Vaadin: Grid duplicates data

Question

I wrote Grid, as shown in example.

public class MainView extends VerticalLayout {

    private final UserService userService;
    private Label label;
    private Grid<UserDto> grid;

    public MainView(UserService userService) {
        this.userService = userService;
        initComponents(userService);
    }

    private void initComponents(UserService userService) {
        initMainGrid(userService);
    }

    private void initMainGrid(UserService userService) {
        grid = new Grid<>(UserDto.class);

        grid.setItems(userService.getAll());

        grid.addColumn(UserDto::getId).setHeader("ID");
        grid.addColumn(UserDto::getUsername).setHeader("Имя пользователя");
        grid.addColumn(UserDto::getPassword).setHeader("Пароль");
        grid.addColumn(UserDto::getEmail).setHeader("email");
        grid.addColumn(UserDto::getPhone).setHeader("Телефон");
        grid.addColumn(UserDto::getActive).setHeader("Активен");

        add(grid);
    }
}

But data duplicates:

As we see, data shows two times.

Please advice, what wrong? How to fix it?

Answer 1

Passing Class object to Grid constructor

This constructor grid = new Grid<>(UserDto.class); will automatically add columns according to setters and getters of UserDto class.

Not passing Class object to Grid constructor

If you want to configure columns using addColumn method, you need to instantiate Grid using grid = new Grid<>(); without passing UserDto.class.