Illegal assignment from System.JSONParser to JsonParser - json

Question

In JsnoToApex class I try to GET JSON file from https://openweathermap.org/current. When I try to parse JSON.CreateParses I get these error: Illegal assignment from System.JSONParser to JsonParser
I try to make API that show weather in London.
public with sharing class JsonToApex {
#future(callout=true)
public static void parseJSONResponse() {
String resp;
Http httpProtocol = new Http();
// Create HTTP request to send.
HttpRequest request = new HttpRequest();
// Set the endpoint URL.
String endpoint = 'https://samples.openweathermap.org/data/2.5/weather?q=London,uk&appid=b6907d289e10d714a6e88b30761fae22';
request.setEndPoint(endpoint);
// Set the HTTP verb to GET.
request.setMethod('GET');
// Send the HTTP request and get the response.
// The response is in JSON format.
HttpResponse response = httpProtocol.send(request);
resp = response.getBody();
JSONParser parser = JSON.createParser(resp);
JsonMapper response = (JsonMapper) System.JSON.deserialize(res.getBody(), JsonMapper.class);
}
}
I expect to get Json file and in future map it using https://json2apex.herokuapp.com/

Answer 1

The problem was in first JSONParser. I had to add System.JSONParser to make it work.
System.JSONParser parser = JSON.createParser(resp);

Answer 2

You may have two approaches:
If you have already map the JSON into an Apex class, you may just use
JSON2Apex aClass = (JSON2Apex) System.JSON.deserialize(resp, JSON2Apex.class);
Where JSON2Apex is the mapping Apex class.
Use the JSON.deserializeUntyped(String jsonString) to deserialize the JSON to any Object in Apex class, like:
Map<String, Object> objMap = (Map<String, Object>) JSON.deserializeUntyped(resp);