jsonista

jsonissa / jsonista / jsoniin, jsonilla / jsonilta / jsonille

Clojure library for fast JSON encoding and decoding.

• Explicit configuration
• Embrace Java for speed
• Uses Jackson directly
• API docs

Aiming to be faster than Cheshire while still having all the necessary features for web development. Designed for use with Muuntaja.

Blogged:

• Faster JSON processing with jsonista

Latest version

Quickstart

(require '[jsonista.core :as j])

(j/write-value-as-string {"hello" 1})
;; => "{\"hello\":1}"

(j/read-value *1)
;; => {"hello" 1}

More examples

Changing how map keys are encoded & decoded:

(defn reverse-string [s] (apply str (reverse s)))

(def mapper
  (j/object-mapper 
    {:encode-key-fn (comp reverse-string name)
     :decode-key-fn (comp keyword reverse-string)}))

(-> {:kikka "kukka"} 
    (doto prn) 
    (j/write-value-as-string mapper) 
    (doto prn) 
    (j/read-value mapper)
    (prn))
; {:kikka "kukka"}
; "{\"akkik\":\"kukka\"}"
; {:kikka "kukka"}

Reading & writing directly into a file:

(def file (java.io.File. "hello.json"))

(j/write-value file {"hello" "world"})

(slurp file)
;; => "{\"hello\":\"world\"}"

(j/read-value file)
;; => {"hello" "world"}

Performance

• All standard encoders and decoders are written in Java
• Protocol dispatch with read-value & write-value
• Jackson ObjectMapper is used directly
• Small functions to support JVM Inlining

See perf-tests for details.

License

Copyright © 2016-2017 Metosin Oy.

Distributed under the Eclipse Public License, the same as Clojure.