Android Open Source - Android-NFC-WiFi-Controller Nfc Utils

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License

The source code is released under:

MIT License

Java Source Code

package sanchezsobrino.multimedia.anwc;
//  w  w  w  .ja  v a 2 s  .  c  o  m
import java.io.IOException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.app.PendingIntent;
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.nfc.tech.NdefFormatable;
import android.os.Parcelable;
import android.text.TextUtils;
import android.util.Log;

/**
 * A collection of utility methods for NFC data
 */
public class NfcUtils {
  private static final String LOG_TAG = "NfcUtils";

  /**
   * Creates a custom MIME type encapsulated in an NDEF record for a given
   * payload
   * 
   * @param mimeType
   */
  public static NdefRecord createRecord(String mimeType, byte[] payload) {
    byte[] mimeBytes = mimeType.getBytes(Charset.forName("US-ASCII"));
    NdefRecord mimeRecord = new NdefRecord(NdefRecord.TNF_MIME_MEDIA, mimeBytes, new byte[0], payload);
    return mimeRecord;
  }

  /**
   * Creates an Ndef message
   * 
   * @param payload
   * @return
   */
  public static NdefMessage createMessage(String mimeType, byte[] payload) {
    // Min API Level of 14 requires an array as the argument
    return new NdefMessage(new NdefRecord[] { createRecord(mimeType, payload) });
  }

  /**
   * Write an NDEF message to a Tag
   * 
   * @param message
   * @param tag
   * @return true if successful, false if not written to
   */
  public static 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()) {
          Log.e(LOG_TAG, "Not writing to tag- tag is not writable");
          return false;
        }
        if (ndef.getMaxSize() < size) {
          Log.e(LOG_TAG, "Not writing to tag- message exceeds the max tag size of " + ndef.getMaxSize());
          return false;
        }
        ndef.writeNdefMessage(message);
        return true;
      } else {
        NdefFormatable format = NdefFormatable.get(tag);
        if (format != null) {
          try {
            format.connect();
            format.format(message);
            return true;
          } catch (IOException e) {
            Log.e(LOG_TAG, "Not writing to tag", e);
            return false;
          }
        } else {
          Log.e(LOG_TAG, "Not writing to tag- undefined format");
          return false;
        }
      }
    } catch (Exception e) {
      Log.e(LOG_TAG, "Not writing to tag", e);
      return false;
    }
  }

  /**
   * Parse an intent for non-empty strings within an NDEF message
   * 
   * @param intent
   * @return an empty list if the payload is empty
   */
  public static List<String> getStringsFromNfcIntent(Intent intent) {
    List<String> payloadStrings = new ArrayList<String>();

    for (NdefMessage message : getMessagesFromIntent(intent)) {
      for (NdefRecord record : message.getRecords()) {
        byte[] payload = record.getPayload();
        String payloadString = new String(payload);

        if (!TextUtils.isEmpty(payloadString))
          payloadStrings.add(payloadString);
      }
    }

    return payloadStrings;
  }

  /**
   * Parses an intent for NDEF messages, returns all that are found
   * 
   * @param intent
   * @return an empty list if there are no NDEF messages found
   */
  public static List<NdefMessage> getMessagesFromIntent(Intent intent) {
    List<NdefMessage> intentMessages = new ArrayList<NdefMessage>();
    String action = intent.getAction();
    if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(action) || NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) {
      Log.i(LOG_TAG, "Reading from NFC " + action);
      Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
      if (rawMsgs != null) {
        for (Parcelable msg : rawMsgs) {
          if (msg instanceof NdefMessage) {
            intentMessages.add((NdefMessage) msg);
          }
        }
      } else {
        // Unknown tag type
        byte[] empty = new byte[] {};
        final NdefRecord record = new NdefRecord(NdefRecord.TNF_UNKNOWN, empty, empty, empty);
        final NdefMessage msg = new NdefMessage(new NdefRecord[] { record });
        intentMessages = new ArrayList<NdefMessage>() {
          /**
           * 
           */
          private static final long serialVersionUID = 1L;

          {
            add(msg);
          }
        };
      }
    }
    return intentMessages;
  }

  /**
   * A pending intent is required to enable foreground NDEF dispatch
   * 
   * @param context
   * @return
   */
  public static PendingIntent getPendingIntent(Activity context) {
    return PendingIntent.getActivity(context, 0,
        new Intent(context, context.getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
  }

}

Java Source Code List

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