Question

Using Jersey/JAX-RS I have a get handler that contains code to copy a large file to another location. I want to be able to go to a URL and be able to see the current state of the copying (i.e. time elapsed). How do I accomplish this?

Answer 1

On which side? The sender or the receiver?

The sender could expose a link or something, as part of the request.

You could arguably do something like

POST receiver/foo/incoming

<incoming-foo>
    <link rel="status" uri="sender/foo/abc/status">
</incoming-foo>

receiver might ‘201 Created’ or ‘303 See Other’ sender to the URI receiver/foo/1

at this time, a

GET receiver/foo/1

might simply return the provided status link, or embed it in the representation:

<foo>
    <status>incoming</status>
    <link rel="status" href="sender/foo/abc/status" />
</foo>

GET sender/foo/abc/status

Might return, at this time, “pending” or “queued” or something like that.

…

Then, sender is free to

PUT receiver/foo/1

<foo>
    <content>...</content>
</foo>

During the PUT, async GET to the services can still GET the status from the origin service, which might now be “transmitting” or include the bytes/total, etc.