Integrating HTML2PDF in laravel 5.1

I am trying to integrate html2pdf library in laravel 5.1. But it is showing error like as follows Class 'App\Http\Controllers\HTML2PDF' not found and my controller code is as follows

require_once(dirname(__FILE__).'/libs/html2pdf/html2pdf.class.php');
$html2pdf = new HTML2PDF('P','A4','en',true,'UTF-8',array(0, 0, 0, 0));
$html2pdf->pdf->SetDisplayMode('fullpage');
$html2pdf->WriteHTML($html22);

my folder path is app/Http/Controllers/libs/html2pdf/html2pdf.class.php

i had given the correct path but still it is showing error like HTML2PDF not found. Please anyone let me know how to integrate html2pdf ? or should i do any changes in compose.json file ?

and even i included the line App\Http\Controllers\HTML2PDF at the top of the Controller page but no use.

please help me out .

Thanks

via Chebli Mohamed