1. public class ExcelTemplate {
    3.     /**
    4.      * 下载Excel模板工具类
    5.      * @param response 响应
    6.      * @param obj 注解对象
    7.      * @param fileName 模板名称
    8.      */
    9.     public static void downloadExcelTemplate(HttpServletResponse response, Object obj, String fileName) {
    10.         //获取字段注解的值
    11.         List<String> titles = getAnnotationValue(obj);
    12.         XSSFWorkbook hwb = new XSSFWorkbook();
    13.         //创建一个sheet
    14.         XSSFSheet sheet = hwb.createSheet("测试");
    15.         //创建第一行
    16.         XSSFRow row = sheet.createRow(0);
    17.         //创建一个居中格式
    18.         XSSFCellStyle style = hwb.createCellStyle();
    19.         style.setAlignment(XSSFCellStyle.ALIGN_CENTER);
    20.         //创建列对象
    21.         XSSFCell cell;
    22.         for (int i = 0; i < titles.size(); i++) {
    23.             //创建行
    24.             cell = row.createCell(i);
    25.             //给第一行的每一列的单元格设置值
    26.             cell.setCellValue(titles.get(i));
    27.             //设置一个居中样式  里面有很多样式可以去看官方文档
    28.             cell.setCellStyle(style);
    29.             sheet.setColumnWidth(i, 256 * 30);
    30.         }
    31.         try {
    32.             try {
    33.                 fileName = new String(fileName.getBytes(), "ISO8859-1");
    34.             } catch (UnsupportedEncodingException e) {
    35.                 e.printStackTrace();
    36.             }
    37.             response.setContentType("application/octet-stream;charset=utf-8");
    38.             response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
    39.             response.addHeader("Pargam", "no-cache");
    40.             response.addHeader("Cache-Control", "no-cache");
    41.         } catch (Exception ex) {
    42.             ex.printStackTrace();
    43.         }
    44.         ServletOutputStream outputStream = null;
    45.         try {
    46.             outputStream = response.getOutputStream();
    47.             hwb.write(outputStream);
    48.             outputStream.flush();
    49.         } catch (IOException e) {
    50.             e.printStackTrace();
    51.         } finally {
    52.             try {
    53.                 outputStream.close();
    54.             } catch (IOException e) {
    55.                 e.printStackTrace();
    56.             }
    57.         }
    58.     }
    60.     /**
    61.      * 获取@ExcelField注解对象的字段名称以及注解的title值
    62.      * -annotationList：存储@ExcelField注解对象的字段名称
    63.      */
    64.     public static List<String> getAnnotationValue(Object obj) {
    65.         List<String> annotationList = new ArrayList<>();
    66.         Field[] fields = obj.getClass().getDeclaredFields();
    67.         for (int i = 0; i < fields.length; i++) {
    68.             fields[i].setAccessible(true);
    69.             ExcelField annotation = fields[i].getAnnotation(ExcelField.class);
    70.             if (Objects.isNull(annotation)) continue;
    71.             String value = annotation.title();
    72.             annotationList.add(value);
    73.         }
    74.         return annotationList;
    75.     }
    76. }