HTTP GET request desterilize with wrapper class 'non static method' error

Question

Hi all i'm trying to retrive data from a source which gives me a json with all of a certain property listing details such as bedrooms bathrooms etc...

so I'm trying to parse the data using a wrapper class to then display in a visualforce page...

here is my controller:

public class DomainAPI {
    public List<DomainWrapperClass> ListingWrapperList{get;set;}
    
    public List<DomainWrapperClass> getperformcallout(){
        ListingWrapperList = new List<DomainWrapperClass>();
    
        HttpRequest req = new HttpRequest();
        HttpResponse res = new HttpResponse();
        Http http = new Http();
        req.setEndpoint('callout:Domain/v1/listings/2017755932');
        req.setMethod('GET');

        res = http.send(req);
    
        if(res.getstatusCode() == 200 && res.getbody() != null){
            ListingWrapperList = (List<DomainWrapperClass>)json.deserialize(
                res.getbody(),
                List<DomainWrapperClass>.class);
        }
    
        return ListingWrapperList;
    }

Here is my Wrapper Class from Json to Apex using the response body.

public class DomainWrapperClass {
    public class PriceDetails {
        public Integer priceFrom;
        public Integer priceTo;
        public String gstOption;
        public String priceUnit;
        public Boolean canDisplayPrice;
        public String displayPrice;
    }

    public String dateUpdated;
    public GeoLocation geoLocation;
    public String objective;
    public String status;
    public String saleMode;
    public String channel;
    public Integer id;
    public AddressParts addressParts;
    public AdvertiserIdentifiers advertiserIdentifiers;
    public ApmIdentifiers apmIdentifiers;
    public Integer bathrooms;
    public Integer bedrooms;
    public String buildingArea;
    public Integer buildingAreaSqm;
    public Integer carspaces;
    public String dateCreated;
    public String dateMinorUpdated;
    public String dateListed;
    public String description;
    public String headline;
    public Boolean isNewDevelopment;
    public PriceDetails priceDetails;
    public List<String> propertyTypes;
    public ProviderDetails providerDetails;
    public SaleDetails saleDetails;
    public Boolean isWithdrawn;
    public String seoUrl;
    public Boolean homepassEnabled;

    public class ApmIdentifiers {
        public Integer addressId;
        public Integer streetId;
        public Integer suburbId;
        public Integer cadastreId;
        public Integer postcodeId;
        public Integer stateId;
        public String state;
        public Integer propertyTypeId;
        public Integer propertyTypeCategoryId;
        public String streetNumber;
    }

    public class AuctionSchedule {
        public String locationDescription;
        public String openingDateTime;
    }

    public class TenantDetails {
    }

    public class AdvertiserIdentifiers {
        public String advertiserType;
        public Integer advertiserId;
        public List<Integer> contactIds;
        public List<String> agentIds;
    }

    public class ProviderDetails {
        public String providerSystem;
        public String providerAdID;
    }

    public class GeoLocation {
        public Double latitude;
        public Double longitude;
    }

    public class AuctionDetails {
        public AuctionSchedule auctionSchedule;
    }

    public class SaleDetails {
        public String saleMethod;
        public AuctionDetails auctionDetails;
        public TenantDetails tenantDetails;
    }

    public class AddressParts {
        public String streetNumber;
        public String postcode;
        public String street;
        public String suburb;
        public String stateAbbreviation;
        public String displayType;
        public String displayAddress;
    }
}

Now when I try and run it I'm getting

Non static method cannot be referenced from a static context: List<DomainWrapperClass> DomainAPI.getperformcallout()

any pointers on this would be fantastic.

Answer 1

Whatever is calling getPerformCallout is marked as static. You need to make getPerformCallout static as well.

Answer 2

The code calling this method needs to construct an instance of the Domain API class:

new DomainAPI().getperformcallout();