go - 从 golang 代码将文件发送到 Google Drive API 会产生错误 : Unsupported content with type: image/jpeg

Question

基于 Google Drive API docs上传文件的正确方法是:

curl -v -H '授权:不记名 mytoken' -F 'metadata={"name": "test3.jpeg"};type=application/json' -F file=@jpeg_image.jpeg 'https ://www.googleapis.com/upload/drive/v3/files?uploadType=multipart'

现在，我需要从 golang 代码执行相同的请求，但我很难将其转换为 golang，这是我经过多次尝试后使用的代码:

// fileBytes are of type []byte
buffer := &bytes.Buffer{}
    multipartWriter := multipart.NewWriter(buffer)
    multipartWriter.WriteField("metadata", "{\"name\": \"test3.jpef\"};type=application/json")
    partHeader := textproto.MIMEHeader{}
    partHeader.Add("Content-Type", "image/jpeg")
    filePartWriter, _ := multipartWriter.CreatePart(partHeader)
    io.Copy(filePartWriter, bytes.NewReader(fileBytes))
    multipartWriter.Close()

    googleDriveRequest, _ := http.NewRequest(http.MethodPost, "https://www.googleapis.com/upload/drive/v3/files?uploadType=multipart", buffer)
    googleDriveRequest.Header.Add("Authorization", "Bearer "+accessToken)
    googleDriveRequest.Header.Add("Content-Type", multipartWriter.FormDataContentType())

    googleDriveAPIResponse, googleDriveAPIError := lib.HttpClient.Do(googleDriveRequest)

使用curl请求成功:

{
 "kind": "drive#file",
 "id": "1DwsbQGP3-QtS5p0iQqRtAjcCCsAfxzGD",
 "name": "test3.jpeg",
 "mimeType": "image/jpeg"
}

使用 Golang，我得到 400:

{\n \"error\": {\n  \"errors\": [\n   {\n    \"domain\": \"global\",\n    \"reason\": \"badContent\",\n    \"message\": \"Unsupported content with type: image/jpeg \"\n   }\n  ],\n  \"code\": 400,\n  \"message\": \"Unsupported content with type: image/jpeg\"\n }\n}\n

我还尝试了 partHeader.Add("Content-Type", "image/jpeg") 的不同值，我尝试了 application/x-www-form-urlencoded 同样，我也注释掉了这一行，并让golang进行检测，但仍然得到相同的错误。

有什么建议或想法吗？

问候，

Answer 1

问题出在您发送的 JSON 元数据中。这是一个可以工作的示例代码(使用适当的错误检查)，

import (
    "bytes"
    "fmt"
    "io"
    "io/ioutil"
    "log"
    "mime/multipart"
    "net/http"
    "net/textproto"
)

func main() {
    accessToken := "YOUR-TOKEN"

    client := http.Client{}
    mediaData, _ := ioutil.ReadFile("test.png")

    body := &bytes.Buffer{}
    writer := multipart.NewWriter(body)

    // JSON Metadata (part-1)
    jsonMetadata := textproto.MIMEHeader{}
    metadata := `{"name": "test.png"}`
    jsonMetadata.Set("Content-Type", "application/json")
    part, _ := writer.CreatePart(jsonMetadata)
    part.Write([]byte(metadata))

    // Image bytes (part-2)
    imageData := textproto.MIMEHeader{}
    partAttach, _ := writer.CreatePart(imageData)
    io.Copy(partAttach, bytes.NewReader(mediaData))
    writer.Close()

    // Request Content Type with boundary
    contentType := fmt.Sprintf("multipart/related; boundary=%s", writer.Boundary())

    // HTTP Request with auth and content type headers
    req, _ := http.NewRequest(http.MethodPost, "https://www.googleapis.com/upload/drive/v3/files?uploadType=multipart", bytes.NewReader(body.Bytes()))
    req.Header.Add("Authorization", "Bearer "+accessToken)
    req.Header.Add("Content-Type", contentType)

    // Send request
    resp, err := client.Do(req)
    if err != nil {
        log.Fatalf("failed to send request: %v", err)
    }
    defer resp.Body.Close()
    content, _ := ioutil.ReadAll(resp.Body)

    log.Printf("http status: %d", resp.StatusCode)
    log.Printf("response: %s", string(content))
}

引用:https://developers.google.com/drive/api/v3/manage-uploads?authuser=1#send_a_multipart_upload_request