POI合并单元格后设置边框

//创建行Row row = sheet.createRow(30);//创建列Cell cell = row.createCell(1);//合并单元格,参数1，起始行，参数2，终止行，参数3，起始列，参数4，终止列//合并第30行的1到3列CellRangeAddress region = new CellRangeAddress(30, 30, 1, 3);//合并sheet.addMergedRegion(region);//合并后设置下边框RegionUtil.setBorderBottom(BorderStyle.THIN, region, sheet);