Im pretty clear on how to parse JSON from http requests. But I have a JSON file locally I would like to use within my code.

I have tried to find a solution on google but I am struggling to figure out how to read a local JSON file from the file system

Thanks

Vinn

CodePudding user response：

Use clojure/data.json library:

• Add this dependency into project.clj:

[org.clojure/data.json "2.4.0"]

• Add this requirement into namespace definition:

(:require [clojure.data.json :as json])

• Then use read-str with slurp. I made example file filename.json with this content:

{"name":"John", "age":30, "car":null}

and read it like this:

(json/read-str (slurp "filename.json"))
=> {"name" "John", "age" 30, "car" nil}

CodePudding user response：

Well, what's the difference between a json arriving from an http request and a json arriving from a local file? I suppose the real question then is "how to read from a local file", no?

Here is how to read a json from a string using clojure/data.json:

(def json-str (json/read-str "{\"a\":1,\"b\":{\"c\":\"d\"}}"))

Now, lets put the same string into a file

echo '{"a":1,"b":{"c":"d"}}' > /tmp/a.json

And lets read it from the file:

(def from-file (slurp "/tmp/a.json"))
(def json-file (json/read-str from-file))

Make sure they are the same:

(when (= json-str json-file)
  (println "same" json-file))

Which would print "same" and the parsed json value.