将 MimeMessage 附加到另一个 MimeMessage

Posted 2023-03-15

【中文标题】将 MimeMessage 附加到另一个 MimeMessage

【英文标题】：Attach a MimeMessage to another MimeMessage

【发布时间】：2019-04-10 02:52:32

【问题描述】：

我有一个 MimeMessage A，想添加另一个 MimeMessage B 作为附件。

我的（不工作）尝试：

MimeBodyPart mimeBodyPart = new MimeBodyPart();
mimeBodyPart.setContent(base64mimeMessage, "message/rfc822");
mimeBodyPart.setHeader("Content-Transfer-Encoding", "base64");
multipart.addBodyPart(mimeBodyPart);

当我尝试签名或加密结果时，这会导致java.io.IOException: unsupported object at com.sun.mail.handlers.message_rfc822.writeTo。

【参考方案1】：

也许它对其他人有帮助，所以这是一个可行的解决方案

MimeBodyPart mimeBodyPart = new MimeBodyPart();
DataSource dataSource = new ByteArrayDataSource(Base64.decode(itemAttachment.getMimeContent(), Base64.DEFAULT), "message/rfc822");
mimeBodyPart.setDataHandler(new DataHandler(dataSource));
multipart.addBodyPart(mimeBodyPart);

【参考方案2】：

Session session = Session.getInstance(new Properties());
MimeMessage mimeMessageToAttach = new MimeMessage(session);

MimeBodyPart attachment = new MimeBodyPart();
String contentType = "message/rfc822; name=mymail.eml";
attachment.setContent(mimeMessageToAttach, contentType);

MimeMultipart multipart = new MimeMultipart();
multipart.addBodyPart(mimeBodyPart);