The browser encodes form data very differently for
application/x-www-form-urlencoded and
"multipart/form-data".
application/x-www-form-urlencoded
POST /cgi-bin/maillist.cgi HTTP/1.0 Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */* Referer: http://www.anydomain.com/submit.html Accept-Language: en Content-Type: application/x-www-form-urlencoded UA-pixels: 640x480 UA-color: color8 UA-OS: Windows 95 UA-CPU: x86 User-Agent: Mozilla/2.0 (compatible; MSIE 3.0; Windows 95) Host: 10.10.10.20 Content-Length: 45 Pragma: No-Cache Connection: Keep-Alive realname=John+Doe&email=john@anydomain.com
multipart/form-data
POST /cgi-bin/maillist.cgi HTTP/1.0 Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */* Referer: http://www.anydomain.com/submit.html Accept-Language: en Content-type: multipart/form-data; boundary=---------------------------7cd1d6371ec UA-pixels: 640x480 UA-color: color8 UA-OS: Windows 95 UA-CPU: x86 User-Agent: Mozilla/2.0 (compatible; MSIE 3.0; Windows 95) Host: 10.10.10.20 Content-Length: 25852 Pragma: No-Cache Connection: Keep-Alive -----------------------------7cd1d6371ec Content-Disposition: form-data; name="realname" John Doe -----------------------------7cd1d6371ec Content-Disposition: form-data; name="email" john@anydomain.com -----------------------------7cd1d6371ec Content-Disposition: form-data; name="MyPicture"; filename="C:\My Documents\Java\misc\pics\john.jpg" Content-Type: image/jpeg ÿØÿà