如何为使用spring的JavaMailSenderImpl发送的电子邮件设置内容类型

<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
    <property name="host" value="your_smtp_host" />
    <property name="port" value="your_smtp_port" />
    <property name="username" value="your_username" />
    <property name="password" value="your_password" />
    <property name="javaMailProperties">
        <props>
            <prop key="mail.smtp.auth">true</prop>
            <prop key="mail.smtp.starttls.enable">true</prop>
        </props>
    </property>
</bean>

@Autowired
private JavaMailSender mailSender;

public void sendEmail() {
    MimeMessage message = mailSender.createMimeMessage();
    MimeMessageHelper helper = new MimeMessageHelper(message);

    try {
        helper.setSubject("Your email subject");
        helper.setText("Your email content", true); // 设置邮件内容类型为HTML
        helper.setTo("recipient@example.com");
        mailSender.send(message);
    } catch (MessagingException e) {
        e.printStackTrace();
    }
}