ListDataProvider refreshAll() does not update the grid

Vaadin 6 / 7 / 8 Framework Data Binding
1

I could not figure out how to refresh the ListDataProvider from the backend when the underlying data in the database is changed (i.e. after deleting a row with repository.delete() the entry is deleted from the mysql db, or changing a row manually through mysql console) dataprovider.refreshAll() method does not update the grid.

What I am missing?

If I set the grid dataprovider to lazy load from the callbacks, there is no refresh problem, however the grid does not seem to correctly list all entries this time


UI;

    ....
    ListDataProvider<Account> ldp = DataProvider.ofCollection(service.findAll());
    grid.setDataProvider(ldp);
    ...
    // editing an entry works fine
    grid.getEditor().setEnabled(true).addSaveListener(e -> {
        Account bean = e.getBean();
        service.save(bean);
    });
    grid.getEditor().setBuffered(true);
    ...
    // refresh after deleting, or changing the entry in the DB directly does not update the grid
    getBtn_refresh().addClickListener( event -> ldp.refreshAll() );


Service;

@Stateless
// The service needs to be marked as LocalBean if it implements an interface otherwise we get the error
// WELD-001408: Unsatisfied dependencies for type with qualifiers @Default when implementing interface
// when the application is deployed
@LocalBean
public class AccountService implements AbstractService<Account> {
    @Inject AccountRepository repo;
    public AccountService() {};

    public Account save(Account entity) {
        return repo.save(entity);
    }

    public void delete(Account entity) {
        repo.delete(entity);
    }
 
    public int count() {
        return Math.toIntExact(repo.count());
    }

    public List<Account> findAll() {
        return repo.findAll();
    }

    public List<Account> findAllPaged(int offset, int limit) {
        int page = offset / limit;
        PageRequest pageRequest = new PageRequest(page, limit);
        return repo.findAll(pageRequest).getContent();
    }

    public List<Account> findAllPaged(int offset, int limit, Map<String, Boolean> sortOrders) {
        int page = offset / limit;
        List<Sort.Order> orders = sortOrders.entrySet().stream()
            .map(e -> new Sort.Order(e.getValue() ? Sort.Direction.ASC : Sort.Direction.DESC, e.getKey()))
            .collect(Collectors.toList());
        PageRequest pageRequest = new PageRequest(page, limit, orders.isEmpty() ? null : new Sort(orders));
        return repo.findAll(pageRequest).getContent();
    }

    public Account refreshEntry(Account entry) {
        return repo.findOne(entry.getId());
    }
}


Repository (Spring Data);

@Eager
public interface AccountRepository extends JpaRepository<Account, Long> {
}
2

Do you have a working equals() implementation on the entities?
This was causing me problems.

3

I have the following AbstractEntity class which all other entity classes extend from. Hence I believe equals() should not be the problem.

@MappedSuperclass
public abstract class AbstractEntity implements Serializable, Cloneable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(unique=true, nullable=false)
    private Long id;

    public Long getId() {
        return id;
    }

    protected void setId(Long id) {
        this.id = id;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }

        if(this.id == null) {
            return false;
        }

        if (obj instanceof AbstractEntity && obj.getClass().equals(getClass())) {
            return this.id.equals(((AbstractEntity) obj).id);
        }

        return false;
    }

    @Override
    public int hashCode() {
        int hash = 5;
        hash = 43 * hash + Objects.hashCode(this.id);
        return hash;
    }
}
4

equals() probably is the problem here. If you persist your entity to the database, your entity id stays the same, but you get a new object in return. Your equals method returns true for those two different objects, and so the grid doesn’t get updated.

Try debugging the equals method when dataprovider.refreshAll() is called.

5

Hi innodron,

To me the example looks like you’re using a snapshot of data (
service.findAll()
) and store it in memory behind a
ListDataProvider
. Since you have a service that you use to access the backend data, I’d recommend looking at
DataProvider.fromCallback
 . This method is used to create a
DataProvider
 that will access your fetch and size methods when needed and the data will be more up to date. Also the
refreshAll
 method will be quaranteed re-fetch from the backend. If you still want to keep on using data snapshots in memory, you can do
grid.setItems(service.findAll())
 to repopulate the
Grid
 with the most recent snapshot.

//Teemu