我的应用程序需要发送一个文本文件,需要先将它生成为一个字符串。文本包含非ASCII符号,所以我希望使用UTF-8编码。我尝试了很多变量,但是所有做法都只能得到一些问号作为附件。当我将同样的文本作为消息正文发送时,它可以正常工作。
这是生成带有附件的MimeBodyPart的代码行:
提前感谢。 Timofey.
更新
阅读了你们的回复后,再进行了一些不成功的实验后,我认为最好公布我的邮件发送代码。 我有一个Mailer类,它负责发送邮件,其他类只需调用其静态sendMessage()方法即可发送消息。而且它全部在Google App Engine上运行。
String attachment = "Привет";
messageBodyPart.setContent(new String(attachment.getBytes("UTF-8"),
"UTF-8"),"text/plain; charset=UTF-8");
我也尝试过不进行任何转换,仅使用字节串,现在正试图从字节串生成字符串...我做错了什么?(我记得在另一个项目中这样做是可以的,但我现在无法访问它的源代码)。提前感谢。 Timofey.
更新
阅读了你们的回复后,再进行了一些不成功的实验后,我认为最好公布我的邮件发送代码。 我有一个Mailer类,它负责发送邮件,其他类只需调用其静态sendMessage()方法即可发送消息。而且它全部在Google App Engine上运行。
public static void sendMessage(String to, String subject, String msgBody,
String attachment) throws AddressException, MessagingException {
Properties props = new Properties();
Session mailSession = Session.getDefaultInstance(props, null);
Message msg = new MimeMessage(mailSession);
String email = "bla-bla-bla"; // userService.getCurrentUser().getEmail();
msg.setFrom(new InternetAddress(email));
msg.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
InternetAddress[] addresses = { new InternetAddress("bla-bla-bla") };
msg.setReplyTo(addresses);
msg.setSubject(subject);
Calendar cal = Calendar.getInstance();
String fileName = cal.get(Calendar.YEAR) + "_"
+ cal.get(Calendar.MONTH) + "_"
+ cal.get(Calendar.DAY_OF_MONTH) + "_"
+ cal.get(Calendar.HOUR_OF_DAY) + "_"
+ cal.get(Calendar.MINUTE) + "_" + cal.get(Calendar.SECOND)
+ "_" + cal.get(Calendar.MILLISECOND) + ".txt";
// create the message part
MimeBodyPart messageBodyPart = new MimeBodyPart();
// fill message
// Here we should have the msgBody.
// Sending attachment contents for debugging only.
messageBodyPart.setText(attachment + " - 4", "UTF-8", "plain");
Multipart multipart = new MimeMultipart();
multipart.addBodyPart(messageBodyPart);
MimeBodyPart att = new MimeBodyPart();
att.setText(attachment, "UTF-8", "plain");
att.addHeader("Content-Type", "text/plain; charset=UTF-8");
att.setFileName(fileName);
multipart.addBodyPart(att);
// Put parts in message
msg.setContent(multipart);
Transport.send(msg);
}
并且在另一个类中调用这个东西的行是:
Mailer.sendMessage("mymail@example.com", "Test", "No body", "Привет, Я кусок текста");
而邮件的原始源代码,奇怪的是(省略了看似无关紧要的标头):
Message-ID: <00163662e7107ccbe3049c1402fb@google.com>
Date: Sat, 12 Feb 2011 11:21:01 +0000
Subject: Pages
From: mymail@example.com
To: mymail@example.com
Content-Type: multipart/mixed; boundary=00163662e7107ccbd4049c1402fa
--00163662e7107ccbd4049c1402fa
Content-Type: text/plain; charset=KOI8-R; format=flowed; delsp=yes
Content-Transfer-Encoding: base64
8NLJ18XULCDxIMvV08/LINTFy9PUwSAtIDQNCg==
--00163662e7107ccbd4049c1402fa
Content-Type: text/plain; charset=US-ASCII; name="2011_1_12_11_21_1_691.txt"
Content-Disposition: attachment; filename="2011_1_12_11_21_1_691.txt"
Content-Transfer-Encoding: base64
Pz8/Pz8/LCA/ID8/Pz8/ID8/Pz8/Pw==
--00163662e7107ccbd4049c1402fa--
我就是不明白,为什么字符集与我尝试设置的不同,它们从哪里来的。