Handling file upload in a ring app

app.clj

(ring.adapter.jetty/run-jetty
  (ring.middleware.params/wrap-params
    (ring.middleware.multipart-params/wrap-multipart-params
      (fn [request]
        (if (= :get (:request-method request))
          (render-html-form-with-file-field-called "my-file")
          (let [file (get-in req [:params "my-file" :tempfile])]
            ; file is a java.io.File
            (with-open [reader (clojure.java.io/reader file)]
              ; reader is a--You guessed it!--java.io.Reader
              (render-result
                (clojure.data.csv/read-csv reader))))))))
  {:port 8000})

Used in http://elhumidor.blogspot.com/2012/11/how-to-handle-file-uploads-from-clojure.html