Parse local data store retrieving object values as null

Question

I am trying to save and retrieve some object data on parse local datastore. My problem is that say I have saved two objects in this case LocalPrinterDetail objects, the save and retrieval of the data work fine and data is displayed correctly on my recyclerview, however, when I exit the app and open it up again the printerName and the stationName are null for each of the two objects but the localPrinterDetailObjects shows that it has a size of 2 during debug thus on my recyclerview blank items are shown. Why is this happening on app exit and why can't I cache the data?

Retrieve method

public void retrieveLocalPrinterDetailRecords() {
        ParseQuery<LocalPrinterDetail> query = ParseQuery.getQuery(LocalPrinterDetail.class);
        query.fromLocalDatastore();
        query.findInBackground(new FindCallback<LocalPrinterDetail>() {
            @Override
            public void done(List<LocalPrinterDetail> localPrinterDetailObjects, ParseException e) {
                if (e == null) {
                    if (localPrinterDetailObjects != null && !localPrinterDetailObjects.isEmpty() && localPrinterDetailObjects.get(0) != null) {
                        localPrinterList.clear();
                        localPrinterList.addAll(localPrinterDetailObjects);
                    }
                    setupRecyclerView((RecyclerView) recyclerView);
                    adapter.notifyDataSetChanged();
                } else {
                    e.printStackTrace();
                }
            }
        });
    } 

Save method

public void saveLocalPrinterDetailRecord(String printerStationName) {
        LocalPrinterDetail localPrinterDetail = new LocalPrinterDetail();
        localPrinterDetail.setStationName(printerStationName);
        localPrinterDetail.setPrinterName(printerModelName);
        localPrinterDetail.put("station_name", localPrinterDetail.getStationName());
        localPrinterDetail.put("printer_name", localPrinterDetail.getPrinterName());
        localPrinterDetail.pinInBackground(new SaveCallback() {
            @Override
            public void done(ParseException e) {
                if (e == null) {
                    Toast.makeText(context, "Local Printer Saved", Toast.LENGTH_LONG).show();
                } else {
                    e.printStackTrace();
                }
            }
        });
        localPrinterDetail.saveEventually();
    }

LocalPrinterDetail class

@ParseClassName("LocalPrinterDetail")
public class LocalPrinterDetail extends ParseObject {
    private int printerId;
    private String printerName;
    private String stationName;

    public LocalPrinterDetail() {
    }

    public int getPrinterId() {
        return printerId;
    }

    public void setPrinterId(int printerId) {
        this.printerId = printerId;
    }

    public String getPrinterName() {
        return printerName;
    }

    public void setPrinterName(String printerName) {
        this.printerName = printerName;
    }

    public String getStationName() {
        return stationName;
    }

    public void setStationName(String stationName) {
        this.stationName = stationName;
    }
}

Answer 1

Try to change your subclass declaration to:

@ParseClassName("LocalPrinterDetail")
public class LocalPrinterDetail extends ParseObject {
    public int getPrinterId() {
        return getInt("printerId");
    }

    public void setPrinterId(int printerId) {
        put("printerId", printerId);
    }

    public String getPrinterName() {
        return getString("printerName");
    }

    public void setPrinterName(String printerName) {
        put("printerName", printerName);
    }

    public String getStationName() {
        return getString("stationName");
    }

    public void setStationName(String stationName) {
        put("stationName", stationName);
    }
}