请求要素是json字符串时,php如何获取原生请求体

//this is a common php library by huangwei ,
//date:2014-07-03
//see http://blog.sina.com.cn/s/blog_4657e98e0100dyxp.html //see http://www.cnblogs.com/fullhouse/archive/2012/04/24/2468870.html if(array_key_exists('HTTP_RAW_POST_DATA',$GLOBALS)){//判断是否有key-HTTP_RAW_POST_DATA
$raw_data=$GLOBALS['HTTP_RAW_POST_DATA'];//always_populate_raw_post_data = On
}
if (empty($raw_data)) {
$raw_data=$_POST;
}
if (empty($raw_data)) {
//echo "raw_data is empty";
$raw_data=file_get_contents("php://input");
}
if(empty($raw_data)) {
$raw_data=$_GET;
}
if(empty($raw_data)) {
$raw_data=$_POST;
}

$post_object = json_decode($raw_data);

//convert object to array
function object_to_array($obj){
if(is_array($obj)){
return $obj;
}
$_arr = is_object($obj)? get_object_vars($obj) :$obj;
foreach ($_arr as $key => $val){
$val=(is_array($val)) || is_object($val) ? object_to_array($val) :$val;
$arr[$key] = $val;
}

return $arr;

}

/***
* @return string : windows or linux
*/
function serverOS(){
$os_name=strtolower(php_uname('s'));
$os_pos=strpos($os_name,'linux');
if($os_pos === false) {
return "windows";
}
else {
return "linux";
}
}

$root_path_index;
//echo serverOS();
if(serverOS()=='linux'){
$root_path_index=-9;
}else{
$root_path_index=32;
}

$config['webroot']=substr(dirname(__FILE__), 0, $root_path_index);///var/www/html/exchange

function strexists($a, $b)
{
return !(strpos($a, $b) === FALSE);
}

function mkdirs($dir)
{
return is_dir($dir) or (mkdirs(dirname($dir)) and mkdir($dir, 0777));
}