解决方法

<uses-sdk android:minSdkVersion="14"/>
<uses-permission android:name="android.permission.NFC" />
<!-- 要求当前设备必须要有NFC芯片 -->
<uses-feature android:name="android.hardware.nfc" android:required="true" />

<activity
  android:name=".TagTextActivity"
  android:launchMode="singletop"/>

/**
 * 1.子类需要在onCreate方法中做Activity初始化。
 * 2.子类需要在onNewIntent方法中进行NFC标签相关操作。
 *  当launchMode设置为singletop时，第一次运行调用onCreate方法，
 *  第二次运行将不会创建新的Activity实例，将调用onNewIntent方法
 *  所以我们获取intent传递过来的Tag数据操作放在onNewIntent方法中执行
 *  如果在栈中已经有该Activity的实例，就重用该实例(会调用实例的onNewIntent())
 *  只要NFC标签靠近就执行
 */
public class BaseNfcActivity extends AppCompatActivity {
  private NfcAdapter mNfcAdapter;
  private PendingIntent mPendingIntent;
  /**
   * 启动Activity，界面可见时
   */
  @Override
  protected void onStart() {
    super.onStart();
    mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
    //一旦截获NFC消息，就会通过PendingIntent调用窗口
    mPendingIntent = PendingIntent.getActivity(this,new Intent(this,getClass()),0);
  }
  /**
   * 获得焦点，按钮可以点击
   */
  @Override
  public void onResume() {
    super.onResume();
    //设置处理优于所有其他NFC的处理
    if (mNfcAdapter != null)
      mNfcAdapter.enableForegrounddispatch(this,mPendingIntent,null,null);
  }
  /**
   * 暂停Activity，界面获取焦点，按钮可以点击
   */
  @Override
  public void onPause() {
    super.onPause();
    //恢复默认状态
    if (mNfcAdapter != null)
      mNfcAdapter.disableForegrounddispatch(this);
  }
}

Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);

Ndef ndef = Ndef.get(tag);

ndef.writeNdefMessage(ndefMessage);

public class RunAppActivity extends BaseNfcActivity{
  private String mPackageName = "com.android.mms";//短信
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
  }
  @Override
  public void onNewIntent(Intent intent) {
    if (mPackageName == null)
      return;
    //1.获取Tag对象
    Tag detectedTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
    writeNFCTag(detectedTag);
  }
  /**
   * 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,Toast.LENGTH_SHORT).show();
        } else {
          Toast.makeText(this,"写入失败",Toast.LENGTH_SHORT).show();
        }
      }
    } catch (Exception e) {
    }
  }
}

//直接接受一个Uri
public NdefRecord createUri(String uriString); 
//接受一个Uri的对象
public NdefRecord createUri(Uri uri); 

NdefMessage ndefMessage = new NdefMessage(new NdefRecord[]{NdefRecord
    .createApplicationRecord(mPackageName)});

NdefMessage ndefMessage = new NdefMessage(new NdefRecord[]{NdefRecord
    .createUri(Uri.parse(http://www.baidu.com))});

public class ReadTextActivity extends BaseNfcActivity {
  private TextView mNfcText;
  private String mTagText;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_read_text);
    mNfcText = (TextView) findViewById(R.id.tv_nfctext);
  }
  @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);
  }
  /**
   * 读取NFC标签文本数据
   */
  private void readNfcTag(Intent intent) {
    if (NfcAdapter.ACTION_NDEF_disCOVERED.equals(intent.getAction())) {
      Parcelable[] rawMsgs = intent.getParcelableArrayExtra(
          NfcAdapter.EXTRA_NDEF_MESSAGES);
      NdefMessage msgs[] = null;
      int contentSize = 0;
      if (rawMsgs != null) {
        msgs = new NdefMessage[rawMsgs.length];
        for (int i = 0; i < rawMsgs.length; i++) {
          msgs[i] = (NdefMessage) rawMsgs[i];
          contentSize += msgs[i].toByteArray().length;
        }
      }
      try {
        if (msgs != null) {
          NdefRecord record = msgs[0].getRecords()[0];
          String textRecord = parseTextRecord(record);
          mTagText += textRecord + "\n\ntext\n" + contentSize + " bytes";
        }
      } catch (Exception e) {
      }
    }
  }
  /**
   * 解析NDEF文本数据，从第三个字节开始，后面的文本数据
   * @param ndefRecord
   * @return
   */
  public static String parseTextRecord(NdefRecord ndefRecord) {
    /**
     * 判断数据是否为NDEF格式
     */
    //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();
    }
  }
}

<activity
  android:name=".ReadTextActivity"
  android:launchMode="singletop"/>

public class WriteTextActivity extends BaseNfcActivity {
  private String mText = "NFC-NewText-123";
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_write_text);
  }
  @Override
  public void onNewIntent(Intent intent) {
    if (mText == null)
      return;
    //获取Tag对象
    Tag detectedTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
    NdefMessage ndefMessage = new NdefMessage(
        new NdefRecord[] { createTextRecord(mText) });
    boolean result = writeTag(ndefMessage,detectedTag);
    if (result){
      Toast.makeText(this,Toast.LENGTH_SHORT).show();
    } else {
      Toast.makeText(this,Toast.LENGTH_SHORT).show();
    }
  }
  /**
   * 创建NDEF文本数据
   * @param text
   * @return
   */
  public static NdefRecord createTextRecord(String text) {
    byte[] langBytes = Locale.CHINA.getLanguage().getBytes(Charset.forName("US-ASCII"));
    Charset utfEncoding = Charset.forName("UTF-8");
    //将文本转换为UTF-8格式
    byte[] textBytes = text.getBytes(utfEncoding);
    //设置状态字节编码最高位数为0
    int utfBit = 0;
    //定义状态字节
    char status = (char) (utfBit + langBytes.length);
    byte[] data = new byte[1 + langBytes.length + textBytes.length];
    //设置第一个状态字节，先将状态码转换成字节
    data[0] = (byte) status;
    //设置语言编码，使用数组拷贝方法，从0开始拷贝到data中，拷贝到data的1到langBytes.length的位置
    System.arraycopy(langBytes,data,langBytes.length);
    //设置文本字节，使用数组拷贝方法，从0开始拷贝到data中，拷贝到data的1 + langBytes.length
    //到textBytes.length的位置
    System.arraycopy(textBytes,1 + langBytes.length,textBytes.length);
    //通过字节传入NdefRecord对象
    //NdefRecord.RTD_TEXT：传入类型 读写
    NdefRecord ndefRecord = new NdefRecord(NdefRecord.TNF_WELL_KNowN,NdefRecord.RTD_TEXT,new byte[0],data);
    return ndefRecord;
  }
  /**
   * 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;
  }
}

public class UriPrefix {
  public static final Map<Byte,String> URI_PREFIX_MAP = new HashMap<Byte,String>();
  // 预先定义已知Uri前缀
  static {
    URI_PREFIX_MAP.put((byte) 0x00,"");
    URI_PREFIX_MAP.put((byte) 0x01,"http://www.");
    URI_PREFIX_MAP.put((byte) 0x02,"https://www.");
    URI_PREFIX_MAP.put((byte) 0x03,"http://");
    URI_PREFIX_MAP.put((byte) 0x04,"https://");
    URI_PREFIX_MAP.put((byte) 0x05,"tel:");
    URI_PREFIX_MAP.put((byte) 0x06,"mailto:");
    URI_PREFIX_MAP.put((byte) 0x07,"ftp://anonymous:anonymous@");
    URI_PREFIX_MAP.put((byte) 0x08,"ftp://ftp.");
    URI_PREFIX_MAP.put((byte) 0x09,"ftps://");
    URI_PREFIX_MAP.put((byte) 0x0A,"sftp://");
    URI_PREFIX_MAP.put((byte) 0x0B,"smb://");
    URI_PREFIX_MAP.put((byte) 0x0C,"nfs://");
    URI_PREFIX_MAP.put((byte) 0x0D,"ftp://");
    URI_PREFIX_MAP.put((byte) 0x0E,"dav://");
    URI_PREFIX_MAP.put((byte) 0x0F,"news:");
    URI_PREFIX_MAP.put((byte) 0x10,"telnet://");
    URI_PREFIX_MAP.put((byte) 0x11,"imap:");
    URI_PREFIX_MAP.put((byte) 0x12,"rtsp://");
    URI_PREFIX_MAP.put((byte) 0x13,"urn:");
    URI_PREFIX_MAP.put((byte) 0x14,"pop:");
    URI_PREFIX_MAP.put((byte) 0x15,"sip:");
    URI_PREFIX_MAP.put((byte) 0x16,"sips:");
    URI_PREFIX_MAP.put((byte) 0x17,"tftp:");
    URI_PREFIX_MAP.put((byte) 0x18,"btspp://");
    URI_PREFIX_MAP.put((byte) 0x19,"btl2cap://");
    URI_PREFIX_MAP.put((byte) 0x1A,"btgoep://");
    URI_PREFIX_MAP.put((byte) 0x1B,"tcpobex://");
    URI_PREFIX_MAP.put((byte) 0x1C,"irdaobex://");
    URI_PREFIX_MAP.put((byte) 0x1D,"file://");
    URI_PREFIX_MAP.put((byte) 0x1E,"urn:epc:id:");
    URI_PREFIX_MAP.put((byte) 0x1F,"urn:epc:tag:");
    URI_PREFIX_MAP.put((byte) 0x20,"urn:epc:pat:");
    URI_PREFIX_MAP.put((byte) 0x21,"urn:epc:raw:");
    URI_PREFIX_MAP.put((byte) 0x22,"urn:epc:");
    URI_PREFIX_MAP.put((byte) 0x23,"urn:nfc:");
  }
}

<activity
  android:name=".ReadWriteUriActivity"
  android:label="读写NFC标签的Uri"
  android:launchMode="singletop" >
  <intent-filter>
    <action android:name="android.nfc.action.NDEF_disCOVERED" />
    <category android:name="android.intent.category.DEFAULT" />
    <!-- 拦截NFC标签中存储有以下Uri前缀的 -->
    <data android:scheme="http" />
    <data android:scheme="https" />
    <data android:scheme="ftp" />
  </intent-filter>
  <intent-filter>
    <action android:name="android.nfc.action.NDEF_disCOVERED" />
    <category android:name="android.intent.category.DEFAULT" />
    <!-- 定义可以拦截文本 -->
    <data android:mimeType="text/plain" />
  </intent-filter>
</activity>

public class ReadUriActivity extends BaseNfcActivity {
  private TextView mNfcText;
  private String mTagText;
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_read_uri);
    mNfcText = (TextView) findViewById(R.id.tv_nfctext);
  }
  @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);
  }
  /**
   * 读取NFC标签Uri
   */
  private void readNfcTag(Intent intent) {
    if (NfcAdapter.ACTION_NDEF_disCOVERED.equals(intent.getAction())) {
      Parcelable[] rawMsgs = intent.getParcelableArrayExtra(
          NfcAdapter.EXTRA_NDEF_MESSAGES);
      NdefMessage ndefMessage = null;
      int contentSize = 0;
      if (rawMsgs != null) {
        if (rawMsgs.length > 0) {
          ndefMessage = (NdefMessage) rawMsgs[0];
          contentSize = ndefMessage.toByteArray().length;
        } else {
          return;
        }
      }
      try {
        NdefRecord ndefRecord = ndefMessage.getRecords()[0];
        Log.i("JAVA",ndefRecord.toString());
        Uri uri = parse(ndefRecord);
        Log.i("JAVA","uri:"+uri.toString());
        mTagText += uri.toString() + "\n\nUri\n" + contentSize + " bytes";
      } catch (Exception e) {
      }
    }
  }
  /**
   * 解析NdefRecord中Uri数据
   * @param record
   * @return
   */
  public static Uri parse(NdefRecord record) {
    short tnf = record.getTnf();
    if (tnf == NdefRecord.TNF_WELL_KNowN) {
      return parseWellKNown(record);
    } else if (tnf == NdefRecord.TNF_ABSOLUTE_URI) {
      return parseAbsolute(record);
    }
    throw new IllegalArgumentException("UnkNown TNF " + tnf);
  }
  /**
   * 处理绝对的Uri
   * 没有Uri识别码，也就是没有Uri前缀，存储的全部是字符串
   * @param ndefRecord 描述NDEF信息的一个信息段，一个NdefMessage可能包含一个或者多个NdefRecord
   * @return
   */
  private static Uri parseAbsolute(NdefRecord ndefRecord) {
    //获取所有的字节数据
    byte[] payload = ndefRecord.getPayload();
    Uri uri = Uri.parse(new String(payload,Charset.forName("UTF-8")));
    return uri;
  }
  /**
   * 处理已知类型的Uri
   * @param ndefRecord
   * @return
   */
  private static Uri parseWellKNown(NdefRecord ndefRecord) {
    //判断数据是否是Uri类型的
    if (!Arrays.equals(ndefRecord.getType(),NdefRecord.RTD_URI))
      return null;
    //获取所有的字节数据
    byte[] payload = ndefRecord.getPayload();
    String prefix = UriPrefix.URI_PREFIX_MAP.get(payload[0]);
    byte[] prefixBytes = prefix.getBytes(Charset.forName("UTF-8"));
    byte[] fullUri = new byte[prefixBytes.length + payload.length - 1];
    System.arraycopy(prefixBytes,fullUri,prefixBytes.length);
    System.arraycopy(payload,prefixBytes.length,payload.length - 1);
    Uri uri = Uri.parse(new String(fullUri,Charset.forName("UTF-8")));
    return uri;
  }
}

public class WriteUriActivity extends BaseNfcActivity {
  private String mUri = "http://www.baidu.com";
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_write_uri);
  }
  public void onNewIntent(Intent intent) {
    Tag detectedTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
    NdefMessage ndefMessage = new NdefMessage(new NdefRecord[]{createUriRecord(mUri)});
    boolean result = writeTag(ndefMessage,Toast.LENGTH_SHORT).show();
    }
  }
  /**
   * 将Uri转成NdefRecord
   * @param uriStr
   * @return
   */
  public static NdefRecord createUriRecord(String uriStr) {
    byte prefix = 0;
    for (Byte b : UriPrefix.URI_PREFIX_MAP.keySet()) {
      String prefixStr = UriPrefix.URI_PREFIX_MAP.get(b).toLowerCase();
      if ("".equals(prefixStr))
        continue;
      if (uriStr.toLowerCase().startsWith(prefixStr)) {
        prefix = b;
        uriStr = uriStr.substring(prefixStr.length());
        break;
      }
    }
    byte[] data = new byte[1 + uriStr.length()];
    data[0] = prefix;
    System.arraycopy(uriStr.getBytes(),uriStr.length());
    NdefRecord record = new NdefRecord(NdefRecord.TNF_WELL_KNowN,NdefRecord.RTD_URI,data);
    return record;
  }
  /**
   * 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;
  }
}

public class ReadMUActivity extends BaseNfcActivity {
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_read_mu);
  }
  @Override
  public void onNewIntent(Intent intent) {
    Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
    String[] techList = tag.getTechList();
    boolean havemifareUltralight = false;
    for (String tech : techList) {
      if (tech.indexOf("mifareUltralight") >= 0) {
        havemifareUltralight = true;
        break;
      }
    }
    if (!havemifareUltralight) {
      Toast.makeText(this,"不支持mifareUltralight数据格式",Toast.LENGTH_SHORT).show();
      return;
    }
    String data = readTag(tag);
    if (data != null)
      Toast.makeText(this,Toast.LENGTH_SHORT).show();
  }
  public String readTag(Tag tag) {
    mifareUltralight ultralight = mifareUltralight.get(tag);
    try {
      ultralight.connect();
      byte[] data = ultralight.readPages(4);
      return new String(data,Charset.forName("GB2312"));
    } catch (Exception e) {
    } finally {
      try {
        ultralight.close();
      } catch (Exception e) {
      }
    }
    return null;
  }
}

public class WriteMUActivity extends BaseNfcActivity {
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_write_mu);
  }
  @Override
  public void onNewIntent(Intent intent) {
    Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
    String[] techList = tag.getTechList();
    boolean havemifareUltralight = false;
    for (String tech : techList) {
      if (tech.indexOf("mifareUltralight") >= 0) {
        havemifareUltralight = true;
        break;
      }
    }
    if (!havemifareUltralight) {
      Toast.makeText(this,Toast.LENGTH_SHORT).show();
      return;
    }
    writeTag(tag);
  }
  public void writeTag(Tag tag) {
    mifareUltralight ultralight = mifareUltralight.get(tag);
    try {
      ultralight.connect();
      //写入八个汉字，从第五页开始写，中文需要转换成GB2312格式
      ultralight.writePage(4,"北京".getBytes(Charset.forName("GB2312")));
      ultralight.writePage(5,"上海".getBytes(Charset.forName("GB2312")));
      ultralight.writePage(6,"广州".getBytes(Charset.forName("GB2312")));
      ultralight.writePage(7,"天津".getBytes(Charset.forName("GB2312")));
      Toast.makeText(this,Toast.LENGTH_SHORT).show();
    } catch (Exception e) {
    } finally {
      try {
        ultralight.close();
      } catch (Exception e) {
      }
    }
  }
}

我已将我的模拟器版本和 Android SDK 版本更新为 Android S ( Android
12 )。更新后，我无法运行该项目。我无法运行 Hello,
World！
项目（空项目），但我可以构建 Gradle，但我无法运行该项目。我总是得到错误：

清单合并失败：针对 Android 12 及更高版本的应用需要为android: exported相应组件定义了意图过滤器时指定显式值。有关详细信息，请参阅
https://developer.android.com/guide/topics/manifest/activity-
element#exported 。

我该如何解决？

这是一个屏幕截图：

使用 Android 12 SDK 时如何解决此问题？

解决方法