用springboot 做一个easyExcel写数据库的数据到页面下载

首先导包：

   <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>easyexcelartifactId>
            <version>2.2.7version>
        dependency>

在service层的implment层调用方法：
数据格式为从数据库里得到的已经封装好的数据：

	public void exportWithResponse(String sheetName, String fileName, int columnNumber, Object[] newColumnName,
			List<HashMap<String, Object>> dataList, HttpServletResponse response) throws IOException {

		try (OutputStream out = response.getOutputStream(); XSSFWorkbook wb = new XSSFWorkbook();) {

			XSSFSheet sheet = wb.createSheet(sheetName);

			XSSFRow row = sheet.createRow(0);
			row.setHeightInPoints(37);

			// 第四步,创建表头单元格样式 以及表头的字体样式
			XSSFCellStyle style = wb.createCellStyle();
			setTableHeader(wb, style);

			// 第四,一步,创建表头的列
			for (int i = 0; i < columnNumber; i++) {
				XSSFCell cell = row.createCell(i);
				cell.setCellValue((String) newColumnName[i]);
				cell.setCellStyle(style);
			}

			// 第五步,创建单元格,并设置值

			for (int i = 0; i < dataList.size(); i++) {
				row = sheet.createRow(i + 1);

				// 为数据内容设置特点新单元格样式2 自动换行 上下居中左右也居中
				XSSFCellStyle zidonghuanhang2 = wb.createCellStyle();
				setAutoWrapStyle(zidonghuanhang2);
				XSSFCell datacell = null;

				for (int j = 0; j < newColumnName.length; j++) {
					datacell = row.createCell(j);

					if (dataList.get(i).get(newColumnName[j]) == null) {
						datacell.setCellValue("");
					} else {
						datacell.setCellValue(dataList.get(i).get(newColumnName[j]).toString());
					}

					datacell.setCellStyle(zidonghuanhang2);
				}
			}

			// 第六步,将文件存到浏览器设置的下载位置
			String filename = fileName + ".xlsx";
			response.setContentType("application/ms-excel;charset=UTF-8");
			response.setHeader("Content-Disposition",
					"attachment;filename=".concat(String.valueOf(URLEncoder.encode(filename, "UTF-8"))));

			wb.write(out);
			out.flush();
			String str = "导出" + fileName + "成功!";
			logger.info(str);

		} catch (Exception e) {
			logger.error(e.toString());
		}

	}
	private void setTableHeader(Workbook wb, CellStyle style) {
		style.setWrapText(true); // 设置自动换行
		style.setAlignment(HorizontalAlignment.CENTER);
		style.setVerticalAlignment(VerticalAlignment.CENTER); // 创建一个居中格式

		style.setBottomBorderColor(HSSFColor.HSSFColorPredefined.BLACK.getIndex());
		style.setBorderBottom(BorderStyle.THIN);
		style.setBorderLeft(BorderStyle.THIN);
		style.setBorderRight(BorderStyle.THIN);
		style.setBorderTop(BorderStyle.THIN);

		Font headerFont = wb.createFont(); // 创建字体样式
		headerFont.setBold(true); // 字体加粗
		headerFont.setFontName("黑体"); // 设置字体类型
		headerFont.setFontHeightInPoints((short) 10); // 设置字体大小
		style.setFont(headerFont); // 为标题样式设置字体样式
	}
	private void setAutoWrapStyle(CellStyle zidonghuanhang2) {
		zidonghuanhang2.setWrapText(true);// 设置自动换行
		zidonghuanhang2.setVerticalAlignment(VerticalAlignment.CENTER); // 创建一个上下居中格式
		zidonghuanhang2.setAlignment(HorizontalAlignment.CENTER);// 左右居中

		// 设置边框
		zidonghuanhang2.setBottomBorderColor(HSSFColor.HSSFColorPredefined.BLACK.getIndex());
		zidonghuanhang2.setBorderBottom(BorderStyle.THIN);
		zidonghuanhang2.setBorderLeft(BorderStyle.THIN);
		zidonghuanhang2.setBorderRight(BorderStyle.THIN);
		zidonghuanhang2.setBorderTop(BorderStyle.THIN);
	}

使用如下：

   // 
	SqlDaResult data = sqlHelperService.queryListBySql(customClickHouseJdbcTemplate, sql, params);
	//数据库得到的数据
	List<HashMap<String, Object>> tableData = (List<HashMap<String, Object>>) data.getTables().get(0);
	// 列名
			Object[] colName = null;
			for (Map<String, Object> item : tableData) {
				//把数据库的字段名拿出来
				Set<String> strings = item.keySet();
				colName = strings.toArray();
				break;
			}
			exportWithResponse("问题区域列表", "问题区域列表_"+ new Date().getTime(), colName.length, colName, tableData, response);

缺点就是这个是自用的数据库数据封装，如有mybatis的查询结果可以依照改着使用