在开始之前可以先了解一些NFC的的基础知识。 连接
android nfc中MifareClassic格式的读写 http://www.cnblogs.com/jyycnblogs/p/5077609.html
NFC API Reference中英文 http://www.cnblogs.com/skyseraph/archive/2013/01/27/2876236.html#
感谢Eternal_memory 和 SkySeraph
部分解析
BaseMethodWebActivity是Activity的子类
showToastMessage是单纯的Toast通知
DataValues.NFCWriteLength 是长度限制

下面是我的开发代码，希望对你有帮助。

package com.Base;import java.io.ByteArrayOutputStream;  
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;  
import java.text.DateFormat;  
import java.text.SimpleDateFormat;  
import java.util.Date;  
import java.util.List;  
import java.util.Locale;  
import com.main.HZZH.MenuActivity;
import cn.data.bean.DataValues;
import cn.data.bean.PublicMethod;
import android.app.Activity;  
import android.app.AlertDialog;  
import android.app.PendingIntent;  
import android.content.Context;
import android.content.DialogInterface;  
import android.content.Intent;  
import android.nfc.FormatException;
import android.nfc.NdefMessage;  
import android.nfc.NdefRecord;  
import android.nfc.NfcAdapter;  
import android.nfc.Tag;  
import android.nfc.tech.MifareClassic;  
import android.nfc.tech.MifareUltralight;  
import android.nfc.tech.Ndef;
import android.os.Bundle;  
import android.os.Parcelable;  
import android.provider.Settings;  
import android.text.Selection;
import android.text.Spannable;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;  
import android.widget.Toast;public class NFCActivity extends BaseMethodWebActivity {  private static final DateFormat TIME_FORMAT = SimpleDateFormat  .getDateTimeInstance();  private NfcAdapter mAdapter;  private PendingIntent mPendingIntent;  private NdefMessage mNdefPushMessage;  private Tag intenTag;private String NdefRecordTypeByte01 = "http://";private String NdefRecordTypeByte02 = "www.baidu.com";private String NdefRecordTypeByte03 = "?";private int NFCDataType = 0;private final int MifareClassicType = 1,MifareUltralightType = 2,OtherType = 3;//扇位置private short sectorAddress = 6;//修改密码private byte[] myKeyA = {'h','9','^','a','-','8'}; private int NFCBarCodeLength = 16*3;public EditText NFCEditText = null;@Override  protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  resolveIntent(getIntent());  // 获取默认的NFC控制器  mAdapter = NfcAdapter.getDefaultAdapter(this);  //拦截系统级的NFC扫描，例如扫描蓝牙  mPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this,  getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);  mNdefPushMessage = new NdefMessage(new NdefRecord[] { newTextRecord("",  Locale.ENGLISH, true) });  }  @Override  protected void onResume() {  super.onResume();  if (mAdapter != null) {  //隐式启动  mAdapter.enableForegroundDispatch(this, mPendingIntent, null, null);  mAdapter.enableForegroundNdefPush(this, mNdefPushMessage);  }  }  @Override  protected void onPause() {  super.onPause();  if (mAdapter != null) {  //隐式启动  mAdapter.disableForegroundDispatch(this);  mAdapter.disableForegroundNdefPush(this);  }  }  //  //16进制字符串转换为String  //  private String hexString = "0123456789ABCDEF";  //  public String decode(String bytes) {  //      if (bytes.length() != 30) {  //          return null;  //      }  //      ByteArrayOutputStream baos = new ByteArrayOutputStream(  //              bytes.length() / 2);  //      // 将每2位16进制整数组装成一个字节  //      for (int i = 0; i < bytes.length(); i += 2)  //          baos.write((hexString.indexOf(bytes.charAt(i)) << 4 | hexString  //                  .indexOf(bytes.charAt(i + 1))));  //      return new String(baos.toByteArray());  //  }  //   //字符序列转换为16进制字符串  //    private String bytesToHexString(byte[] src) {  //        StringBuilder stringBuilder = new StringBuilder("0x");  //        if (src == null || src.length <= 0) {  //            return null;  //        }  //        char[] buffer = new char[2];  //        for (int i = 0; i < src.length; i++) {  //            buffer[0] = Character.forDigit((src[i] >>> 4) & 0x0F, 16);  //            buffer[1] = Character.forDigit(src[i] & 0x0F, 16);  //            System.out.println(buffer);  //            stringBuilder.append(buffer);  //        }  //        return stringBuilder.toString();  //    } //  // 字符序列转换为16进制字符串  //  private String bytesToHexString(byte[] src, boolean isPrefix) {  //      StringBuilder stringBuilder = new StringBuilder();  //      if (isPrefix == true) {  //          stringBuilder.append("0x");  //      }  //      if (src == null || src.length <= 0) {  //          return null;  //      }  //      char[] buffer = new char[2];  //      for (int i = 0; i < src.length; i++) {  //          buffer[0] = Character.toUpperCase(Character.forDigit(  //                  (src[i] >>> 4) & 0x0F, 16));  //          buffer[1] = Character.toUpperCase(Character.forDigit(src[i] & 0x0F,  //                  16));  //          System.out.println(buffer);  //          stringBuilder.append(buffer);  //      }  //      return stringBuilder.toString();  //  }/*** 验证扇sector的密码. * @param mfc* @param sector* @return*/private Boolean isKeyMifareClassicEnable(MifareClassic mfc,int sectorIndex){boolean auth = false;  try {auth = mfc.authenticateSectorWithKeyA(sectorIndex,  MifareClassic.KEY_DEFAULT);if(!auth){auth = mfc.authenticateSectorWithKeyA(sectorIndex,  myKeyA); }if(!auth){auth = mfc.authenticateSectorWithKeyA(sectorIndex,  MifareClassic.KEY_NFC_FORUM); }} catch (IOException e) {Log.e(TAG, "IOException while authenticateSectorWithKey MifareClassic...", e);}return auth;}/*** 将数据写入扇，扇中每块必须16位* @param mfc* @param barCodeByte* @param sectorIndex* @return*/private Boolean writeMifareClassicBarCode(MifareClassic mfc,byte[] barCodeByte,int sectorIndex){Boolean flag = false;int bCount = mfc.getBlockCountInSector(sectorIndex);//获取block起始编号int bIndex = mfc.sectorToBlock(sectorIndex);int barIndexCount  = barCodeByte.length/16 +1;for(int i=0;i<bCount - 1 && i < barIndexCount;i++){byte[] bar = new byte[16];if(barCodeByte.length >= 0){for(int j = 0;j < 16;j++){if(j+i*16 < barCodeByte.length){bar[j] = barCodeByte[j+i*16];}else{bar[j] = 0;}}}try {mfc.writeBlock(bIndex, bar);bIndex++;if(i == bIndex - 2){flag = true;}} catch (IOException e) {Log.e(TAG, "IOException while writeMifareClassicBarCode MifareClassic...", e);}}return flag;}/*** 写入数据的方法* @param barCode* @param otherStr*/protected void WriteMothed(String barCode,String otherStr){byte[] data = null;if(otherStr !=null){data = otherStr.getBytes(Charset.forName("UTF-8"));}if(barCode == null || barCode.length() < 4 || barCode.getBytes().length > NFCBarCodeLength){showToastMessage("要写入的数据不正确！");return ;}if(data.length > DataValues.NFCWriteLength){showToastMessage("非条码数据不超过"+DataValues.NFCWriteLength+"！");return ;}if (intenTag != null) {  switch (NFCDataType) {case MifareClassicType://MifareClassicl类型写入MifareClassic mfc = MifareClassic.get(intenTag);  int otherStrIndex = 0;try {  int bAllCount = 0;if(barCode != null){bAllCount = 1;}if(data != null){bAllCount += data.length/16 + 1;}for(int j = sectorAddress;j < 16 && j < bAllCount+sectorAddress;j++){//在删去1 块4、5 写入数据mfc.connect();  boolean auth = false;  byte[] KeyValue = null;if (isKeyMifareClassicEnable(mfc,j)) { KeyValue = mfc.readBlock(4*j+3);}mfc.close();mfc.connect();  if (isKeyMifareClassicEnable(mfc,j) && KeyValue != null) {  if(j == sectorAddress){writeMifareClassicBarCode(mfc,barCode.getBytes(Charset.forName("UTF-8")),j);}else{int count = 16*3;byte[] strByte = new byte[count];for(int z = 0;z < count;z++){if(otherStrIndex < data.length){strByte[z] = data[otherStrIndex];otherStrIndex++;}else{break;}}writeMifareClassicBarCode(mfc, strByte, j);}//修改键值，keyA存放在每扇最后一块for(int i = 0;i<6;i++){KeyValue[i] = myKeyA[i];}mfc.writeBlock(4*j+3, KeyValue);showToastMessage("写入数据成功！");mfc.close();  }else{showToastMessage("块密码不正确！");  }}} catch (Exception e) {  showToastMessage("写入数据失败！"); Log.e(TAG, "IOException while write MifareClassic...", e);} finally {  try {  mfc.close();  } catch (IOException e) {  Log.e(TAG, "IOException while closing MifareClassic...", e); }  } break;case MifareUltralightType:MifareUltralight ultralight = MifareUltralight.get(intenTag);try {ultralight.connect();//每页4个字符2个汉字，共16页ultralight.writePage(4, "abcd".getBytes(Charset.forName("US-ASCII")));ultralight.writePage(5, "efgh".getBytes(Charset.forName("US-ASCII")));ultralight.writePage(6, "ijkl".getBytes(Charset.forName("US-ASCII")));ultralight.writePage(7, "mnop".getBytes(Charset.forName("US-ASCII")));showToastMessage("写入数据成功！");} catch (Exception e) {showToastMessage("写入数据失败！");Log.e(TAG, "IOException while write MifareUltralight...", e);} finally {try {ultralight.close();} catch (IOException e) {Log.e(TAG, "IOException while closing MifareUltralight...", e);}}break;case OtherType://新建NdefRecord数组，本例中数组只有一个元素  NdefRecord re = null;try{re = createRecord(otherStr+barCode); }catch (Exception e) {showToastMessage("新建NdefRecord数组失败！");Log.e(TAG, "IOException while create other NdefRecord...", e);return;}NdefRecord[] records = {re};//新建一个NdefMessage实例  NdefMessage message = new NdefMessage(records);  // 解析TAG获取到NDEF实例  Ndef ndef = Ndef.get(intenTag);  if(ndef != null ){// 打开连接  try {ndef.connect();ndef.writeNdefMessage(message);showToastMessage("写入数据成功！"); } catch (Exception e) {showToastMessage("写入数据失败！");Log.e(TAG, "IOException while write other...", e);} finally{try {  ndef.close(); } catch (Exception e) {  Log.e(TAG, "IOException while closing other...", e);  } } }break;}} else {  showToastMessage("设备与nfc卡连接断开，请重新连接...");  } }/*** 创建NdefRecord实例 * @param str* @return* @throws UnsupportedEncodingException*/protected NdefRecord createRecord( String str ) throws UnsupportedEncodingException {  NdefRecord textRecord = NdefRecord.createMime(NdefRecordTypeByte01+NdefRecordTypeByte02+NdefRecordTypeByte03,str.getBytes(Charset.forName("US-ASCII")));//      //组装字符串，准备好你要写入的信息  //      String msg = str;  //      //将字符串转换成字节数组  //      byte[] textBytes = msg.getBytes();  //      //将字节数组封装到一个NdefRecord实例中去  //      NdefRecord textRecord = new NdefRecord(NdefRecord.TNF_MIME_MEDIA,  //              NdefRecordTypeByte.getBytes(), new byte[] {}, textBytes);return textRecord;  } private NdefRecord newTextRecord(String text, Locale locale,  boolean encodeInUtf8) {  byte[] langBytes = locale.getLanguage().getBytes(  Charset.forName("UTF-8"));  Charset utfEncoding = encodeInUtf8 ? Charset.forName("UTF-8") : Charset  .forName("UTF-16");  byte[] textBytes = text.getBytes(utfEncoding);  int utfBit = encodeInUtf8 ? 0 : (1 << 7);  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);  return new NdefRecord(NdefRecord.TNF_WELL_KNOWN, NdefRecord.RTD_TEXT,  new byte[0], data);  }  //  private void showWirelessSettingsDialog() {  //      AlertDialog.Builder builder = new AlertDialog.Builder(this);  //      builder.setMessage("提示");  //      builder.setPositiveButton(android.R.string.ok,  //              new DialogInterface.OnClickListener() {  //          public void onClick(DialogInterface dialogInterface, int i) {  //              Intent intent = new Intent(  //                      Settings.ACTION_WIRELESS_SETTINGS);  //              startActivity(intent);  //          }  //      });  //      builder.setNegativeButton(android.R.string.cancel,  //              new DialogInterface.OnClickListener() {  //          public void onClick(DialogInterface dialogInterface, int i) {  //              finish();  //          }  //      });  //      builder.create().show();  //      return;  //  }  /*** 初步判断是什么类型NFC卡  * @param intent*/private void resolveIntent(Intent intent) {  String action = intent.getAction();  if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(action)  || NfcAdapter.ACTION_TECH_DISCOVERED.equals(action)  || NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) {  Parcelable[] rawMsgs = intent  .getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);  NdefMessage[] msgs;  intenTag = intent  .getParcelableExtra(NfcAdapter.EXTRA_TAG);if (rawMsgs != null) {  msgs = new NdefMessage[rawMsgs.length];  for (int i = 0; i < rawMsgs.length; i++) {  msgs[i] = (NdefMessage) rawMsgs[i];  }  } else {  // Unknown tag type  byte[] empty = new byte[0];  byte[] id = intent.getByteArrayExtra(NfcAdapter.EXTRA_ID);  byte[] payload = dumpTagData(intenTag).getBytes();  NdefRecord record = new NdefRecord(NdefRecord.TNF_UNKNOWN,  empty, id, payload);  NdefMessage msg = new NdefMessage(new NdefRecord[] { record });  msgs = new NdefMessage[] { msg };  }  // Setup the views  getNFCData(msgs);  }  }  /*** 解析读取的数据* @param p* @return*/private String dumpTagData(Parcelable p) {  StringBuilder sb = new StringBuilder();  Tag tag = (Tag) p;  //      String prefix = "android.nfc.tech.";  //      sb.append("Technologies: ");  //      for (String tech : tag.getTechList()) {  //          sb.append(tech.substring(prefix.length()));  //          sb.append(", ");  //      }  NFCDataType = 3;//      sb.delete(sb.length() - 2, sb.length());  for (String tech : tag.getTechList()) {  if (tech.equals(MifareClassic.class.getName())) {  MifareClassic mifareTag = MifareClassic.get(tag);  String type = "Unknown";  switch (mifareTag.getType()) {  case MifareClassic.TYPE_CLASSIC:  type = "Classic";  break;  case MifareClassic.TYPE_PLUS:  type = "Plus";  break;  case MifareClassic.TYPE_PRO:  type = "Pro";  break;  }  NFCDataType = 1;try {//获取 扇sectorAddress 块barCdeBlock 的内容mifareTag.connect();int bCount;  int bIndex;  if (isKeyMifareClassicEnable(mifareTag,sectorAddress)) {   // 读取扇区中的块总数bCount = mifareTag.getBlockCountInSector(sectorAddress);//获取扇区块的起始编号bIndex = mifareTag.sectorToBlock(sectorAddress);  for (int i = 0; i < bCount-1; i++) {  byte[] data = mifareTag.readBlock(bIndex);  sb.append(new String(data, Charset.forName("UTF-8")));  bIndex++;  }  } else {  showToastMessage("验证失败");  }   } catch (Exception e) {showToastMessage("读取数据失败！"); Log.e(TAG, "IOException while read MifareClassic...", e);}finally{try {mifareTag.close();} catch (IOException e) {Log.e(TAG, "IOException while closing MifareClassic...", e);}}  }  if (tech.equals(MifareUltralight.class.getName())) {  sb.append('\n');  MifareUltralight mifareUlTag = MifareUltralight.get(tag);  String type = "Unknown";  switch (mifareUlTag.getType()) {  case MifareUltralight.TYPE_ULTRALIGHT:  type = "Ultralight";  break;  case MifareUltralight.TYPE_ULTRALIGHT_C:  type = "Ultralight C";  break;  }  NFCDataType = 2;sb.append("Mifare Ultralight type: ");  sb.append(type);  }  }  return sb.toString();  }  //  private String getHex(byte[] bytes) {  //      StringBuilder sb = new StringBuilder();  //      for (int i = bytes.length - 1; i >= 0; --i) {  //          int b = bytes[i] & 0xff;  //          if (b < 0x10)  //              sb.append('0');  //          sb.append(Integer.toHexString(b));  //          if (i > 0) {  //              sb.append(" ");  //          }  //      }  //      return sb.toString();  //  }  //  private long getDec(byte[] bytes) {  //      long result = 0;  //      long factor = 1;  //      for (int i = 0; i < bytes.length; ++i) {  //          long value = bytes[i] & 0xffl;  //          result += value * factor;  //          factor *= 256l;  //      }  //      return result;  //  }  //  private long getReversed(byte[] bytes) {  //      long result = 0;  //      long factor = 1;  //      for (int i = bytes.length - 1; i >= 0; --i) {  //          long value = bytes[i] & 0xffl;  //          result += value * factor;  //          factor *= 256l;  //      }  //      return result;  //  }  /*** 取出NFC扫描的数据  * @param msgs*/private void getNFCData(NdefMessage[] msgs) {  if (msgs == null || msgs.length == 0) {  return;  }  //将字节数组转换成字符串  String str="";byte[] data = null;for(NdefMessage obj:msgs){NdefRecord record[] = obj.getRecords();for(NdefRecord recordObj:record){if(data == null){data = recordObj.getPayload();}else{byte[] oldData = data;data = new byte[oldData.length + recordObj.getPayload().length];for(int i = 0;i < oldData.length;i++){data[i] = oldData[i];}for(int i = 0;i<recordObj.getPayload().length;i++){data[oldData.length +i] = recordObj.getPayload()[i];}}}}if(data != null){str = new String(data, Charset.forName("UTF-8"));}//截取部分字符findNumberFrom（）方法，并展示NFCEditTextEvent(PublicMethod.findNumberFrom(str));}  /*** 用NFCEditText展示数据，并触发keyEvent* @param str*/public void NFCEditTextEvent(String str){if(NFCEditText != null){if(str != null && str.length() > 3){NFCEditText.setText(str);CharSequence text = NFCEditText.getText();if (text instanceof Spannable) {Spannable spanText = (Spannable)text;Selection.setSelection(spanText, text.length());}if(NFCEditText.getText().toString().trim().length() > 3){KeyEvent event = new KeyEvent(KeyEvent.ACTION_UP,KeyEvent.KEYCODE_ENTER);NFCEditText.dispatchKeyEvent(event);}}}}@Override  public boolean dispatchKeyEvent(KeyEvent event) {  if(event.getKeyCode() == KeyEvent.KEYCODE_ENTER){  /*隐藏软键盘*/  InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);  if(inputMethodManager.isActive()){  inputMethodManager.hideSoftInputFromWindow(this.getCurrentFocus().getWindowToken(), 0);  }   return true;  }  return super.dispatchKeyEvent(event);  } //获取系统隐式启动的  @Override  public void onNewIntent(Intent intent) {  setIntent(intent);  resolveIntent(intent);  }  
}  

其他如下：

1 AndroidMainifest.xml中添加权限

<uses-permissionandroid:name="android.permission.NFC"/><uses-featureandroid:name="android.hardware.nfc"android:required="true"/><uses-sdkandroid:minSdkVersion="14"android:targetSdkVersion="21"/>

2、添加过滤器

<!-- TECH_DISCOVERED类型的nfc --><intent-filter><actionandroid:name="android.nfc.action.TECH_DISCOVERED"/></intent-filter><!-- 后设资源  调用自己建立的文件夹xml中的文件 --><meta-data
                android:name="android.nfc.action.TECH_DISCOVERED"android:resource="@xml/nfc_tech_filter"/>

3、添加支持的协议

<?xmlversion="1.0"encoding="utf-8"?>
<resourcesxmlns:xliff="urn:oasis:names:tc:xliff:document:1.2"> <tech-list> <tech>android.nfc.tech.IsoDep</tech>  <tech>android.nfc.tech.NfcA</tech>  <tech>android.nfc.tech.NfcB</tech>  <tech>android.nfc.tech.NfcF</tech>  <tech>android.nfc.tech.NfcV</tech>  <tech>android.nfc.tech.Ndef</tech>  <tech>android.nfc.tech.NdefFormatable</tech>  <tech>android.nfc.tech.MifareClassic</tech>  <tech>android.nfc.tech.MifareUltralight</tech> </tech-list> 
</resources>