Hi,

I want to have a facelet page with a formular and a dropdown menu. With the dropdown menu the user shoul select a POJO of the type Lieferant:

public class Lieferant extends AbstractPersistentWarenwirtschaftsObject {

    private String firma;

    public Lieferant(WarenwirtschaftDatabaseLayer database, String firma) {
        this(database, null, firma);
    }

    public Lieferant(WarenwirtschaftDatabaseLayer database, Long primaryKey, String firma) {
        super(database, primaryKey);
        this.firma = firma;
    }

    public String getFirma() {
        return firma;
    }

    @Override
    public String toString() {
        return getFirma();
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((firma == null) ? 0 : firma.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Lieferant other = (Lieferant) obj;
        if (firma == null) {
            if (other.firma != null)
                return false;
        } else if (!firma.equals(other.firma))
            return false;
        return true;
    }

}

Here is the facelet code that I wrote:

<h:selectOneMenu> 

tag. This tag should display a list of POJOs (not beans) of the type Lieferant. Here is the facelet code:

<h:selectOneMenu id="lieferant" value="#{lieferantenBestellungBackingBean.lieferant}">
 <f:selectItems var="lieferant" value="#{lieferantenBackingBean.lieferanten}" itemLabel="#{lieferant.firma}" itemValue="#{lieferant.primaryKey}" />
 <f:converter converterId="LieferantConverter" />
</h:selectOneMenu>

Here is the refenrenced managed backing bean

@ManagedBean
@RequestScoped
public class LieferantenBackingBean extends AbstractWarenwirtschaftsBackingBean {

    private List<Lieferant> lieferanten;

    public List<Lieferant> getLieferanten() {
        if (lieferanten == null) {
            lieferanten = getApplication().getLieferanten();
        }
        return lieferanten;
    }

}

As far as I know, I need a custom converter, to swap beetween POJO and String representations of the Lieferant objects. Here is what the converter looks like:

@FacesConverter(value="LieferantConverter")
public class LieferantConverter implements Converter {

 @Override
 public Object getAsObject(FacesContext context, UIComponent component, String value) {
  long primaryKey = Long.parseLong(value);
  WarenwirtschaftApplicationLayer application = WarenwirtschaftApplication.getInstance();
  Lieferant lieferant = application.getLieferant(primaryKey);
  return lieferant;
 }

 @Override
 public String getAsString(FacesContext context, UIComponent component, Object value) {
  return value.toString();
 }

}

The page loads without any error. When I fill out the formular and submit it, there is an error message displayed on the page:

Bestellung:lieferantenBestellungForm:lieferant: Validierungsfehler: Wert ist keine gültige Auswahl
translated: validation error: value is not a valid selection

Unfortunaltely it does not say which value it is talking about. The converter seems to work correctly.

I found this similar question from stackoverflow and this article about selectOneMenu and converters, but I was not able to find the problem in my code. Why is

List<SelectItem> 

used in the example from the second link. Gives the same error for me.

Any help would be appreciated. Thanks in advance.