Faulty compression/decompression

foo.clj

(ns foo
  (:require [clojure.data.json :as json])
  (:import java.io.InputStreamReader
           java.io.StringWriter
           java.io.ByteArrayInputStream
           java.io.ByteArrayOutputStream
           java.nio.charset.Charset
           [java.util.zip GZIPInputStream GZIPOutputStream]
           org.apache.commons.io.output.WriterOutputStream))


(defn decompress-json [charset byte-array]
  (with-open [in (java.io.ByteArrayInputStream. byte-array)]
    (-> in
        (GZIPInputStream.)
        (InputStreamReader. (Charset/forName charset))
        (json/read :key-fn keyword))))

(defn compress-json [charset js]
  (with-open [bytes-out (ByteArrayOutputStream.)
              gzip-out  (GZIPOutputStream. bytes-out)]
    (.write gzip-out (.getBytes (json/write-str js) charset))
    (.close gzip-out)
    (.toByteArray bytes-out)))

(decompress-json "UTF-8" (compress-json "UTF-8" {:a 1 :b 2}))
=> java.lang.NoClassDefFoundError: clojure/data/json$read_number$fn__1469