node框架使用express，安装脚手架工具npm i express-generator -g
文件处理中间件使用multer
app.js：
/* 导入upload模块 */
const uploadRouter = require('./routes/upload')
/* */ 允许跨域访问
app.all('*', function(req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Headers", "X-Requested-With");
res.header("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");
res.header("X-Powered-By",' 3.2.1')
res.header("Content-Type", "application/json;charset=utf-8");
next();
});
/* 使用upload路由 */
app.use('/upload', uploadRouter);