Help needed for Service class

Question

When trying to retrieve information for a form that contains textbox so as to display product information on a form I am getting an error which is listed below
java.lang.NullPointerException
file:/K:/Learner/JavaFx2/ProductApplication/dist/run876373360/ProductApplication.jar!/com/product/app/view/viewsingle.fxml
  at com.product.app.controller.ViewSingleController.initialize(ViewSingleController.java:70)
and here is the code for controller as well as service class
package com.product.app.controller;
import com.product.app.model.Product;
import com.product.app.service.ViewProductsService;
import com.product.app.util.JSONParser;
import com.product.app.util.TagConstants;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.ResourceBundle;
import javafx.collections.ObservableList;
import javafx.concurrent.Service;
import javafx.concurrent.Task;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.ProgressIndicator;
import javafx.scene.control.TextArea;
import javafx.scene.control.TextField;
import javafx.scene.layout.Region;
import javafx.stage.Stage;
import javax.swing.JOptionPane;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONObject;
* FXML Controller class
* @author Arun Joseph
public class ViewSingleController implements Initializable {
    private static String action = "";
    @FXML
    private TextField txtID;
    @FXML
    private TextField txtName;
    @FXML
    private TextField txtPrice;
    @FXML
    private TextArea txtDesc;
    @FXML
    private Region veil;
    @FXML
    private ProgressIndicator p;
    private ViewProductsService service = new ViewProductsService();
    private JSONObject product = null;
    private JSONParser parser = new JSONParser();
    private int pid = 1;
    public void setPid(int pid) {
        this.pid = pid;
     * Initializes the controller class.
    @Override
    public void initialize(URL url, ResourceBundle rb) {
        veil.setStyle("-fx-background-color: rgba(0, 0, 0, 0.4)");
        p.setMaxSize(150, 150);
        p.progressProperty().bind(service.progressProperty());
        veil.visibleProperty().bind(service.runningProperty());
        p.visibleProperty().bind(service.runningProperty());
        Product product = new Product();
        service.start();
        ObservableList<Product> products = service.valueProperty().get();
        products.get(pid);
        txtID.textProperty().set(String.valueOf(products.get(pid).getPid()));
        //product = service.valueProperty().get().get(pid);
        //txtID.setText(String.valueOf(product.getPid()));
        txtName.textProperty().set(product.getName());
        txtPrice.textProperty().set(String.valueOf(product.getPrize()));
        txtDesc.textProperty().set(product.getDescription());
    private SomeService someService = new SomeService();
    @FXML
    private void handleUpdateButtonClick(ActionEvent event) {
        action = "update";
        someService.start();
        p.progressProperty().bind(service.progressProperty());
        veil.visibleProperty().bind(service.runningProperty());
        p.visibleProperty().bind(service.runningProperty());
    @FXML
    private void handleDeleteButtonClick(ActionEvent event) {
        action = "delete";
        someService.start();
        p.progressProperty().bind(service.progressProperty());
        veil.visibleProperty().bind(service.runningProperty());
        p.visibleProperty().bind(service.runningProperty());
    @FXML
    private void handleCancelButtonClick(ActionEvent event) {
        closeStage();
    private void closeStage() {
        ViewSingleController.stage.close();
    private static Stage stage = null;
    public static void setStage(Stage stage) {
        ViewSingleController.stage = stage;
    private class SomeService extends Service<String> {
        @Override
        protected Task<String> createTask() {
            return new SomeTask();
        private class SomeTask extends Task<String> {
            @Override
            protected String call() throws Exception {
                String result = "";
                int success = 0;
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                switch (action) {
                    case "update":
                        params.add(new BasicNameValuePair("pid", txtID.getText()));
                        params.add(new BasicNameValuePair("name", txtName.getText()));
                        params.add(new BasicNameValuePair("price", txtPrice.getText()));
                        params.add(new BasicNameValuePair("description", txtDesc.getText()));
                        product = parser.makeHttpRequest(TagConstants.url_update_product_with_id, "POST", params);
                        success = product.getInt(TagConstants.TAG_SUCCESS);
                        if (success == 1) {
                            result = "Successfully Updated the product";
                            JOptionPane.showMessageDialog(null, result);
                            closeStage();
                        break;
                    case "delete":
                        params.add(new BasicNameValuePair("pid", txtID.getText()));
                        product = parser.makeHttpRequest(TagConstants.url_delete_product_with_id, "POST", params);
                        success = product.getInt(TagConstants.TAG_SUCCESS);
                        if (success == 1) {
                            result = "Successfully Deleted the product";
                            JOptionPane.showMessageDialog(null, result);
                            closeStage();
                        break;
                return result;

Answer 1

Is line 70 in the code above
txtPrice.textProperty().set(String.valueOf(product.getPrize()));
also line 70 in your original code? (Sometimes the syntax highlighter seems to delete blank lines.) If so, then txtPrice must be null, which would likely be caused by the fx:id attribute for it being set incorrectly in the fxml file.
Check which is line 70 in the original code though.