Android: 通过Google GeoLocation进行定位

原文链接：http://blog.lxbiao.com/2011/08/26/android%E5%B9%B3%E5%8F%B0%E4%B8%8A%E9%80%9A%E8%BF%87google-geolocation%E8%BF%9B%E8%A1%8C%E5%AE%9A%E4%BD%8D/

最近发现用Android上自带的定位接口在很多机型上都无法通过基站进行定位，使用Geolocation定位接口就能解决这样的问题。

android手机网络复杂，有移动2G的GSM网，有联通3G的WCDMA，还有电信定制机采用的CDMA2000，甚至还有不插SIM卡直接用WIFI的。我们要在所有这些不同的网络环境下进行定位，除了室外才能用的GPS，android自带的基站定位接口是不能完全满足要求的。测试表明，Google提供的GeoLocation接口能支持GSM/WCDMA/CDMA/WIFI室内定位。

具体使用：

接口：Google GeolocationAPI是google的综合定位接口。基站定位，Wi-Fi定位，GPS定位都可以通过gears GeolocationAPI来查询。GeolocationAPIgoogle有官方的详细api说明。GeolocationAPI接口使用HTTP协议，交互数据为json语法。

1. 发送数据

向Google服务器请求的数据格式如下：

{  "version": "1.1.0",  "host": "maps.google.com",  "access_token": "2:k7j3G6LaL6u_lafw:4iXOeOpTh1glSXe",  "home_mobile_country_code": 310,  "home_mobile_network_code": 410,  "radio_type": "gsm",  "carrier": "Vodafone",  "request_address": true,  "address_language": "en_GB",  "location": {    "latitude": 51.0,    "longitude": -0.1  },  "cell_towers": [    {      "cell_id": 42,      "location_area_code": 415,      "mobile_country_code": 310,      "mobile_network_code": 410,      "age": 0,      "signal_strength": -60,      "timing_advance": 5555    },    {      "cell_id": 88,      "location_area_code": 415,      "mobile_country_code": 310,      "mobile_network_code": 580,      "age": 0,      "signal_strength": -70,      "timing_advance": 7777    }  ],  "wifi_towers": [    {      "mac_address": "01-23-45-67-89-ab",      "signal_strength": 8,      "age": 0    },    {      "mac_address": "01-23-45-67-89-ac",      "signal_strength": 4,      "age": 0    }  ]}

其中，radio_type通过TelephonyManager.getNetworkType()获取；signal_strength在PhoneStateListener的回调方法onSignalStrengthChanged中可以得到，mobile_country_code：取telephonyManager.getSimOperator()的前3位数字。剩下的cell_id、location_area_code和mobile_network_code根据网络类型不同而不同：

GSM

cell_id: gsmCellLocation.getCid()

location_area_code：gsmCellLocation.getLac()

mobile_network_code：telephonyManager.getSimOperator()第4位以后的数字

CDMA

cell_id 用 BID值替换 cdmaCellLocation.getBaseStationId()

location_area_code 用NID值替换 cdmaCellLocation.getNetworkId()

mobile_network_code用SID值替换 cdmaCellLocation.getSystemId()

WIFI数据可以通过ScanResult获取：

mac_address: scanResult.BSSID

signal_strength: scanResult.level

ssid: scanResult.SSID

通过Android平台上的相关接口获取到这些数据之后可以用JSONString组织JSON串：

JSONStringer js = new JSONStringer ( ) ;

js. object ( ) ;

js. key ( "version" ). value ( "1.1.0" ) ;

js. key ( "host" ). value ( "maps.google.com" ) ;

js. key ( "request_address" ). value ( true ) ;

js. key ( "address_language" ). value ( "zh_CN" ) ;

if (mRadioData != null &amp ;&amp ; !mRadioData. radioType. equals (RadioDataProvider. RADIO_TYPE_UNKNOWN ) ) {

js. key ( "home_mobile_country_code" ). value (mRadioData. homeMobileCountryCode ) ;

js. key ( "home_mobile_network_code" ). value (mRadioData. homeMobileNetworkCode ) ;

js. key ( "radio_type" ). value (mRadioData. radioType ) ;

js. key ( "carrier" ). value (mRadioData. carrierName ) ;

//cell_towers

JSONObject cell_towers = new JSONObject ( ) ;

cell_towers. put ( "cell_id", mRadioData. cellId ) ;

cell_towers. put ( "location_area_code", mRadioData. locationAreaCode ) ;

cell_towers. put ( "mobile_country_code", mRadioData. mobileCountryCode ) ;

cell_towers. put ( "mobile_network_code", mRadioData. mobileNetworkCode ) ;

cell_towers. put ( "age", 0 ) ;

cell_towers. put ( "signal_strength", mRadioData. signalStrength ) ;

js. key ( "cell_towers" ). value ( new JSONArray ( ). put (cell_towers ) ) ;

}

// wifi_towers

if (mScanResults != null &amp ;&amp ; mScanResults. size ( ) &gt ; 0 ) {

ScanResult result = mScanResults. get ( 0 ) ;

JSONObject wifi_towers = new JSONObject ( ) ;

wifi_towers. put ( "mac_address", result. BSSID ) ;

wifi_towers. put ( "signal_strength", result. level ) ;

wifi_towers. put ( "age", 0 ) ;

wifi_towers. put ( "ssid", result. SSID ) ;

js. key ( "wifi_towers" ). value ( new JSONArray ( ). put (wifi_towers ) ) ;

}

js. endObject ( ) ;

将这样的JSON数据发送到http://www.google.com/loc/json ，然后等待返回结果。

2. 接收数据

Google服务器返回的数据格式如下：

{  "location": {    "latitude": 51.0,    "longitude": -0.1,    "altitude": 30.1,    "accuracy": 1200.4,    "altitude_accuracy": 10.6,    "address": {      "street_number": "100",      "street": "Amphibian Walkway",      "postal_code": "94043",      "city": "Mountain View",      "county": "Mountain View County",      "region": "California",      "country": "United States of America",      "country_code": "US"    }  },  "access_token": "2:k7j3G6LaL6u_lafw:4iXOeOpTh1glSXe"}

使用JSONObject可以很方便的解析出需要的经纬度和地址信息了。

更多相关文章

随机推荐