一、EasyExcel写操作使用

①实体类（加上注解，也就是生成的excel中的列名）

@Data
@AllArgsConstructor
@NoArgsConstructor
public class ExcelCategoryVo {
    @ExcelProperty("分类id")
    private Long id;
    @ExcelProperty("分类名")
    private String name;
    @ExcelProperty("描述")
    private String description;
    @ExcelProperty("状态:(0正常,1禁用)")
    private String status;
}

②请求

@GetMapping("/category/export")
    public void downloadFailedUsingJson(HttpServletResponse response) throws IOException {
            try {
                //设置响应的请求头
                WebUtils.setDownLoadHeader("分类.xlsx",response);
                //获取需要导出的数据(从数据库查)
                List<Category> categories = categoryService.list();
                List<ExcelCategoryVo> excelCategoryVos = BeanCopyUtils.copyBeanList(categories, ExcelCategoryVo.class);
                //将数据导入excel中，这里需要设置不关闭流
                EasyExcel.write(response.getOutputStream(), ExcelCategoryVo.class).autoCloseStream(Boolean.FALSE).sheet("分类导出")
                        .doWrite(excelCategoryVos);
            } catch (Exception e) {
                // 重置response
                response.reset();
                response.setContentType("application/json");
                response.setCharacterEncoding("utf-8");
                Map<String, String> map = MapUtils.newHashMap();
                map.put("status", "failure");
                map.put("message", "下载文件失败" + e.getMessage());
                response.getWriter().println(JSON.toJSONString(map));
            }
        }

③工具类（设置响应的请求头）

 public static void setDownLoadHeader(String filename, HttpServletResponse response) throws UnsupportedEncodingException {
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        response.setCharacterEncoding("utf-8");
        String fname= URLEncoder.encode(filename,"UTF-8").replaceAll("\\+", "%20");
        response.setHeader("Content-disposition","attachment; filename="+fname);
    }