SpringBoot导出Excel

 这次项目的过程中，需要做的的一个模块是导出功能，将一个页面的数据以Excel导出。
 详细详细记录下这次的做法；
 首先是在HTML处的写法。

 导出信息 

然后是在JS中发送请求；

   $("#jsonstr").val(JSON.stringify($scope.commit))
        document.form.action = "/vehicle/ViolationInformation";
        document.form.submit();

前端是通过这种JSON方式发送。
接下来描述后端的写法：
DAO层以下是熟悉的对数据库的操作，不予讲解。
接下来是Service的实现。

  @Override
    public ResponseEntity responseViolationInfromation(Map map) {
        HSSFWorkbook wkb = new HSSFWorkbook();
        HSSFSheet cardExcelTemplate = wkb.createSheet("车辆报表信息导出");
        cardExcelTemplate.setDefaultColumnWidth(33);
        HSSFCellStyle style = wkb.createCellStyle();
        HSSFFont font = wkb.createFont();
        font.setColor(HSSFColor.RED.index);
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
        style.setFont(font);
        HSSFRow row2 = cardExcelTemplate.createRow(0);
        row2.createCell(0).setCellValue("城市");
        row2.createCell(1).setCellValue("车牌号码");
        row2.createCell(2).setCellValue("车辆品牌");
        row2.createCell(3).setCellValue("车辆类型");
        row2.createCell(4).setCellValue("所属仓库");
        row2.createCell(5).setCellValue("加油卡账号");
        row2.createCell(6).setCellValue("保险时间的到期");
        row2.createCell(7).setCellValue("保险状态");
        row2.createCell(8).setCellValue("年检有效期止");
        row2.createCell(9).setCellValue("年检状态");
        row2.createCell(10).setCellValue("行驶里程数");
        row2.createCell(11).setCellValue("未处理违章数");
        row2.createCell(12).setCellValue("车辆状态");
        List vehicleInformation = carMapper.listViolationInformation(map);
        Date date = new Date();
        Calendar cal = Calendar.getInstance();
        int yearNow = cal.get(Calendar.YEAR);
        int monthNow = cal.get(Calendar.MONTH) + 1;
        int result = yearNow * 12 + monthNow;
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
        SimpleDateFormat simp = new SimpleDateFormat("yyyy-MM");
        HSSFRow otherRow = null;
        for (int i = 0; i < vehicleInformation.size(); i++) {
            otherRow = cardExcelTemplate.createRow(i + 1);
            // 0.城市
            otherRow.createCell(0).setCellValue(vehicleInformation.get(i).getCity());
            // 1.车牌号
            otherRow.createCell(1).setCellValue(vehicleInformation.get(i).getCarNumber());
            // 2.车辆品牌
            otherRow.createCell(2).setCellValue(vehicleInformation.get(i).getBrandModelNumber());
            // 3.车辆类型
            otherRow.createCell(3).setCellValue(vehicleInformation.get(i).getVehicleType());
            // 4.所属仓库
            otherRow.createCell(4).setCellValue(vehicleInformation.get(i).getWarehouse());
            // 5.加油卡账号
            if (null == vehicleInformation.get(i).getViceCardNumber()) {
                otherRow.createCell(5).setCellValue("无");
            } else {
                otherRow.createCell(5).setCellValue(vehicleInformation.get(i).getViceCardNumber());
            }
            // 6.保险时间
            if (null == vehicleInformation.get(i).getStopDate()) {
                otherRow.createCell(6).setCellValue("无");
            } else {
                otherRow.createCell(6).setCellValue(simpleDateFormat.format(vehicleInformation.get(i).getStopDate()));
            }
            // 7.保险状态
            if (null != vehicleInformation.get(i).getStopDate()) {
                Long insuranceStopDate = (vehicleInformation.get(i).getStopDate().getTime() - date.getTime()) / (1000 * 60 * 60 * 24);
                if (insuranceStopDate != null && insuranceStopDate >= 60) {
                    otherRow.createCell(7).setCellValue("正常");
                }
                if (insuranceStopDate != null && insuranceStopDate < 60 && insuranceStopDate >= 0) {
                    otherRow.createCell(7).setCellValue("即将到期");
                }
                if (insuranceStopDate != null && insuranceStopDate < 0) {
                    otherRow.createCell(7).setCellValue("已过期");
                }
            } else {
                otherRow.createCell(7).setCellValue("未上传");
            }
            // 8.年检有效期止
            if (null == vehicleInformation.get(i).getValidityDate()) {
                otherRow.createCell(8).setCellValue("无");
            } else {
                otherRow.createCell(8).setCellValue(simp.format(vehicleInformation.get(i).getValidityDate()));
            }
            // 9.年检状态
            if (null != vehicleInformation.get(i).getValidityDate()) {
                String validityDate = simp.format(vehicleInformation.get(i).getValidityDate());
                String[] strs = validityDate.split("-");
                Integer validityYear = Integer.valueOf(strs[0]);
                Integer validityMonth = Integer.valueOf(strs[1]);
                Integer validityResult = validityYear * 12 + validityMonth;
                Integer ending = validityResult - result;
                if (ending >= 2) {
                    otherRow.createCell(9).setCellValue("正常");
                }
                if (ending < 2 && ending >= 0) {
                    otherRow.createCell(9).setCellValue("即将到期");
                }
                if (ending < 0) {
                    otherRow.createCell(9).setCellValue("已过期");
                }
            } else {
                otherRow.createCell(9).setCellValue("未上传");
            }
            // 10.总行驶里程数
            if (null == vehicleInformation.get(i).getCurrentMileage()) {
                otherRow.createCell(10).setCellValue("无");
            } else {
                otherRow.createCell(10).setCellValue(new Double(vehicleInformation.get(i).getCurrentMileage().toString()));
            }
            // 11.未处理违章数
            otherRow.createCell(11).setCellValue(vehicleInformation.get(i).getViolationNumber());
            // 12：待审核
            if (vehicleInformation.get(i).getStatus() == 1) {
                otherRow.createCell(12).setCellValue("启用");
            }
            if (vehicleInformation.get(i).getStatus() == 2) {
                otherRow.createCell(12).setCellValue("待审核");
            }
            if (vehicleInformation.get(i).getStatus() == 0) {
                otherRow.createCell(12).setCellValue("停用");
            }
        }

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        try {
            wkb.write(out);
        } catch (IOException e) {
            LOGGER.info("excel内存文件转换为的字节数组写到输出流中时产生错误，" + e);
            throw new RuntimeException("excel内存文件转换为的字节数组写到输出流中时产生错误，" + e);
        }
        HttpHeaders headers = new HttpHeaders();
        String fileName = null;
        try {
            fileName = new String("车辆报表信息导出.xls".getBytes("utf-8"), "iso-8859-1");
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("字符编码格式不支持，" + e);
        }
        headers.setContentDispositionFormData("attachment", fileName);
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        byte[] outputStreamByte = out.toByteArray();
        ResponseEntity filebyte = new ResponseEntity(outputStreamByte, headers, HttpStatus.CREATED);
        try {
            out.close();
        } catch (IOException e) {
            throw new RuntimeException("excel内存文件转换为的字节数组写到输出流中关闭输出流时产生错误，" + e);
        }
        return filebyte;
    }

通过这个方法，实现了从数据库中查找出数据，然后插入到Excel中。
在controller中：

 /**
     * 返回一个车辆报表信息的excel文件 年检、保险即将到期，未处理违章的统计
     */
    @RequestMapping(value = "vehicle/ViolationInformation", method = RequestMethod.POST)
    public ResponseEntity resoibseVehicleInformation(String jsonstr) {
        JSONObject obj = JSONObject.fromObject(jsonstr);
        VehicleConditionQueryVO vehicleConditionQueryVO = (VehicleConditionQueryVO) JSONObject.toBean(obj, VehicleConditionQueryVO.class);
        Map map = getMap(vehicleConditionQueryVO);
        ResponseEntity responseEntity = carService.responseViolationInfromation(map);
        return responseEntity;
    }

到此，可以实现一个从网页导出到Excel的操作了。