hostage/src/de/tudarmstadt/informatik/hostage/sync/NFCSync.java

/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package de.tudarmstadt.informatik.hostage.sync;

import android.annotation.TargetApi;
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.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.Parcelable;
import android.widget.TextView;
import android.widget.Toast;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.HashMap;

import de.tudarmstadt.informatik.hostage.R;
import de.tudarmstadt.informatik.hostage.logging.DatabaseHandler;


@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
public class NFCSync extends Activity implements CreateNdefMessageCallback,
        OnNdefPushCompleteCallback {
    NfcAdapter mNfcAdapter;
    TextView mInfoText;
    private static final int MESSAGE_SENT = 1;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_nfc);

        mInfoText = (TextView) findViewById(R.id.textView);
        // Check for available NFC Adapter
        mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
        if (mNfcAdapter == null) {
            mInfoText = (TextView) findViewById(R.id.textView);
            mInfoText.setText("NFC is not available on this device.");
        } else {
            // Register callback to set NDEF message
            mNfcAdapter.setNdefPushMessageCallback(this, this);
            // Register callback to listen for message-sent success
            mNfcAdapter.setOnNdefPushCompleteCallback(this, this);
        }
    }

    /**
     * Implementation for the CreateNdefMessageCallback interface
     */
    @Override
    public NdefMessage createNdefMessage(NfcEvent event) {
    	// Get Networkdata
    	DatabaseHandler dbh = new DatabaseHandler(this);
		ArrayList<HashMap<String, Object>> localNetworkInformation = dbh.getNetworkInformation();

        NdefMessage msg = null;
		try {
			msg = new NdefMessage(NdefRecord.createMime(
			        "application/de.tudarmstadt.informatik.hostage", serialize(localNetworkInformation))
			 /**
			  * The Android Application Record (AAR) is commented out. When a device
			  * receives a push with an AAR in it, the application specified in the AAR
			  * is guaranteed to run. The AAR overrides the tag dispatch system.
			  * You can add it back in to guarantee that this
			  * activity starts when receiving a beamed message. For now, this code
			  * uses the tag dispatch system.
			  */
			  //,NdefRecord.createApplicationRecord("com.example.android.beam")
			);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        return msg;
    }

    /**
     * Implementation for the OnNdefPushCompleteCallback interface
     */
    @Override
    public void onNdefPushComplete(NfcEvent arg0) {
        // A handler is needed to send messages to the activity when this
        // callback occurs, because it happens from a binder thread
        mHandler.obtainMessage(MESSAGE_SENT).sendToTarget();
    }

    /** This handler receives a message from onNdefPushComplete */
    private final Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case MESSAGE_SENT:
                Toast.makeText(getApplicationContext(), "Message sent!", Toast.LENGTH_LONG).show();
                break;
            }
        }
    };

    @Override
    public void onResume() {
        super.onResume();
        // Check to see that the Activity started due to an Android Beam
        if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(getIntent().getAction())) {
            processIntent(getIntent());
        }
    }

    @Override
    public void onNewIntent(Intent intent) {
        // onResume gets called after this to handle the intent
        setIntent(intent);
    }

    /**
     * Parses the NDEF Message from the intent and prints to the TextView
     */
    void processIntent(Intent intent) {
        Parcelable[] rawMsgs = intent.getParcelableArrayExtra(
                NfcAdapter.EXTRA_NDEF_MESSAGES);
        // only one message sent during the beam
        NdefMessage msg = (NdefMessage) rawMsgs[0];
        // record 0 contains the MIME type, record 1 is the AAR, if present
    	Object object;
		try {
			object = deserialize(msg.getRecords()[0].getPayload());
	    	ArrayList<HashMap<String, Object>> remoteNetworkInformation = (ArrayList<HashMap<String, Object>>) object;
	    	DatabaseHandler dbh = new DatabaseHandler(this);
	    	dbh.updateNetworkInformation(remoteNetworkInformation);
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}		
    }
    
    //HELPER

    public static byte[] serialize(Object obj) throws IOException {
    	ByteArrayOutputStream out = new ByteArrayOutputStream();
    	ObjectOutputStream os = new ObjectOutputStream(out);
    	os.writeObject(obj);
    	return out.toByteArray();
    }
    public static Object deserialize(byte[] data) throws IOException, ClassNotFoundException {
    	ByteArrayInputStream in = new ByteArrayInputStream(data);
    	ObjectInputStream is = new ObjectInputStream(in);
    	return is.readObject();
    }	

}