无法使用JavaMailAPI发送带有附件的邮件

Question

嗨，我想使用javaMailAPI通过邮件发送附件。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);
        }
    }    
}

我得到了这个例外：

    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"

Answer 1

当我运行您的代码示例时，它对我有效，这表明环境有所不同。我在谷歌上找到了这篇帖子，我相信它回答了你的问题。