用Java创建一个.eml(email)文件

Question

谁知道怎么做？我收到了电子邮件的所有信息(正文,主题,从,到,cc,密送),需要生成一个.eml文件.

Answer 1

您可以构造javax.mail.Message对象(或者已经从邮件服务器构造它),然后您可以使用writeTo()方法将其保存到文件.有关更多信息,请参阅JavaMail API.

Answer 2

您可以使用以下代码创建eml文件.它可以与雷鸟以及其他电子邮件客户端一起使用:

public static void createMessage(String to, String from, String subject, String body, List<File> attachments) {
    try {
        Message message = new MimeMessage(Session.getInstance(System.getProperties()));
        message.setFrom(new InternetAddress(from));
        message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(to));
        message.setSubject(subject);
        // create the message part 
        MimeBodyPart content = new MimeBodyPart();
        // fill message
        content.setText(body);
        Multipart multipart = new MimeMultipart();
        multipart.addBodyPart(content);
        // add attachments
        for(File file : attachments) {
            MimeBodyPart attachment = new MimeBodyPart();
            DataSource source = new FileDataSource(file);
            attachment.setDataHandler(new DataHandler(source));
            attachment.setFileName(file.getName());
            multipart.addBodyPart(attachment);
        }
        // integration
        message.setContent(multipart);
        // store file
        message.writeTo(new FileOutputStream(new File("c:/mail.eml")));
    } catch (MessagingException ex) {
        Logger.getLogger(Mailkit.class.getName()).log(Level.SEVERE, null, ex);
    } catch (IOException ex) {
        Logger.getLogger(Mailkit.class.getName()).log(Level.SEVERE, null, ex);
    }
}

Answer 3

EML文件只是纯文本文件.标题通过空行与主体分开.标题看起来像这样:

From: "DR CLEMENT OKON" <drclement@nigerianspam.com>
To: "You" <you@yourdomain.com>
Subject: REQUEST FOR URGENT BUSINESS RELATIONSHIP 
Date: Tue, 30 Sep 2008 09:42:47 -0400

有关更多信息,官方规范是RFC 2822.它实际上并不像某些RFC那样难以阅读.

编辑:当我说"纯文本"时,我应该想一下.我真的是指普通的ASCII - 而不是8位"扩展ASCII" - 直到字符127.如果你想要超过7位,你需要某种编码,事情变得复杂.