Primefaces, dataexporter and watermark

问题

i have a dataTable with filtered columns and using watermark to set input value and save some space in header, but when try to use dataExport the pdf file is rendered with some kind of reference from waterMark, like:

Column Title

---

org.primefaces.component.watermark.Watermark@46339a4c
The desired column content (...)

and the structure of my xhtml is basically:

    <h:form id="formID">

    <p:commandButton value="Export"ajax="false">
        <p:dataExporter type="pdf" fileName="file" preProcessor="#{my.stuff}" target="tableID" />
    </p:commandButton>

    <p:dataTable id="tableID" value="#{my.content}" var="myTable">
        <p:column id="columnID1" filterBy="#{myTable.Item}">
            <p:watermark value="Item" forElement="formID:tableID:columnID1" />
            <p:outputText value=#{myTable.Item}" />
        </p:column>
    </p:dataTable>

</h:form>

Thanks in advance and sorry for the bad english.

来源：https://stackoverflow.com/questions/15166012/primefaces-dataexporter-and-watermark