java – 在Clojure中制作缩略图

[weixin_38083228]

我在终端中运行以下命令来运行存储在以下文件中的代码： java -cp clojure.jar clojure.main thumbmaker.clj thumbmaker.clj的内容是(此代码已在多个地方引用)： (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) 我收到以下错误： Exception in thread “main” java.lang.IllegalArgumentException: No matching method found: read (thumbmaker.clj:0) 我已经独立检查了REPL中的import和use语句,它们似乎被接受了很好. 我检查了ImageIO的Java参考,并且读取函数就在那里. 我已经完成了Java-Interop的写法,这似乎是非常标准的方式,所以我无法弄清楚为什么读取不起作用.

[weixin_38091120]

见http://docs.oracle.com/javase/1.5.0/docs/api/javax/imageio/ImageIO.html javax.imageio.ImageIO / read需要URL,File,InputStream或ImageInputStream.不是字符串. 执行(javax.imageio.ImageIO / read(as-file input))解决了这个问题.