go 文件上传

func newfileUploadRequest(uri string, form map[string]string, formFileName, path string) error {
    file, err := os.Open(path)
    if err != nil {
        return err
    }
    defer file.Close()

    body := &bytes.Buffer{}
    writer := multipart.NewWriter(body)
    part, err := writer.CreateFormFile(formFileName, filepath.Base(path))
    if err != nil {
        return err
    }
    _, err = io.Copy(part, file)
    if err != nil {
        return err
    }

    for key, val := range form {
        err = writer.WriteField(key, val)
        if err != nil {
            return err
        }
    }
    err = writer.Close()
    if err != nil {
        return err
    }
    req, err := http.NewRequest("POST", uri, body)
    req.Header.Add("Content-Type", writer.FormDataContentType())
    if err != nil {
        return err
    }
    resp, err := http.DefaultClient.Do(req)
    if err != nil {
        return err
    }
    defer resp.Body.Close()
    Body, err := ioutil.ReadAll(resp.Body)
    if err != nil {
        return err
    }
    fmt.Println(string(Body))
    return nil
}

package Network

import (
    "SQL/myDB"
    "fmt"
    "io"
    "logs"
    "mime/multipart"
    "net/http"
    "os"
)

const publicFileDir = "./public"
const maxIconSize = 20 << 20

func alterIcon(w http.ResponseWriter, req *http.Request) {
    var (
        code   int         = Success
        msg    string      = ""
        result interface{} = nil
    )
    defer func() {
        writeHTTPResult(w, code, msg, result)
    }()
    err := req.ParseMultipartForm(32 << 20)
    if err != nil {
        code = errParseForm
        msg = err.Error()
        return
    }
    logs.Print(req.Form)
    logs.Print(req.MultipartForm)
    token := req.FormValue("token")
    code, msg, userID := judgeToken(token)
    if code != Success {
        return
    }
    icon, _, err := req.FormFile("icon")
    if statInterface, ok := icon.(Stat); ok {
        fileInfo, err := statInterface.Stat()
        if err == nil {
            if fileInfo.Size() > (maxIconSize) {
                code = errParseFileFailed
                msg = fmt.Sprint("上传文件不要超过", maxIconSize>>20, "M")
                return
            }
        } else if sizeInterface, ok := icon.(Size); ok {
            if sizeInterface.Size() > (maxIconSize) {
                code = errParseFileFailed
                msg = fmt.Sprint("上传文件不要超过", maxIconSize>>20, "M")
                return
            }
        }
    }
    if err != nil {
        code = errParseFileFailed
        msg = err.Error()
        return
    }
    defer icon.Close()
    code, msg, result = dealAlterIcon(userID, icon)
    return
}
func dealAlterIcon(userID string, icon multipart.File) (code int, msg string, result interface{}) {
    fileName := "/icon/" + userID + ".ico"
    code, msg = saveFile(fileName, icon, publicFileDir, maxIconSize)
    if code != Success {
        return code, msg, nil
    }
    err := myDB.ExecSql("update objects set iconURL = $1 where id = $2", fileName, userID)
    if err != nil {
        return errDBExecFailed, err.Error(), nil
    }
    return Success, "", map[string]string{"IconURL": fileName}
}

func saveFile(fileName string, file multipart.File, fileDir string, maxSize int64) (code int, msg string) {
    File, err := os.OpenFile(publicFileDir+fileName, os.O_WRONLY|os.O_CREATE, 0666)
    if err != nil {
        code = errWriteFileFailed
        msg = err.Error()
        return
    }
    defer File.Close()
    n, err := io.Copy(File, file)
    if err != nil {
        code = errWriteFileFailed
        msg = err.Error()
        return
    }
    if n > (maxSize) {
        os.Remove(fileDir + fileName)
        code = errRequestEntityTooLarge
        msg = fmt.Sprint("上传文件不要超过", maxSize>>20, "M")
        return
    }
    return Success, ""
}

go用multipart form上传文件