public static void setTableFormula(Element table,int row,int column,String formula){
if(table!=null){
Elements trs = table.select("tr");
if(trs.size()>row){
Element tr = trs.get(row);
Elements tds = tr.children();
if(tds.size()>column){
Element td = tds.get(column);
if(!StringUtils.isBlank(formula)){
if(formula.startsWith("=")){
td.attr("formula",formula);