Getting the name of each field in JSON - json

Question

I'm trying to parse a random JSON file in Grails.
First I need to get the name of each field
For example, given below JSON file,
{
"abbreviation": "EX",
"guid": "1209812-1l2kj1j-fwefoj9283jf-ae",
"metadata": {
"dataOrigin": "Example"
},
"rooms":
[
],
"site": {
"guid": "1209812-1l2kj1j-fwefoj9283jf-ae"
},
"title": "Example!!"
}
I want to find out the structure of the JSON file(lists of keys maybe), for example I want to save the list of keys such as 'abbreviation', 'guid', 'metadata', 'rooms', 'site', 'title' from this JSON file.
How would I do this?
(We need the name of the keys in order to get the value of that key, so with a arbitrarily structured JSON file I need to find out the keys first)

Answer 1

You can try below code
def filePath = "JSONFILE.json"
def text = new File(filePath).getText()
def json = JSON.parse(text)
def jsonKeys = json.collect{it.key}
println(jsonKeys)
This will print all json keys

Answer 2

From what dmahaptro commented, I figured out how to get all the keys within a JSON object.
Here is a simple sample code I wrote to test it
String jsonFile = new JsonSlurper().parseText(new URL(path to the json file).text)
JSONArray jsonParse = new JSONArray(jsonFile)
int len = jsonParse.length()
def names = []
def keys = []
(0..len-1).each {
JSONObject val = jsonParse.getJSONObject(it)
int numKeys = val.length()
names = val.names()
keys = val.keySet()
(0..numKeys-1).each {
def field = names[it]
println field +" : " + val."${field}"
}
}
This will print the key:value pair given a JSON file.