javafx8 TableView Multiselection returns one of the selected items as null

Question

TableView multi selection returns one of the selected objects as null. This doesn't happen every time but happens most of the times when i try to select two rows in the table.similar to the issue defined in this question

Best way of reproducing the issue is , try selecting two sequential rows . FXML :

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Label?>
<?import javafx.scene.control.ProgressBar?>
<?import javafx.scene.control.TableColumn?>
<?import javafx.scene.control.TableView?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.control.cell.PropertyValueFactory?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.Region?>
<?import javafx.scene.layout.StackPane?>




<AnchorPane  xmlns="http://javafx.com/javafx/8.0.65" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.test.controller.TestController">
                <children>
                    <TableView fx:id="personsTable" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="35.0">
                        <placeholder>
                            <Label text="" />
                        </placeholder>
                        <columns>
                            <TableColumn text="Name">
                                <cellValueFactory>
                                    <PropertyValueFactory property="name" />
                                </cellValueFactory>
                            </TableColumn>
                            <TableColumn text="Address">
                                <cellValueFactory>
                                    <PropertyValueFactory property="address" />
                                </cellValueFactory>
                            </TableColumn>
                            <TableColumn text="Course">
                                <cellValueFactory>
                                    <PropertyValueFactory property="course" />
                                </cellValueFactory>
                            </TableColumn>
                            <TableColumn text="Country">
                                <cellValueFactory>
                                    <PropertyValueFactory property="country" />
                                </cellValueFactory>
                            </TableColumn>
                        </columns>
                    </TableView>
                </children>
            </AnchorPane>

Controller :

import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.ResourceBundle;



import com.test.model.Person;

import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.ContextMenu;
import javafx.scene.control.MenuItem;
import javafx.scene.control.SelectionMode;
import javafx.scene.control.TableView;


public class TestController implements Initializable {

    @FXML
    TableView<Person> personsTable = new TableView<Person>();

    @Override
    public void initialize(URL location, ResourceBundle resources) {
        // TODO Auto-generated method stub
        MenuItem combine = new MenuItem("Select");
        combine.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {
                List<Person> selectedPersons = new ArrayList<Person>(
                        personsTable.getSelectionModel().getSelectedItems());
                for (Person person : selectedPersons) {
                    System.out.println("  the object is " + person);
                }
            }
        });

        ContextMenu contextMenu = new ContextMenu();
        contextMenu.getItems().add(combine);

        personsTable.setContextMenu(contextMenu);

        personsTable.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);

        personsTable.setItems(getPendingOrders());
    }

    public ObservableList<Person> getPendingOrders() {
        ObservableList<Person> persons = FXCollections.observableArrayList();
        for (int i = 0; i < 100; i++) {
            Person person = new Person();
            person.setName("Name" + i);
            person.setAddress("Address" + i);
            person.setCountry("Country" + i);
            person.setCourse("Course" + i);
            persons.add(person);

        }

        return persons;
    }
}

Model :

public class Person {

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }

    public String getCourse() {
        return course;
    }

    public void setCourse(String course) {
        this.course = course;
    }

    private String name;
    private String address;
    private String country;
    private String course;

}

Answer 1

1: add a default cell factory to your TableView

2: override either updateItem or updateIndex

hope it helpls