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android可以借助于gps实现定位,但是很多地方是使用gps无法定位比如在室内,而且gps定位的话速度慢。
那么如何克服这样的缺点使得应用程序在室内也可以定位呢?办法是有的借助于基站和wifi进行定位。具体的细节可参考:
http://code.google.com/intl/zh-CN/apis/gears/geolocation_network_protocol.html
下面的代码实现了定位的大致功能
CellIDInfo.java 封装了cellid的信息
public class CellIDInfo {
public int cellId;
public String mobileCountryCode;
public String mobileNetworkCode;
public int locationAreaCode;
public String radioType;
public CellIDInfo(){}
}
WifiInfo.java 封装了wifi的信息
public class WifiInfo {
public String mac;
public WifiInfo(){}
}
CellIDInfoManager.java 可获取所有的CellIDInfo
import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.telephony.NeighboringCellInfo;
import android.telephony.PhoneStateListener;
import android.telephony.TelephonyManager;
import android.telephony.cdma.CdmaCellLocation;
import android.telephony.gsm.GsmCellLocation;
public class CellIDInfoManager {
private TelephonyManager manager;
private PhoneStateListener listener;
private GsmCellLocation gsm;
private CdmaCellLocation cdma;
int lac;
String current_ci,mcc, mnc;
public CellIDInfoManager(){}
public ArrayList<CellIDInfo> getCellIDInfo(Context context){
manager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
listener = new PhoneStateListener();
manager.listen(listener, 0);
ArrayList<CellIDInfo> CellID = new ArrayList<CellIDInfo>();
CellIDInfo currentCell = new CellIDInfo();
int type = manager.getNetworkType();
if (type == TelephonyManager.NETWORK_TYPE_GPRS || type ==TelephonyManager.NETWORK_TYPE_EDGE
|| type ==TelephonyManager.NETWORK_TYPE_HSDPA) {
gsm = ((GsmCellLocation) manager.getCellLocation());
if (gsm == null) return null;
lac = gsm.getLac();
mcc = manager.getNetworkOperator().substring(0, 3);
mnc = manager.getNetworkOperator().substring(3, 5);
currentCell.cellId = gsm.getCid();
currentCell.mobileCountryCode = mcc;
currentCell.mobileNetworkCode = mnc;
currentCell.locationAreaCode = lac;
currentCell.radioType = "gsm";
CellID.add(currentCell);
List<NeighboringCellInfo> list = manager.getNeighboringCellInfo();
int size = list.size();
for (int i = 0; i < size; i++) {
CellIDInfo info = new CellIDInfo();
info.cellId = list.get(i).getCid();
info.mobileCountryCode = mcc;
info.mobileCountryCode = mnc;
info.locationAreaCode = lac;
CellID.add(info);
}
return CellID;
} else if (type == TelephonyManager.NETWORK_TYPE_CDMA || type ==TelephonyManager.NETWORK_TYPE_1xRTT) {
cdma = ((CdmaCellLocation) manager.getCellLocation());
if (cdma == null) return null;
if ("460".equals(manager.getSimOperator().substring(0, 3)))
return null;
}
return null;
}
}
WifiInfoManager.java 可获取wifi的信息,目前我只取了当前连接的wifi,没有获取所有能扫描到的wifi信息。
import java.util.ArrayList;
import android.content.Context;
import android.net.wifi.WifiManager;
public class WifiInfoManager {
WifiManager wm;
public WifiInfoManager(){}
public ArrayList getWifiInfo(Context context){
ArrayList<WifiInfo> wifi = new ArrayList();
wm = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
WifiInfo info = new WifiInfo();
info.mac = wm.getConnectionInfo().getBSSID();
wifi.add(info);
return wifi;
}
}
调用google gears的方法,该方法调用gears来获取经纬度
private Location callGear(ArrayList<WifiInfo> wifi,
ArrayList<CellIDInfo> cellID) {
if (cellID == null) return null;
DefaultHttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(
"http://www.google.com/loc/json");
JSONObject holder = new JSONObject();
try {
holder.put("version", "1.1.0");
holder.put("host", "maps.google.com");
holder.put("home_mobile_country_code", cellID.get(0).mobileCountryCode);
holder.put("home_mobile_network_code", cellID.get(0).mobileNetworkCode);
holder.put("radio_type", cellID.get(0).radioType);
holder.put("request_address", true);
if ("460".equals(cellID.get(0).mobileCountryCode))
holder.put("address_language", "zh_CN");
else
holder.put("address_language", "en_US");
JSONObject data,current_data;
JSONArray array = new JSONArray();
current_data = new JSONObject();
current_data.put("cell_id", cellID.get(0).cellId);
current_data.put("mobile_country_code", cellID.get(0).mobileCountryCode);
current_data.put("mobile_network_code", cellID.get(0).mobileNetworkCode);
current_data.put("age", 0);
array.put(current_data);
if (cellID.size() > 2) {
for (int i = 1; i < cellID.size(); i++) {
data = new JSONObject();
data.put("cell_id", cellID.get(i).cellId);
data.put("location_area_code", cellID.get(0).locationAreaCode);
data.put("mobile_country_code", cellID.get(0).mobileCountryCode);
data.put("mobile_network_code", cellID.get(0).mobileNetworkCode);
data.put("age", 0);
array.put(data);
}
}
holder.put("cell_towers", array);
if (wifi.get(0).mac != null) {
data = new JSONObject();
data.put("mac_address", wifi.get(0).mac);
data.put("signal_strength", 8);
data.put("age", 0);
array = new JSONArray();
array.put(data);
holder.put("wifi_towers", array);
}
StringEntity se = new StringEntity(holder.toString());
Log.e("Location send", holder.toString());
post.setEntity(se);
HttpResponse resp = client.execute(post);
HttpEntity entity = resp.getEntity();
BufferedReader br = new BufferedReader(
new InputStreamReader(entity.getContent()));
StringBuffer sb = new StringBuffer();
String result = br.readLine();
while (result != null) {
Log.e("Locaiton reseive", result);
sb.append(result);
result = br.readLine();
}
data = new JSONObject(sb.toString());
data = (JSONObject) data.get("location");
Location loc = new Location(LocationManager.NETWORK_PROVIDER);
loc.setLatitude((Double) data.get("latitude"));
loc.setLongitude((Double) data.get("longitude"));
loc.setAccuracy(Float.parseFloat(data.get("accuracy").toString()));
loc.setTime(AppUtil.getUTCTime());
return loc;
} catch (JSONException e) {
return null;
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
目前已经测试过
中国移动、
联通的卡,以及测试过中兴的MIC,都可以准确定位。
不支持的是cdma,将cdma的数据传入到gears后返回的经纬度显示是在美国。
提外话,将gps和基站、wifi三者定位
结合的话效果更好。基站的定位没有wifi准确,gps的定位速度比基站、wifi都来得更慢。