Question

我们有发送到个人邮箱的代码，并将带有附件的电子邮件复制到文件系统。

用于复制邮件和附件的代码对于大多数文件都适用，但是文件名过长存在问题。

if (attachment instanceof FileAttachment || attachment.getIsInline()) {
    System.out.println(attachment.getName());
    String FILE_NAME = "C:path\\" + attachment.getName();
    attachment.load(FILE_NAME);

    MimeBodyPart attachmentMime = new MimeBodyPart();
    attachmentMime.setContent(new MimeMultipart(attachment.getContentType()));
    javax.activation.DataSource source = new FileDataSource(FILE_NAME);
    attachmentMime.setDataHandler(new DataHandler(source));
    attachmentMime.setFileName(attachment.getName());
    multipart.addBodyPart(attachmentMime);
}

例如，文件名：“ CRLM人口的SKI17042外科CPT选择的副本。xlsx”显示在电子邮件附件中，名称为“无标题的附件00006.dat”。当我查看创建的.eml文件时，看起来JavaMail在文件名中间插入了一个换行符，这可能是导致问题的原因。

当我在文本编辑器中打开.eml时，我看到带有换行符的标题（请注意，跨越文件名的3/4和7/8行中的换行符：

------=_Part_3_840180718.1542390637623
Content-Type: application/octet-stream; 
    name*0="Copy of SKI17042 surgery CPT choices for CRLM
 population.xls"; name*1=x
Content-Transfer-Encoding: base64
Content-Disposition: attachment; 
    filename*0="Copy of SKI17042 surgery CPT choices for CRLM
 population.xls"; filename*1=x

文件内容很好，如果您将文件放到.xlsx上，则它会在Excel中打开，并具有预期的内容。

有人对解决JavaMail中文件附件名称的问题有任何信息或想法吗？

谢谢！

编辑-解决方案

    Properties props = System.getProperties();

    props.put("mail.mime.splitlongparameters", false);

    Session session = Session.getInstance(props, null);

    createProjectFolder(folder);

    Message message = new MimeMessage(session);
    message.setFrom(new InternetAddress(objectJSON.getString("from"), objectJSON.getString("fromName")));
    message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(objectJSON.getString("to")));
    message.setRecipients(Message.RecipientType.CC, InternetAddress.parse(objectJSON.getString("cc")));
    message.setSubject(objectJSON.getString("subject"));
    message.setSentDate(new SimpleDateFormat("yyyy-MM-dd hh:mm:ss a").parse(objectJSON.getString("date")));

    // create the message part 
    Multipart multipart = new MimeMultipart("mixed");
    MimeBodyPart content = new MimeBodyPart();

    // fill message
    if (objectJSON.getString("body").toLowerCase().contains("html")) {
        content.setContent( objectJSON.getString("body"), "text/html; charset=utf-8" );
    }
    else {
        content.setText(objectJSON.getString("body"), "utf-8");
    }

    multipart.addBodyPart(content);

        if (objectJSON.getInt("hasAttachment") == 1) {

            ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2010_SP2);

            service.setUrl(new URI("https://mail/ews/Exchange.asmx"));

            ExchangeCredentials credentials = new WebCredentials(developerEmail, password);

            service.setCredentials(credentials);

            try {

                EmailMessage messageWithAttachment = EmailMessage.bind(service, new ItemId(emailId));

                    AttachmentCollection attachmentsCol = messageWithAttachment.getAttachments(); 
                    System.out.println("attachments: " + attachmentsCol.getCount());
                    for (int i = 0; i < attachmentsCol.getCount(); i++) { 
                        FileAttachment attachment = (FileAttachment)attachmentsCol.getPropertyAtIndex(i); 

                        if (attachment instanceof FileAttachment || attachment.getIsInline()) {
                            System.out.println(attachment.getName());
                            String FILE_NAME = "C:\\R2D4\\eclipse-workspace\\DataLine\\WebContent\\WEB-INF\\email_attachments\\" + attachment.getName();
                            attachment.load(FILE_NAME);

                            MimeBodyPart attachmentMime = new MimeBodyPart();
                            attachmentMime.setContent(new MimeMultipart(attachment.getContentType()));
                            javax.activation.DataSource source = new FileDataSource(FILE_NAME);
                            attachmentMime.setDataHandler(new DataHandler(source));
                            attachmentMime.setFileName(attachment.getName());
                            multipart.addBodyPart(attachmentMime);

                        } 

                    }

            }
            catch(Exception e) {
                e.printStackTrace();
            }

            service.close();

        }


    // integration
    message.setContent(multipart);
    message.saveChanges();

Answer 1

如果文件名长于60个字符，则会按照RFC 2231中的描述将其拆分为多个参数。看来您处理消息的代码不了解如何处理RFC 2231编码的参数。您可以通过将属性mail.mime.encodeparameters设置为false来禁用所有对RFC 2231编码的使用。您可以通过将{遗憾的是，未记录的）属性mail.mime.splitlongparameters设置为false来禁用长参数的拆分。

好像JavaMail的MimeBodyPart.setFileName在电子邮件中插入换行符，并导致文件名显示为无效

1 个答案: