php如何将word文档转化为pdf

代码如下：

<?php
    set_time_limit(0);
    function MakePropertyValue($name,$value,$osm){
    $oStruct = $osm->Bridge_GetStruct(\"com.sun.star.beans.PropertyValue\");
    $oStruct->Name = $name;
    $oStruct->Value = $value;
    return $oStruct;
    }
    function word2pdf($doc_url, $output_url){
    $osm = new COM(\"com.sun.star.ServiceManager\") or die (\"Please be sure that OpenOffice.org is installed.\\n\");
    $args = array(MakePropertyValue(\"Hidden\",true,$osm));
    $oDesktop = $osm->createInstance(\"com.sun.star. .Desktop\");
    $oWriterDoc = $oDesktop->loadComponentFromURL($doc_url,\"_blank\", 0, $args);
    $export_args = array(MakePropertyValue(\"FilterName\",\"writer_pdf_Export\",$osm));
    //print_r($export_args);

    $oWriterDoc->storeToURL($output_url,$export_args);
    $oWriterDoc->close(true);
    }
    $output_dir = \"C:/wamp/www/projectfolder/\";
    $doc_file = \"C:/wamp/www/projectfolder/wordfile.docx\";
    $pdf_file = \"outputfile_name.pdf\";
    $output_file = $output_dir . $pdf_file;
    $doc_file = \"file:///\" . $doc_file;
    $output_file = \"file:///\" . $output_file;
    word2pdf($doc_file,$output_file);
    ?>