android nfc中MifareClassic格式的读写

Android支持的数据格式



数据格式的Intent filter

AndroidManifest.xml文件中，要像向下列示例那样，在<activity>元素内的<meta-data>元素中指定你创建的资源文件：

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

nfc_tech_filter.xml文件（一个Tag标签只有全部匹配tech-list元素中的tech元素指定的nfc芯片时才认为被匹配）：

<resources xmlns: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>

也可创建多个资源文件（多个资源文件是OR关系，每个资源文件中的芯片是AND关系）：

<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">

<tech-list>
<tech>android.nfc.tech.NfcA</tech>
<tech>android.nfc.tech.Ndef</tech>
<tech>android.nfc.tech.NdefFormatable</tech>
</tech-list>
</resources>

<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
<tech-list>
<tech>android.nfc.tech.Ndef</tech>
<tech>android.nfc.tech.NdefFormatable</tech>
</tech-list>
</resources>

或者在同一个资源文件中创建多个<tech-list>元素（多个<tech-list>元素之间是OR关系，<tech-list>元素中的<tech>是AND关系）：

<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
<tech-list>
<tech>android.nfc.tech.NfcA</tech>
</tech-list>
<tech-list>
<tech>android.nfc.tech.NfcB</tech>
</tech-list>
<tech-list>
<tech>android.nfc.tech.MifareClassic</tech>
</tech-list>
</resources>

查看标签支持数据格式的方法：

通过Tag.getTechlist()方法，获得标签所支持的数据格式

通过Tag.getId（）方法，获得标签的唯一ID标识

NfcAdapter == null：表示设备不支持NFC硬件

NfcAdapter.isEnable（）方法：判断NFC是否开启

综上所述：

一个Tag通过Tag.getTechlist()方法获取它所支持的所有标签类型，如果清单文件中所引用的<tech-list>资源文件中所有的<tech>中的芯片是Tag标签所有支持标签的子集则被匹配的，可以写多个<tech-list>，每个<tech-list>时独立的，只要有其中一个<tech-list>中的所有的<tech>中的芯片类型全部匹配Tag所支持的芯片则认为是匹配的。多个<tech-list>是OR关系，<tech-list>中的<tech>是AND关系。

MifareClassic标签的外形结构



MifareClassic标签的数据结构



MifareClassic类的常用方法

get（）：根据Tag对象来获得MifareClassic对象；

Connect（）：允许对MifareClassic标签进行IO操作；

getType()：获得MifareClassic标签的具体类型：TYPE_CLASSIC，TYPE_PLUA，TYPE_PRO，TYPE_UNKNOWN；

getSectorCount（）：获得标签总共有的扇区数量；

getBlockCount（）：获得标签总共有的的块数量；

getSize（）：获得标签的容量：SIZE_1K,SIZE_2K,SIZE_4K,SIZE_MINI

authenticateSectorWithKeyA（int SectorIndex，byte[] Key）：验证当前扇区的KeyA密码，返回值为ture或false。

常用KeyA：默认出厂密码：KEY_DEFAULT，

各种用途的供货商必须配合该技术的MAD：KEY_MIFARE_APPLICATION_DIRECTORY

被格式化成NDEF格式的密码：KEY_NFC_FORUM

getBlockCountInSector(int):获得当前扇区的所包含块的数量；

sectorToBlock（int）：当前扇区的第1块的块号；

WriteBlock（int，data）：将数据data写入当前块；

readBlock（int）：读取当前块的数据。

close（）：禁止对标签的IO操作，释放资源。

MifareClassic标签的读写流程

获得Adapter对象

获得Tag对象

获得MifareClassic对象

读取数据块的数据

Connect（），readBlock（），close（）

获得Adapter对象

获得Tag对象

获得MifareClassic对象

将数据块写入标签

Connect（），writeBlock（），close（）

例子程序：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<CheckBox
android:id="@+id/checkbox_write"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="是否向NFC标签写入数据" />

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:text="请将NFC标签或贴纸靠近手机背面"
android:textSize="16sp" />

<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="10dp"
android:src="@drawable/read_nfc_tag" />

</LinearLayout>

MainActivity：

package mobile.android.mifareultralight;

import java.io.IOException;
import java.nio.charset.Charset;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.Intent;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.MifareClassic;
import android.os.Bundle;
import android.util.Log;
import android.widget.CheckBox;
import android.widget.Toast;

public class MifareultralightMainActivity extends Activity {

private CheckBox	  mWriteData;

private NfcAdapter	mNfcAdapter;

private PendingIntent mPendingIntent;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

setContentView(R.layout.activity_mifareultralight);
mWriteData = (CheckBox) findViewById(R.id.checkbox_write);
mNfcAdapter = mNfcAdapter.getDefaultAdapter(this);
if (mNfcAdapter == null) {
Toast.makeText(this, "设备不支持NFC！", Toast.LENGTH_LONG).show();
finish();
return;
}
if (!mNfcAdapter.isEnabled()) {
Toast.makeText(this, "请在系统设置中先启用NFC功能！", Toast.LENGTH_LONG).show();
finish();
return;
}
mPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this,
getClass()), 0);

}

@Override
public void onResume() {
super.onResume();
if (mNfcAdapter != null)
mNfcAdapter.enableForegroundDispatch(this, mPendingIntent, null,
null);
}

@Override
public void onNewIntent(Intent intent) {

Tag tag = intent.getParcelableExtra(mNfcAdapter.EXTRA_TAG);
String[] techList = tag.getTechList();
boolean haveMifareUltralight = false;
for (String tech : techList) {
if (tech.indexOf("MifareClassic") >= 0) {
haveMifareUltralight = true;
break;
}
}
if (!haveMifareUltralight) {
Toast.makeText(this, "不支持MifareClassic", Toast.LENGTH_LONG).show();
return;
}
if (mWriteData.isChecked()) {
writeTag(tag);
} else {
String data = readTag(tag);
if (data != null) {
Log.i(data, "ouput");
Toast.makeText(this, data, Toast.LENGTH_LONG).show();
}
}

}

@Override
public void onPause() {
super.onPause();
if (mNfcAdapter != null)
mNfcAdapter.disableForegroundDispatch(this);

}

public void writeTag(Tag tag) {

MifareClassic mfc = MifareClassic.get(tag);

try {
mfc.connect();
boolean auth = false;
short sectorAddress = 1;
auth = mfc.authenticateSectorWithKeyA(sectorAddress,
MifareClassic.KEY_NFC_FORUM);
if (auth) {
// the last block of the sector is used for KeyA and KeyB cannot be overwritted
mfc.writeBlock(4, "1313838438000000".getBytes());
mfc.writeBlock(5, "1322676888000000".getBytes());
mfc.close();
Toast.makeText(this, "写入成功", Toast.LENGTH_SHORT).show();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
try {
mfc.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

//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();
}

public String readTag(Tag tag) {
MifareClassic mfc = MifareClassic.get(tag);
for (String tech : tag.getTechList()) {
System.out.println(tech);
}
boolean auth = false;
//读取TAG

try {
String metaInfo = "";
//Enable I/O operations to the tag from this TagTechnology object.
mfc.connect();
int type = mfc.getType();//获取TAG的类型
int sectorCount = mfc.getSectorCount();//获取TAG中包含的扇区数
String typeS = "";
switch (type) {
case MifareClassic.TYPE_CLASSIC:
typeS = "TYPE_CLASSIC";
break;
case MifareClassic.TYPE_PLUS:
typeS = "TYPE_PLUS";
break;
case MifareClassic.TYPE_PRO:
typeS = "TYPE_PRO";
break;
case MifareClassic.TYPE_UNKNOWN:
typeS = "TYPE_UNKNOWN";
break;
}
metaInfo += "卡片类型：" + typeS + "\n共" + sectorCount + "个扇区\n共"
+ mfc.getBlockCount() + "个块\n存储空间: " + mfc.getSize()
+ "B\n";
for (int j = 0; j < sectorCount; j++) {
//Authenticate a sector with key A.
auth = mfc.authenticateSectorWithKeyA(j,
MifareClassic.KEY_NFC_FORUM);
int bCount;
int bIndex;
if (auth) {
metaInfo += "Sector " + j + ":验证成功\n";
// 读取扇区中的块
bCount = mfc.getBlockCountInSector(j);
bIndex = mfc.sectorToBlock(j);
for (int i = 0; i < bCount; i++) {
byte[] data = mfc.readBlock(bIndex);
metaInfo += "Block " + bIndex + " : "
+ bytesToHexString(data) + "\n";
bIndex++;
}
} else {
metaInfo += "Sector " + j + ":验证失败\n";
}
}
return metaInfo;
} catch (Exception e) {
Toast.makeText(this, e.getMessage(), Toast.LENGTH_LONG).show();
e.printStackTrace();
} finally {
if (mfc != null) {
try {
mfc.close();
} catch (IOException e) {
Toast.makeText(this, e.getMessage(), Toast.LENGTH_LONG)
.show();
}
}
}
return null;

}
}

清单文件：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="mobile.android.mifareultralight"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="15"
android:targetSdkVersion="15" />

<uses-permission android:name="android.permission.NFC" />

<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MifareultralightMainActivity"
android:label="Mifareultralight"
android:launchMode="singleTop"
android:screenOrientation="portrait" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>