int[] techList) {
final int size = techList.length;
String[] strings = new String[size];
for (int i = 0; i < size; i++) {
switch (techList[i]) {
case TagTechnology.ISO_DEP:
strings[i] = IsoDep.class.getName();
break;
case TagTechnology.MIFARE_CLASSIC:
strings[i] = MifareClassic.class.getName();
break;
case TagTechnology.MIFARE_ULTRALIGHT:
strings[i] = MifareUltralight.class.getName();
break;
case TagTechnology.NDEF:
strings[i] = Ndef.class.getName();
break;
case TagTechnology.NDEF_FORMATABLE:
strings[i] = NdefFormatable.class.getName();
break;
case TagTechnology.NFC_A:
strings[i] = NfcA.class.getName();
break;
case TagTechnology.NFC_B:
strings[i] = NfcB.class.getName();
break;
case TagTechnology.NFC_F:
strings[i] = NfcF.class.getName();
break;
case TagTechnology.NFC_V:
strings[i] = NfcV.class.getName();
break;
case TagTechnology.NFC_BARCODE:
strings[i] = NfcBarcode.class.getName();
break;
default:
throw new IllegalArgumentException("Unknown tech type " + techList[i]);
}
}
return strings;
}
public static String[][] TechFilters() {
return new String[][]{new String[]{Ndef.class.getName()}};
}
/**
* 往标签写数据的方法
*
* @param tag
*/
public void writeNFCTag(Tag tag) {
if (tag == null) {
return;
}
NdefMessage ndefMessage = new NdefMessage(new NdefRecord[]{NdefRecord
.createApplicationRecord(mPackageName)});
//转换成字节获得大小
int size = ndefMessage.toByteArray().length;
try {
//2.判断NFC标签的数据类型（通过Ndef.get方法）
Ndef ndef = Ndef.get(tag);
//判断是否为NDEF标签
if (ndef != null) {
ndef.connect();
//判断是否支持可写
if (!ndef.isWritable()) {
return;
}
//判断标签的容量是否够用
if (ndef.getMaxSize() < size) {
return;
}
//3.写入数据
ndef.writeNdefMessage(ndefMessage);
Toast.makeText(this, "写入成功", Toast.LENGTH_SHORT).show();
} else { //当我们买回来的NFC标签是没有格式化的，或者没有分区的执行此步
//Ndef格式类
NdefFormatable format = NdefFormatable.get(tag);
//判断是否获得了NdefFormatable对象，有一些标签是只读的或者不允许格式化的
if (format != null) {
//连接
format.connect();
//格式化并将信息写入标签
format.format(ndefMessage);
Toast.makeText(this, "写入成功", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(this, "写入失败", Toast.LENGTH_SHORT).show();
}
}
} catch (Exception e) {
}
}
/**
* 往标签写数据的方法
*
* @param tag
*/
public void writeNFCTag(Tag tag) {
if (tag == null) {
return;
}
NdefMessage ndefMessage = new NdefMessage(new NdefRecord[]{NdefRecord
.createUri(Uri.parse("http://www.baidu.com"))});
//转换成字节获得大小
int size = ndefMessage.toByteArray().length;
try {
//2.判断NFC标签的数据类型（通过Ndef.get方法）
Ndef ndef = Ndef.get(tag);
//判断是否为NDEF标签
if (ndef != null) {
ndef.connect();
//判断是否支持可写
if (!ndef.isWritable()) {
return;
}
//判断标签的容量是否够用
if (ndef.getMaxSize() < size) {
return;
}
//3.写入数据
ndef.writeNdefMessage(ndefMessage);
Toast.makeText(this, "写入成功", Toast.LENGTH_SHORT).show();
} else { //当我们买回来的NFC标签是没有格式化的，或者没有分区的执行此步
//Ndef格式类
NdefFormatable format = NdefFormatable.get(tag);
//判断是否获得了NdefFormatable对象，有一些标签是只读的或者不允许格式化的
if (format != null) {
//连接
format.connect();
//格式化并将信息写入标签
format.format(ndefMessage);
Toast.makeText(this, "写入成功",
Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(this, "写入失败", Toast.LENGTH_SHORT).show();
}
}
} catch (Exception e) {
}
}
AsyncWriteTag(Ndef ndef, Uri uri) {
this.ndef = ndef;
this.uri = uri;
}
/**
* Listen to NFC incomming data
*/
@Override
public void onNewIntent(Intent intent) {
MLog.d(TAG, "New intent " + intent);
if (intent.getAction() != null) {
MLog.d(TAG, "Discovered tag with intent: " + intent);
Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
String nfcID = StrUtils.bytetostring(tag.getId());
// if there is a message waiting to be written
if (PNfc.nfcMsg != null) {
MLog.d(TAG, "->" + PNfc.nfcMsg);
PNfc.writeTag(this, tag, PNfc.nfcMsg);
if (onNFCWrittenListener != null) onNFCWrittenListener.onNewTag();
onNFCWrittenListener = null;
PNfc.nfcMsg = null;
// read the nfc tag info
} else {
// get NDEF tag details
Ndef ndefTag = Ndef.get(tag);
if (ndefTag == null) {
return;
}
int size = ndefTag.getMaxSize(); // tag size
boolean writable = ndefTag.isWritable(); // is tag writable?
String type = ndefTag.getType(); // tag type
String nfcMessage = "";
// get NDEF message details
NdefMessage ndefMesg = ndefTag.getCachedNdefMessage();
if (ndefMesg != null) {
NdefRecord[] ndefRecords = ndefMesg.getRecords();
int len = ndefRecords.length;
String[] recTypes = new String[len]; // will contain the
// NDEF record types
String[] recPayloads = new String[len]; // will contain the
// NDEF record types
for (int i = 0; i < len; i++) {
recTypes[i] = new String(ndefRecords[i].getType());
recPayloads[i] = new String(ndefRecords[i].getPayload());
}
nfcMessage = recPayloads[0];
}
if (onNFCListener != null) onNFCListener.onNewTag(nfcID, nfcMessage);
}
}
}
public void onNfcDetected(Ndef ndef, String messageToWrite){
mProgress.setVisibility(View.VISIBLE);
writeToNfc(ndef,messageToWrite);
}
NdefHandler(Ndef ndef) {
mNdef = ndef;
}
public void onNfcIntent(Intent intent) {
if ((!isNfcEnabled())
|| (intent == null)
|| (!"android.nfc.action.NDEF_DISCOVERED".equals(intent
.getAction()))) {
return;
}
Uri uri = intent.getData();
Tag nfcTag = (Tag) intent.getParcelableExtra("android.nfc.extra.TAG");
if ((uri == null) || (nfcTag == null)) {
return;
}
Ndef ndef = Ndef.get(nfcTag);
if ((ndef == null)
|| (!uri.getScheme().equals("cardboard"))
|| ((!uri.getHost().equals("v1.0.0")) && (uri.getPathSegments()
.size() == 2))) {
return;
}
synchronized (this.mTagLock) {
boolean isSameTag = false;
if (this.mCurrentTag != null) {
byte[] tagId1 = nfcTag.getId();
byte[] tagId2 = this.mCurrentTag.getTag().getId();
isSameTag = (tagId1 != null) && (tagId2 != null)
&& (Arrays.equals(tagId1, tagId2));
closeCurrentNfcTag();
if (!isSameTag) {
sendDisconnectionEvent();
}
}
NdefMessage nfcTagContents;
try {
ndef.connect();
nfcTagContents = ndef.getCachedNdefMessage();
} catch (Exception e) {
Log.e("NfcSensor", "Error reading NFC tag: " + e.toString());
if (isSameTag) {
sendDisconnectionEvent();
}
return;
}
this.mCurrentTag = ndef;
if (!isSameTag) {
synchronized (this.mListeners) {
for (ListenerHelper listener : this.mListeners) {
listener.onInsertedIntoCardboard(CardboardDeviceParams
.createFromNfcContents(nfcTagContents));
}
}
}
this.mTagConnectionFailures = 0;
this.mNfcDisconnectTimer = new Timer("NFC disconnect timer");
this.mNfcDisconnectTimer.schedule(new TimerTask() {
public void run() {
synchronized (NfcSensor.this.mTagLock) {
if (!NfcSensor.this.mCurrentTag.isConnected()) {
NfcSensor.access$204(NfcSensor.this);
if (NfcSensor.this.mTagConnectionFailures > 1) {
NfcSensor.this.closeCurrentNfcTag();
NfcSensor.this.sendDisconnectionEvent();
}
}
}
}
}, 250L, 250L);
}
}
@Override
public boolean writeToNdef(NdefMessage message, Ndef ndef) throws ReadOnlyTagException, InsufficientCapacityException, FormatException {
return mNdefWrite.writeToNdef(message, ndef);
}
@Override
public boolean writeToNdefAndMakeReadonly(NdefMessage message, Ndef ndef) throws ReadOnlyTagException, InsufficientCapacityException, FormatException {
return mNdefWrite.writeToNdefAndMakeReadonly(message, ndef);
}
public static Pair<String, String> getCameraWifiSettingsFromTag(Tag tag, Parcelable[] messages)
throws Exception {
Ndef ndef = Ndef.get(tag);
ndef.connect();
NdefRecord record = ((NdefMessage) messages[0]).getRecords()[0];
Pair<String, String> cameraWifiSettings = decodeSonyPPMMessage(record);
ndef.close();
return cameraWifiSettings;
}