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Read /Write NFC Tag With Android.
NFC App Tutorial
NFC :- NFC is the Near field communication, NFC short range
wireless technology. NFC allows you to share small payload of Data between an NFC
tag and an Android device.
The spectrum range from simple sticker and key ring to
complex cards with integrated cryptographic hardware. Tag also differ in their
chip technology.
NFC Access in the Android Manifest.
To get access to the NFC hardware, you have to apply for
permission in the manifest. The element
so that your application shows up in google paly only for devices that have NFC
Hardware.
<uses-permission android:name="android.permission.NFC"
/>
<uses-feature android:name="android.hardware.nfc" android:required="true" />
<uses-feature android:name="android.hardware.nfc" android:required="true" />
Filtering for NFC Intents :- Used only three filter for
tag.
1.ACTION_NDEF_DISCOVERED
2.ACTION_TAG_DISCOVERED
3ACTION_TECH_DISCOVERED
ACTION_NDEF_DISCOVERED
<intent-filter>
<action android:name="android.nfc.action.NDEF_DISCOVERED" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="text/plain" />
</intent-filter>
<action android:name="android.nfc.action.NDEF_DISCOVERED" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="text/plain" />
</intent-filter>
ACTITON_TECH_DISCOVERED
Create nfc_tech_filter .xml inside res folder…
xml version="1.0" encoding="utf-8"?>
<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
<tech-list>
<tech>android.nfc.tech.Ndef</tech>
</tech-list>
</resources>
<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
<tech-list>
<tech>android.nfc.tech.Ndef</tech>
</tech-list>
</resources>
ACTION_TAG_DISCOVERED
<intent-filter>
<action android:name="android.nfc.action.TAG_DISCOVERED" />
</intent-filter>
<action android:name="android.nfc.action.TAG_DISCOVERED" />
</intent-filter>
EXPLAIN HOW TO USED ALL THOSE REQUIRED PERMISSIONS AND
FUCTION.
1. First you have to Enable you NFC Option in android device.
2. Create new android project in android studio.
3. Add some required permission in manifest.
Manifest.xml
xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.project.example.nfcreader">
<uses-permission android:name="android.permission.NFC" />
<uses-feature android:name="android.hardware.nfc" android:required="true" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<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:mimeType="text/plain" />
</intent-filter>
<meta-data
android:name="android.nfc.action.TECH_DISCOVERED"
android:resource="@xml/nfc_tech_filter" />
</activity>
<activity android:name=".SecondActivity"></activity>
</application>
</manifest>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.project.example.nfcreader">
<uses-permission android:name="android.permission.NFC" />
<uses-feature android:name="android.hardware.nfc" android:required="true" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<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:mimeType="text/plain" />
</intent-filter>
<meta-data
android:name="android.nfc.action.TECH_DISCOVERED"
android:resource="@xml/nfc_tech_filter" />
</activity>
<activity android:name=".SecondActivity"></activity>
</application>
</manifest>
4 Create nfc _tech_filter.xml inside res/xml directory.
xml version="1.0" encoding="utf-8"?>
<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
<tech-list>
<tech>android.nfc.tech.Ndef</tech>
</tech-list>
</resources>
<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
<tech-list>
<tech>android.nfc.tech.Ndef</tech>
</tech-list>
</resources>
5 Create activity_main.xml layout inside layout folder.
xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20sp"
android:visibility="gone">
<EditText
android:id="@+id/edit_message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="2"
android:hint="message" />
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Write" />
<TextView
android:id="@+id/nfc_contents"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
</LinearLayout>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20sp"
android:visibility="gone">
<EditText
android:id="@+id/edit_message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="2"
android:hint="message" />
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Write" />
<TextView
android:id="@+id/nfc_contents"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
</LinearLayout>
6 Add Main_activity.java.
package com.project.example.nfcreader;
import android.app.Activity;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.nfc.FormatException;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.Ndef;
import android.os.Parcelable;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
public class MainActivity extends Activity {
public static final String ERROR_DETECTED = "No NFC tag detected!";
public static final String WRITE_SUCCESS = "Text written to the NFC tag successfully!";
public static final String WRITE_ERROR = "Error during writing, is the NFC tag close enough to your device?";
NfcAdapter nfcAdapter;
PendingIntent pendingIntent;
IntentFilter writeTagFilters[];
boolean writeMode;
Tag myTag;
Context context;
TextView tvNFCContent;
TextView message;
Button btnWrite;
public static String Id_Value;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context = this;
tvNFCContent = (TextView) findViewById(R.id.nfc_contents);
message = (TextView) findViewById(R.id.edit_message);
btnWrite = (Button) findViewById(R.id.button);
btnWrite.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v) {
try {
if(myTag ==null) {
Toast.makeText(context, ERROR_DETECTED, Toast.LENGTH_LONG).show();
} else {
write(message.getText().toString(), myTag);
Toast.makeText(context, WRITE_SUCCESS, Toast.LENGTH_LONG ).show();
}
} catch (IOException e) {
Toast.makeText(context, WRITE_ERROR, Toast.LENGTH_LONG ).show();
e.printStackTrace();
} catch (FormatException e) {
Toast.makeText(context, WRITE_ERROR, Toast.LENGTH_LONG ).show();
e.printStackTrace();
}
}
});
nfcAdapter = NfcAdapter.getDefaultAdapter(this);
if (nfcAdapter == null) {
// Stop here, we definitely need NFC
Toast.makeText(this, "This device doesn't support NFC.", Toast.LENGTH_LONG).show();
finish();
}
readFromIntent(getIntent());
pendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
IntentFilter tagDetected = new IntentFilter(NfcAdapter.ACTION_TAG_DISCOVERED);
tagDetected.addCategory(Intent.CATEGORY_DEFAULT);
writeTagFilters = new IntentFilter[] { tagDetected };
}
/**************Read From NFC Tag**********************************/
private void readFromIntent(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 = null;
if (rawMsgs != null) {
msgs = new NdefMessage[rawMsgs.length];
for (int i = 0; i < rawMsgs.length; i++) {
msgs[i] = (NdefMessage) rawMsgs[i];
}
}
buildTagViews(msgs);
}
}
private void buildTagViews(NdefMessage[] msgs) {
if (msgs == null || msgs.length == 0) return;
String text = "";
// String tagId = new String(msgs[0].getRecords()[0].getType());
byte[] payload = msgs[0].getRecords()[0].getPayload();
String textEncoding = ((payload[0] & 128) == 0) ? "UTF-8" : "UTF-16"; // Get the Text Encoding
int languageCodeLength = payload[0] & 0063; // Get the Language Code, e.g. "en"
// String languageCode = new String(payload, 1, languageCodeLength, "US-ASCII");
try {
// Get the Text
text = new String(payload, languageCodeLength + 1, payload.length - languageCodeLength - 1, textEncoding);
} catch (UnsupportedEncodingException e) {
Log.e("UnsupportedEncoding", e.toString());
}
tvNFCContent.setText("NFC Content: " + text);
}
/****Write to NFC Tag**************************************************/
private void write(String text, Tag tag) throws IOException, FormatException {
NdefRecord[] records = { createRecord(text) };
NdefMessage message = new NdefMessage(records);
// Get an instance of Ndef for the tag.
Ndef ndef = Ndef.get(tag);
// Enable I/O
ndef.connect();
// Write the message
ndef.writeNdefMessage(message);
// Close the connection
ndef.close();
}
private NdefRecord createRecord(String text) throws UnsupportedEncodingException {
String lang = "en";
byte[] textBytes = text.getBytes();
byte[] langBytes = lang.getBytes("US-ASCII");
int langLength = langBytes.length;
int textLength = textBytes.length;
byte[] payload = new byte[1 + langLength + textLength];
// set status byte (see NDEF spec for actual bits)
payload[0] = (byte) langLength;
// copy langbytes and textbytes into payload
System.arraycopy(langBytes, 0, payload, 1, langLength);
System.arraycopy(textBytes, 0, payload, 1 + langLength, textLength);
NdefRecord recordNFC = new NdefRecord(NdefRecord.TNF_WELL_KNOWN, NdefRecord.RTD_TEXT, new byte[0], payload);
return recordNFC;
}
@Override
protected void onNewIntent(Intent intent) {
setIntent(intent);
readFromIntent(intent);
if(NfcAdapter.ACTION_TAG_DISCOVERED.equals(intent.getAction())){
myTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
}
}
@Override
public void onPause(){
super.onPause();
WriteModeOff();
}
@Override
public void onResume(){
super.onResume();
WriteModeOn();
}
/********Enable Write**********************/
private void WriteModeOn(){
writeMode = true;
nfcAdapter.enableForegroundDispatch(this, pendingIntent, writeTagFilters, null);
}
/* *****Disable Write**********************************************/
private void WriteModeOff(){
writeMode = false;
nfcAdapter.disableForegroundDispatch(this);
}
}
import android.app.Activity;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.nfc.FormatException;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.Ndef;
import android.os.Parcelable;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
public class MainActivity extends Activity {
public static final String ERROR_DETECTED = "No NFC tag detected!";
public static final String WRITE_SUCCESS = "Text written to the NFC tag successfully!";
public static final String WRITE_ERROR = "Error during writing, is the NFC tag close enough to your device?";
NfcAdapter nfcAdapter;
PendingIntent pendingIntent;
IntentFilter writeTagFilters[];
boolean writeMode;
Tag myTag;
Context context;
TextView tvNFCContent;
TextView message;
Button btnWrite;
public static String Id_Value;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context = this;
tvNFCContent = (TextView) findViewById(R.id.nfc_contents);
message = (TextView) findViewById(R.id.edit_message);
btnWrite = (Button) findViewById(R.id.button);
btnWrite.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v) {
try {
if(myTag ==null) {
Toast.makeText(context, ERROR_DETECTED, Toast.LENGTH_LONG).show();
} else {
write(message.getText().toString(), myTag);
Toast.makeText(context, WRITE_SUCCESS, Toast.LENGTH_LONG ).show();
}
} catch (IOException e) {
Toast.makeText(context, WRITE_ERROR, Toast.LENGTH_LONG ).show();
e.printStackTrace();
} catch (FormatException e) {
Toast.makeText(context, WRITE_ERROR, Toast.LENGTH_LONG ).show();
e.printStackTrace();
}
}
});
nfcAdapter = NfcAdapter.getDefaultAdapter(this);
if (nfcAdapter == null) {
// Stop here, we definitely need NFC
Toast.makeText(this, "This device doesn't support NFC.", Toast.LENGTH_LONG).show();
finish();
}
readFromIntent(getIntent());
pendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
IntentFilter tagDetected = new IntentFilter(NfcAdapter.ACTION_TAG_DISCOVERED);
tagDetected.addCategory(Intent.CATEGORY_DEFAULT);
writeTagFilters = new IntentFilter[] { tagDetected };
}
/**************Read From NFC Tag**********************************/
private void readFromIntent(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 = null;
if (rawMsgs != null) {
msgs = new NdefMessage[rawMsgs.length];
for (int i = 0; i < rawMsgs.length; i++) {
msgs[i] = (NdefMessage) rawMsgs[i];
}
}
buildTagViews(msgs);
}
}
private void buildTagViews(NdefMessage[] msgs) {
if (msgs == null || msgs.length == 0) return;
String text = "";
// String tagId = new String(msgs[0].getRecords()[0].getType());
byte[] payload = msgs[0].getRecords()[0].getPayload();
String textEncoding = ((payload[0] & 128) == 0) ? "UTF-8" : "UTF-16"; // Get the Text Encoding
int languageCodeLength = payload[0] & 0063; // Get the Language Code, e.g. "en"
// String languageCode = new String(payload, 1, languageCodeLength, "US-ASCII");
try {
// Get the Text
text = new String(payload, languageCodeLength + 1, payload.length - languageCodeLength - 1, textEncoding);
} catch (UnsupportedEncodingException e) {
Log.e("UnsupportedEncoding", e.toString());
}
tvNFCContent.setText("NFC Content: " + text);
}
/****Write to NFC Tag**************************************************/
private void write(String text, Tag tag) throws IOException, FormatException {
NdefRecord[] records = { createRecord(text) };
NdefMessage message = new NdefMessage(records);
// Get an instance of Ndef for the tag.
Ndef ndef = Ndef.get(tag);
// Enable I/O
ndef.connect();
// Write the message
ndef.writeNdefMessage(message);
// Close the connection
ndef.close();
}
private NdefRecord createRecord(String text) throws UnsupportedEncodingException {
String lang = "en";
byte[] textBytes = text.getBytes();
byte[] langBytes = lang.getBytes("US-ASCII");
int langLength = langBytes.length;
int textLength = textBytes.length;
byte[] payload = new byte[1 + langLength + textLength];
// set status byte (see NDEF spec for actual bits)
payload[0] = (byte) langLength;
// copy langbytes and textbytes into payload
System.arraycopy(langBytes, 0, payload, 1, langLength);
System.arraycopy(textBytes, 0, payload, 1 + langLength, textLength);
NdefRecord recordNFC = new NdefRecord(NdefRecord.TNF_WELL_KNOWN, NdefRecord.RTD_TEXT, new byte[0], payload);
return recordNFC;
}
@Override
protected void onNewIntent(Intent intent) {
setIntent(intent);
readFromIntent(intent);
if(NfcAdapter.ACTION_TAG_DISCOVERED.equals(intent.getAction())){
myTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
}
}
@Override
public void onPause(){
super.onPause();
WriteModeOff();
}
@Override
public void onResume(){
super.onResume();
WriteModeOn();
}
/********Enable Write**********************/
private void WriteModeOn(){
writeMode = true;
nfcAdapter.enableForegroundDispatch(this, pendingIntent, writeTagFilters, null);
}
/* *****Disable Write**********************************************/
private void WriteModeOff(){
writeMode = false;
nfcAdapter.disableForegroundDispatch(this);
}
}
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