Android NFC example to read tag info of RFID key and card

A simple Android example to read info of RFID tag (key and card in this demo) using NFC.

Edit src/main/AndroidManifest.xml to add <intent-filter> with action of "android.nfc.action.TAG_DISCOVERED" and category of "android.intent.category.DEFAULT", such that the app will be started when RFID tag place near NFC; if no other apps registered.

And add <uses-permission> of "android.permission.NFC", and <uses-feature> of "android.hardware.nfc"

<?xml version="1.0" encoding="utf-8"?>
<manifest 
 package="com.blogspot.android_er.androidnfctagdiscovered" >

 <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_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.TAG_DISCOVERED"/>
 <category android_name="android.intent.category.DEFAULT"/>
 </intent-filter>
 </activity>
 </application>

</manifest>

In MainActivity.java:

In onCreate():
Create NfcAdapter object by calling NfcAdapter.getDefaultAdapter(this). And check if NFC supported and enabled.

Override onResume():
Check if intent is ACTION_TAG_DISCOVERED. if yes, we can obtain a Tag object from the intent, by calling intent.getParcelableExtra(NfcAdapter.EXTRA_TAG).

package com.blogspot.android_er.androidnfctagdiscovered;

import android.content.Intent;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

 private NfcAdapter nfcAdapter;
 TextView textViewInfo;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 textViewInfo = (TextView)findViewById(R.id.info);

 nfcAdapter = NfcAdapter.getDefaultAdapter(this);
 if(nfcAdapter == null){
 Toast.makeText(this,
 "NFC NOT supported on this devices!",
 Toast.LENGTH_LONG).show();
 finish();
 }else if(!nfcAdapter.isEnabled()){
 Toast.makeText(this,
 "NFC NOT Enabled!",
 Toast.LENGTH_LONG).show();
 finish();
 }
 }

 @Override
 protected void onResume() {
 super.onResume();

 Intent intent = getIntent();
 String action = intent.getAction();

 if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(action)) {
 Toast.makeText(this,
 "onResume() - ACTION_TAG_DISCOVERED",
 Toast.LENGTH_SHORT).show();

 Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
 if(tag == null){
 textViewInfo.setText("tag == null");
 }else{
 String tagInfo = tag.toString() + " ";

 tagInfo += " Tag Id: ";
 byte[] tagId = tag.getId();
 tagInfo += "length = " + tagId.length +" ";
 for(int i=0; i<tagId.length; i++){
 tagInfo += Integer.toHexString(tagId[i] & 0xFF) + " ";
 }
 tagInfo += " ";

 String[] techList = tag.getTechList();
 tagInfo += " Tech List ";
 tagInfo += "length = " + techList.length +" ";
 for(int i=0; i<techList.length; i++){
 tagInfo += techList[i] + " ";
 }

 textViewInfo.setText(tagInfo);
 }
 }else{
 Toast.makeText(this,
 "onResume() : " + action,
 Toast.LENGTH_SHORT).show();
 }

 }
}

layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 
 
 android_layout_width="match_parent"
 android_layout_height="match_parent"
 android_padding="16dp"
 android_orientation="vertical"
 tools_context=".MainActivity">

 <TextView
 android_layout_width="wrap_content"
 android_layout_height="wrap_content"
 android_layout_margin="10dp"
 android_layout_gravity="center_horizontal"
 android_autoLink="web"
 android_text="http://android-er.blogspot.com/"
 android_textStyle="bold"/>

 <TextView
 android_id="@+id/info"
 android_layout_width="match_parent"
 android_layout_height="wrap_content" />

</LinearLayout>

Tag info of RFID card

Tag info of RFID key

reference: http://developer.android.com/guide/topics/connectivity/nfc/nfc.html

Next:
- Android NFC read MifareClassic RFID tag, with android.nfc.action.TECH_DISCOVERED
- Android NFC: readBlock() for MifareClassic, to dump data in RFID tag

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