Parsing JSON response that only has "rows" and "columns" to POJO

Question

Is it possible to parse a JSON response to POJO, even though the response only sends back Rows and Columns?

I get this response from an API:

{
"rows": [
[
  "FIRST NATIONAL BANK OF OMAHA",
  36644,
  "COM",
  44527,
  198809,
  "SH",
  -1.5631,
  "Put",
  "2019-09-30"
],
[
  "WAYNE HUMMER INVESTMENTS L.L.C.",
  49096,
  "COM",
  17975,
  90817,
  "SH",
  2.8971,
  "Put",
  "2019-06-30"
]
],
"columns": [
"Institution Name",
"Institution CIK",
"Class of Security Held",
"Value of Security Held",
"Volume of Security Held",
"Type of Security Held",
"Quarterly Change in Security Held",
"Put/Call",
"Report Date"
]
}

This is the code I am using, shortened for brevity, to connect to the API and get the JSON response which I pass through deserializer class using Gson:

public static void requestResponse(){

   URL apiURL = new URL("http://apilink.com/api/getSomething.json?T=gnbuweiogh9y89234y&symbol=GOOG");

   String readLine = null;

   HttpConnection apiConnection =  (HttpConnection) apiURL.openConnection();

   apiConnection.setRequestMethod("GET");

   int responseCode = apiConnection.getResponseCode();

   if(responseCode == HttpConnection.HTTP_OK) {

       BufferedReader in = new BufferedReader(new InputStreamReader(apiConnection.getInputStream()));

       StringBuffer response = new StringBuffer();

       while((readLine = in.readLine()) != null) {
           response.append(readLine);
       }
       in.close();

       String jsonResponse = response.toString();

       Deserializer deSerializer = new Gson().fromJson(jsonResponse, Deserializer .class);
       List<String> columns = deSerializer.getColumns;
       // Do something with the data
   }
}

This is the deserialization class I made:

public class deSerializer {

@SerializedName("rows")
@Expose
private List<List<String>> rows = null;
@SerializedName("columns")
@Expose
private List<String> columns = null;

public List<List<String>> getRows() {
return rows;
}

public void setRows(List<List<String>> rows) {
this.rows = rows;
}

public List<String> getColumns() {
return columns;
} 

public void setColumns(List<String> columns) {
this.columns = columns;
}

}

I was expecting the JSON response to be in this format which would have made the serialization simpler:

{
 "data": [{
"Institution Name": "FIRST NATIONAL BANK OF OMAHA",
"Institution CIK": 36644,
"Class of Security Held": "COM",
"Value of Security Held": 44527
 } ]
}

Sorry for the long post, but what would be the best approach to deserialize the response to POJO?

Thanks a lot.

Answer 1

You can convert it to the format you want by adding the following helper method to your deSerializer class:

public List<Map<String, Object>> asListOfMaps() {
    List<Map<String, Object>> list = new ArrayList<>(this.rows.size());
    for (List<Object> data : this.rows) {
        Map<String, Object> row = new LinkedHashMap<>(this.columns.size());
        for (int i = 0; i < this.columns.size(); i++)
            row.put(this.columns.get(i), data.get(i));
        list.add(row);
    }
    return list;
}