How to deserialize the following JSON to get the list of values? [duplicate]

Question

I have used the code below to deserialize the json but throwing an error.

Map<String,Object> root =(Map<String,Object>)JSON.deserializeUntyped(res.getBody()));

"Callout error Invalid conversion from runtime type List<ANY> to Map<String,ANY>"

I want to deserialize the JSON using an apex class to get the list of values?

{
   "controllerValues": {},
   "defaultValue": null,
   "eTag" : "",
   "url" : "",
   "values" : [
    {
            "attributes": null,
            "label": "PicklistValue1",
            "validFor": [],
            "value": "PicklistValue1"
    },
    {
            "attributes": null,
            "label": "PicklistValue2",
            "validFor": [],
            "value": "PicklistValue2"
    }
   ]
}

Answer 1

This error message:

Callout error Invalid conversion from runtime type List to Map

suggests that the JSON in the body you are receiving is a list i.e. starts with [ and ends with ].

If the data is a list, change to e.g.:

List<Object> root = (List<Object>) JSON.deserializeUntyped(res.getBody());