12、NFC技术：读写NFC标签中的Uri数据

import cn.read.write.uri.library.UriRecord;
import android.app.Activity;
import android.content.Intent;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.Ndef;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;

/**
* 读写NFC标签的Uri
* @author dr
*
*/
public class ReadWriteUriMainActivity extends Activity {
private TextView mSelectUri;
private String mUri;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_read_write_uri_main);
mSelectUri = (TextView) findViewById(R.id.textview_uri);
}

public void onClick_SelectUri(View view) {
Intent intent = new Intent(this, UriListActivity.class);
startActivityForResult(intent, 1);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1 && resultCode == 1) {
mUri = data.getStringExtra("uri");
mSelectUri.setText(mUri);
}
}

public void onNewIntent(Intent intent) {
if (mUri == null) {
Intent myIntent = new Intent(this, ShowNFCTagContentActivity.class);
myIntent.putExtras(intent);
myIntent.setAction(NfcAdapter.ACTION_NDEF_DISCOVERED);
startActivity(myIntent);
} else {  // write nfc
Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
NdefMessage ndefMessage = new NdefMessage(
new NdefRecord[] { createUriRecord(mUri) });
if (writeTag(ndefMessage, tag)) {
mUri = null;
mSelectUri.setText("");
}
}
}

public NdefRecord createUriRecord(String uriStr) {
byte prefix = 0;
for (Byte b : UriRecord.URI_PREFIX_MAP.keySet()) {
String prefixStr = UriRecord.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(), 0, data, 1, uriStr.length());

NdefRecord record = new NdefRecord(NdefRecord.TNF_WELL_KNOWN,
NdefRecord.RTD_URI, new byte[0], data);
return record;
}

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);
Toast.makeText(this, "ok", Toast.LENGTH_LONG).show();
return true;
}
} catch (Exception e) {
// TODO: handle exception
}
return false;
}
}

<?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" >

<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="onClick_SelectUri"
android:text="选择Uri" />

<TextView
android:id="@+id/textview_uri"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="16sp" />

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="30dp"
android:text="请将NFC标签靠近手机背面读取或写入Uri"
android:textColor="#F00"
android:textSize="16sp" />

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

</LinearLayout>

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;

/**
* 显示URI列表
* @author dr
*
*/
public class UriListActivity extends ListActivity implements
OnItemClickListener {
private String uris[] = new String[] { "http://www.google.com",
"http://www.apple.com", "http://developer.apple.com",
"http://www.126.com", "ftp://192.168.17.160",
"https://192.168.17.120", "smb://192.168.17.100" };

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, android.R.id.text1, uris);
setListAdapter(arrayAdapter);
getListView().setOnItemClickListener(this);
}

@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
Intent intent = new Intent();
intent.putExtra("uri", uris[position]);
setResult(1, intent);
finish();
}

}

import android.app.Activity;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.Ndef;
import android.os.Bundle;
import android.os.Parcelable;
import android.widget.TextView;
import cn.read.write.uri.library.UriRecord;

/**
* 显示NFC标签内容
* @author dr
*
*/
public class ShowNFCTagContentActivity extends Activity {
private TextView mTagContent;
private Tag mDetectedTag;
private String mTagText;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_show_nfctag_content);
mTagContent = (TextView) findViewById(R.id.textview_tag_content);
mDetectedTag = getIntent().getParcelableExtra(NfcAdapter.EXTRA_TAG);
Ndef ndef = Ndef.get(mDetectedTag);
mTagText = ndef.getType() + "\n max size:" + ndef.getMaxSize()
+ " bytes\n\n";

readNFCTag();

mTagContent.setText(mTagText);
}

private void readNFCTag() {
if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(getIntent().getAction())) {
Parcelable[] rawMsgs = getIntent().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];
UriRecord uriRecord = UriRecord.parse(ndefRecord);
mTagText += uriRecord.getUri().toString() + "\n\nUri\n"
+ contentSize + " bytes";
} catch (Exception e) {
// TODO: handle exception
}
}
}

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<TextView
android:id="@+id/textview_tag_content"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="6dp"
android:textSize="16sp" />

</LinearLayout>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="cn.eoe.read.write.uri"
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=".ReadWriteUriMainActivity"
android:label="读写NFC标签的Uri"
android:launchMode="singleTask" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
<action android:name="android.nfc.action.NDEF_DISCOVERED" />

<category android:name="android.intent.category.DEFAULT" />

<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" />
<data android:mimeType="text/plain" />
</intent-filter>
</activity>
<activity
android:name="cn.eoe.read.write.uri.ShowNFCTagContentActivity"
android:label="显示NFC标签内容" />
<activity
android:name="cn.eoe.read.write.uri.UriListActivity"
android:label="选择Uri" />
</application>

</manifest>