Android Open Source - ubihelper Wifi Scanner Channel

• Back to Network/sensor  ↑

From Project

Back to project page ubihelper.

License

The source code is released under:

GNU General Public License

Java Source Code

/**
 * Copyright (c) 2012 The University of Nottingham
 * //  w w w  .j a  v  a2  s  .c om
 * This file is part of ubihelper
 *
 *  ubihelper is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  ubihelper is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with ubihelper. If not, see <http://www.gnu.org/licenses/>.
 *  
 *  @author Chris Greenhalgh (cmg@cs.nott.ac.uk), The University of Nottingham
 */
package uk.ac.horizon.ubihelper.service.channel;

import java.util.HashMap;
import java.util.List;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import android.os.Handler;
import android.util.Log;

/**
 * @author cmg
 *
 */
public class WifiScannerChannel extends PollingChannel {
  private static final String KEY_TIME = "time";
  private static final String KEY_NETWORKS = "networks";
  private static final String KEY_ADDRESS = "address";
  private static final String KEY_CAPABILITIES = "capabilities";
  private static final String KEY_NAME = "name";
  private static final String KEY_LEVEL = "level";

  static String TAG = "ubihelper-wifichan";
  private WifiManager wifi;
  private Service service;
  /**
   * @param handler
   * @param name
   */
  public WifiScannerChannel(Service service, Handler handler, String name) {
    super(handler, name);
    wifi = (WifiManager)service.getSystemService(Service.WIFI_SERVICE);
    this.service = service;
    if (wifi==null)
      Log.w(TAG,"No WifiManager");
    IntentFilter filter = new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
    filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
    this.service.registerReceiver(receiver, filter);
  }
  
  @Override
  public synchronized void close() {
    super.close();
    service.unregisterReceiver(receiver);
  }

  private BroadcastReceiver receiver = new BroadcastReceiver() {
    
    @Override
    public void onReceive(Context context, Intent intent) {
      if (WifiManager.SCAN_RESULTS_AVAILABLE_ACTION.equals(intent.getAction())) {
        handlePollComplete();
      }
      else if (WifiManager.WIFI_STATE_CHANGED_ACTION.equals(intent.getAction())) {
        // turned off?
        if (!wifi.isWifiEnabled())
          synchronized (WifiScannerChannel.this) {
            if (pollInProgress)
              pollComplete();
          }
      }
    }
  };

  @Override
  protected boolean startPoll() {
    if (wifi==null) {
      return false;
    }
    if (!wifi.isWifiEnabled()) {
      Log.d(TAG,"startPoll: wifi disabled");
      return false;
    }
    if (!wifi.startScan()) {
      Log.d(TAG,"startPoll: could not startScan");
      return false;
    }
    return true;
  }

  protected synchronized void handlePollComplete() {
    if (pollInProgress)
      pollComplete();
    try {
      JSONObject value = new JSONObject();
      value.put(KEY_TIME, System.currentTimeMillis());
      JSONArray ds = new JSONArray();
      value.put(KEY_NETWORKS, ds);
      List<ScanResult> results = wifi.getScanResults();
      for (ScanResult result : results) {
        JSONObject d = new JSONObject();
        if (result.BSSID!=null)
          d.put(KEY_ADDRESS, result.BSSID);
        if (result.SSID!=null)
          d.put(KEY_NAME, result.SSID);
        if (result.capabilities!=null)
          d.put(KEY_CAPABILITIES, result.capabilities);
        d.put(KEY_LEVEL, result.level);
        ds.put(d);
      }
      onNewValue(value);
    }
    catch(JSONException e) {
      // shouldn't
    }
  }

}

Java Source Code List

• Back to Network/sensor  ↑