各种包对比介绍：https://www.cnblogs.com/sky6699/p/12738930.html

    1. const router = require('koa-router')();
    2. const nodeExcel = require('excel-export');
    3. const fs = require('fs');
    4. const path = require('path');
    6. const readData = (path) => {
    7.   return new Promise(function (resolve, reject) {
    8.     fs.readFile(path, function (err, data) {
    9.       if (err) {
    10.         reject(err);//文件存在返回true
    11.       } else {
    12.         resolve(data);//文件不存在，这里会抛出异常
    13.       }
    14.     });
    15.   }).then(function (data) {
    16.     console.log(data);
    17.     return data;
    18.   }, function (err) {
    19.     console.log(err);
    20.     return err;
    21.   });
    22. };
    24. router.post('/exportExcel', async (ctx, next) => {
    25.   const conf = {};
    26.   conf.name = "exportTest";
    27.   // cols可以为设置列类型的：caption为表头，type为列数据类型，beforeCellWrite可以在填充之前对数据进行逻辑处理，width可以定义列宽
    28.   // excel-export提供了4种类型的数据格式，number，bool，date，默认string
    29.   conf.cols = [{
    30.     caption: '表头1',
    31.     type: 'string',
    32.     // beforeCellWrite: function (row, cellData) {
    33.     //   return cellData.toUpperCase();
    34.     // },
    35.     // width: 28
    36.   }, {
    37.     caption: '表头2',
    38.     type: 'number',
    39.   }, {
    40.     caption: '表头3',
    41.     type: 'bool',
    42.   }, {
    43.     caption: '表头4',
    44.     type: 'date',
    45.   }, {
    46.     caption: '表头5',
    47.     type: 'string',
    48.   }, {
    49.     caption: '表头6',
    50.     type: 'string',
    51.   }];
    52.     // 行数据
    53.   conf.rows = [
    54.       ['content1', 1, true, (new Date(Date.UTC(2013, 4, 1))).oaDate(), '55', '66'], // 这里是value组成的数组
    55.     ['content2', 2, true, (new Date(Date.UTC(2013, 4, 1))).oaDate(), '55', '66'],
    56.     ['content3', 3, false, (new Date(Date.UTC(2013, 4, 1))).oaDate(), '55', '66'],
    57.   ];
    58.   var result = nodeExcel.execute(conf);
    59.   ctx.set('Content-Type', 'application/vnd.openxmlformats');
    60.   ctx.set("Content-Disposition", "attachment; filename=" + "Report.xlsx");
    62.   fs.writeFile(path.join(__dirname, '../files/', 'log.xlsx'), result, { encoding: 'binary' }, function (err) {
    63.     if (err) { console.log('写入错误'); }
    64.   })
    66.   let data = readData(path.join(__dirname, '../files/', 'log.xlsx'));
    67.   ctx.body = data;
    68. });
    70. module.exports = router;