protected void exportExcel(final String filenameIdentifier, final String sheetTitle) { refresh(); final DOListExcelExporter exporter = createExcelExporter(filenameIdentifier); if (exporter == null) { // Nothing to export. form.addError("validation.error.nothingToExport"); return; } final List<?> list = getList(); if (list != null && list.size() > 0) { final ExportSheet sheet = exporter.addSheet(sheetTitle != null ? sheetTitle : "data"); exporter.addList(sheet, list); if (exporter.isExcelAutoFilter() == true) { sheet.setAutoFilter(); } } exporter.onBeforeDownload(); if (exporter.getWorkbook().getNumberOfSheets() == 0) { // Nothing to export. form.addError("validation.error.nothingToExport"); return; } DownloadUtils.setDownloadTarget(exporter.getWorkbook().getAsByteArray(), exporter.getFilename()); }