clojure classpath problem for (require) function?

Question

CLASSPATH has the "/Users/smcho/Desktop/clojure" as one of its path, and this directory has the file hello.clj.

Running clojure, and running (require 'hello) give this error message.

java.io.FileNotFoundException: Could not locate hello__init.class or hello.clj on classpath:  (NO_SOURCE_FILE:0)

When I change directory to "/Users/.../clojure", and run the same (require 'hello), there's no problem. The . is on the CLASSPATH.

Running

java -cp /Users/smcho/bin/jar/clojure.jar:/Users/smcho/Desktop/clojure clojure.lang.Repl

also works.

Why clojure can't find the source on the CLASSPATH?

Answer 1

Like Alex mentioned, if you start java with the -cp argument, then the CLASSPATH environment is not referenced. So, instead of

java -cp /Users/smcho/bin/jar/clojure.jar clojure.lang.Repl

use

java -cp /Users/smcho/bin/jar/clojure.jar:$CLASSPATH clojure.lang.Repl

You can examine your java classpath from within the Clojure repl:

(doseq [p (.getURLs (java.lang.ClassLoader/getSystemClassLoader))] (println (.getPath p)))

Answer 2

您没有指定用于第一个示例的命令行，但请注意，如果使用-cp标志，则不会引用CLASSPATH环境变量。