[Building Sakai] How to get attachment content? (Assignment tool)

[le tan vu]

Hi guys.
I want to ask the simplest way to get attachment content. The scenario is:
I submit the attachment in my assignment submission. After that, the tool
will get content of my attachment to test with compiler. (only 1 attachment)
I use the following to try:
Process p = Runtime.getRuntime().exec("javac
"+sAttachmentReference.getEntity().getReference());
But it display error file not found.
Please instruct me.
Thank you!
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://collab.sakaiproject.org/pipermail/sakai-dev/attachments/20100517/a5b27e10/attachment.html