package com.nfclab.stuCard;
 
import java.io.IOException;
 
import android.app.Activity;
import android.app.PendingIntent;
import android.content.Intent;
import android.content.IntentFilter;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.Ndef;
import android.nfc.tech.NdefFormatable;
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;
 
public class stuCardActivity extends Activity {
   
    private NfcAdapter mNfcAdapter;
    private PendingIntent mPendingIntent;
    private IntentFilter[] mFilters;
    private String[][] mTechLists;
    private String studentId="";
    private String studentName=" ";
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
 
        final EditText studentIdEditText = (EditText)this.findViewById(R.id.studentIdEditText);
        final EditText studentNameEditText = (EditText)this.findViewById(R.id.studentNameEditText);
 
        Button writeStudentButton = (Button)this.findViewById(R.id.writeStudentButton);
        writeStudentButton.setOnClickListener(new android.view.View.OnClickListener() 
        {
            public void onClick(View view) {
                studentId = studentIdEditText.getText().toString();
                studentName = studentNameEditText.getText().toString();
                 TextView messageText = (TextView)findViewById(R.id.messageText);
                 messageText.setText("Touch NFC Tag to write \n");
                 messageText.append("Student id:" + studentId + "\nStudent Name: " + studentName );
            }
        });
    
        Button exitButton = (Button)findViewById(R.id.exitButton);
         exitButton.setOnClickListener(new android.view.View.OnClickListener() 
        {
            public void onClick(View v) {
                finish();
            }
        });  
 
          mNfcAdapter = NfcAdapter.getDefaultAdapter(this); 
          mPendingIntent = PendingIntent.getActivity(this, 0,
                 new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
             IntentFilter ndef = new IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED);
             //ndef.addDataScheme("http");
             mFilters = new IntentFilter[] {
              ndef,
             };
           mTechLists = new String[][] { new String[] { Ndef.class.getName() },
                   new String[] { NdefFormatable.class.getName() }};
    }
    
    @Override
    public void onResume() {
        super.onResume();
        if (mNfcAdapter != null) mNfcAdapter.enableForegroundDispatch(this, mPendingIntent, mFilters,
                mTechLists);
    }
 
    @Override
    public void onNewIntent(Intent intent) {
        Log.i("Foreground dispatch", "Discovered tag with intent: " + intent);
        Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);  
        
        String externalType = "nfclab.com:transport";
        String payload = studentId+":"+studentName;
        NdefRecord extRecord1 = new NdefRecord(NdefRecord.TNF_EXTERNAL_TYPE, externalType.getBytes(), new byte[0], payload.getBytes());
        NdefMessage newMessage = new NdefMessage(new NdefRecord[] { extRecord1});
        writeNdefMessageToTag(newMessage, tag);   
    }
 
    @Override
    public void onPause() {
        super.onPause();
        mNfcAdapter.disableForegroundDispatch(this);
    }
    
    boolean writeNdefMessageToTag(NdefMessage message, Tag detectedTag) {
        int size = message.toByteArray().length;
        try {
            Ndef ndef = Ndef.get(detectedTag);
            if (ndef != null) {
                ndef.connect();
 
                if (!ndef.isWritable()) {
                    Toast.makeText(this, "Tag is read-only.", Toast.LENGTH_SHORT).show();
                    return false;
                }
                if (ndef.getMaxSize() < size) {
                    Toast.makeText(this, "The data cannot written to tag, Tag capacity is " + ndef.getMaxSize() + " bytes, message is " + size + " bytes.", Toast.LENGTH_SHORT).show();
                    return false;
                }
 
                ndef.writeNdefMessage(message);
                ndef.close();                
                Toast.makeText(this, "Message is written tag.", Toast.LENGTH_SHORT).show();
                return true;
            } else {
                NdefFormatable ndefFormat = NdefFormatable.get(detectedTag);
                if (ndefFormat != null) {
                    try {
                        ndefFormat.connect();
                        ndefFormat.format(message);
                        ndefFormat.close();
                        Toast.makeText(this, "The data is written to the tag ", Toast.LENGTH_SHORT).show();
                        return true;
                    } catch (IOException e) {
                         Toast.makeText(this, "Failed to format tag", Toast.LENGTH_SHORT).show();
                        return false;
                    }
                } else {
                     Toast.makeText(this, "NDEF is not supported", Toast.LENGTH_SHORT).show();
                    return false;
                }
            }
        } catch (Exception e) {
            Toast.makeText(this, "Write opreation is failed", Toast.LENGTH_SHORT).show();
        }
        return false;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="fill_parent"
    android:columnCount="2"
    android:orientation="horizontal"
    android:rowCount="5" >
 
    <TextView
        android:id="@+id/requestStudentId"
        android:layout_row="0"
        android:layout_column="0"
        android:text="@string/requestStudentIdText"
        android:textSize="16sp" />
 
    <EditText
        android:id="@+id/studentIdEditText"
        android:layout_row="0"
        android:layout_column="1"
        android:inputType="text"
        android:text="@string/emptyText" >
        <requestFocus />
    </EditText>
 
    <TextView
        android:id="@+id/requestName"
        android:layout_row="1"
        android:layout_column="0"
        android:text="@string/requestStudentNameText"
        android:textSize="16sp" ></TextView>
 
    <EditText
        android:id="@+id/studentNameEditText"
        android:layout_row="1"
        android:layout_column="1"
        android:inputType="text"
        android:text="@string/emptyText" >
    </EditText>
 
    <TextView
        android:id="@+id/messageText"
        android:layout_row="3"
        android:layout_column="0"
        android:layout_columnSpan="2"
        android:gravity="left"
        android:text="@string/emptyText"
        android:textSize="24sp" />
 
    <Button
        android:id="@+id/writeStudentButton"
        android:layout_row="2"
        android:layout_column="0"
        android:gravity="left"
        android:text="@string/writeButtonText" />
 
    <Button
        android:id="@+id/exitButton"
        android:layout_row="2"
        android:layout_column="1"
         android:gravity="left"
        android:text="@string/exitButtonText" />
 
</GridLayout>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.nfclab.transportationwriter"
    android:versionCode="1"
    android:versionName="1.0" >
 
    <uses-sdk android:minSdkVersion="14" />
        <uses-permission android:name="android.permission.NFC" />
 
    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".stuCardActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
 
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
 
</manifest>