Edit: you should probably use with-open at some point, to make sure
you close the output writer. I copied pretty badly from my own
example :P. So more like:
(let [pipe-in (PipedInputStream.)]
(future ; new thread to prevent blocking deadlock
(with-open [out (-> pipe-in (PipedOutputStream.) (PrintWriter.))]
(binding [*out* out]
(do-whatever))))
pipe-in)
On Dec 16, 1:49 am, Alan Malloy <[email protected]> wrote:
> You can't really do this in a single thread without risking blocking.
> But with another thread, it's fairly simple. For example, I do this in
> my gzip-middleware, copying an InputStream through a pipe with GZIP
> wrapping:https://github.com/amalloy/ring-gzip-middleware/blob/master/src/ring/...
>
> I'm turning an input stream into another input stream, but you can do
> something similar. It's a bit weird, because you're really *not*
> attempting to convert an outputstream to an inputstream in your
> example. You're calling a function that writes to stdout and returns
> nil, and hoping that somehow a stream gets created. Really using with-
> out-str is a reasonable approach here; just create a StringReader from
> the resulting string.
>
> But if you need asynchronicity, you can probably do something like
>
> (let [pipe-in (PipedInputStream.)
> pipe-out (PipedOutputStream. pipe-in)]
> (future ; new thread to prevent blocking deadlock
> (binding [*out* (PrintWriter. pipe-out)]
> (ofn var)))
> pipe-in)
>
> This lets ofn run in another thread, writing its output to *out*,
> which passes through the pipe and becomes an input stream for ring to
> use.
>
> On Dec 15, 1:01 pm, Trevor <[email protected]> wrote:
>
>
>
>
>
>
>
> > I have created an output stream, which appears to work fine, however
> > I get an error when trying to convert the output stream into an input
> > stream for use in ring:
>
> > ('use [clojure.java.io :only [input-stream]])
>
> > => (with-out-str (ofn var))
> > "it works!"
>
> > Now when I use ring:
> > {:body (input-stream (ofn var))}
>
> > java.lang.IllegalArgumentException: No implementation of method: :make-
> > input-stream of protocol: #'clojure.java.io/IOFactory found for class:
> > nil
>
> > Is there something special I need to do to convert output stream into
> > an input stream ?
>
> > Thanks,
> > Trevor
--
You received this message because you are subscribed to the Google
Groups "Clojure" group.
To post to this group, send email to [email protected]
Note that posts from new members are moderated - please be patient with your
first post.
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
