如何使用JavaMail将多个文件附加到电子邮件？

Question

以下Java代码用于将文件附加到电子邮件。我想通过电子邮件发送 多个 文件附件。任何建议，将不胜感激。

public class SendMail {

    public SendMail() throws MessagingException {
        String host = "smtp.gmail.com";
        String Password = "mnmnn";
        String from = "[e-mail]";
        String toAddress = "[e-mail]";
        String filename = "C:/Users/hp/Desktop/Write.txt";
        // Get system properties
        Properties props = System.getProperties();
        props.put("mail.smtp.host", host);
        props.put("mail.smtps.auth", "true");
        props.put("mail.smtp.starttls.enable", "true");
        Session session = Session.getInstance(props, null);

        MimeMessage message = new MimeMessage(session);
        message.setFrom(new InternetAddress(from));
        message.setRecipients(Message.RecipientType.TO, toAddress);
        message.setSubject("JavaMail Attachment");
        BodyPart messageBodyPart = new MimeBodyPart();
        messageBodyPart.setText("Here's the file");
        Multipart multipart = new MimeMultipart();
        multipart.addBodyPart(messageBodyPart);
        messageBodyPart = new MimeBodyPart();
        DataSource source = new FileDataSource(filename);
        messageBodyPart.setDataHandler(new DataHandler(source));
        messageBodyPart.setFileName(filename);
        multipart.addBodyPart(messageBodyPart);
        message.setContent(multipart);

        try {
            Transport tr = session.getTransport("smtps");
            tr.connect(host, from, Password);
            tr.sendMessage(message, message.getAllRecipients());
            System.out.println("Mail Sent Successfully");
            tr.close();
        } catch (SendFailedException sfe) {
            System.out.println(sfe);
        }
    }
}`

Answer 1

好吧，自从我完成JavaMail工作已经有一段时间了，但是看起来您可以重复多次此代码：

DataSource source = new FileDataSource(filename);
messageBodyPart.setDataHandler(new DataHandler(source));
messageBodyPart.setFileName(filename);
multipart.addBodyPart(messageBodyPart);

例如，您可以编写一个方法来做到这一点：

private static void addAttachment(Multipart multipart, String filename)
{
    DataSource source = new FileDataSource(filename);
    BodyPart messageBodyPart = new MimeBodyPart();        
    messageBodyPart.setDataHandler(new DataHandler(source));
    messageBodyPart.setFileName(filename);
    multipart.addBodyPart(messageBodyPart);
}

然后从您的主要代码中，只需调用：

addAttachment(multipart, "file1.txt");
addAttachment(multipart, "file2.txt");

等等