poi 控制excel 边框有关问题

poi 控制excel 边框问题
POI 如何去除excel原有的空白白色边框？请各路大神相助

HSSFCellStyle center20 = wwb.createCellStyle();
center20.setBorderTop(HSSFCellStyle.BORDER_NONE);
center20.setBorderBottom(HSSFCellStyle.BORDER_NONE);

------解决方案--------------------
sheet.setDisplayGridlines(false);

http://poi.apache.org/apidocs/org/apache/poi/ss/usermodel/Sheet.html#setDisplayGridlines%28boolean%29