Making thumbnails in Clojure

Question

I'm running the following command in my terminal to run the code stored in the following file:

java -cp clojure.jar clojure.main thumbmaker.clj

Where the content of thumbmaker.clj is (this code has been referenced at several places):

(import javax.imageio.ImageIO)
(import java.awt.image.BufferedImage)
(use '[clojure.java.io :only [as-file input-stream output-stream] :as io])

(defn make-thumbnail-generic [input new-filename width]
  (let [img (javax.imageio.ImageIO/read input)
        imgtype (java.awt.image.BufferedImage/TYPE_INT_ARGB)
        width (min (.getWidth img) width)
        height (* (/ width (.getWidth img)) (.getHeight img))
        simg (java.awt.image.BufferedImage. width height imgtype)
        g (.createGraphics simg)]
    (.drawImage g img 0 0 width height nil)
    (.dispose g)

(defn make-thumbnail-from-file [filename new-filename width]
  (make-thumbnail-generic filename new-filename width))

(make-thumbnail-from-file "thumb.png" "test.png" 100)

And I'm getting the following error:

Exception in thread "main" java.lang.IllegalArgumentException: No matching method found: read (thumbmaker.clj:0)

I have checked the import and use statements in the REPL independently and they seem to be accepted pretty fine.

I checked the Java reference for ImageIO and the read function is there.

I've gone through the Java-Interop writeup and this seems to be very much the standard way, so I can't figure out why the read is not working.

Answer 1

See http://docs.oracle.com/javase/1.5.0/docs/api/javax/imageio/ImageIO.html

javax.imageio.ImageIO/read expects a URL, File, InputStream or ImageInputStream. Not a string.

Doing (javax.imageio.ImageIO/read (as-file input)) solves the problem.