Deserialize JSON string to custom Apex class

Question

I'm building an API to show data in a Visualforce page. After I created the classes and the callout it responses with a JSON string. For now I use a mock JSON string to test my deserialize function.

Sadly it does not work, it says in the log files that the object contains attributes which are still null.

My classes:

public class MortgageContract {
    //@SerializedName('Number')
    public String Id {get;set;}
    public String Description {get;set;}
    public Collateral Collateral {get;set;}
    public String EffectiveDate {get;set;}
    public String InitialAmount {get;set;}
    public String ProRestoAmount {get;set;}
    public List<Borrower> Borrowers {get;set;}
    public List<LoanPart> LoanParts {get;set;}
}

public class Collateral{
    public Address Address {get;set;}
    public String MarketValue {get;set;}
}

public class Address{
    public String StreetAddress {get;set;}
    public String ZipCode {get;set;}
    public String City {get;set;}
}

public class Borrower{
    public String Name {get;set;}
}

public class LoanPart{
    public String Loanpartid {get;set;}
    public String Description {get;set;}
    public String ProRestoAmount {get;set;}
    public String InterestRate {get;set;}
    public String InterestType {get;set;}
    public String TermAmount {get;set;}
    public String TermPayment {get;set;}
    public String TimePayment {get;set;}
    public Boolean NHG {get;set;}
    public String EffectiveDate {get;set;}
    public String EndDateLoanpart {get;set;}
    public String DurationLoanpart {get;set;}
    public String EndDateFixedInterestRatePeriod {get;set;}
}

My JSON response:

{
"mortgageContract": {
    "id": "H0000000",
    "number": "H0000000",
    "productcode": "COM",
    "description": "Combinatiehypotheek",
    "collateral": {
        "address": {
            "streetAddress": "A VD NEERSTR 9",
            "zipCode": "5702 CJ",
            "city": "HELMOND"
        },
        "marketValue": "167500.00"
    },
    "effectiveDate": "2007-06-01",
    "initialAmount": "209375.00",
    "redemptionAmount": "35142.96",
    "proRestoAmount": "174232.04",
    "redemptionPercentage": "16.78",
    "loanToValue": "106.00",
    "prepayments": {
        "redemptionAmountActual": "0.00",
        "redemptionFreeAmountActual": "0.00",
        "redemptionFreeAmount": "20937.50",
        "redemptionFreePercentage": "10.00"
    },
    "borrowers": [{
        "name": "T.G.V.T. Sick - Bos"
    }],
    "lifeInsurances": [{
        "number": "2134437"
    }],
    "loanParts": [{
            "loanpartid": "H0000000-1",
            "loanpartnumber": "1",
            "productcode": "USH",
            "description": "Spaarhypotheek",
            "proRestoAmount": "50000.00",
            "interestRate": "5.30",
            "interestType": "Variabele rente",
            "termAmount": "0.00",
            "termType": "Rente",
            "termPayment": "Maandelijks",
            "timePayment": "Achteraf",
            "termComposition": {
                "termCompositionType": "Alleen rente",
                "termInterestAmount": "0.00"
            },
            "NHG": false,
            "redemptionDescription": "Bij deze hypotheekvorm betaalt u alleen rente, en lost u tijdens de looptijd niet direct af. Pas aan het einde van de looptijd lost u de hele hypotheek in één keer af. U spaart hiervoor in de gekoppelde levensverzekering.",
            "effectiveDate": "2007-06-01",
            "endDateLoanpart": "2037-06-01",
            "durationLoanpart": "30",
            "endDateFixedInterestRatePeriod": "2017-06-01",
            "prepayment": {
                "isAllowed": false,
                "producttype": "Non-ALA-PR"
            }
        },
        {
            "loanpartid": "H0000000-2",
            "loanpartnumber": "2",
            "productcode": "ALV",
            "description": "Aflossingsvrije hypotheek",
            "proRestoAmount": "67076.73",
            "interestRate": "2.34",
            "interestType": "Vaste rente",
            "termAmount": "130.80",
            "termType": "Rente",
            "termPayment": "Maandelijks",
            "timePayment": "Achteraf",
            "termComposition": {
                "termCompositionType": "Alleen rente",
                "termInterestAmount": "130.80"
            },
            "NHG": false,
            "redemptionDescription": "Bij deze hypotheekvorm lost u tijdens de looptijd niets af. U betaalt de openstaande lening terug aan het einde van de looptijd. Of op het moment dat u verhuist. Hiervoor gebruikt u eigen geld. Maar u kunt ook de opbrengst uit de verkoop van uw woning gebruiken.",
            "effectiveDate": "2007-06-01",
            "endDateLoanpart": "2037-06-01",
            "durationLoanpart": "30",
            "endDateFixedInterestRatePeriod": "2019-06-01",
            "prepayment": {
                "isAllowed": false,
                "producttype": "NON-ALA"
            }
        }
    ]
}
}

My deserialize function:

public static MortgageContract deserialize(httpResponse res){
    System.debug('Begin deserializing: + '+ res.getBody());
    return (MortgageContract)JSON.deserialize(res.getBody(),MortgageContract.class);
}

Please help me out!

Answer 1

Problem is that your JSON is not really a MortrageContract entity but rather a wrapper above it, so it is actually an object with property named mortgageContract and type MortgageContract .

To make it working, you need to define yet another class, for example, MCWrapper:

public class MCWrapper {
    MortgageContract mortgageContract{get;set;}
}

And in this case, just use similar code:

public static MortgageContract deserialize(httpResponse res){
    System.debug('Begin deserializing: '+ res.getBody());
    MortgageContractWrapper mc_wrapper;
    mc_wrapper =(MCWrapper) JSON.deserialize(res.getBody(),MCWrapper.class); 
    System.debug('Resultaat deserializing: '+ mc_wrapper.mortgageContract);
    return mc_wrapper.mortgageContract;
}