How to add new json field to existing json in groovy

Question

My existing Json looks like:

def json_req = "{\"date\":\"Tue, 06 Oct 2015 09:10:52 GMT\",\"nonce\":\"6cm7PmwDOKs\",\"devId\":\"<value>\",\"appId\":\"<value>\"}

Perform the operation I can get sig field with value. I need to append this additional field with value as below:

"sig":"<value>"

So that the new json looks like:

def json_req = "{\"date\":\"Tue, 06 Oct 2015 09:10:52 GMT\",\"nonce\":\"6cm7PmwDOKs\",\"devId\":\"<value>\",\"appId\":\"<value>\",\"sig\":\"<value>\"}"

Within the same script can I append this new parameter with the value in json?

Answer 1

You can parse the json with JsonSlurper, and since the result of that is a LazyMap, you can simply add the new entry to it (lines with println added as hints):

import groovy.json.*

def json_req = '''{
"date":"Tue, 06 Oct 2015 09:10:52 GMT", 
"nonce":"6cm7PmwDOKs",
"devId":"<value>",
"appId": "<value>"
}'''

def json = new JsonSlurper().parseText(json_req)
println json.getClass().getName()
json << [sig: "<value>"] // json.put('sig', '<value>')
println JsonOutput.toJson(json)

Try it on the groovy web console