require_once（PHPExcel / Classes / PHPExcel.php）：无法打开流

I am trying to include PHPExcel to a Silverstripe 3 site to export excel sheets. Right now I am just trying to test, but I get this error when trying to do it:

[Warning] require_once(/sitename/mysite/AddOns/PHPExcel/Classes/PHPExcel.php): failed to open stream: No such file or directory

Thing is I know this file exists since I copied it over myself and have rechecked the path over and over. So I decided "well check if the file exists" using this code:

    if(!file_exists(Director::baseURL().'mysite/AddOns/PHPExcel/Classes/PHPExcel.php')) {
        echo 'sdf';exit;
}

The path is correct (that is where it is saved) according to the error, but- file does not exist. I am also requiring the file in the same way, with no luck

require_once Director::baseURL().'mysite/AddOns/PHPExcel/Classes/PHPExcel.php';

I have tried everything-checking file permissions, referencing parent folders using ../../, calling it directly like AddOns/PHPExcel, moving it to this new AddOns folder (first tried placing the PHPExcel classes on the root and discovered that Silverstripe doesn't read it then :) )

I know I am doing something wrong but for the life of me I cannot see what. Please help

Thanks

BASE_PATH is the best way to access the web root folder.

require_once(BASE_PATH . '/AddOns/PHPExcel/Classes/PHPExcel.php');

Also this is only an issue if you are not using composer, to solve this issue in the correct way you should use composer.

As pointed out Director::baseURL() will return the URL rather than the filepath.

Instead require relative to the file web root like so:

require_once(BASE_PATH . '/AddOns/PHPExcel/Classes/PHPExcel.php');

As pointed out by both Dan and Barry in the other answers, it's preferable to use composer for dependency management.

You should consider using composer to include the PHPExcel class, this will avoid the need to manually require the class and will help you with dependency management.

composer require phpoffice/phpexcel