php 根据经纬度获取城市 百度接口

   // 根据经纬度获取城市
    public function getCityByLongLat() {
        $data = file_get_contents('php://input'); // 接收过来的json数据
        $input = json_decode($data, true);// 转化为数组
        if (empty($input['lon']) || !isset($input['lon']) || empty($input['lat']) || !isset($input['lat'])) {
            return $this->json_data(array('st' => 0, 'msg' => '缺少必要参数'));
        }
        $lon = $input['lon'];
        $lat = $input['lat'];
        // lon 经度 lat 纬度
        if ($lon == '' || $lat == '') return '';
            $url = "http://api.map.baidu.com/geocoder?location={$lon},{$lat}";
            $ch = curl_init($url);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_BINARYTRANSFER, true);
            $output = curl_exec($ch);
            curl_close($ch);
            $result = $this->XmlToArr($output);
       
            return $this->json_data(array('st' => 1, 'msg' =>'获取成功','city'=>$result['result']['addressComponent']['city']));
    }