Java - SimpleMimeMessage 未设置主题

Question

我使用 Apache Commons Mail 并发现根本没有使用电子邮件主题(以及字符编码等其他设置):

    props.put("mail.smtp.host", "localhost");
    Session s = Session.getInstance(props, null);
    s.setDebug(true);

    MimeMessage message = new MimeMessage(s);
    message.setHeader("Content-Type", "text/plain; charset=UTF-8");
    message.addHeader("Content-Transfer-Encoding", "quoted-printable");
    message.setFrom(new InternetAddress("me@home.com"));
    message.addRecipient(javax.mail.Message.RecipientType.TO, new InternetAddress("you@abroad.com"));
    String subj = MimeUtility.encodeText("");
    message.setSubject("my subject with specials äöü");

    message.setText("Some text with special äöü");
    Transport.send(message);

调试输出显示:

 DEBUG SMTP: useEhlo true, useAuth false
 DEBUG SMTP: trying to connect to host "localhost", port 25, isSSL false
 220 mydomain ESMTP Postfix
 DEBUG SMTP: connected to host "localhost", port: 25

 EHLO MyComputer
 250-PIPELINING
 250-SIZE 10485760
 250-VRFY
 250-ETRN
 250-ENHANCEDSTATUSCODES
 250-8BITMIME
 250 DSN
 DEBUG SMTP: Found extension "PIPELINING", arg ""
 DEBUG SMTP: Found extension "SIZE", arg "10485760"
 DEBUG SMTP: Found extension "VRFY", arg ""
 DEBUG SMTP: Found extension "ETRN", arg ""
 DEBUG SMTP: Found extension "ENHANCEDSTATUSCODES", arg ""
 DEBUG SMTP: Found extension "8BITMIME", arg ""
 DEBUG SMTP: Found extension "DSN", arg ""
 DEBUG SMTP: use8bit false
 MAIL FROM:<me@home.com>
 250 2.1.0 Ok
 RCPT TO:<you@abroad.com>
 250 2.1.5 Ok
 DEBUG SMTP: Verified Addresses
 DEBUG SMTP:   you@abroad.com
 DATA
 354 End data with <CR><LF>.<CR><LF>

 Some text with specials =C3=A4=C3=B6=C3=BC
 .
 250 2.0.0 Ok: queued as 9F623345F99
 QUIT
 221 2.0.0 Bye

据我了解，主题应该设置在 SMTP 消息的数据部分。

我该如何解决这个问题？

Answer 1

如果你看一下这个(抱歉有缓存的链接，但 Oracle 似乎已(重新)移动了此链接或其他内容):

• http://webcache.googleusercontent.com/search?q=cache:CNbquKi8OesJ:forums.sun.com/thread.jspa%3FthreadID%3D5360448+setSubject+commons+email+doesn 't+work&cd=3&hl=en&ct=clnk&gl=us&client=firefox-a

Apache Commons 似乎在某种程度上影响了 Java Mail。您提供的示例似乎是发送邮件的标准 Java Mail 方式。那么，您可以尝试:

• 从类路径中删除 commons-email JAR 并重试上述操作，
  • 或者使用其他示例，例如从这里:http://www.go4expert.com/forums/showthread.php?t=3649
• 使用公共(public)电子邮件网站的(第一个)示例:http://commons.apache.org/email/userguide.html