express实现图片上传

参考：https://cloud.tencent.com/developer/article/1730338

1.安装

npm install express body-parser cors express-fileupload morgan lodash --save

2.新建index.js

const express = require('express');
const fileUpload = require('express-fileupload');
const cors = require('cors');
const bodyParser = require('body-parser');
const morgan = require('morgan');
const _ = require('lodash');

const app = express();

// enable files upload
app.use(fileUpload({
    createParentPath: true
}));

//add other middleware
app.use(cors());
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: true}));
app.use(morgan('dev'));

//start app 
const port = process.env.PORT || 3000;

app.listen(port, () => 
  console.log(`App is listening on port ${port}.`)
);

3.还是在index.js加上图片上传接口

app.post('/upload-avatar', async (req, res) => {
    try {
        if(!req.files) {
            res.send({
                status: false,
                message: 'No file uploaded'
            });
        } else {
            //Use the name of the input field (i.e. "avatar") to retrieve the uploaded file
            let avatar = req.files.file;
            
            //Use the mv() method to place the file in upload directory (i.e. "uploads")
            avatar.mv('./uploads/' + avatar.name);

            //send response
            res.send({
                status: true,
                message: 'File is uploaded',
                data: {
                    name: avatar.name,
                    mimetype: avatar.mimetype,
                    size: avatar.size
                }
            });
        }
    } catch (err) {
        res.status(500).send(err);
    }
});

3.1. 多文件上传

app.post('/upload-photos', async (req, res) => {
    try {
        if(!req.files) {
            res.send({
                status: false,
                message: 'No file uploaded'
            });
        } else {
            let data = []; 
    
            //loop all files
            _.forEach(_.keysIn(req.files.photos), (key) => {
                let photo = req.files.photos[key];
                
                //move photo to uploads directory
                photo.mv('./uploads/' + photo.name);

                //push file details
                data.push({
                    name: photo.name,
                    mimetype: photo.mimetype,
                    size: photo.size
                });
            });
    
            //return response
            res.send({
                status: true,
                message: 'Files are uploaded',
                data: data
            });
        }
    } catch (err) {
        res.status(500).send(err);
    }
});

5. 运行

node index.js

6. 文件大小限制

app.use(fileUpload({
    createParentPath: true,
    limits: { 
        fileSize: 2 * 1024 * 1024 * 1024 //2MB max file(s) size
    },
}));