PHP地址反查返回经纬度 百度API

/**
* 百度地图 根据地址反查经纬度
*/

public function search_xy(){
$address = str_replace(' ','',$address);
$rows = file_get_contents("http://api.map.baidu.com/geocoder/v2/?ak=xxxxxxxxxxxxxx&callback=renderOption&output=json&address=首都图书馆&city=北京市朝阳区);
$start = $this->getPos($rows,"{",2);
$end = $this->getPos($rows,"}",2);
$json = mb_substr($rows, $start[2],intval($end[3])-intval($start[2])+1);
$xy = json_decode($json,true);
return $xy;
}