Fast JSON encoding and decoding for Clojure via the Jackson library.

(require '(clj-json [core :as json]))
(import '(java.io StringReader BufferedReader))

(json/generate-string {"foo" "bar"})
"{\"foo\":\"bar\"}"

(json/parse-string "{\"foo\":\"bar\"}")
{"foo" "bar"}

(json/parsed-seq
  (BufferedReader. (StringReader. "{\"foo\":\"bar\"}{\"biz\":\"bat\"}")))
({"foo" "bar"} {"biz" "bat"})

clj-json is available as a Maven artifact from Clojars.

clj-json can generate JSON for maps, vectors, lists, keywords, strings, integers, doubles, floats, and booleans.

Note that keywords generate as strings without a leading :, and will read via parse-string and parsed-seq as strings, however both have an optional boolean argument to keywordize the keys of maps.

Coercions can be redefined by binding *coercions*. For example, to coerce sets into existence map:

(binding [clj-json.core/*coercions* {clojure.lang.PersistentHashSet (fn [x] (reduce (fn [acc x] (assoc acc x true)) {} x))}]
  (is (= {"foo" {"bang" true, "bar" true}}
       (json/parse-string
        (json/generate-string {"foo" #{"bar" "bang"}})))))

To build, test, and package the clj-json source using Leiningen:

$ lein deps
$ lein javac
$ lein test
$ lein jar

Release under an MIT license.