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NFC读取写入简单使用

NFC数据读取写入的方法

/** * 读取NFC数据 */public static String readNfcData(Intent intent) {
           String text = "";        if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(intent.getAction())) {
               Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);            NdefMessage msgs[] = null;            if (rawMsgs != null) {
                   msgs = new NdefMessage[rawMsgs.length];                for (int i = 0; i < rawMsgs.length; i++) {
                       msgs[i] = (NdefMessage) rawMsgs[i];                }            }            try {
                   if (msgs != null) {
                       NdefRecord record = msgs[0].getRecords()[0];                    text = parseTextRecord(record);                }            } catch (Exception e) {
                   e.printStackTrace();            }        }        return text;    }/***写入NFC数据*/public static boolean writeNfc(NdefMessage ndefMessage, Tag tag) {
           try {
               Ndef ndef = Ndef.get(tag);            if (ndef != null) {
                   ndef.connect();                boolean isWritable = ndef.isWritable();                int maxSize = ndef.getMaxSize();                int msgLength = ndefMessage.toByteArray().length;                if (!isWritable || maxSize < msgLength) {
                       return false;                }                ndef.writeNdefMessage(ndefMessage);                ndef.close();            } else {
                   NdefFormatable formatable = NdefFormatable.get(tag);                if (formatable != null) {
                       formatable.connect();                    formatable.format(ndefMessage);                    formatable.close();                }            }            return true;        } catch (Exception e) {
               e.printStackTrace();        }        return false;    }public static NdefRecord createTextRecord(String text) {
           byte[] langBytes = Locale.CHINA.getLanguage().getBytes(Charset.forName("US-ASCII"));        Charset utfEncoding = Charset.forName("UTF-8");        byte[] textBytes = text.getBytes(utfEncoding);        int utfBit = 0;        char status = (char) (utfBit + langBytes.length);        byte[] data = new byte[1 + langBytes.length + textBytes.length];        data[0] = (byte) status;        System.arraycopy(langBytes, 0, data, 1, langBytes.length);        System.arraycopy(textBytes, 0, data, 1 + langBytes.length, textBytes.length);        NdefRecord ndefRecord = new NdefRecord(NdefRecord.TNF_WELL_KNOWN,NdefRecord.RTD_TEXT, new byte[0], data);        return ndefRecord;    }public static String parseTextRecord(NdefRecord ndefRecord) {
           //判断TNF        if (ndefRecord.getTnf() != NdefRecord.TNF_WELL_KNOWN) {
               return null;        }        //判断可变的长度的类型        if (!Arrays.equals(ndefRecord.getType(), NdefRecord.RTD_TEXT)) {
               return null;        }        try {
               //获得字节数组，然后进行分析            byte[] payload = ndefRecord.getPayload();            //下面开始NDEF文本数据第一个字节，状态字节            //判断文本是基于UTF-8还是UTF-16的，取第一个字节"位与"上16进制的80，16进制的80也就是最高位是1，            //其他位都是0，所以进行"位与"运算后就会保留最高位            String textEncoding = ((payload[0] & 0x80) == 0) ? "UTF-8" : "UTF-16";            //3f最高两位是0，第六位是1，所以进行"位与"运算后获得第六位            int languageCodeLength = payload[0] & 0x3f;            //下面开始NDEF文本数据第二个字节，语言编码            //获得语言编码            String languageCode = new String(payload, 1, languageCodeLength, "US-ASCII");            //下面开始NDEF文本数据后面的字节，解析出文本            String textRecord = new String(payload, languageCodeLength + 1,payload.length - languageCodeLength - 				1,textEncoding);            return textRecord;        } catch (Exception e) {
               throw new IllegalArgumentException();        }    }

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