因为升级到新的node版本，之前的通过很多上传图片的方式都已经不适用了，所以自己就写了一个对于 koa2上传图片的小demo,记录一下心得。
废话不多说，下面直接上代码，里面都有注释。
const Koa = require('koa'); const route = require('koa-route'); const serve = require('koa-static'); const inspect = require('util').inspect const path = require('path') const os = require('os') const fs = require('fs') const Busboy = require('busboy') const qiniu = require('qiniu') const qiniuConfig = require('./qiniuconfig') const app = new Koa(); app.use(serve(__dirname + '/public/')); // 写入目录 const mkdirsSync = (dirname) => { if (fs.existsSync(dirname)) { return true } else { if (mkdirsSync(path.dirname(dirname))) { fs.mkdirSync(dirname) return true } } return false } function getSuffix (fileName) { return fileName.split('.').pop() } // 重命名 function Rename (fileName) { return Math.random().toString(16).substr(2) + '.' + getSuffix(fileName) } // 删除文件 function removeTemImage (path) { fs.unlink(path, (err) => { if (err) { throw err } }) } // 上传到七牛 function upToQiniu (filePath, key) { const accessKey = qiniuConfig.accessKey // 你的七牛的accessKey const secretKey = qiniuConfig.secretKey // 你的七牛的secretKey const mac = new qiniu.auth.digest.Mac(accessKey, secretKey) const options = { scope: qiniuConfig.scope // 你的七牛存储对象 } const putPolicy = new qiniu.rs.PutPolicy(options) const uploadToken = putPolicy.uploadToken(mac) const config = new qiniu.conf.Config() // 空间对应的机房 config.zone = qiniu.zone.Zone_z2 const localFile = filePath const formUploader = new qiniu.form_up.FormUploader(config) const putExtra = new qiniu.form_up.PutExtra() // 文件上传 return new Promise((resolved, reject) => { formUploader.putFile(uploadToken, key, localFile, putExtra, function (respErr, respBody, respInfo) { if (respErr) { reject(respErr) } if (respInfo.statusCode == 200) { resolved(respBody) } else { resolved(respBody) } }) }) } // 上传到本地服务器 function uploadFile (ctx, options) { const _emmiter = new Busboy({headers: ctx.req.headers}) const fileType = options.fileType const filePath = path.join(options.path, fileType) const confirm = mkdirsSync(filePath) if (!confirm) { return } console.log('start uploading...') return new Promise((resolve, reject) => { _emmiter.on('file', function (fieldname, file, filename, encoding, mimetype) { const fileName = Rename(filename) const saveTo = path.join(path.join(filePath, fileName)) file.pipe(fs.createWriteStream(saveTo)) file.on('end', function () { resolve({ imgPath: `/${fileType}/${fileName}`, imgKey: fileName }) }) }) _emmiter.on('finish', function () { console.log('finished...') }) _emmiter.on('error', function (err) { console.log('err...') reject(err) }) ctx.req.pipe(_emmiter) }) } app.use(route.post('/upload', async function(ctx, next) { const serverPath = path.join(__dirname, './uploads/') // 获取上存图片 const result = await uploadFile(ctx, { fileType: 'album', path: serverPath }) const imgPath = path.join(serverPath, result.imgPath) // 上传到七牛 const qiniu = await upToQiniu(imgPath, result.imgKey) // 上存到七牛之后 删除原来的缓存图片 removeTemImage(imgPath) ctx.body = { imgUrl: `(你的外链或者解析后七牛的路径)/${qiniu.key}` } })); app.listen(3001); console.log('listening on port 3001');
然后在同一级目录下，创建一个public文件夹，然后在下面新建一个 index.html，因为我们上面已经把这个文件夹设置为静态访问文件夹了， public/index.html 的代码为
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Document</title> </head> <body> <input type="file"/> <input type="submit" value="提交"/> </body> <script> var btn1 = document.querySelector('#btn1') var btn2 = document.querySelector('#btn2') var file = null btn1.addEventListener('change', function(e){ file = e.target.files[0] }) btn2.onclick = function(){ var _data = new FormData(); _data.append('file', file); xhr(_data) } var xhr = function(formdata){ var xmlHttp = new XMLHttpRequest(); xmlHttp.open("post","http://127.0.0.1:3001/upload", true); xmlHttp.send(formdata); xmlHttp.onreadystatechange = function(){ if(xmlHttp.readyState==4){ if(xmlHttp.status==200){ var data = xmlHttp.responseText; console.log(data); } } } } </script> </html>
选择好图片，然后点击提交，就可以上传到你的七牛空间啦！
源代码在 github: https://github.com/naihe138/koa-upload