Java代码生成excel文件下载

List <IPSumCountVO> ipscList = changeStringToVO(ipSourceReport);
        	SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
			String fileName = "IP资源统计列表_" + sdf.format(new Date());
			outputStream = WebUtils.getOutputStream(response, fileName + ".xls", "UTF-8");

public static OutputStream getOutputStream(HttpServletResponse response,
			String fileName, String encode) throws IOException {
		String finalFileName = "";
		String userAgent = WebUtils.getRequest().getHeader("User-Agent");
		// 对文件名进行编码，防止文件名乱码
		// 如果是火狐或者苹果浏览器
		if (userAgent.toLowerCase().indexOf("firefox".toLowerCase()) != -1
				|| userAgent.toLowerCase().indexOf("safari".toLowerCase()) != -1) {
			finalFileName = new String(fileName.getBytes(encode), "ISO-8859-1");
		} else {
			finalFileName = URLEncoder.encode(fileName,encode);
		}
		// 设置头信息
		response.reset();
		response.setHeader("Content-Disposition", "attachment; filename="+finalFileName);
		response.setContentType("application/octet-stream; charset="+encode);
		return response.getOutputStream();
	}

WritableWorkbook workbook = Workbook.createWorkbook(outputStream);
			// 创建excel
			createDeviceOrderListExcel(ipscList, workbook);
			// 释放资源
			workbook.write();
			workbook.close();

private void createDeviceOrderListExcel(List<IPSumCountVO> ipscList, WritableWorkbook workbook) throws Exception {
		try{
			WritableSheet wsheet = workbook.createSheet("IP资源统计列表", 0);
			wsheet.getSettings().setVerticalFreeze(1);
			
			// 定义title单元格样式:字体 下划线 斜体 粗体 颜色
			WritableFont wf_title = new WritableFont(WritableFont.ARIAL, 9, WritableFont.NO_BOLD, false, UnderlineStyle.NO_UNDERLINE, Colour.BLACK);
			// 单元格定义
			WritableCellFormat wcf_title = new WritableCellFormat(wf_title);
			// 设置单元格的背景颜色
			wcf_title.setBackground(Colour.GRAY_25);
			// 设置对齐方式
			wcf_title.setAlignment(Alignment.CENTRE);
			wcf_title.setVerticalAlignment(VerticalAlignment.CENTRE);
			//设置边框
			wcf_title.setBorder(Border.ALL, BorderLineStyle.THIN,Colour.BLACK);
			
			// 定义body单元格样式:定义格式 字体 下划线 斜体 粗体 颜色 
			WritableFont wf_table = new WritableFont(WritableFont.ARIAL, 9, WritableFont.NO_BOLD, false, UnderlineStyle.NO_UNDERLINE, Colour.BLACK);
			WritableCellFormat wcf_table = new WritableCellFormat(wf_table);
			wcf_table.setBackground(Colour.WHITE);
			wcf_table.setAlignment(Alignment.RIGHT);
			wcf_table.setVerticalAlignment(VerticalAlignment.CENTRE);
			wcf_table.setBorder(Border.ALL, BorderLineStyle.THIN,Colour.BLACK);
			
			String[] str = {"IP地址组","规划IP数量","子网数量","使用率","使用数量","预留数量","冻结数量"};
			for (int i = 0; i < 7; i++) {
				wsheet.setColumnView(i, 20);
				Label label = new Label(i, 0, str[i], wcf_title);
				wsheet.addCell(label);
			}
			int j = 1;
			for (IPSumCountVO ipso : ipscList) {
				int index = 0;
				//IP地址组
				wsheet.addCell(new Label(index++, j,ipso.getIpAddressGroupName()== null?"":ipso.getIpAddressGroupName(),wcf_table));
				//规划IP数量
				wsheet.addCell(new Label(index++, j,ipso.getPlanIpCount() + "",wcf_table));
				//子网数量
				wsheet.addCell(new Label(index++, j,ipso.getSubNetCount() + "",wcf_table));
				//使用率
				wsheet.addCell(new Label(index++, j,ipso.getUseRate()== null?"":ipso.getUseRate(),wcf_table));
				//使用
				wsheet.addCell(new Label(index++, j,ipso.getUseCount() + "",wcf_table));
				//预留
				wsheet.addCell(new Label(index++, j,ipso.getObligateCount() + "",wcf_table));
				//冻结
				wsheet.addCell(new Label(index++, j,ipso.getFrozenCount() + "",wcf_table));
				j++;
			}
		}catch(Exception e){
			e.printStackTrace();
			BeanLog.getLogger().fatal("构造book", e);
			throw e;
		}
	}