一、poi excel 分组(group)
sheet.groupRow(1, 3);
ungroupRow(xxx,xxx);
Workbook wb = new HSSFWorkbook();
Sheet sheet1 = wb.createSheet("new sheet");
sheet1.groupRow( 5, 14 );
sheet1.groupColumn( (short)4, (short)7 );
//To collapse (or expand) an outline use the following calls:
//大致翻译就是:用如下的调用折叠或展开一个边框
sheet1.setRowGroupCollapsed( 7, true );
sheet1.setColumnGroupCollapsed( (short)4, true );