参照网站的例子，写了如下代码，最后一句代码总是失败，求大侠指点
vendor("PHPExcel.PHPExcel");
vendor("PHPExcel.PHPExcel.IOFactory");

if (strtolower($fileextension)=='.xls') {
vendor("PHPExcel.PHPExcel.Reader.Excel5");
$objReader = PHPExcel_IOFactory::createReader('Excel5');
}elseif (strtolower($fileextension)=='.xlsx'){
vendor("PHPExcel.PHPExcel.Reader.Excel2007");
$objReader = PHPExcel_IOFactory::createReader('Excel2007');
}

$objReader->setReadDataOnly(true);
$objPHPExcel = $objReader->load($tmp_file);