Connecting to another computer has nothing to do with Struts and everything to do with how your computers and network are configured. What connection options do you have (Samba, NFS, SFTP, HTTP)?
It is actually far from obvious that HTTP would be the method of connection, and HTTP is one of the methods I would have considered rather unlikely.
If it's HTTP, why can't the client access the file directly (assuming that the client is an HTTP browser, but that seems likely since we're talking about a Struts application) ? Does the Struts app live on a publicly accessible server, whereas the HTTP server where the PDF file lives is not publicly accessible?
It just occurs to me that we may be misunderstanding what you're asking, and you may have misunderstood what Joe said. Is it actually the case that this PDF file is on a server other than the web app? Or are they on the same server, and all you're asking is how a Struts web app can stream that file to the client?
My direct question is how we can access PDF files from UNIX folder(residing on different location) to show it in web page when the user request for that file.