public void startRow(int rowNum) {
            try {
                // Missing rows, if desired, with a single empty row
                if (includeMissingRows && rowNum > (lastSeenRow + 1)) {
                    for (int rn = lastSeenRow + 1; rn < rowNum; rn++) {
                        xhtml.startElement("tr");
                        xhtml.startElement("td");
                        xhtml.endElement("td");
                        xhtml.endElement("tr");
                    }
                }

                // Start the new row
                xhtml.startElement("tr");
                lastSeenCol = -1;
            } catch (SAXException e) {
                //swallow
                throw new RuntimeSAXException(e);
            }

        }
Turns formatted sheet events into HTML
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/ooxml/XSSFExcelExtractorDecorator.java