public class MailUtils {

    public static void sendMail(String email, String emailMsg)
            throws AddressException, MessagingException {
        // 1.创建一个程序与邮件服务器会话对象 Session

        Properties props = new Properties();
        props.setProperty("mail.transport.protocol", "SMTP");
        props.setProperty("mail.host", "smtp.126.com");
        props.setProperty("mail.smtp.auth", "true");// 指定验证为true

        // 创建验证器
        Authenticator auth = new Authenticator() {
            public PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication("haohao_itcast", "hao12345");
            }
        };

        Session session = Session.getInstance(props, auth);

        // 2.创建一个Message，它相当于是邮件内容
        Message message = new MimeMessage(session);

        message.setFrom(new InternetAddress("haohao_itcast@126.com")); // 设置发送者

        message.setRecipient(RecipientType.TO, new InternetAddress(email)); // 设置发送方式与接收者

        message.setSubject("用户激活");
        // message.setText("这是一封激活邮件，请<a href=‘#‘>点击</a>");

        message.setContent(emailMsg, "text/html;charset=utf-8");

        // 3.创建 Transport用于将邮件发送

        Transport.send(message);
    }
}

public class BirthdayListener implements ServletContextListener{

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        //当web应用启动 开启任务调动---功能在用户的生日当前发送邮件
        //开启一个定时器
        Timer timer = new Timer();
        timer.scheduleAtFixedRate(new TimerTask() {
            
            @Override
            public void run() {
                // 为当前的生日的用户发邮件
                //1、获得今天过生日的人
                //获得今天的日期
                SimpleDateFormat format = new SimpleDateFormat("MM-dd");
                String currentDate = format.format(new Date());
                //根据当前时间从数据查询今天过生日的人
                QueryRunner runner = new QueryRunner(DataSourceUtils.getDataSource());
                String sql = "select * from customer where birthday like ?";
                List<Customer> customerList = null;
                try {
                    customerList = runner.query(sql, new BeanListHandler<Customer>(Customer.class) ,"%"+currentDate+"%");
                } catch (SQLException e) {
                    e.printStackTrace();
                } //08-18
                //2、发邮件
                if(customerList!=null&&customerList.size()>0){
                    for(Customer c : customerList){
                        String emailMsg = "亲爱的："+c.getRealname()+",生日快乐！";
                        try {
                            MailUtils.sendMail(c.getEmail(), "生日祝福", emailMsg);
                            System.out.println(c.getRealname()+"邮件发送完毕");
                        } catch (MessagingException e) {
                            e.printStackTrace();
                        }
                    }
                }
                
                
            }
        }, new Date(), 1000*10);
        //实际开发中起始时间是一个固定的时间
        //实际开发中间隔时间是1天
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        
    }

}