How do I concatenate a dynamic string value using Groovy to JSON response after it's parsed to get a specific node value in JSON - json

Question

slurperresponse = new JsonSlurper().parseText(responseContent)
log.info (slurperresponse.WorkItems[0].WorkItemExternalId)
The above code helps me get the node value "WorkItems[0].WorkItemExternalId" using Groovy. Below is the response.
{
"TotalRecordCount": 1,
"TotalPageCount": 1,
"CurrentPage": 1,
"BatchSize": 10,
"WorkItems": [ {
"WorkItemUId": "4336c111-7cd6-4938-835c-3ddc89961232",
"WorkItemId": "20740900",
"StackRank": "0",
"WorkItemTypeUId": "00020040-0200-0010-0040-000000000000",
"WorkItemExternalId": "79853"
}
I need to append the string "WorkItems[0].WorkItemExternalId" (being read from a excel file) and multiple other such nodes dynamically to "slurperresponse" to get the value of nodes rather than directly hard coding as slurperresponse.WorkItems[0].WorkItemExternalId..
Tried append and "+" operator but i get a compilation error. What other way can I do this?

Answer 1

slurperrsesponse is an object its not a string that's why the concatenation does not work
Json Slurper creates an object out of the input string. This object is dynamic by nature, you can access it, you can add fields to it or alter the existing fields. Contatenation won't work here.
Here is an example:
import groovy.json.*
​def text = '{"total" : 2, "students" : [{"name": "John", "age" : 20}, {"name": "Alice", "age" : 21}] }'
def json = new JsonSlurper().parseText(text)​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​
json.total = 3 // alter the value of the existing field
json.city = 'LA' // add a totally new field
json.students[0].age++ // change the field in a list
println json​
This yields the output:
[total:3, students:[[name:John, age:21], [name:Alice, age:21]], city:LA]
Now if I've got you right you want to add a new student dynamically and the input is a text that you've read from Excel. So here is the example:
json.students << new JsonSlurper().parseText('{"name" : "Tom", "age" : 25}')
// now there are 3 students in the list
Update
Its also possible to get the values without 'hardcoding' the property name:
// option 1
println json.city // prints 'LA'
// option 2
println json.get('city') // prints 'LA' but here 'city' can be a variable
// option 3
println json['city'] // the same as option 2