Transfer large files via Hessian

[pwyngaard]

This question has been asked a couple of times before, but there doesn't appear to be a complete answer yet, so I'm going to ask again. Here are the references to the previous questions:

http://forum.springframework.org/viewtopic.php?t=1179

http://forum.springframework.org/viewtopic.php?t=1186

The Hessian code examples included in those two posts appear to be adapted from the code snippet on the Caucho Hessian web site:

http://www.caucho.com/resin-3.0/prot...ge-binary-data

The idea being that if you're transfering a large amount of data between client/server in a Hessian call, you're better off handling the data transfer yourself with streams, rather than allowing Hessian to buffer the big file in memory before it handles the transfer for you.

I am trying to implement this very thing: big file upload/download.

But, I can't figure out how to use the Spring wrappers around the Hessian classes in order to gain access to the HessianInput and HessianOutput streams I need. Here's the example code snippet from the last URL I listed above:

OutputStream os = conn.getOutputStream();

HessianOutput out = new HessianOutput(os);
out.startCall("download");
out.writeString("my-file.txt");
out.completeCall();

InputStream is = conn.getInputStream();

HessianInput in = new HessianInput(is);

in.startReply();

InputStream is = in.readInputStream();

... // save the input stream data somewhere

in.completeReply();

Thanks!

Peter

[aaime]

I had to solve this very problem, and I did by brute force, without using spring remoting at all, just mimicking its behaviour. I created a specialized servlet on the server side that can process multiparts using commons-fileupload, and on the client side I've used httpclient to
invoke the servlet.

Basically, I'm doing POST requests, every parameter in the remote call is a field in the POST request, and some happen to be InputStreams and OutputStreams handled internally by a multipart POST. The response is a serialized object that contains a result (serialized) and eventually an exception, just like the way Spring remoting is working.

Hope this helps.

[sedrik]

I'm facing the exact same problem now. Has there been any development over the past couple months to ease this burden? Were you forced to interact directly w/ the Hessian API?

Unfortunately it appears Spring changed their board software, so the links you present are not working any longer, either.