无法使用JavaMailAPI发送带有附件的邮件

嗨，我想用javaMailAPI发送邮件附件。我的代码是：

public class GmailSender {

    private static String HOST = "smtp.gmail.com";
    private static String USER = "######";
    private static String PASSWORD = "######";
    private static String PORT = "465";
    private static String FROM = "######";
    private static String TO = "######";

    private static String STARTTLS = "true";
    private static String AUTH = "true";
    private static String DEBUG = "true";
    private static String SOCKET_FACTORY = "javax.net.ssl.SSLSocketFactory";
    private static String SUBJECT = "Testing JavaMail API";
    private static String TEXT = "This is a test message from my java application. Just ignore it";

    public static void main(String[] args){
        GmailSender.send();
    } 


    public static void makeAttachment(MimeMessage message){

        try{

            Multipart mp = new MimeMultipart();

            //start Code for Attachment

            String fileName = "c:/tmp/f.txt";
            File f = new File(fileName);


            //read file and make byte array
            FileInputStream fi = new FileInputStream(f);
            byte[] attachmentData = new byte[8000000];

            // Create the message part 
            BodyPart messageBodyPart = new MimeBodyPart();
            // Fill the message
            messageBodyPart.setText("hi");

            Multipart multipart = new MimeMultipart();
            multipart.addBodyPart(messageBodyPart);

            // Part two is attachment
            messageBodyPart = new MimeBodyPart();
            String filename = "c:/tmp/f.txt";
            DataSource source = new FileDataSource(filename);
            messageBodyPart.setDataHandler(new DataHandler(source));
            messageBodyPart.setFileName(filename);
            multipart.addBodyPart(messageBodyPart);

            // Put parts in message
            message.setContent(multipart);



        }catch(Exception e){
            System.out.println(">>Exception "+e);
        }       

    }
    public static synchronized void send() {
        //Use Properties object to set environment properties
        Properties props = new Properties();

        props.put("mail.smtp.host", HOST);
        props.put("mail.smtp.port", PORT);
        props.put("mail.smtp.user", USER);

        props.put("mail.smtp.auth", AUTH);
        props.put("mail.smtp.starttls.enable", STARTTLS);
        props.put("mail.smtp.debug", DEBUG);

        props.put("mail.smtp.socketFactory.port", PORT);
        props.put("mail.smtp.socketFactory.class", SOCKET_FACTORY);
        props.put("mail.smtp.socketFactory.fallback", "false");

        try {

            //Obtain the default mail session
            Session session = Session.getDefaultInstance(props, null);
            session.setDebug(true);

            //Construct the mail message
            MimeMessage message = new MimeMessage(session);
            message.setText(TEXT);
            message.setSubject(SUBJECT);
            message.setFrom(new InternetAddress(FROM));
            message.addRecipient(RecipientType.TO, new InternetAddress(TO));

            makeAttachment(message);

            message.saveChanges();

            //Use Transport to deliver the message
            Transport transport = session.getTransport("smtp");
            transport.connect(HOST, USER, PASSWORD);          

            transport.sendMessage(message, message.getAllRecipients());

            transport.close();

        } catch (Exception e) {
                System.out.println(">>GmailSender "+e);

        }
    }    
}

我得到一个例外：

    javax.activation.UnsupportedDataTypeException: no object DCH for MIME type multipart/mixed; 
    boundary="----=_Part_1_21944831.1329056547036"
    at javax.activation.ObjectDataContentHandler.writeTo(DataHandler.java:877)
    at javax.activation.DataHandler.writeTo(DataHandler.java:302)
    at javax.mail.internet.MimeBodyPart.writeTo(MimeBodyPart.java:1403)
    at javax.mail.internet.MimeMessage.writeTo(MimeMessage.java:1745)
    at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:636)
    at GmailSender.send(GmailSender.java:117)
    at GmailSender.main(GmailSender.java:34)
>>GmailSender javax.mail.MessagingException: IOException while sending message;
  nested exception is:
    javax.activation.UnsupportedDataTypeException: no object DCH for MIME type multipart/mixed; 
    boundary="----=_Part_1_21944831.1329056547036"

---

当我运行您的代码示例时，它可以为我工作，这表明环境中存在差异。我在谷歌上搜索并找到了，我相信这回答了你的问题。

当我运行它时，你的代码示例对我来说很有用，这表明了环境的不同。我通过谷歌搜索找到了答案。

感谢HighlyCaffined，我尝试了你的建议，当我从中输入最新的mail.jar时，代码正常工作。感谢HighlyCaffined，我尝试了你的建议，当我从中输入最新的mail.jar时，代码正常工作。