Golang Writer.CreatePart方法代码示例

func writeJSONPart(writer *multipart.Writer, contentType string, body Body, compressed bool) (err error) {
	bytes, err := json.Marshal(body)
	if err != nil {
		return err
	}
	if len(bytes) < kMinCompressedJSONSize {
		compressed = false
	}

	partHeaders := textproto.MIMEHeader{}
	partHeaders.Set("Content-Type", contentType)
	if compressed {
		partHeaders.Set("Content-Encoding", "gzip")
	}
	part, err := writer.CreatePart(partHeaders)
	if err != nil {
		return err
	}

	if compressed {
		gz := gzip.NewWriter(part)
		_, err = gz.Write(bytes)
		gz.Close()
	} else {
		_, err = part.Write(bytes)
	}
	return
}

// Write the attachment to the specified multipart writer.
func (a Attachment) Write(w *multipart.Writer) error {
	headers := make(textproto.MIMEHeader)
	if len(a.Filename) != 0 {
		headers.Add("Content-Type", fmt.Sprintf("%s; name=%s", a.ContentType, a.Filename))
	} else {
		headers.Add("Content-Type", a.ContentType)
	}
	if a.Encoded {
		headers.Add("Content-Transfer-Encoding", "base64")
	} else {
		headers.Add("Content-Transfer-Encoding", "quoted-printable")
	}
	p, err := w.CreatePart(headers)
	if err != nil {
		return err
	}
	if a.Encoded {
		if _, err := p.Write([]byte(a.Content)); err != nil {
			return err
		}
	} else {
		q := quotedprintable.NewWriter(p)
		if _, err := q.Write([]byte(a.Content)); err != nil {
			return err
		}
		return q.Close()
	}
	return nil
}

// Adds a new part to the given multipart writer, containing the given revision.
// The revision will be written as a nested multipart body if it has attachments.
func (db *Database) WriteRevisionAsPart(revBody Body, isError bool, compressPart bool, writer *multipart.Writer) error {
	partHeaders := textproto.MIMEHeader{}
	docID, _ := revBody["_id"].(string)
	revID, _ := revBody["_rev"].(string)
	if len(docID) > 0 {
		partHeaders.Set("X-Doc-ID", docID)
		partHeaders.Set("X-Rev-ID", revID)
	}

	if hasInlineAttachments(revBody) {
		// Write as multipart, including attachments:
		// OPT: Find a way to do this w/o having to buffer the MIME body in memory!
		var buffer bytes.Buffer
		docWriter := multipart.NewWriter(&buffer)
		contentType := fmt.Sprintf("multipart/related; boundary=%q",
			docWriter.Boundary())
		partHeaders.Set("Content-Type", contentType)
		db.WriteMultipartDocument(revBody, docWriter, compressPart)
		docWriter.Close()
		content := bytes.TrimRight(buffer.Bytes(), "\r\n")

		part, err := writer.CreatePart(partHeaders)
		if err == nil {
			_, err = part.Write(content)
		}
		return err
	} else {
		// Write as JSON:
		contentType := "application/json"
		if isError {
			contentType += `; error="true"`
		}
		return writeJSONPart(writer, contentType, revBody, compressPart)
	}
}

// Writes a revision to a MIME multipart writer, encoding large attachments as separate parts.
func (db *Database) WriteMultipartDocument(body Body, writer *multipart.Writer) {
	// First extract the attachments that should follow:
	following := []attInfo{}
	for name, value := range BodyAttachments(body) {
		meta := value.(map[string]interface{})
		var info attInfo
		info.contentType, _ = meta["content_type"].(string)
		info.data, _ = decodeAttachment(meta["data"])
		if info.data != nil && len(info.data) > kMaxInlineAttachmentSize {
			info.name = name
			following = append(following, info)
			delete(meta, "data")
			meta["follows"] = true
		}
	}

	// Write the main JSON body:
	jsonOut, _ := json.Marshal(body)
	partHeaders := textproto.MIMEHeader{}
	partHeaders.Set("Content-Type", "application/json")
	part, _ := writer.CreatePart(partHeaders)
	part.Write(jsonOut)

	// Write the following attachments
	for _, info := range following {
		partHeaders := textproto.MIMEHeader{}
		if info.contentType != "" {
			partHeaders.Set("Content-Type", info.contentType)
		}
		partHeaders.Set("Content-Disposition", fmt.Sprintf("attachment; filename=%q", info.name))
		part, _ := writer.CreatePart(partHeaders)
		part.Write(info.data)
	}
}

func createFormFile(writer *multipart.Writer, fieldname, filename string) {
	// Try to open the file.
	file, err := os.Open(filename)
	if err != nil {
		panic(err)
	}
	defer file.Close()

	// Create a new form-data header with the provided field name and file name.
	// Determine Content-Type of the file by its extension.
	h := textproto.MIMEHeader{}
	h.Set("Content-Disposition", fmt.Sprintf(
		`form-data; name="%s"; filename="%s"`,
		escapeQuotes(fieldname),
		escapeQuotes(filepath.Base(filename)),
	))
	h.Set("Content-Type", "application/octet-stream")
	if ct := mime.TypeByExtension(filepath.Ext(filename)); ct != "" {
		h.Set("Content-Type", ct)
	}
	part, err := writer.CreatePart(h)
	if err != nil {
		panic(err)
	}

	// Copy the content of the file we have opened not reading the whole
	// file into memory.
	_, err = io.Copy(part, file)
	if err != nil {
		panic(err)
	}
}

func createBlobletPartWriter(i int, path string, size int64, hash string, writer *multipart.Writer) (io.Writer, error) {
	h := make(textproto.MIMEHeader)
	h.Set("Content-Disposition", fmt.Sprintf(`form-data; name="bloblet-%d"; path="%s"; filename="%s"; hash="%s"`, i, path, bloblet.BlobletFileName, hash))
	h.Set("Content-Type", "application/zip")
	h.Set("Content-Length", fmt.Sprintf("%d", size))
	h.Set("Content-Transfer-Encoding", "binary")
	return writer.CreatePart(h)
}

func createZipPartWriter(zipStats os.FileInfo, writer *multipart.Writer) (io.Writer, error) {
	h := make(textproto.MIMEHeader)
	h.Set("Content-Disposition", `form-data; name="application"; filename="application.zip"`)
	h.Set("Content-Type", "application/zip")
	h.Set("Content-Length", fmt.Sprintf("%d", zipStats.Size()))
	h.Set("Content-Transfer-Encoding", "binary")
	return writer.CreatePart(h)
}

func createJpegFormFile(w *multipart.Writer, fieldname, filename string) (io.Writer, error) {
	h := make(textproto.MIMEHeader)
	h.Set("Content-Disposition",
		fmt.Sprintf(`form-data; name="%s"; filename="%s"`,
			escapeQuotes(fieldname), escapeQuotes(filename)))
	// Major change from the stock function is to declare this with
	// type == image/jpeg, otherwise Shutterfly's API will choke on
	// the request:
	h.Set("Content-Type", "image/jpeg")
	return w.CreatePart(h)
}

/*
 * extra.CheckCrc:
 *      0:     不进行crc32校验
 *      1:     以writeMultipart自动生成crc32的值，进行校验
 *      2:     以extra.Crc32的值，进行校验
 *      other: 和2一样， 以 extra.Crc32的值，进行校验
 */
func writeMultipart(writer *multipart.Writer, uptoken, key string, hasKey bool, extra *PutExtra) (err error) {

	if extra == nil {
		extra = &PutExtra{}
	}

	//token
	if err = writer.WriteField("token", uptoken); err != nil {
		return
	}

	//key
	if hasKey {
		if err = writer.WriteField("key", key); err != nil {
			return
		}
	}

	// extra.Params
	if extra.Params != nil {
		for k, v := range extra.Params {
			err = writer.WriteField(k, v)
			if err != nil {
				return
			}
		}
	}

	//extra.CheckCrc
	if extra.CheckCrc != 0 {
		err = writer.WriteField("crc32", strconv.FormatInt(int64(extra.Crc32), 10))
		if err != nil {
			return
		}
	}

	//file
	head := make(textproto.MIMEHeader)

	// default the filename is same as key , but ""
	var fileName = key
	if fileName == "" {
		fileName = "filename"
	}

	head.Set("Content-Disposition",
		fmt.Sprintf(`form-data; name="file"; filename="%s"`, escapeQuotes(fileName)))
	if extra.MimeType != "" {
		head.Set("Content-Type", extra.MimeType)
	}

	_, err = writer.CreatePart(head)
	return err
}

// CreateFormFile creates a form file
func CreateFormFile(w *multipart.Writer, fieldname, filename, contentType string) (io.Writer, error) {
	h := make(textproto.MIMEHeader)
	h.Set("Content-Type", contentType)
	h.Set("Content-Disposition",
		fmt.Sprintf(`form-data; name="%s"; filename="%s"`,
			escapeQuotes(fieldname), escapeQuotes(filename)))
	if contentType == "" {
		contentType = "application/octet-stream"
	}
	return w.CreatePart(h)
}

func multipartMIME(
	writer *multipart.Writer,
	msg string,
	attachments []*Attachment,
) error {
	// write message
	mh := make(textproto.MIMEHeader)
	mh.Add("Content-Type", "text/plain")
	mh.Add("Content-Transfer-Encoding", "base64")
	msgWriter, err := writer.CreatePart(mh)
	if err != nil {
		return log.Error(err)
	}
	_, err = io.WriteString(msgWriter, base64.Encode([]byte(msg)))
	if err != nil {
		return log.Error(err)
	}

	// write attachments
	for _, attachment := range attachments {
		mh = make(textproto.MIMEHeader)
		base := filepath.Base(attachment.Filename)
		if attachment.ContentType != "" {
			mh.Add("Content-Type", attachment.ContentType)
		} else {
			ct := mime.TypeByExtension(filepath.Ext(base))
			if ct != "" {
				mh.Add("Content-Type", ct)
			} else {
				mh.Add("Content-Type", "application/octet-stream")
			}
		}
		mh.Add("Content-Transfer-Encoding", "base64")
		mh.Add("Content-Disposition", "attachment; filename="+base)
		if attachment.Inline {
			mh.Add("Content-Disposition", "inline")
		}
		attachmentWriter, err := writer.CreatePart(mh)
		if err != nil {
			return log.Error(err)
		}
		encoder := base64.NewEncoder(attachmentWriter)
		if _, err := io.Copy(encoder, attachment.Reader); err != nil {
			return log.Error(err)
		}
		if err := encoder.Close(); err != nil {
			return log.Error(err)
		}
	}
	return nil
}

func appendPart(w *multipart.Writer, headers func(h textproto.MIMEHeader), body string) {
	if body == "" {
		return
	}

	h := textproto.MIMEHeader{}
	h.Set("Content-Transfer-Encoding", "quoted-printable")
	headers(h)
	partW, err := w.CreatePart(h)
	log.Panice(err, "create MIME part")
	quoW := quotedprintable.NewWriter(partW)
	defer quoW.Close()
	io.WriteString(quoW, body)
}

// Write the body of the email to the specified writer.
func (e *Email) writeBody(w *multipart.Writer) error {
	var (
		buff      = &bytes.Buffer{}
		altWriter = multipart.NewWriter(buff)
	)
	p, err := w.CreatePart(textproto.MIMEHeader{
		"Content-Type": []string{
			fmt.Sprintf("multipart/alternative; boundary=%s", altWriter.Boundary()),
		},
	})
	if err != nil {
		return err
	}
	if e.Text == "" {
		e.Text = sanitize.HTML(e.Html)
	}
	if e.Html == "" {
		e.Html = toHTML(e.Text)
	}
	if err := (Attachment{
		ContentType: "text/plain; charset=utf-8",
		Content:     e.Text,
	}.Write(altWriter)); err != nil {
		return err
	}
	if err := (Attachment{
		ContentType: "text/html; charset=utf-8",
		Content:     e.Html,
	}.Write(altWriter)); err != nil {
		return err
	}
	if err := altWriter.Close(); err != nil {
		return err
	}
	if _, err := io.Copy(p, buff); err != nil {
		return err
	}
	return nil
}

// Writes a revision to a MIME multipart writer, encoding large attachments as separate parts.
func (db *Database) WriteMultipartDocument(body Body, writer *multipart.Writer, compress bool) {
	// First extract the attachments that should follow:
	following := []attInfo{}
	for name, value := range BodyAttachments(body) {
		meta := value.(map[string]interface{})
		if meta["stub"] != true {
			var err error
			var info attInfo
			info.contentType, _ = meta["content_type"].(string)
			info.data, err = decodeAttachment(meta["data"])
			if info.data == nil {
				base.Warn("Couldn't decode attachment %q of doc %q: %v", name, body["_id"], err)
				meta["stub"] = true
				delete(meta, "data")
			} else if len(info.data) > kMaxInlineAttachmentSize {
				info.name = name
				following = append(following, info)
				meta["follows"] = true
				delete(meta, "data")
			}
		}
	}

	// Write the main JSON body:
	writeJSONPart(writer, "application/json", body, compress)

	// Write the following attachments
	for _, info := range following {
		partHeaders := textproto.MIMEHeader{}
		if info.contentType != "" {
			partHeaders.Set("Content-Type", info.contentType)
		}
		partHeaders.Set("Content-Disposition", fmt.Sprintf("attachment; filename=%q", info.name))
		part, _ := writer.CreatePart(partHeaders)
		part.Write(info.data)
	}
}

//.........这里部分代码省略.........
			return nil, err
		}
		header = textproto.MIMEHeader{}
		// Write the start of our `multipart/mixed` body.
		_, err = fmt.Fprintf(buffer, "--%s%s", mixedw.Boundary(), crlf)
		if err != nil {
			return nil, err
		}
	}

	var altw *multipart.Writer
	if m.Body != "" && m.HTMLBody != "" {
		// Nested multipart writer for our `multipart/alternative` body.
		altw = multipart.NewWriter(buffer)

		header.Add("Content-Type", fmt.Sprintf("multipart/alternative;%s boundary=%s", crlf, altw.Boundary()))
		err := writeHeader(buffer, header)
		if err != nil {
			return nil, err
		}
	}

	// Only include an empty plain text body if the html body is also empty.
	if m.Body != "" || m.Body == "" && m.HTMLBody == "" {
		if altw != nil {
			header = textproto.MIMEHeader{}
		}
		header.Add("Content-Type", "text/plain; charset=utf-8")
		header.Add("Content-Transfer-Encoding", "quoted-printable")
		//header.Add("Content-Transfer-Encoding", "base64")

		var writer io.Writer
		if altw != nil {
			partw, err := altw.CreatePart(header)
			if err != nil {
				return nil, err
			}
			writer = partw
		} else {
			writer = buffer
			err = writeHeader(buffer, header)
			if err != nil {
				return nil, err
			}
		}

		bodyBytes := []byte(m.Body)
		//encoder := NewBase64MimeEncoder(writer)
		encoder := qprintable.NewEncoder(qprintable.DetectEncoding(m.Body), writer)
		_, err = encoder.Write(bodyBytes)
		if err != nil {
			return nil, err
		}
		err = encoder.Close()
		if err != nil {
			return nil, err
		}
	}

	if m.HTMLBody != "" {
		if altw != nil {
			header = textproto.MIMEHeader{}
		}
		header.Add("Content-Type", "text/html; charset=utf-8")
		//header.Add("Content-Transfer-Encoding", "quoted-printable")
		header.Add("Content-Transfer-Encoding", "base64")