We're modifying feng office (a wide open source, group-ware in PHP, Apache and MySQL). We are attempting to implement the multiple file upload functionality. This is actually the flow:

(1) User clicks a control button (inside a web site), a JNLP is downloaded (2) which in turn causes a "Choose File" dialog to look. User chooses multiple files and presses "Upload", (3) then files are submitted inside a loop along with a progress bar will get up-to-date after each file.

Now, within the mfu.jar (multiple file upload core). We use apache httpclient-4.1.1 together with SwingWorker to upload files increase the progress bar [ multi-thread stuff, have I said how awesome we're? -) ]. Strange factor is, on machines using Sun's java (Sun logo design seems) the truth is working perfectly. On machines using either Open JDK or Oracle's Java (Oracle logo design seems, either Linux or Home windows, 32bit or 64 bit), rather than getting different files being submitted exactly once, we finish up and among them being submitted multiple occasions (same title, same content) !

any clues ?

P.S: I am sorry if information is insufficient, I attempted to remain centered on the issue regarding my knowledge of the adding factors.

EIDT: Apparently httpclient-4.1.1 uses some kinda cache mechanism, still aren't able to find any rigorous relation.

Problemo solved. In some way we didn't remember to think about a few of the very fundamental recommendations of multi-threads and all sorts of the SwingWorkers were attempting to make use of the same uploader concurrently. We gave each SwingWorkrer their very own uploader and situations are working perfectly.