数据导出器在筛选后返回空行

Question

我的xhtml视图中有一个启用了筛选的数据表。此外，关联菜单中还有Primefaces导出（用于Excel）功能。当我使用这个函数而不过滤数据表时，它工作得很好，但当我首先过滤并拒绝导出数据时，我会得到一个空行的文件。

这是我的代码：

<p:panel header="#{msg['prs.list']}">
    <p:contextMenu for="persons">
        <p:menuitem value="#{msg['com.view']}" icon="#{msg['icon.view']}"
                    action="#{personBean.redirectToEditPerson}"/>
        <p:menuitem value="#{msg['student.new']}" icon="#{msg['icon.new']}"
                    action="#{personBean.redirectToNewStudent}"/>
        <p:menuitem value="#{msg['prs.new']}" icon="#{msg['icon.new']}"
                    url="edit.xhtml"/>
        <p:menuitem value="#{msg['report.export.excel']}" ajax="false" icon="#{msg['icon.export']}">
            <p:dataExporter type="xls" target="persons" fileName="export"  />
        </p:menuitem>
    </p:contextMenu>
    <p:dataTable id="persons" var="person" value="#{personBean.personList}"
                 rowKey="#{person.id}" selection="#{personBean.selectedPerson}" selectionMode="single"
                 emptyMessage="#{msg['com.noEntries']}" paginator="true" rows="15">
        <p:column headerText="Id">
            <h:outputText value="#{person.id}"/>
        </p:column>
        <p:column headerText="#{msg['prs.name']}" filterBy="name" filterMatchMode="contains">
            <h:outputText value="#{person.name}"/>
        </p:column>
        <p:column headerText="#{msg['prs.surname']}" filterBy="surname" filterMatchMode="contains">
            <h:outputText value="#{person.surname}"/>
        </p:column>
        <p:column headerText="#{msg['prs.email']}" filterBy="email" filterMatchMode="contains">
            <h:outputText value="#{person.email}"/>
        </p:column>
    </p:dataTable>
    <f:facet name="footer">
        <p:button value="#{msg['prs.new']}" icon="#{msg['icon.new']}"
                  outcome="edit"/>
    </f:facet>
</p:panel>

我在Wildfly 8 上使用Primefaces 4、JSF 2和Java 7

Answer 1

已解决。我在日志中发现了一条关于数据表的filteredValue属性的警告。

[0m[33m17:26:45,701 WARNING [org.primefaces.component.datatable.DataTable] (default task-4) DataTable form:persons has filtering enabled but no filteredValue model reference is defined, for backward compatibility falling back to page viewstate method to keep filteredValue. It is highly suggested to use filtering with a filteredValue model reference as viewstate method is deprecated and will be removed in future.

因此，我添加了这个属性，从而解决了问题

<p:dataTable id="persons" var="person" value="#{personBean.personList}" 
    rowKey="#{person.id}" selection="#{personBean.selectedPerson}" 
    selectionMode="single" emptyMessage="#{msg['com.noEntries']}" 
    paginator="true" rows="15" filteredValue="#{personBean.filtered}">

并在PersonBean以及中添加了以下属性

private List<PersonEntity> filtered;
public List<PersonEntity> getFiltered() { return filtered; }
public void setFiltered(List<PersonEntity> filtered) { this.filtered = filtered; }