| career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (serialization.clj)

This example Java source code file (serialization.clj) is included in the "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

byte/type, bytearrayinputstream, bytearrayoutputstream, character/type, chas, copyright, deserializes, double/type, license, objectinputstream, objectoutputstream, serializationrecord, serializationstruct, the

The serialization.clj Java example source code

;   Copyright (c) Rich Hickey. All rights reserved.
;   The use and distribution terms for this software are covered by the
;   Eclipse Public License 1.0 (
;   which can be found in the file epl-v10.html at the root of this distribution.
;   By using this software in any fashion, you are agreeing to be bound by
;   the terms of this license.
;   You must not remove this notice, or any other, from this software.

;; Author: Chas Emerick

(ns clojure.test-clojure.serialization
  (:use clojure.test)
  (:import ( ObjectOutputStream ObjectInputStream
             ByteArrayOutputStream ByteArrayInputStream)))

(defn- serialize
  "Serializes a single object, returning a byte array."
  (with-open [bout (ByteArrayOutputStream.)
              oos (ObjectOutputStream. bout)]
    (.writeObject oos v)
    (.flush oos)
    (.toByteArray bout)))

(defn- deserialize
  "Deserializes and returns a single object from the given byte array."
  (with-open [ois (-> bytes ByteArrayInputStream. ObjectInputStream.)]
    (.readObject ois)))

(defrecord SerializationRecord [a b c])
(defstruct SerializationStruct :a :b :c)

(defn- build-via-transient
    (reduce conj! (transient coll) (map vec (partition 2 (range 1000))))))

(defn- roundtrip
  (let [rt (-> v serialize deserialize)
        rt-seq (-> v seq serialize deserialize)]
    (and (= v rt)
      (= (seq v) (seq rt))
      (= (seq v) rt-seq)
      (= (hash v) (hash rt))
      (= (.hashCode v) (.hashCode rt)))))

(deftest sequable-serialization
  (are [val] (roundtrip val)
    ; lists and related
    (apply list (range 10))
    (cons 0 nil)
    (clojure.lang.Cons. 0 nil)

    ; vectors
    (into [] (range 10))
    (into [] (range 25))
    (into [] (range 100))
    (into [] (range 500))
    (into [] (range 1000))

    ; maps
    {:a 5 :b 0}
    (apply array-map (range 100))
    (apply hash-map (range 100))

    ; sets
    #{'a 'b 'c}
    (set (range 10))
    (set (range 25))
    (set (range 100))
    (set (range 500))
    (set (range 1000))
    (sorted-set 'a 'b 'c)
    (apply sorted-set (reverse (range 10)))
    (apply sorted-set (reverse (range 25)))
    (apply sorted-set (reverse (range 100)))
    (apply sorted-set (reverse (range 500)))
    (apply sorted-set (reverse (range 1000)))

    ; queues
    (into clojure.lang.PersistentQueue/EMPTY (range 50))

    ; lazy seqs
    (lazy-seq nil)
    (lazy-seq (list* (range 50)))

    ; transient / persistent! round-trip
    (build-via-transient [])
    (build-via-transient {})
    (build-via-transient #{})

    ; array-seqs
    (seq (make-array Object 10))
    (seq (make-array Boolean/TYPE 10))
    (seq (make-array Byte/TYPE 10))
    (seq (make-array Character/TYPE 10))
    (seq (make-array Double/TYPE 10))
    (seq (make-array Float/TYPE 10))
    (seq (make-array Integer/TYPE 10))
    (seq (make-array Long/TYPE 10))

    ; "records"
    (SerializationRecord. 0 :foo (range 20))
    (struct SerializationStruct 0 :foo (range 20))

    ; misc seqs
    (seq "s11n")
    (range 50)
    (rseq (apply sorted-set (reverse (range 100))))

    ;; partially realized chunked range
    (let [r (range 50)]
      (nth r 35)

(deftest misc-serialization
  (are [v] (= v (-> v serialize deserialize))

(deftest tostringed-bytes
  (let [rt #(-> % serialize seq)
        s1 (rt 'sym123)
        k1 (rt :kw123)
        _ (.toString 'sym123)
        _ (.toString :kw123)
        s2 (rt 'sym123)
        k2 (rt :kw123)]
    (is (= s1 s2))
    (is (= k1 k2))))

(deftest interned-serializations
  (are [v] (identical? v (-> v serialize deserialize))
    ; namespaces just get deserialized back into the same-named ns in the present runtime
    ; (they're referred to by defrecord instances)

(deftest function-serialization
  (let [capture 5]
    (are [f] (= capture ((-> f serialize deserialize)))
      (constantly 5)
      (fn [] 5)
      #(do 5)
      (constantly capture)
      (fn [] capture)
      #(do capture))))

(deftest check-unserializable-objects
  (are [t] (thrown? (serialize t))
    ;; transients
    (transient [])
    (transient {})
    (transient #{})

    ;; reference types
    (atom nil)
    (ref nil)
    (agent nil)

    ;; stateful seqs
    (enumeration-seq (java.util.Collections/enumeration (range 50)))
    (iterator-seq (.iterator (range 50)))))

Other Java examples (source code examples)

Here is a short list of links related to this Java serialization.clj source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller


new blog posts


Copyright 1998-2021 Alvin Alexander,
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.