jsf - Primefaces PickList 目标在 ajax 传输侦听器上为空

Question

我有以下内容p:pickList：

<p:pickList id="activityUser" value="#{activityEntryController.activityUserDualListModel}" var="model" itemLabel="#{model.fullName}"
    itemValue="#{model}" converter="activityUserListConverter" styleClass="activityUser" required="true" showSourceFilter="true"
    showTargetFilter="true" filterMatchMode="contains">

    <f:facet name="sourceCaption">Available</f:facet>
    <f:facet name="targetCaption">Selected</f:facet>

    <p:column style="width: 400px">
        <h:outputText value="#{model.fullName}" />
    </p:column>

    <p:ajax event="transfer" listener="#{activityEntryController.sortUsersOnTransfer}" update="activityUser" />
</p:pickList>

这value是p:pickList一个扩展的类DualListModel<T>：

public class ActivityUserDualListModel extends DualListModel<ActivityUserDTO> {

    private static final long serialVersionUID = -5369543532197736480L;

    public ActivityUserDualListModel() {
        super();
        initModel();
    }

    public ActivityUserDualListModel(List<ActivityUserDTO> source, List<ActivityUserDTO> target) {
        super(source, target);
        initModel();
    }

    private void initModel() {
        IServiceProvider serviceProvider = (IServiceProvider) ContextLoader.getCurrentWebApplicationContext().getBean(Beans.SERVICE_PROVIDER.getName());
        IUserService userService = serviceProvider.getUserService();

        List<ActivityUserDTO> activityUserDTOs = new ArrayList<ActivityUserDTO>();

        for(User user : userService.getAllUser()) {
            if(user.isActive()) {
                activityUserDTOs.add(constructActivityUserDTO(user));
            }
        }

        Collections.sort(activityUserDTOs, ComparatorUtils.getActivityUserFullNameComparator());

        setSource(activityUserDTOs);
        setTarget(new ArrayList<ActivityUserDTO>());
    }

    private ActivityUserDTO constructActivityUserDTO(User user) {
        ActivityUserDTO activityUserDTO = new ActivityUserDTO();
        activityUserDTO.setId(user.getId());
        activityUserDTO.setUsername(user.getUsername());
        activityUserDTO.setFullName(user.getFullName());

        return activityUserDTO;
    }
}

我是ActivityUserDualListModel从托管 bean的PostConstruct方法中实例化的。ActivityEntryController

在事件发生时触发的listener是：p:ajaxtransfer

public void sortUsersOnTransfer(TransferEvent event) {      
    List<ActivityUserDTO> source = activityUserDualListModel.getSource();
    List<ActivityUserDTO> target = activityUserDualListModel.getTarget();
    System.out.println("=============================================");
    for(ActivityUserDTO dto : source) {
        System.out.println(dto.getFullName());
    }
    System.out.println("=============================================");
    System.out.println("=============================================");
    for(ActivityUserDTO dto : target) {
        System.out.println(dto.getFullName());
    }
    System.out.println("=============================================");

    if(source != null) {
        Collections.sort(source, ComparatorUtils.getActivityUserFullNameComparator());
    }

    if(target != null) {
        Collections.sort(target, ComparatorUtils.getActivityUserFullNameComparator());
    }
}

奇怪的是target上面方法中的列表是空的。我无法找到我所缺少的。任何指针都会对我很有帮助。

编辑：

下面的类是转换器：

@FacesConverter("activityUserListConverter")
public class ActivityUserListConverter implements Converter {

    @Override
    public Object getAsObject(FacesContext context, UIComponent component, String submittedValue) {
        if (!(component instanceof PickList)) {
            return null;
        }

        if (StringUtils.isBlank(submittedValue)) {
            return null;
        }

        @SuppressWarnings("unchecked")
        DualListModel<ActivityUserDTO> pickListModel = (DualListModel<ActivityUserDTO>) ((PickList) component).getValue();
        ActivityUserDTO ret = null;

        for (ActivityUserDTO activityUserDTO : pickListModel.getSource()) {
            if (activityUserDTO.getId().equals(Long.parseLong(submittedValue))) {
                ret = activityUserDTO;
                break;
            }
        }

        if (ret == null) {
            for (ActivityUserDTO activityUserDTO : pickListModel.getTarget()) {
                if (activityUserDTO.getId().equals(Long.parseLong(submittedValue))) {
                    ret = activityUserDTO;
                    break;
                }
            }
        }

        return ret;
    }

    @Override
    public String getAsString(FacesContext context, UIComponent component, Object value) {
        if (value == null || value.equals("")) {
            return "";
        }

        if (value instanceof ActivityUserDTO) {
            return String.valueOf(((ActivityUserDTO) value).getId());
        }

        return "";
    }
}

我也有以下p:commandButton提交表格。现在actionListener没有触发，但是如果我删除p:pickList了 xhtml 的表单，它就会触发。