How to use Java to develop the site online warning function of CMS system

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class SiteMonitor {
    public static void main(String[] args) {
        String url = "http://www.example.com";
        try {
            URL siteUrl = new URL(url);
            HttpURLConnection connection = (HttpURLConnection) siteUrl.openConnection();
            int responseCode = connection.getResponseCode();
            if (responseCode == 200) {
                System.out.println("站点正常运行");
            } else {
                System.out.println("站点异常，响应码：" + responseCode);
                // TODO 发送报警通知
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.util.Timer;
import java.util.TimerTask;

public class SiteMonitor {
    public static void main(String[] args) {
        TimerTask task = new TimerTask() {
            @Override
            public void run() {
                checkSiteStatus();
            }
        };

        Timer timer = new Timer();
        long delay = 0;
        long period = 60 * 1000; // 每分钟执行一次
        timer.schedule(task, delay, period);
    }

    private static void checkSiteStatus() {
        // TODO 监控站点的运行状态
    }
}

import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.util.Properties;

public class EmailSender {
    public static void main(String[] args) {
        String to = "admin@example.com";
        String subject = "站点异常预警";
        String body = "站点出现异常，请及时处理！";

        sendEmail(to, subject, body);
    }

    private static void sendEmail(String to, String subject, String body) {
        String from = "noreply@example.com";
        String host = "smtp.example.com";
        String username = "username";
        String password = "password";

        Properties properties = new Properties();
        properties.put("mail.smtp.auth", "true");
        properties.put("mail.smtp.starttls.enable", "true");
        properties.put("mail.smtp.host", host);
        properties.put("mail.smtp.port", "587");

        Session session = Session.getInstance(properties, new Authenticator() {
            @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(username, password);
            }
        });

        try {
            MimeMessage message = new MimeMessage(session);
            message.setFrom(new InternetAddress(from));
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
            message.setSubject(subject);
            message.setText(body);

            Transport.send(message);
            System.out.println("邮件通知已发送");
        } catch (MessagingException e) {
            e.printStackTrace();
        }
    }
}