Clojure base64 encoding

Question

I want something as simple as "string" -> base64. With the older base64.encode-str it was easy (and sounded "more clojure", but the newer clojure.data.codec.base64 requires input and output streams and seems an ugly wrapper around Java way of doing things.

So, what is the way, having a string, to get a base64 encoded array? Thanks

nlloyd · Answer 1 · 2016-08-28T07:18:13.813

46

Four years later, but I think this is worth mentioning if you're at JDK 1.8 or greater. It just uses java.util.Base64

To Encode String -> Base64:

(:import java.util.Base64)

(defn encode [to-encode]
  (.encode (Base64/getEncoder) (.getBytes to-encode)))

To Encode String -> Base64 (String):

(:import java.util.Base64)

(defn encode [to-encode]
  (.encodeToString (Base64/getEncoder) (.getBytes to-encode)))

To Decode Base64 (byte[] or String) -> String:

(:import java.util.Base64)

(defn decode [to-decode]
  (String. (.decode (Base64/getDecoder) to-decode)))

edited Aug 28 '16 at 07:18

answered Aug 28 '16 at 07:09

nlloyd

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Note, if you want the string to be [URL safe](https://docs.oracle.com/javase/8/docs/api/java/util/Base64.html#getUrlEncoder--) use (Base64/getUrlEncoder) – KendallB Oct 27 '21 at 22:14

score 20 · Answer 2 · answered May 27 '13 at 22:35

20

There's one more step needed for the other answer: converting the byte-array result of encode into a string. Here's what I do:

(:require [clojure.data.codec.base64 :as b64])

(defn string-to-base64-string [original]
  (String. (b64/encode (.getBytes original)) "UTF-8"))

answered May 27 '13 at 22:35

Brian Marick

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I do think that a string-to-string function would be a helpful addition to clojure.data. – Brian Marick May 27 '13 at 22:36
1

It seems safer to me to include encoding for the getBytes call as well: (.getBytes original "UTF-8") – LOAS Dec 22 '14 at 08:42

Mikita Belahlazau · Accepted Answer · 2012-08-06T09:27:55.367

12

You can use encode function and pass array of bytes:

(encode (.getBytes "Hello world!"))

edited Aug 06 '12 at 09:27

answered Aug 06 '12 at 09:19

Mikita Belahlazau

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Yup, though the charset can screw that up, which is one reason I omitted the string-related functions. – Alex Taggart Aug 06 '12 at 19:46
2

What should I use now (may 2014)? Because this data.codec have last commit 3 years ago. – invis May 28 '14 at 20:50

score 3 · Answer 4 · answered Jan 31 '17 at 07:50

3

ztellman/byte-transforms also support base64 encode/decode.

(encode "hello" :base64 {:url-safe? true})

answered Jan 31 '17 at 07:50

ruseel

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score 3 · Answer 5 · answered Mar 20 '18 at 13:25

For those trying (as I was) to turn images into data URIs (for embedding images in HTML):

(defn data-uri
  [imagepath]
  (str
   "data:image/"
   (second
    (re-find #"\.(.*$)" imagepath))
   ";base64,"
   (.encodeToString
    (java.util.Base64/getEncoder)
    (org.apache.commons.io.FileUtils/readFileToByteArray
     (clojure.java.io/file filepath)))))

score 1 · Answer 6 · edited May 23 '17 at 12:34

Possible duplicate of Clojure equivalent of python's base64 encode and decode

The Tupelo library has Clojure wrappers around the base Java Base64 and Base64Url functionality. A look at the unit tests show the code in action:

(ns tst.tupelo.base64
  (:require [tupelo.base64 :as b64] ))

code-str    (b64/encode-str  orig)
result      (b64/decode-str  code-str) ]
(is (= orig result))

where the input & output values are plain strings (there is also a variant for byte arrays).

The API docs are here.

Clojure base64 encoding

6 Answers6

To Encode String -> Base64:

To Encode String -> Base64 (String):

To Decode Base64 (byte[] or String) -> String:

Linked

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