Facelet selectOneMenu with POJOs and converter problem
- by c0d3x
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.
