Question

I’ve created a picklist via PrimeFaces. Now i want to handle the selected items which are listed in the target list when i click the commandButton.

I want to pass the data through the controller and store them in my database. But everytime i call the function duallist.getTarget() it’s empty.

I’ve crated a foreach-Loop where i want to select all items in the target list:

Controller (Bean):

private List<DTOAktivitaet> source = new ArrayList<DTOAktivitaet>();
private List<DTOAktivitaet> target = new ArrayList<DTOAktivitaet>();

private List<DTOAktivitaet> zwischen = new ArrayList<DTOAktivitaet>();

public void speicherAktiZug() {

    DTOAktivitaet aktivitaet_vorgaenger = null;

    for (DTOAktivitaet item : controller.getAktivitaeten()) {
        if (item.toString().equals(selected)) {
            aktivitaet_vorgaenger = item;
        }
    }

    for (DTOAktivitaet aktivitaet : zwischen) {
        try {
            dao.aktiZugAkt(aktivitaet_vorgaenger, aktivitaet);
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}

public AktiListController() {
    for (DTOAktivitaet ak : controller.getAktivitaeten()) {
        source.add(ak);
    }
    aktis = new DualListModel<DTOAktivitaet>(source, target);
    zwischen = aktis.getTarget();
}

JSF:

        <h:form id="form" name="formular">
                <h:outputText id="aktivitaet"
                                value="#{aktiListController.selected}" />


                <p:pickList id="pickList" value="#{aktiListController.aktis}"
                    var="aktivitaet" itemValue="#{aktivitaet}"
                    itemLabel="#{aktivitaet}" converter="aktivitaetsConverter"
                    showSourceControls="true" showTargetControls="true" />
                <h:commandButton
                    action="#{aktiListController.speicherAktiZug}"
                    value="Aktivität-Abhängigkeit anlegen" class="commandButton">
                </h:commandButton>
            </h:form>

Converter:

@EJB
public class AktiListConverter implements Converter {

private InitialisierungController controller = InitialisierungController
        .getInstance();
DTOAktivitaet aktivitaet = new DTOAktivitaet();
String name = "";

@Override
public Object getAsObject(FacesContext arg0, UIComponent arg1, String arg2) {

    for (DTOAktivitaet item : controller.getAktivitaeten()) {
        if (item.toString().equalsIgnoreCase(arg2)) {
            this.aktivitaet = item;
            System.out.println(aktivitaet);
            return aktivitaet;
        }

    }

    return null;

}

@Override
public String getAsString(FacesContext arg0, UIComponent arg1, Object arg2) {

    this.aktivitaet = (DTOAktivitaet) arg2;

    return this.name = aktivitaet.getTeambezeichnung();

}
}

My Problem: The target-List is empty before i want to store the items in my database.

Answer 1

I don’t fully understand your code as it is not written in English but as far as I can see your Converter is written badly. As far as I can see you do a toString() and a fromString() basically. This is quite error prone and the way you did it, heavy in performance. It is a better idea to use unique ID’s (business or database).

Example:

@FacesConverter(value = "aktiListConverter")
public class AktiListConverter implements Converter
{
    private InitialisierungController controller = InitialisierungController.getInstance();

    @Override
    public Object getAsObject(FacesContext arg0, UIComponent arg1, String arg2)
    {
        //Get object by it's unique ID
        return controller.getById(Long.parseLong(arg2));
    }

    @Override
    public String getAsString(FacesContext arg0, UIComponent arg1, Object arg2)
    {
        //Return object's unique ID
        return ((DTOAktivitaet) arg2).getId();
    }
}

In stead of using the object as itemLabel (which performs a toString()) use something that generates a nice label like getName() for a person.

itemLabel="#{aktivitaet.nameOrSomething}"

The speicherAktiZug() method doesn’t really make sense to me so I came this far:

public class AktiListController
{
    private List<DTOAktivitaet> source;
    private List<DTOAktivitaet> target = new ArrayList<DTOAktivitaet>();
    private DualListModel<DTOAktivitaet> aktis;

    public AktiListController()
    {
        source = controller.getAktivitaeten();
        aktis = new DualListModel<DTOAktivitaet>(source, target);
    }

    //Getters and setters

    public void speicherAktiZug()
    {
        target = aktis.getTarget();

        //target should contain the picked items here.
    }
}

I see you are also using aktiListController.selected but I cannot see what it’s used for.