xlsx组件几个重要组成对象和函数
workbook, 技术xlsx整个文件
worksheet, xlsx文件里的sheet,一个workbook由多个worksheet组成
XLSX.utils.json_to_sheet方法，将json数据转换成worksheet对象
例子：
var data = [
{"name":"John", "city": "Seattle"},
{"name":"Mike", "city": "Los Angeles"},
{"name":"Zach", "city": "New York"}
];if(typeof XLSX == 'undefined') XLSX = require('xlsx');var ws = XLSX.utils.json_to_sheet(data);var wb = XLSX.utils.book_new();
XLSX.utils.book_append_sheet(wb, ws, "People");XLSX.writeFile(wb, "sheetjs.xlsx");
作者：秦洛1023
链接：https://www.jianshu.com/p/059a203e094d
