Scrollabledatatable not show scrollbar with CachedrowSetDataModel

[jgarcia2020]

I want to know why to link a scrollabledatatable with a cachedrowsetdatamodel not appear scrollbars

Example:

In jsp:

  <rich:scrollableDataTable   id="sampleData2" width="200px" height="300px"
                              value="#{PruebaDataTable.dataTable1Model}" var="currentRow"
                             frozenColCount="1" first="0" rows="5">
                                    <rich:column>
                                        <f:facet name="header"><h:outputText value="ID" /></f:facet>
                                        <h:outputText value="#{currentRow.idservidores}" />
                                    </rich:column>
                                    <rich:column >
                                        <f:facet name="header"><h:outputText value="Nombre" /></f:facet>
                                        <h:outputText value="#{currentRow.nombre}" />
                                    </rich:column>
                                    <rich:column>
                                        <f:facet name="header"><h:outputText value="Descripcion" /></f:facet>
                                        <h:outputText value="#{currentRow.descripcion}"/>
                                    </rich:column>
                                </rich:scrollableDataTable>

In .java:

private void _init() throws Exception {
             dataTable1Model.setCachedRowSet((javax.sql.rowset.CachedRowSet) getValue("#{SessionBean1.servidoresRowSet}"));
         }

private CachedRowSetDataModel dataTable1Model = new CachedRowSetDataModel();

    public CachedRowSetDataModel getDataTable1Model() {
        return dataTable1Model;
    }

    public void setDataTable1Model(CachedRowSetDataModel crsdm) {
        this.dataTable1Model = crsdm;
    }

In SessionBean1.java:

  private void _init() throws Exception {

        servidoresRowSet.setDataSourceName("java:comp/env/jdbc/info_sistemas_MySQL");
        servidoresRowSet.setCommand("SELECT idservidores,nombre,descripcion FROM servidores");
        servidoresRowSet.setTableName("servidores");
    }
    // </editor-fold>

     private CachedRowSetXImpl servidoresRowSet = new CachedRowSetXImpl();

    public CachedRowSetXImpl getServidoresRowSet() {
        return servidoresRowSet;
    }

    public void setServidoresRowSet(CachedRowSetXImpl crsxi) {
        this.servidoresRowSet = crsxi;
    }

[konstantin.mishin]

Because method getRowCount() of CachedRowSetDataModel always returns -1.

http://download.oracle.com/docs/cd/E17824_01/dsc_docs/docs/jscreator/apis/jsfcl/com/sun/jsfcl/data/CachedRowSetDataModel.html.