code: public static boolean list2Xls(ExcelConfig config, List<?> list, String filePath, String fileName) throws Exception {
          //创建目录
          File file = new File(filePath);
          if (!(file.exists())) {
              if (!file.mkdirs()) {
                  throw new RuntimeException("创建导出目录失败!");
              }
          }
          OutputStream outputStream = null;
          try {
              if (!fileName.toLowerCase().endsWith(EXCEL)) {
                  fileName += EXCEL;
              }
              File excelFile = new File(filePath + "/" + fileName);
              outputStream = new FileOutputStream(excelFile);
              return list2Xls(config, list, outputStream);
          } catch (Exception e1) {
              return false;
          } finally {
              if(outputStream != null){
                  outputStream.close();
              }
          }
      }
docs: 导出list对象到excel
  
  @param config   配置
  @param list     导出的list
  @param filePath 保存xls路径
  @param fileName 保存xls文件名
  @return 处理结果，true成功，false失败
  @throws Exception