附：MIME类型
| csv | application/vnd.ms-excel |
| css | text/css |
| js | text/javascript |
| doc | application/msword |
| gif | image/gif |
| bmp | image/bmp |
| htm | text/html |
| html | text/html |
| jpeg | image/jpeg |
| jpg | image/jpeg |
| application/pdf | |
| png | image/png |
| ppt | application/vnd.ms-powerpoint |
| rtf | application/msword |
| txt | text/plain |
| xls | application/vnd.ms-excel |
| xml | text/xml |
| wmv | video/x-ms-wmv |
| wma | video/x-ms-wmv |
| mpeg | video/mpeg |
| mpg | video/mpeg |
| mpa | video/mpeg |
| mpe | video/mpeg |
| mov | video/quicktime |
| qt | video/quicktime |
| avi | video/x-msvideo |
| asf | video/x-ms-asf |
| asr | video/x-ms-asf |
| asx | video/x-ms-asf |
| swf | application/x-shockwave-flash |