PrimeFaces PickList

Question

我使用的是PickList，它包含我的bean列表CountryCountry -> Region -> Company.The，当我将picklist.getTarget()值转换到Country时，它会抛出类强制转换异常。我也在用乡村转换器。我不知道有什么问题吗？

这是我的密码，

XHTML：

<p:pickList id="pickListId" required="true"
    value="#{countryBean.countryDualModel}" var="avlCountry"
    itemValue="#{avlCountry}"
    itemLabel="#{avlCountry.region.company.companyName}"
    converter="#{countryDualListConverter}" showCheckbox="true"
    showSourceFilter="true" showTargetFilter="true"
    filterMatchMode="contains">
    <p:ajax event="transfer" listener="#{countryBean.transferEvent}"></p:ajax>
    <p:column style="width:75%;">#{avlCountry.region.company.companyName}</p:column>
</p:pickList>

转换器：

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

    @Override
    public Object getAsObject(FacesContext arg0, UIComponent arg1, String arg2) {
        Object ret = null;
        if (arg1 instanceof PickList) {
            Object dualList = ((PickList) arg1).getValue();
            @SuppressWarnings("unchecked")
            DualListModel<Country> dl = (DualListModel<Country>) dualList;
            for (Object o : dl.getSource()) {
                String id = "" + ((Country) o).getRegion().getCompanyId();
                if (arg2.equals(id)) {
                    ret = o;
                    break;
                }
            }
            for(Object o : dl.getTarget()){
                String id = "" + ((Country) o).getRegion().getCompanyId();
                if(arg2.equals(id)){
                    ret = o;
                    break;
                }
            }
            if (ret == null)
                for (Object o : dl.getTarget()) {
                    String id = "" + ((Country) o).getRegion().getCompanyId();
                    if (arg2.equals(id)) {
                        ret = o;
                        break;
                    }
                }
        }
        return ret;
    }

    @Override
    public String getAsString(FacesContext arg0, UIComponent arg1, Object arg2) {
        String str = "";
        if (arg2 instanceof Country) {
            str = "" + ((Country) arg2)..getRegion().getCompanyId();
        }
        return str;
    }

CountryBean：

Popuate DualListModel：

DualListModel countryDualModel =新DualListModel<>(sourceCountryList，targetCountryList)；

OnTransfer侦听器：

public void transferEvent(TransferEvent event){
    int size = countryDualModel .getTarget().size();
    for(Country ctry : (Country) countryDualModel .getTarget()){
        //
    }
}

//当它出现时，它抛出类强制转换异常: java.lang.ClassCastException: java.lang.String不能转换为com.test.Country

Answer 1

缺少转换器名converter="#{countryDualListConverter}"？

改为converter="#{bizEntityDualListConverter}"。

您也可以使用欧米诺的ListIndexConverter。这是一个不错的JSF Utility。