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;