Android Open Source - MyNFCWriter2 Nfc Writer

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Back to project page MyNFCWriter2.

License

The source code is released under:

Apache License

Java Source Code

/**
 * /*  w w  w.  j ava 2s . co m*/
 */
package jp.co.iti.mynfcwriter2;

import java.io.IOException;
import java.nio.charset.Charset;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.nfc.FormatException;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.TagLostException;
import android.nfc.tech.Ndef;

public class NfcWriter {

  private NfcAdapter nfcAdapter = null;
  private String errorMessage = null;

  /**
   * Constructor
   * @param context context object.
   */
  public NfcWriter(Context context) {
    // Get default NFC adapter
    this.nfcAdapter = NfcAdapter.getDefaultAdapter(context);
  }

  /**
   * Enable the NFC adapter.
   * @param activity target activity.
   * @param pendingIntent pendingIntent object.
   */
  public void enable(Activity activity, PendingIntent pendingIntent) {
    this.nfcAdapter.enableForegroundDispatch(activity, pendingIntent, null, null);
  }

  /**
   * Disable the NFC adapter.
   * @param activity target activity.
   */
  public void disable(Activity activity) {
    this.nfcAdapter.disableForegroundDispatch(activity);
  }

  /**
   * Write the URL data to NFC tag.
   * @param context context object.
   * @param intent intent object.
   * @param targetUrl target URL.
   * @return true: completed.
   */
  public boolean write(Context context, Intent intent, String targetUrl) {
    boolean result = false;

    this.errorMessage = null;

    Tag tag = (Tag)intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
    if (tag == null) {
      this.errorMessage = "Failed: Tag is null.";
      return result;
    }

    Ndef ndef = Ndef.get(tag);
    if (ndef == null) {
      this.errorMessage = "Failed: Wrong tag format.";
      return result;
    }

    NdefMessage ndefMessage = this.createMessage(targetUrl);
    if (ndefMessage == null) {
      this.errorMessage = "Failed: NdefMessage is null.";
      return result;
    }

    if (this.writeMessage(ndef, ndefMessage)) {
      result = true;
    }

    return result;
  }

  /**
   * Get error message.
   * @return error message.
   */
  public String getErrorMessage() {
    return this.errorMessage;
  }

  private NdefMessage createMessage(String targetUrl) {
    NdefRecord[] rs = new NdefRecord[] {
      createUriRecord(targetUrl),
      createActionRecord() 
    };
    NdefMessage spPayload = new NdefMessage(rs);

    NdefRecord spRecord = new NdefRecord(NdefRecord.TNF_WELL_KNOWN,
                      NdefRecord.RTD_SMART_POSTER,
                      new byte[0],
                      spPayload.toByteArray());
    return new NdefMessage(new NdefRecord[]{spRecord});
  }

  private NdefRecord createUriRecord(String url) {
    return NdefRecord.createUri(url);
  }

  private NdefRecord createActionRecord() {
    byte[] typeField = "act".getBytes(Charset.forName("US-ASCII"));
    byte[] payload = {(byte) 0x00};
    return new NdefRecord(NdefRecord.TNF_WELL_KNOWN, 
                typeField,
                new byte[0],
                payload); // ?y2?z
  }

  private boolean writeMessage(Ndef ndef, NdefMessage ndefMessage) {
    boolean result = false;
   
    if (!ndef.isWritable()) {
      this.errorMessage = "Failed: Readonly.";
      return result;
    }

    int messageSize = ndefMessage.toByteArray().length;
    if (messageSize > ndef.getMaxSize()) {
      this.errorMessage = "Failed: Overflow.";
      return false;

    }

    try {
      if (!ndef.isConnected()) {
        ndef.connect();
      }
      ndef.writeNdefMessage(ndefMessage);
      result = true;

    } catch (TagLostException e) {
      this.errorMessage = "Failed: " + e.getLocalizedMessage();

    } catch (IOException e) {
      this.errorMessage = "Failed: " + e.getLocalizedMessage();

    } catch (FormatException e) {
      this.errorMessage = "Failed: " + e.getLocalizedMessage();

    } finally {
      try {
        ndef.close();
      } catch (IOException e) {
        // ignore.
      }
    }

    return result;
  }
}

Java Source Code List

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