Communication between Android using NFC to send text

This example send text between Android devices using NFC. Modify from last post of sending Uri between Android devices using NFC.


Modify AndroidManifest.xml include <intent-filter> of "android.nfc.action.NDEF_DISCOVERED".

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.androidnfc"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="16"
        android:targetSdkVersion="19" />
    <uses-permission android:name="android.permission.NFC"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.androidnfc.MainActivity"
            android:label="@string/app_name" >
            <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>
            
        </activity>
    </application>

</manifest>

MainActivity.java

package com.example.androidnfc;

import android.app.Activity;
import android.content.Intent;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.NfcAdapter.CreateNdefMessageCallback;
import android.nfc.NfcAdapter.OnNdefPushCompleteCallback;
import android.nfc.NfcEvent;
import android.os.Bundle;
import android.os.Parcelable;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity implements 
 CreateNdefMessageCallback, OnNdefPushCompleteCallback{
 
 TextView textInfo;
 EditText textOut;
 
 NfcAdapter nfcAdapter;

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

  nfcAdapter = NfcAdapter.getDefaultAdapter(this);
  if(nfcAdapter==null){
   Toast.makeText(MainActivity.this, 
    "nfcAdapter==null, no NFC adapter exists", 
    Toast.LENGTH_LONG).show();
  }else{
   Toast.makeText(MainActivity.this, 
     "Set Callback(s)", 
     Toast.LENGTH_LONG).show();
   nfcAdapter.setNdefPushMessageCallback(this, this);
   nfcAdapter.setOnNdefPushCompleteCallback(this, this);
  }
 }

 @Override
 protected void onResume() {
  super.onResume();
  Intent intent = getIntent();
  String action = intent.getAction();
  if(action.equals(NfcAdapter.ACTION_NDEF_DISCOVERED)){
   Parcelable[] parcelables = 
    intent.getParcelableArrayExtra(
      NfcAdapter.EXTRA_NDEF_MESSAGES);
   NdefMessage inNdefMessage = (NdefMessage)parcelables[0];
   NdefRecord[] inNdefRecords = inNdefMessage.getRecords();
   NdefRecord NdefRecord_0 = inNdefRecords[0];
   String inMsg = new String(NdefRecord_0.getPayload());
   textInfo.setText(inMsg);
  }
 }

 @Override
 protected void onNewIntent(Intent intent) {
  setIntent(intent);
 }

 @Override
 public void onNdefPushComplete(NfcEvent event) {
  
  final String eventString = "onNdefPushComplete\n" + event.toString();
  runOnUiThread(new Runnable() {
   
   @Override
   public void run() {
    Toast.makeText(getApplicationContext(), 
      eventString, 
      Toast.LENGTH_LONG).show();
   }
  });

 }

 @Override
 public NdefMessage createNdefMessage(NfcEvent event) {
  
  String stringOut = textOut.getText().toString();
  byte[] bytesOut = stringOut.getBytes();
  
  NdefRecord ndefRecordOut = new NdefRecord(
    NdefRecord.TNF_MIME_MEDIA, 
    "text/plain".getBytes(),
                new byte[] {}, 
                bytesOut);

  NdefMessage ndefMessageout = new NdefMessage(ndefRecordOut);
  return ndefMessageout;
 }

}

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context="com.example.androidnfc.MainActivity" >
    
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold" />

    <EditText
        android:id="@+id/textout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    
    <TextView
        android:id="@+id/info"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

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