<form action="/upload" method="post" enctype="multipart/form-data">
  <input type="file" name="files" multiple>
  <button type="submit">上传文件</button>
</form>

package main

import (
    "fmt"
    "io"
    "net/http"
    "os"
    "path/filepath"
)

func uploadHandler(w http.ResponseWriter, r *http.Request) {
    // 只允许 POST 方法
    if r.Method != "POST" {
        http.Error(w, "方法不被允许", http.StatusMethodNotAllowed)
        return
    }

    // 解析 multipart 表单，内存限制 32MB
    err := r.ParseMultipartForm(32 << 20)
    if err != nil {
        http.Error(w, "解析表单失败", http.StatusBadRequest)
        return
    }

    // 获取名为 "files" 的所有上传文件
    files := r.MultipartForm.File["files"]

    var uploadedFiles []string
    for _, fileHeader := range files {
        // 打开上传的文件
        file, err := fileHeader.Open()
        if err != nil {
            http.Error(w, "无法打开文件", http.StatusInternalServerError)
            return
        }
        defer file.Close()

        // 创建目标文件（防止路径遍历攻击）
        filename := filepath.Base(fileHeader.Filename)
        dst, err := os.Create("./uploads/" + filename)
        if err != nil {
            http.Error(w, "创建本地文件失败", http.StatusInternalServerError)
            return
        }

        // 复制文件内容
        _, err = io.Copy(dst, file)
        dst.Close() // 立即关闭
        if err != nil {
            http.Error(w, "保存文件失败", http.StatusInternalServerError)
            return
        }

        uploadedFiles = append(uploadedFiles, filename)
    }

    // 返回成功信息
    fmt.Fprintf(w, "成功上传 %d 个文件: %v", len(uploadedFiles), uploadedFiles)
}

func main() {
    // 确保上传目录存在
    os.MkdirAll("./uploads", os.ModePerm)

    http.HandleFunc("/upload", uploadHandler)
    http.Handle("/", http.FileServer(http.Dir("."))) // 提供静态页面

    fmt.Println("服务器启动在 :8080")
    http.ListenAndServe(":8080", nil)
}

go run main.go