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: `http://xxxxx(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 id="btn1" type="file" name="file"/>
<input id="btn2" 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
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持编程网。
