nfc sample

NfcUtils.java

package com.meetup.utils;

import android.annotation.TargetApi;
import android.app.Activity;
import android.net.Uri;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.NfcEvent;
import android.os.Build;

public class NfcUtils {
    public static void setBeamCallback(UriNfcSharer sharer, Activity activity) {
        if (Build.VERSION.SDK_INT >= 14) {
            icsSetBeamCallback(sharer, activity);
        }
    }

    @TargetApi(14)
    private static void icsSetBeamCallback(UriNfcSharer sharer, Activity activity) {
        NfcAdapter adapter = NfcAdapter.getDefaultAdapter(activity);
        if (adapter == null)
            return;

        adapter.setNdefPushMessageCallback(new UriNfcCreator(sharer), activity);
    }

    public static interface UriNfcSharer {
        public Uri getNfcUri();
    }

    @TargetApi(14)
    private static class UriNfcCreator implements NfcAdapter.CreateNdefMessageCallback {
        private final UriNfcSharer sharer;

        private UriNfcCreator(UriNfcSharer sharer) {
            this.sharer = sharer;
        }

        @Override
        public NdefMessage createNdefMessage(NfcEvent event) {
            final Uri uri = sharer.getNfcUri();
            if (uri == null) {
                return null;
            } else {
                return new NdefMessage(new NdefRecord[] {
                        NdefRecord.createUri(uri),
                        NdefRecord.createApplicationRecord("com.meetup")
                });
            }
        }
    }
}

SampleActivity.java

public class SampleActivity extends Activity {
    @Override
    protected void onCreate(Bundle icicle) {
      // ...
      NfcUtils.setBeamCallback(new NfcCallback(), this);
    }
    
    public class NfcCallback implements NfcUtils.UriNfcSharer {
        @Override
        public Uri getNfcUri() {
            Uri.Builder bld = Uri.parse("http://www.meetup.com/members/").buildUpon()
                    .appendPath(getMemberId());
            final String groupId = getGroupId();
            if (groupId != null)
                bld.appendQueryParameter("groupId", groupId);
            return bld.build();
        }
    }
}