java自动发送邮件

我希望邮件在特定时间自动发送。我可以发送邮件，但无法使其自动完成。谁能告诉我如何自动发送？以下是我发送邮件的代码：

public class SendEmail {

    String d_email = "[email protected] /cdn-cgi/l/email-protection",
            d_password = "",
            d_host = "smtp.gmail.com",
            d_port = "465",
            m_to = "[email protected] /cdn-cgi/l/email-protection",
            m_subject = "Testing",
            m_text = "Hey, this is the testing email.";

    // Those are the values that have the email information
    public void send(String from, String pass, String host, String port, String to, String subject, String text) {

        Properties props = new Properties();

        // Read properties file.

        props.put("mail.smtp.user", from);
        props.put("mail.smtp.host", host);
        props.put("mail.smtp.port", port);
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.socketFactory.port", port);
        props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
        props.put("mail.smtp.socketFactory.fallback", "false");

        SecurityManager security = System.getSecurityManager();

        try {
            Authenticator auth = new SMTPAuthenticator();
            Session session = Session.getInstance(props, auth);
            MimeMessage msg = new MimeMessage(session);

            msg.setText(text);
            msg.setSubject(subject);
            msg.setFrom(new InternetAddress(from));
            msg.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
            Transport.send(msg);
        } catch (Exception mex) {
            mex.printStackTrace();
        }
    }

    public class SMTPAuthenticator extends javax.mail.Authenticator {

        public PasswordAuthentication getPasswordAuthentication() {
            return new PasswordAuthentication(d_email, d_password);
        }
    }
}

查看java.util.Timer如果这对您来说还不够，请阅读Quartz http://quartz-scheduler.org/- 纯java cron 兼容调度程序。