Golang分片上传实现与校验方法

const chunkSize = 5 file, _ := os.Open("large-file.zip")
defer file.Close()
fi, _ := file.Stat()
totalSize := fi.Size()
uuid := generateFileID() // 可基于文件路径+时间生成唯一 ID
for i := 0; ; i++ {
chunk := make([]byte, chunkSize)
n, err := file.Read(chunk)
if n <= 0 {
break
}
// 发送第 i 片
uploadChunk(uuid, i, chunk[:n], totalSize)
}

func handleUploadChunk(c *gin.Context) {
    fileID := c.PostForm("file_id")
    indexStr := c.PostForm("chunk_index")
    chunkIndex, _ := strconv.Atoi(indexStr)
    data, _ := c.FormFile("data")
src, _ := data.Open()
defer src.Close()

dir := filepath.Join("tmp", fileID, "chunks")
os.MkdirAll(dir, 0755)

destPath := filepath.Join(dir, fmt.Sprintf("%d.part", chunkIndex))
dest, _ := os.Create(destPath)
io.Copy(dest, src)
dest.Close()

// 更新已接收分片列表（可用 map 或 Redis）
recordReceivedChunk(fileID, chunkIndex)

c.JSON(200, gin.H{"success": true})
}

func mergeChunks(fileID string, total int, outputPath string) error {
    outFile, err := os.Create(outputPath)
    if err != nil {
        return err
    }
    defer outFile.Close()
for i := 0; i < total; i++ {
    chunkPath := filepath.Join("tmp", fileID, "chunks", fmt.Sprintf("%d.part", i))
    chunkData, err := os.ReadFile(chunkPath)
    if err != nil {
        return err
    }
    outFile.Write(chunkData)
}

// 合并成功后删除临时文件
os.RemoveAll(filepath.Join("tmp", fileID))
return nil
}

func calculateSHA256(filePath string) (string, error) {
    f, err := os.Open(filePath)
    if err != nil {
        return "", err
    }
    defer f.Close()
h := sha256.New()
io.Copy(h, f)
return hex.EncodeToString(h.Sum(nil)), nil
}
// 使用方式
originalHash := getOriginalHashFromClient() // 客户端传入
mergedPath := "uploads/" + fileID + ".zip"
actualHash, _ := calculateSHA256(mergedPath)
if originalHash != actualHash {
return errors.New("文件校验失败，数据不一致")
}