gt:     final ExportWorkbook xls = new ExportWorkbook();
context: /////////////////////////////////////////////////////////////////////////////
  //
  // Project ProjectForge Community Edition
  //         www.projectforge.org
  //
  // Copyright (C) 2001-2014 Kai Reinhard (k.reinhard@micromata.de)
  //
  // ProjectForge is dual-licensed.
  //
  // This community edition is free software; you can redistribute it and/or
  // modify it under the terms of the GNU General Public License as published
  // by the Free Software Foundation; version 3 of the License.
  //
  // This community edition is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  // Public License for more details.
  //
  // You should have received a copy of the GNU General Public License along
  // with this program; if not, see http://www.gnu.org/licenses/.
  //
  /////////////////////////////////////////////////////////////////////////////
  
  package org.projectforge.fibu;
  
  import java.math.BigDecimal;
  import java.util.List;
  import java.util.Set;
  
  import org.apache.commons.collections.CollectionUtils;
  import org.projectforge.access.AccessChecker;
  import org.projectforge.common.DateFormatType;
  import org.projectforge.common.DateFormats;
  import org.projectforge.common.NumberHelper;
  import org.projectforge.excel.ContentProvider;
  import org.projectforge.excel.ExportColumn;
  import org.projectforge.excel.ExportSheet;
  import org.projectforge.excel.ExportWorkbook;
  import org.projectforge.excel.I18nExportColumn;
  import org.projectforge.excel.PropertyMapping;
  import org.projectforge.export.MyXlsContentProvider;
  import org.projectforge.registry.Registry;
  import org.projectforge.task.TaskNode;
  import org.projectforge.task.TaskTree;
  import org.projectforge.user.PFUserContext;
  import org.projectforge.user.PFUserDO;
  
  /**
   * For excel export.
   * 
   * @author Kai Reinhard (k.reinhard@micromata.de)
   */
  public class OrderExport
  {
    private class MyContentProvider extends MyXlsContentProvider
    {
      public MyContentProvider(final ExportWorkbook workbook)
      {
        super(workbook);
      }
  
      @Override
      public org.projectforge.excel.ContentProvider newInstance()
      {
        return new MyContentProvider(this.workbook);
      }
    };
  
    private static final org.apache.log4j.Logger log = org.apache.log4j.Logger.getLogger(OrderExport.class);
  
    protected AccessChecker accessChecker;
  
    private AuftragDao auftragDao;
  
    private RechnungCache rechnungCache;
  
    private TaskTree taskTree;
  
    private enum OrderCol
    {
      NUMMER, NUMBER_OF_POSITIONS, DATE, ORDER_DATE, STATUS, PROJECT, PROJECT_CUSTOMER, TITLE, NETSUM, INVOICED, TO_BE_INVOICED, COMPLETELY_INVOICED, INVOICES, CONTACT_PERSON, REFERENCE, COMMENT;
    }
  
    private enum PosCol
    {
      NUMBER, POS_NUMBER, DATE, PROJECT, ORDER_TITLE, TITLE, TYPE, STATUS, PERSON_DAYS, NETSUM, INVOICED, TO_BE_INVOICED, COMPLETELY_INVOICED, INVOICES, PERIOD_OF_PERFORMANCE_BEGIN, PERIOD_OF_PERFORMANCE_END, TASK, COMMENT;
    }
  
    private ExportColumn[] createOrderColumns()
    {
      return new ExportColumn[] { //
          new I18nExportColumn(OrderCol.NUMMER, "fibu.auftrag.nummer.short", MyXlsContentProvider.LENGTH_ID),
          new I18nExportColumn(OrderCol.NUMBER_OF_POSITIONS, "fibu.auftrag.positions", MyXlsContentProvider.LENGTH_ID),
          new I18nExportColumn(OrderCol.DATE, "fibu.auftrag.datum", MyXlsContentProvider.LENGTH_DATE),
          new I18nExportColumn(OrderCol.ORDER_DATE, "fibu.auftrag.beauftragungsdatum", MyXlsContentProvider.LENGTH_DATE),
          new I18nExportColumn(OrderCol.STATUS, "status", 10),
          new I18nExportColumn(OrderCol.PROJECT, "fibu.projekt", MyXlsContentProvider.LENGTH_STD),
          new I18nExportColumn(OrderCol.PROJECT_CUSTOMER, "fibu.kunde", MyXlsContentProvider.LENGTH_STD),
          new I18nExportColumn(OrderCol.TITLE, "fibu.auftrag.titel", MyXlsContentProvider.LENGTH_STD),
          new I18nExportColumn(OrderCol.NETSUM, "fibu.auftrag.nettoSumme", MyXlsContentProvider.LENGTH_CURRENCY), //
          new I18nExportColumn(OrderCol.INVOICED, "fibu.fakturiert", MyXlsContentProvider.LENGTH_CURRENCY), //
          new I18nExportColumn(OrderCol.TO_BE_INVOICED, "fibu.tobeinvoiced", MyXlsContentProvider.LENGTH_CURRENCY),
          new I18nExportColumn(OrderCol.COMPLETELY_INVOICED, "fibu.auftrag.vollstaendigFakturiert", MyXlsContentProvider.LENGTH_BOOLEAN),
          new I18nExportColumn(OrderCol.INVOICES, "fibu.rechnungen", MyXlsContentProvider.LENGTH_STD),
          new I18nExportColumn(OrderCol.CONTACT_PERSON, "contactPerson", MyXlsContentProvider.LENGTH_STD),
          new I18nExportColumn(OrderCol.REFERENCE, "fibu.common.reference", MyXlsContentProvider.LENGTH_STD),
          new I18nExportColumn(OrderCol.COMMENT, "comment", MyXlsContentProvider.LENGTH_COMMENT)};
    }
  
    private void addOrderMapping(final PropertyMapping mapping, final AuftragDO order, final Object... params)
    {
      auftragDao.calculateInvoicedSum(order);
      mapping.add(OrderCol.NUMMER, order.getNummer());
      mapping.add(OrderCol.NUMBER_OF_POSITIONS, "#" + (order.getPositionen() != null ? order.getPositionen().size() : "0"));
      mapping.add(OrderCol.DATE, order.getAngebotsDatum());
      mapping.add(OrderCol.ORDER_DATE, order.getBeauftragungsDatum());
      mapping.add(OrderCol.STATUS,
          order.getAuftragsStatus() != null ? PFUserContext.getLocalizedString(order.getAuftragsStatus().getI18nKey()) : "");
      mapping.add(OrderCol.PROJECT, order.getProjektAsString());
      final ProjektDO project = order.getProjekt();
      final String projectCustomer = KundeFormatter.formatKundeAsString(project != null ? project.getKunde() : null, order.getKundeText());
      mapping.add(OrderCol.PROJECT_CUSTOMER, projectCustomer);
      mapping.add(OrderCol.TITLE, order.getTitel());
      final BigDecimal netSum = order.getNettoSumme() != null ? order.getNettoSumme() : BigDecimal.ZERO;
      final BigDecimal invoicedSum = order.getFakturiertSum() != null ? order.getFakturiertSum() : BigDecimal.ZERO;
      final BigDecimal toBeInvoicedSum = netSum.subtract(invoicedSum);
      mapping.add(OrderCol.NETSUM, netSum);
      addCurrency(mapping, OrderCol.INVOICED, invoicedSum);
      addCurrency(mapping, OrderCol.TO_BE_INVOICED, toBeInvoicedSum);
      mapping.add(OrderCol.COMPLETELY_INVOICED, order.isVollstaendigFakturiert() == true ? "x" : "");
      final Set<RechnungsPositionVO> invoicePositions = rechnungCache.getRechnungsPositionVOSetByAuftragId(order.getId());
      mapping.add(OrderCol.INVOICES, getInvoices(invoicePositions));
      final PFUserDO contactPerson = Registry.instance().getUserGroupCache().getUser(order.getContactPersonId());
      mapping.add(OrderCol.CONTACT_PERSON, contactPerson != null ? contactPerson.getFullname() : "");
      mapping.add(OrderCol.REFERENCE, order.getReferenz());
      mapping.add(OrderCol.COMMENT, order.getBemerkung());
    }
  
    private ExportColumn[] createPosColumns()
    {
      return new ExportColumn[] { //
          new I18nExportColumn(PosCol.NUMBER, "fibu.auftrag.nummer.short", MyXlsContentProvider.LENGTH_ID),
          new I18nExportColumn(PosCol.POS_NUMBER, "fibu.auftrag.position", 5),
          new I18nExportColumn(PosCol.DATE, "fibu.auftrag.datum", MyXlsContentProvider.LENGTH_DATE),
          new I18nExportColumn(PosCol.PROJECT, "fibu.projekt", MyXlsContentProvider.LENGTH_STD),
          new I18nExportColumn(PosCol.ORDER_TITLE, "fibu.auftrag.titel", MyXlsContentProvider.LENGTH_STD),
          new I18nExportColumn(PosCol.TITLE, "fibu.auftrag.titel", MyXlsContentProvider.LENGTH_STD),
          new I18nExportColumn(PosCol.TYPE, "fibu.auftrag.position.art", 10),
          new I18nExportColumn(PosCol.STATUS, "status", 10),
          new I18nExportColumn(PosCol.PERSON_DAYS, "projectmanagement.personDays.short", 8),
          new I18nExportColumn(PosCol.NETSUM, "fibu.auftrag.nettoSumme", MyXlsContentProvider.LENGTH_CURRENCY), //
          new I18nExportColumn(PosCol.INVOICED, "fibu.fakturiert", MyXlsContentProvider.LENGTH_CURRENCY), //
          new I18nExportColumn(PosCol.TO_BE_INVOICED, "fibu.tobeinvoiced", MyXlsContentProvider.LENGTH_CURRENCY),
          new I18nExportColumn(PosCol.COMPLETELY_INVOICED, "fibu.auftrag.vollstaendigFakturiert", MyXlsContentProvider.LENGTH_BOOLEAN),
          new I18nExportColumn(PosCol.INVOICES, "fibu.rechnungen", MyXlsContentProvider.LENGTH_STD),
          new I18nExportColumn(PosCol.PERIOD_OF_PERFORMANCE_BEGIN, null, MyXlsContentProvider.LENGTH_DATE),
          new I18nExportColumn(PosCol.PERIOD_OF_PERFORMANCE_END, null, MyXlsContentProvider.LENGTH_DATE),
          new I18nExportColumn(PosCol.TASK, "task", MyXlsContentProvider.LENGTH_STD),
          new I18nExportColumn(PosCol.COMMENT, "comment", MyXlsContentProvider.LENGTH_COMMENT)};
    }
  
    private void addPosMapping(final PropertyMapping mapping, final AuftragDO order, final AuftragsPositionDO pos, final Object... params)
    {
      mapping.add(PosCol.NUMBER, order.getNummer());
      mapping.add(PosCol.POS_NUMBER, "#" + pos.getNumber());
      mapping.add(PosCol.DATE, order.getAngebotsDatum());
      mapping.add(PosCol.PROJECT, order.getProjektAsString());
      mapping.add(PosCol.ORDER_TITLE, order.getTitel());
      mapping.add(PosCol.TITLE, pos.getTitel());
      mapping.add(PosCol.TYPE, pos.getArt() != null ? PFUserContext.getLocalizedString(pos.getArt().getI18nKey()) : "");
      mapping.add(PosCol.STATUS, pos.getStatus() != null ? PFUserContext.getLocalizedString(pos.getStatus().getI18nKey()) : "");
      mapping.add(PosCol.PERSON_DAYS, pos.getPersonDays());
      final BigDecimal netSum = pos.getNettoSumme() != null ? pos.getNettoSumme() : BigDecimal.ZERO;
      final BigDecimal invoicedSum = pos.getFakturiertSum() != null ? pos.getFakturiertSum() : BigDecimal.ZERO;
      final BigDecimal toBeInvoicedSum = netSum.subtract(invoicedSum);
      mapping.add(PosCol.NETSUM, netSum);
      addCurrency(mapping, PosCol.INVOICED, invoicedSum);
      addCurrency(mapping, PosCol.TO_BE_INVOICED, toBeInvoicedSum);
      mapping.add(PosCol.COMPLETELY_INVOICED, pos.isVollstaendigFakturiert() == true ? "x" : "");
      final Set<RechnungsPositionVO> invoicePositions = rechnungCache.getRechnungsPositionVOSetByAuftragsPositionId(pos.getId());
      mapping.add(PosCol.INVOICES, getInvoices(invoicePositions));
      mapping.add(PosCol.PERIOD_OF_PERFORMANCE_BEGIN, pos.getPeriodOfPerformanceBegin());
      mapping.add(PosCol.PERIOD_OF_PERFORMANCE_END, pos.getPeriodOfPerformanceEnd());
      final TaskNode node = taskTree.getTaskNodeById(pos.getTaskId());
      mapping.add(PosCol.TASK, node != null ? node.getTask().getTitle() : "");
      mapping.add(PosCol.COMMENT, pos.getBemerkung());
    }
  
    private String getInvoices(final Set<RechnungsPositionVO> invoicePositions)
    {
      final StringBuilder sb = new StringBuilder();
      if (invoicePositions != null) {
        String delimiter = "";
        for (final RechnungsPositionVO invoicePos : invoicePositions) {
          sb.append(delimiter).append(invoicePos.getRechnungNummer());
          delimiter = ", ";
        }
      }
      return sb.toString();
    }
  
    private void addCurrency(final PropertyMapping mapping, final Enum< ? > col, final BigDecimal value)
    {
      if (NumberHelper.isNotZero(value) == true) {
        mapping.add(col, value);
      } else {
        mapping.add(col, "");
      }
    }
  
    /**
     * Exports the filtered list as table with almost all fields. For members of group FINANCE_GROUP (PF_Finance) and MARKETING_GROUP
     * (PF_Marketing) all addresses are exported, for others only those which are marked as personal favorites.
     * @param list by sub classes such as AddressCampaignValueExport.
     * @param params
     */
    public byte[] export(final List<AuftragDO> list, final Object... params)
    {
      if (CollectionUtils.isEmpty(list) == true) {
        return null;
      }
      log.info("Exporting order list.");
  