The Seam component is provided by the package jboss-seam-excel itself, I've not developped it (this component is named excelReporter).

The servlet response is made by this component. Please see below its implementation:

Regards,

package org.jboss.seam.excel.exporter;

import java.io.IOException;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import javax.faces.component.UIComponent;

import javax.faces.component.UIData;

import javax.faces.component.UIOutput;

import javax.faces.context.FacesContext;

import org.jboss.seam.ScopeType;

import org.jboss.seam.annotations.Install;

import org.jboss.seam.annotations.Name;

import org.jboss.seam.annotations.Scope;

import org.jboss.seam.annotations.intercept.BypassInterceptors;

import org.jboss.seam.core.Interpolator;

import org.jboss.seam.core.Manager;

import org.jboss.seam.document.ByteArrayDocumentData;

import org.jboss.seam.document.DocumentData;

import org.jboss.seam.document.DocumentStore;

import org.jboss.seam.excel.ExcelFactory;

import org.jboss.seam.excel.ExcelWorkbook;

import org.jboss.seam.excel.ExcelWorkbookException;

import org.jboss.seam.excel.css.CSSNames;

import org.jboss.seam.excel.css.ColumnStyle;

import org.jboss.seam.excel.css.Parser;

import org.jboss.seam.excel.css.StyleMap;

import org.jboss.seam.excel.ui.ExcelComponent;

import org.jboss.seam.excel.ui.UICell;

import org.jboss.seam.excel.ui.UIColumn;

import org.jboss.seam.excel.ui.UIWorkbook;

import org.jboss.seam.excel.ui.UIWorksheet;

import org.jboss.seam.navigation.Pages;

/**

* Excel export class that exports a UIData component to an Excel workbook

*

* @author Nicklas Karlsson (nickarls@gmail.com)

* @author Daniel Roth (danielc.roth@gmail.com)

*

*/

@Name("org.jboss.seam.excel.exporter.excelExporter")

@Scope(ScopeType.EVENT)

@Install(precedence = Install.BUILT_IN)

@BypassInterceptors

public class ExcelExporter

{

   // The excel workbook implementation

   private ExcelWorkbook excelWorkbook = null;

   // A map of known column widths

   private Map<Integer, Integer> columnWidths = new HashMap<Integer, Integer>();

   /**

    * Helper method to call the exporter and use the default excel workbook

    * implementation

    *

    * @param dataTableId

    */

   public void export(String dataTableId)

   {

      export(dataTableId, "");

   }

   /**

    * Exports the UIData object to Excel workbook. Looks up the component, parse

    * the templates, iterates the columns and the UIOutput elements within

    *

    * @param dataTableId id of data table to export

    * @param type ExcelWorkbook implementation to use

    */

   @SuppressWarnings("unchecked")

   public void export(String dataTableId, String type)

   {

      excelWorkbook = ExcelFactory.instance().getExcelWorkbook(type);

      Parser parser = new Parser();

      // Gets the datatable

      UIData dataTable = (UIData) FacesContext.getCurrentInstance().getViewRoot().findComponent(dataTableId);

      if (dataTable == null)

      {

         throw new ExcelWorkbookException(Interpolator.instance().interpolate("Could not find data table with id #0", dataTableId));

      }

      // Inits the workbook and worksheet

      UIWorkbook uiWorkbook = new UIWorkbook();

      excelWorkbook.createWorkbook(uiWorkbook);

      UIWorksheet uiWorksheet = new UIWorksheet();

      uiWorkbook.getChildren().add(uiWorksheet);

      uiWorksheet.setStyle(Parser.getStyle(dataTable));

      uiWorksheet.setStyleClass(Parser.getStyleClass(dataTable));

      excelWorkbook.createOrSelectWorksheet(uiWorksheet);

      // Saves the datatable var

      String dataTableVar = dataTable.getVar();

      Object oldValue = FacesContext.getCurrentInstance().getExternalContext().getRequestMap().get(dataTableVar);

      // Processes the columns

      List<javax.faces.component.UIColumn> columns = ExcelComponent.getChildrenOfType(dataTable.getChildren(), javax.faces.component.UIColumn.class);

      columnWidths = parseColumnWidths(uiWorksheet);

      int col = 0;

      for (javax.faces.component.UIColumn column : columns)

      {

         ColumnStyle columnStyle = new ColumnStyle(parser.getCascadedStyleMap(column));

         boolean cssExport = columnStyle.export == null || columnStyle.export;

         if (column.isRendered() && cssExport)

         {

            uiWorksheet.getChildren().add(column);

            Iterator iterator = UIWorksheet.unwrapIterator(dataTable.getValue());

            processColumn(column, iterator, dataTableVar, col++);

            excelWorkbook.nextColumn();

         }

      }

      // Restores the data table var

      if (oldValue == null)

      {

         FacesContext.getCurrentInstance().getExternalContext().getRequestMap().remove(dataTableVar);

      }

      else

      {

         FacesContext.getCurrentInstance().getExternalContext().getRequestMap().put(dataTableVar, oldValue);

      }

      // Redirects to the generated document

      redirectExport();

   }

   /**

    * Parses column widths from a worksheet tag

    *

    * @param worksheet The worksheet to get the style from

    * @return The map of column number -> column width

    */

   private Map<Integer, Integer> parseColumnWidths(UIWorksheet worksheet)

   {

      Map<Integer, Integer> columnWidths = new HashMap<Integer, Integer>();

      Parser parser = new Parser();

      StyleMap styleMap = parser.getCascadedStyleMap(worksheet);

      for (Map.Entry<String, Object> entry : styleMap.entrySet())

      {

         String key = entry.getKey();

         if (key.startsWith(CSSNames.COLUMN_WIDTHS))

         {

            String columnIndexString = key.substring(CSSNames.COLUMN_WIDTHS.length());

            int columnIndex = Integer.parseInt(columnIndexString);

            columnWidths.put(columnIndex, (Integer) entry.getValue());

         }

      }

      return columnWidths;

   }

   /**

    * Puts document in store and redirects

    */

   private void redirectExport()

   {

      String viewId = Pages.getViewId(FacesContext.getCurrentInstance());

      String baseName = Pages.getCurrentBaseName();

      DocumentData documentData = new ByteArrayDocumentData(baseName, excelWorkbook.getDocumentType(), excelWorkbook.getBytes());

      String id = DocumentStore.instance().newId();

      String url = DocumentStore.instance().preferredUrlForContent(baseName, excelWorkbook.getDocumentType().getExtension(), id);

      url = Manager.instance().encodeConversationId(url, viewId);

      DocumentStore.instance().saveData(id, documentData);

      try

      {

         FacesContext.getCurrentInstance().getExternalContext().redirect(url);

      }

      catch (IOException e)

      {

         throw new ExcelWorkbookException(Interpolator.instance().interpolate("Could not redirect to #0", url), e);

      }

   }

   /**

    * Processes a datatable column

    *

    * @param column The column to parse

    * @param iterator The iterator to the data

    * @param var The binding var

    * @param col

    */

   @SuppressWarnings("unchecked")

   private void processColumn(javax.faces.component.UIColumn column, Iterator iterator, String var, int columnIndex)

   {

      // Process header facet

      UIComponent headerFacet = column.getFacet(UIColumn.HEADER_FACET_NAME);

      if (headerFacet != null && UIOutput.class.isAssignableFrom(headerFacet.getClass()))

      {

         List<UIOutput> headerOutputs = new ArrayList<UIOutput>();

         headerOutputs.add((UIOutput) headerFacet);

         processOutputs(column, headerOutputs);

      }

      // Process data

      while (iterator.hasNext())

      {

         FacesContext.getCurrentInstance().getExternalContext().getRequestMap().put(var, iterator.next());

         List<UIOutput> dataOutputs = ExcelComponent.getChildrenOfType(column.getChildren(), UIOutput.class);

         processOutputs(column, dataOutputs);

      }

      Integer columnWidth = columnWidths.get(columnIndex);

      if (columnWidth != null)

      {

         UIColumn uiColumn = new UIColumn();

         uiColumn.setStyle(CSSNames.COLUMN_WIDTH + ":" + columnWidth);

         excelWorkbook.applyColumnSettings(uiColumn);

      }

   }

   /**

    * Processes all output type elements (in column)

    *

    * @param outputs The list of outputs to process

    * @param preTemplates The pre-pushed templates

    */

   private void processOutputs(javax.faces.component.UIColumn column, List<UIOutput> outputs)

   {

      for (UIOutput output : outputs)

      {

         if (!output.isRendered())

         {

            continue;

         }

         UICell cell = new UICell();

         column.getChildren().add(cell);

         cell.setId(output.getId());

         cell.setValue(output.getValue());

         cell.setStyle(Parser.getStyle(output));

         cell.setStyleClass(Parser.getStyleClass(output));

         excelWorkbook.addItem(cell);

      }

   }

}

Hello,

No there is no exception raised in the console.

In attachment, a simple (very) test case. A table with just headers.

When accesing the application outside of portlet, an excel file can be downloaded (http://localhost:8080/TestExcel/test.seam).

The portlet is available under demo 'tab'.

Thanks and regards,

Sorry, I missed the jxl-2.6 lib in the war.

Can you please try again with the version below in attachment. I've tested against a fresh jboss portal installation.

Regards,