clojure.java.io/resource

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Type: function Added: Clojure 1.2 Examples: 3 Runnable: 0

([n] [n loader])

Returns the URL for a named resource. Use the context class loader if no loader is specified.

Examples

by cloojure on 2014-05-02 . May have evaluation errors. ▶

; Use clojure.java.io/resource to read resources from the classpath: (ns rescue.core (:require [clojure.java.io :as io] )) ; Populate the file on the command line: ; echo "Hello Resources!" > resources/hello.txt (def data-file (io/resource "hello.txt" )) (defn -main [] (println (slurp data-file)) ) ; When do "lein run" ; => Hello Resources!

by phreed on 2015-06-23 . May have evaluation errors. ▶

(require '(clojure.java.io :as io)) ;; If the resource does not exist on the classpath a nil is returned. (io/resource "I_do_not_exist.txt") ;;=> nil

by charlot-shaw on 2026-06-18 . May have evaluation errors. ▶

(require '(clojure.java.io :as io)) ;; If the resource named did not exist when the JVM was started, `nil` will be returned. ;; Start your REPL, then create a file. (io/resource "new_file.txt") ;;=> nil ;; Relaunch the REPL, rerun the above and now the file will be found.

Note by kyptin

If you need to slurp a file from a JAR file, don't call io/file on the result of calling io/resource, or you will get an exception that says the resource is "not a file". Instead, call slurp directly on the result of io/resource.

Note by benwhorwood

If you need to copy a binary file from a running JAR (or WAR), don't call slurp as it will try and decode the file. Instead, extract similarily to:

(with-open [in (io/input-stream (io/resource "file.dat"))] ;; resources/file.dat
    (io/copy in (io/file "/path/to/extract/file.dat"))))

See also

• clojure.core/slurp (2)
• clojure.java.io/reader (0)
• clojure.core/line-seq (0)

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