Problem while uploading file from remote client using servlet!

[Madni]

Dear All,

I am using an upload utility which works very well if i test it using
single machine making it work both as client and server. But while i
was trying to upload ,relatively bigger file (50 mb),over a LAN it
throws exception randomly(sometimes it works and sometimes not ) .
Consider following lines of code :

public void doPost(HttpServletRequest req, HttpServletResponse res)
throws
ServletException, IOException {

//.......................................................
//...................................................... some code here


try {
UploadRead obj = new UploadRead(req,
strProjPath,req.getContentLength());
//UploadRead(HttpServletRequest,String,int);
//..........................................................
//.......................................................... remaining
code

exception is thrown soon as it strats with UploadRead instantiation
.......
When i replaced req.getContentLength() with some hard coded figure
(like 209715200 which is 200 MB) ... it works well with the remote
client upload operation.

can anyone please guide me in this ...

Regards,