Clojure android fails to read file

Question

I'm trying to create a simple android app using a clojure that reads a csv file and allows users to do a regex like search on the data. The problem is that when I try to read the data, I get the following exception.

IllegalArgumentException No implementation of method: :make-reader of protocol: #'clojure.java.io/IOFactory found for class: nil clojure.core/-cache-protocol-fn (core_deftype.clj:554)

My research says that this usually means that clojure is looking for something and can't find it. But I can't figure out what it could be or why.

Here is the Clojure code that is throwing the exception:

(ns org.stuff.events.data
  (:require [clojure.java.io :as io]))

(def data-file (io/file (io/resource "kamus.csv")))

(defn read-data [_]
  (slurp data-file))

From the best I can tell "kamus.csv" is in the correct directory, so I don't think that's it. If I evaluate the data-file in the repl I get nil.

Does someone have any ideas to resolve my problem?

---

Here are the other project files just for reference:

main.clj:

(ns org.stuff.events.main
    (:require [neko.activity :refer [defactivity set-content-view!]]
              [neko.debug :refer [*a]]
              [neko.notify :refer [toast]]
              [neko.ui :refer [config]]
              [neko.resource :as res]
              [neko.find-view :refer [find-view]]
              [neko.threading :refer [on-ui]]
              [org.stuff.events.data :as data]
              [clojure.data.csv :as csv])
    (:import android.widget.TextView))

;; We execute this function to import all subclasses of R class. This gives us
;; access to all application resources.
(res/import-all)



(def listing (atom ""))


(defn get-elem [activity id]
  (str (.getText (find-view activity id))))

(defn set-elem [activity id s]
  (on-ui (config (find-view activity id) :text s)))

(defn add-event [activity]
  (swap! listing str (get-elem activity ::search-box) "\n")
  (set-elem activity ::results @listing))


(defn main-layout [activity]
  [:linear-layout {:orientation :vertical}
   [:linear-layout {:orientation :horizontal                
                     :layout-height :wrap}
         [:edit-text {:id ::search-box
                      :hint "cari..."
                      :layout-width :fill}]
         [:button {:text "Cari"
                   :on-click (fn [_] (add-event (*a)))}]]
   [:text-view {:text @listing
                :id ::results}]])


;; This is how an Activity is defined. We create one and specify its onCreate
;; method. Inside we create a user interface that consists of an edit and a
;; button. We also give set callback to the button.
(defactivity org.stuff.events.MainActivity
  :key :main

  (onCreate [this bundle]
    (.superOnCreate this bundle)
    (neko.debug/keep-screen-on this)
    (on-ui
      (set-content-view! (*a)  (main-layout (*a))))))

project.csj:

(defproject events/events "0.1.0-SNAPSHOT"
  :description "FIXME: Android project description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}

  :global-vars {*warn-on-reflection* true}

  :source-paths ["src/clojure" "src"]
  :res-path "src/main/resources"
  :java-source-paths ["src/java"]
  :javac-options ["-target" "1.6" "-source" "1.6" "-Xlint:-options"]
  :plugins [[lein-droid "0.4.3"]]

  :dependencies [[org.clojure-android/clojure "1.7.0-r2"]
                 [neko/neko "4.0.0-alpha5"]
                 [org.clojure/data.csv "0.1.3"] ]
  :profiles {:default [:dev]

             :dev
             [:android-common :android-user
              {:dependencies [[org.clojure/tools.nrepl "0.2.10"]]
               :target-path "target/debug"
               :android {:aot :all-with-unused
                         :rename-manifest-package "org.stuff.events.debug"
                         :manifest-options {:app-name "EventsListing      (debug)"}}}]
             :release
             [:android-common
               {:target-path "target/release"
               :android
               {;; :keystore-path "/home/user/.android/private.keystore"
                ;; :key-alias "mykeyalias"
                ;; :sigalg "MD5withRSA"

                :ignore-log-priority [:debug :verbose]
                :aot :all
                :build-type :release}}]}

  :android {;; Specify the path to the Android SDK directory.
            :sdk-path "C:\\Users\\fhard\\AppData\\Local\\Android\\sdk"

            ;; Try increasing this value if dexer fails with
            ;; OutOfMemoryException. Set the value according to your
            ;; available RAM.
            :dex-opts ["-JXmx4096M" "--incremental"]

            :target-version "15"
            :aot-exclude-ns ["clojure.parallel" "clojure.core.reducers"
                         "cider.nrepl" "cider-nrepl.plugin"
                             "cider.nrepl.middleware.util.java.parser"
                             #"cljs-tooling\..+"]})

Answer 1

From the exception, it looks like you've got the path wrong according to this answer. When I try to open a file with io/resource, I get the same error as you even though the file is actually there. io/reader might be easier to use since it will coerce your input into a reader object. io/resource on the other hand returns a URL whose path changes once inside of a jar. Check this.