如何在Javax.mail中设置Content-ID图像的样式？

import javax.mail.*;
import javax.mail.internet.*;
import java.util.*;

public class EmailSender {
    public static void main(String[] args) {
        // 邮件服务器配置
        String host = "smtp.example.com";
        String username = "your_username";
        String password = "your_password";

        // 发件人和收件人
        String from = "sender@example.com";
        String to = "recipient@example.com";

        // 创建邮件会话
        Properties props = new Properties();
        props.put("mail.smtp.host", host);
        props.put("mail.smtp.auth", "true");
        Session session = Session.getInstance(props, new Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(username, password);
            }
        });

        try {
            // 创建邮件内容
            MimeMessage message = new MimeMessage(session);
            message.setFrom(new InternetAddress(from));
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
            message.setSubject("Sample Email");

            // 创建邮件的多部分内容
            MimeMultipart multipart = new MimeMultipart();

            // 创建文本部分
            MimeBodyPart textPart = new MimeBodyPart();
            textPart.setText("This is the text content of the email.");

            // 创建图像部分
            MimeBodyPart imagePart = new MimeBodyPart();
            imagePart.setDataHandler(new DataHandler("path_to_image", "image/jpeg"));
            imagePart.setContentID("<image_cid>");

            // 将部分添加到多部分内容中
            multipart.addBodyPart(textPart);
            multipart.addBodyPart(imagePart);

            // 设置邮件内容为多部分内容
            message.setContent(multipart);

            // 发送邮件
            Transport.send(message);
            System.out.println("Email sent successfully.");
        } catch (MessagingException e) {
            e.printStackTrace();
        }
    }
}