1. If users access our server via https://.... through the web
server, it fails to upload. Backend source encountered
NullPointerException when accessing the FileItem requested.
2. But if users access our server via http://... through the web
server, there is no that problem.
Hence I think there should be something wrong with the request parsing
through https.
Any advice/clue to check where or how to solve it is greatly
appreciated. Thanks in advance.
A couple of suggestions: (1) turn on debug logging in mod_ssl... this will give you a byte-by-byte dump of the SSL transaction in the log file. (2) try connecting to your https server with "openssl s_client" and then issuing a GET request by hand. That can often be instructive.
--Cliff