Base64字符串作为附件

Question

我将PDF文件转换为Base64字符串，现在我想将此字符串用作Java中的电子邮件附件

        MimeMessage message = new MimeMessage(ssn);
        InternetAddress fromAddress = new InternetAddress(from);
        message.setFrom(fromAddress);
        InternetAddress toAddress = new InternetAddress(to);
        message.addRecipient(Message.RecipientType.TO, toAddress);

        message.setSubject(subject);
        message.setContent(body, "text/plain");