常见的MIME（Multipart Internet Mail Extensions）

application/x-javascript     js
text/css     css
application/octet-stream     *
application/octet-stream     bin
application/octet-stream     class
application/octet-stream     dms
application/octet-stream     exe

text/plain     c
text/plain     h
text/plain     txt

multipart/form-data HTML FORM data