Handle JSON array from REST call

Question

I'm trying to do my first REST integration between PHP and Salesforce, and am having some trouble understanding how to handle the JSON objects. Basically I'm sending over a list/array of objects in JSON format and then want to put them back in object format.

Right now, my JSON string looks like

[{"TransDate":"2017-01-01","Sales":"161776","InvoiceNo":"C017665","CustNm":"Coomber, Skip","ProductGroup":"APCCSERV"},...]

Which I believe should be an array of objects

Then I'm trying to parse it in Salesforce with the following

    if (response.getStatusCode() == 200) {
        // Deserialize the JSON string into collections of primitive data types.
         List<SalesData> resultList = (list<SalesData>)JSON.deserializeStrict(response.getBody(), SalesData.class);

       //  system.debug(results);
    }        
}

Class SalesData {
    Date TransDate;
    String Sales;
    String InvoiceNo;
    String CustNm;
    String ProductGroup;

}

But I get the following error

"Line: 19, Column: 1 System.JSONException: Malformed JSON: Expected '{' at the beginning of object"

Which maybe makes sense because I am passing in an array of objects not an object, but then how do I get around that?

side note the PHP I'm using is

    while (odbc_fetch_row($result) ) { 
    $row = new stdClass();

    $TransDate = odbc_result($result, 'TransDate'); $row->TransDate = $TransDate;
    $Sales = odbc_result($result, 'Sales'); $row->Sales = $Sales;
    $InvoiceNo = odbc_result($result, 'InvoiceNo'); $row->InvoiceNo = $InvoiceNo;
    $CustNm = odbc_result($result, 'CustNm'); $row->CustNm = $CustNm;
    $ProductGroup = odbc_result($result, 'ProductGroup'); $row->ProductGroup = $ProductGroup;




    array_push($post_data, $row);

    }


if (isset($_POST)) {

    $json_params = file_get_contents("php://input");
    echo json_encode($post_data);

}

Answer 1

You have an array of objects, so you should use:

List<SalesData> resultList =
    (list<SalesData>)
    JSON.deserializeStrict(
         response.getBody(),
         List<SalesData>.class);

The problem is that you told the JSON parser that it was expecting a single SalesData object. Instead, we have to tell the JSON parser to expect a list of SalesData objects, so we use List<SalesData>.class to indicate this.