PHP根据地理位置信息获取经纬度

<span style="font-size:14px;"><?php $address = !emptyempty($_POST['address'])?$_POST['address']:"上海徐汇区漕宝70号";// Google HQ  $prepAddr = str_replace(' ','+',$address);    $geocode=file_get_contents('http://maps.google.com/maps/api/geocode/json?address='.$prepAddr.'&sensor=false');    $output= json_decode($geocode);    $lat = $output->results[0]->geometry->location->lat;  $lng = $output->results[0]->geometry->location->lng;    ?>  </span>