如何使用java发送电子邮件？

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

public class EmailSender {
    public static void main(String[] args) {
        // 配置SMTP服务器和认证信息
        String host = "smtp.example.com";
        String username = "your_username";
        String password = "your_password";

        // 创建Properties对象，设置邮件服务器和认证信息
        Properties props = new Properties();
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.host", host);
        props.put("mail.smtp.port", "587");

        // 创建Session对象
        Session session = Session.getInstance(props, new Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(username, password);
            }
        });

        try {
            // 创建MimeMessage对象
            Message message = new MimeMessage(session);

            // 设置发件人
            message.setFrom(new InternetAddress("sender@example.com"));

            // 设置收件人
            message.setRecipients(Message.RecipientType.TO, InternetAddress.parse("recipient@example.com"));

            // 设置邮件主题
            message.setSubject("Hello JavaMail");

            // 设置邮件内容
            message.setText("This is a test email sent from Java.");

            // 发送邮件
            Transport.send(message);

            System.out.println("Email sent successfully.");
        } catch (MessagingException e) {
            e.printStackTrace();
        }
    }
}