nodejs实现文件上传名

npm install express multer --save

const express = require('express');const multer  = require('multer');const app = express();const upload = multer({ dest: 'uploads/' });app.post('/upload', upload.single('file'), function(req, res) {    res.send('文件上传成功！');});app.listen(3000, function() {    console.log('服务器已启动，端口号：3000');});

const upload = multer({  dest: 'uploads/',  limits: {    fileSize: 1024 * 1024 //限制1M  }});

app.post('/upload', upload.single('file'), function(req, res) {    // 文件大小超出限制    if (req.file.size > 1024 * 1024) {        return res.status(400).send('文件大小不能超过1M');    }    res.send('文件上传成功！');});

const storage = multer.diskStorage({    destination: function(req, file, cb) {        cb(null, './uploads')    },    filename: function(req, file, cb) {        // 只允许上传后缀名为jpg, jpeg和png的文件        if (!/.(jpg|jpeg|png)$/.test(file.originalname)) {            return cb(new Error('只能上传jpg, jpeg和png格式的图片'));        }        //自定义文件名称        let timestamp = Date.now();        cb(null, timestamp + '.' + file.originalname.split('.').pop());    }});const upload = multer({    storage: storage,    limits: {        fileSize: 1024 * 1024 //限制1M    },    fileFilter: function(req, file, cb) {        // 检查文件类型        if (!file.originalname.match(/.(jpg|jpeg|png)$/)) {            return cb(new Error('只能上传jpg, jpeg和png格式的图片'));        }        // 继续上传        cb(null, true);    }});app.post('/upload', upload.single('file'), function(req, res) {    res.send('文件上传成功！');});