大文件分段上传，前后端写法都有（分别使用node和golang实现）

问题：为什么需要分段上传？

前端项目开发阶段是node环境，上传文件非常迅速，很大的文件也能轻松上传，但是生产环境一般都是用nginx部署，nginx对上传文件大小默认是1M，即使是修改文件大小限制后，由于传输速度问题，要是上传个几兆几十兆的文件问题不大，要是上百兆甚至几百兆，大多数情况会出现超时，导致上传失败，体验很差，分段上传就可以很大程度解决这个问题

大致思路

分段上传需要前后端配合，

前端部分：

首先是前端要把需要上传的大文件分成若干段，按序号命名，循环上传每一段
前端循环上传完所有分段后调用合并接口

后端部分：

递归循环接收前端上传的分段，新建一个和文件同名的文件夹，把接收到的分段都存入该文件夹
合并接口接收文件夹名为参数，把该文件夹下所有文件按序号排序后合并为一个文件
合并文件后在同目录生成合并后的文件，并删除分段文件夹

node版本

代码仓库 gitee.com/liyefeng123... 主要是两个接口，上传文件切片接口和合并切片接口 index.js 入口

javascript 复制代码

const express=require("express")
const bodyparser=require("body-parser")
const multiparty=require("multiparty")
const fse=require("fs-extra")
const fs=require("fs")
const path = require('path')
const app =express()
const UPLOAD_DIR=path.resolve(__dirname,"public/upload")
app.use(express.static(__dirname+"/public"))
app.use(bodyparser.urlencoded({extended:true}))

app.post("/upload",function(req,res){
  const form=new multiparty.Form({uploadDir:"template"})
  form.parse(req)
  form.on("file",async(name,chunk)=>{
    
    let chunkDir=`${UPLOAD_DIR}/${chunk.originalFilename.split(".")[0]}`
    if(!fse.existsSync(chunkDir)){
      await fse.mkdirs(chunkDir)
    }
    var dpath=path.join(chunkDir,chunk.originalFilename.split(".")[1])
    await fse.move(chunk.path,dpath,{overwrite:true})
    res.send("文件上传成功")
  })
  
})
app.get("/merge", async function (req,res){
  let name=req.query.name
  let fname=name.split(".")[0]
  let chunDir=path.join(UPLOAD_DIR,fname)
  let chunks=await fse.readdir(chunDir)
  let sortArr=chunks.sort((a,b)=>a-b)
  sortArr.map(chunkPath=>{
    fs.appendFileSync(
      path.join(UPLOAD_DIR,name),
      fs.readFileSync(`${chunDir}/${chunkPath}`)
    )
  })
  fse.removeSync(chunDir)
  res.send({msg:"合并成功",url:`http://localhost:3000/upload/${name}`})
})
app.listen("3000")
console.log("listen 3000")

index.html

xml 复制代码

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>文件上传</title>

</head>

<body>
  <input type="file" id="btnfile">
  <input type="button" value="上传" onclick="upload(0)">
  <button id="btn">0%</button>
  <script src="./axios.js"></script>
  <script>
    let chunkSize = 1024 * 1024
    let index=0
    let size=0
    let radio=0
    function upload(index) {
      let file = btnfile.files[0]
      console.log("file",file)
      size=file.size
      let [fname, fext] = file.name.split(".")
      
      let start = index * chunkSize
      radio=(index/(size/chunkSize))*100
      radio=Math.floor(radio)
      console.log("size/chunkSize",index/(size/chunkSize))
      btn.innerText=`${radio>100?100:radio}%`
      if (start > file.size) {
        merge(file.name)
        return
      }
      let blob = file.slice(start, start + chunkSize)
      let blobName = `${fname}.${index}.${fext}`
      let blobFile = new File([blob], blobName)
      let formData = new FormData()
      formData.append("file", blobFile)
      index++
      axios.post("/upload", formData).then(res => {
        console.log("rea", res)

        upload(index)
      })
    }
    function merge(name){
      axios.get("/merge?name="+name).then(res=>{
        console.log("merge",res)
      })
    }
    window.onload = () => {
      let btnfile = document.getElementById("btnfile")

    }
  </script>
</body>

</html>

golang版本

前端表单

ini 复制代码

<div class="upload_wrap" v-show="percentage<1">
  <input type="file" name="file" id="uploadVideo">
  <input type="button" value="开始上传" @click="uploadBiger">
</div>
<div class="loading"  style="width: 100%" v-show="percentage>1">
  <el-progress  :stroke-width="11" :percentage="percentage" />
</div>

ini 复制代码

/**
 * 上传大文件
 */
let uploadStep=ref(0)
let chunkSize = 1024 * 1024
let uploadSize=0
let index=0
let size=0
let percentage=ref(0)
const uploadBiger=()=>{
  const uploadVideo=document.getElementById("uploadVideo")
  let file=uploadVideo.files[0]
  size=file.size
  uploadSize=file.size
  let start = index * chunkSize
  let [fname, fext] = file.name.split(".")
  percentage.value=Math.floor((index/(size/chunkSize))*100)
  percentage.value=percentage.value>=100?100:percentage.value
  if (start > file.size) {
    mergeVideo(file.name)
    return
  }
  let blob = file.slice(start, start + chunkSize)
  let blobName = `${fname}.${index}.${fext}`
  let blobFile = new File([blob], blobName)
  let formData = new FormData()
  formData.append("file", blobFile)
  index++
  server.post("/admin/uploadVideo",formData).then(res=>{
    console.log("up",res)
    if(res.status==200){
      uploadBiger(index)
    }
  })
  
}
const mergeVideo=(fileName)=>{
  let data={
    fileName
  }
  server.post("/admin/mergeVideo",data).then(res=>{
    if(res.status==200){
      form.url=res.data.url
    }
  })
}

golang后端代码

go 复制代码

func (this VideoController) UploadVideo(ctx *gin.Context) {
	file, err := ctx.FormFile("file")
	if err == nil {
            config, _ := ini.Load("./conf/app.ini")
            musiclocal := config.Section("").Key("mlocal").String()
            println(musiclocal)
            nameStr := strings.Split(file.Filename, ".")
            dsn := path.Join("./static/upload/video/"+nameStr[0]+"/", nameStr[1])
            if err := ctx.SaveUploadedFile(file, dsn); err == nil {
                ctx.JSON(200, gin.H{
                        "success": true,
                        "message": "上传成功",
                })
            } else {
                ctx.JSON(400, gin.H{
                        "success": false,
                        "message": "上传失败",
                })
            }
	} else {
            ctx.JSON(400, gin.H{
                    "success": false,
                    "message": "上传失败",
            })
	}
}
func (this VideoController) appendFile(fout *os.File, infile string) {
    fin, err := os.Open(infile)
    if err != nil {
        panic(err)
    }
    defer fin.Close()
    buffer := make([]byte, 1024)
    for {
        n, err := fin.Read(buffer)
        if err != nil {
            if err == io.EOF {
                if n > 0 {
                    fout.Write(buffer[:n])
                }
            } else {
                println(err)
            }
            break
        } else {
            fout.Write(buffer[:n])
        }
    }
}
func (this VideoController) MergeVideos(ctx *gin.Context) {
    name := ctx.PostForm("fileName")
    fileName := strings.Split(name, ".")
    config, _ := ini.Load("./conf/app.ini")
    videolocal := config.Section("").Key("mlocal").String()
    dsn := path.Join("./static/upload/video/" + fileName[0] + "/")
    files, err := ioutil.ReadDir(dsn)
    if err != nil {
        ctx.JSON(400, gin.H{
                "success": false,
                "message": "合并失败",
        })
    } else {
        fileDsn := dsn + "." + fileName[1]
        fout, err := os.OpenFile(fileDsn, os.O_CREATE|os.O_APPEND|os.O_WRONLY, os.ModePerm)
        if err != nil {
            panic(err)
        }
        defer fout.Close()
        if fileInfos, err := os.ReadDir(dsn); err != nil {
            panic(err)
        } else {
            sort.Slice(fileInfos, func(i, j int) bool {
                return files[i].Name() < files[j].Name()
            })
            for _, fileInfo := range fileInfos {
                if fileInfo.Type().IsRegular() {
                    infile := filepath.Join(dsn, fileInfo.Name())
                    this.appendFile(fout, infile)
                }
            }
            fn := path.Join("./static/upload/video/" + fileName[0])
            err3 := os.RemoveAll(fn)
            if err3 != nil {
                println("文件删除失败")
            }
            ctx.JSON(200, gin.H{
                "success": true,
                "message": "合并成功",
                "url":     videolocal + "/static/upload/video/" + name,
            })
        }
    }

}

方法写的有点简略，有感兴趣的小伙伴可以单聊