php 导入excel

$cwd = getcwd();
chdir( DIR_SYSTEM.'PHPExcel' );
require_once( 'Classes/PHPExcel.php' );
chdir( $cwd );
// parse uploaded spreadsheet file
$inputFileType = PHPExcel_IOFactory::identify($filename);
$objReader = PHPExcel_IOFactory::createReader($inputFileType);
$objReader->setReadDataOnly(true);
$reader = $objReader->load($filename);
         set_time_limit(0);
$data = $reader->getSheetByName( 'Categories' );
$i = 0;
$k = $data->getHighestRow();

for ($i=0; $i<$k; $i+=1) {
   if ($i==0) {
      $max_col = PHPExcel_Cell::columnIndexFromString( $data->getHighestColumn() );
      for ($j=1; $j<=$max_col; $j+=1) {
         $first_row[] = $this->getCell($data,$i,$j);
      }
      continue;
   }
   $j = 1;