java 使用监听器完成定时生日祝福

阳光穿透心脏的1/2处 2022-04-08 11:44 259阅读 0赞

### 监听ServletContext域的创建与销毁的监听器ServletContextListener ###

1.Servlet域的生命周期：

何时创建：服务器启动创建

何时销毁：服务器关闭销毁

2.监听器的编写步骤：

（1）编写一个监听器类去实现监听器接口

（2）覆盖监听器的方法

（3）需要在web.xml中进行配置---注册

Customer主体

package domain;
    
    public class Customer {
    
    	private int id;
    	private String username;
    	private String password;
    	private String realname;
    	private String birthday;
    	private String email;
    	public int getId() {
    		return id;
    	}
    	public void setId(int id) {
    		this.id = id;
    	}
    	public String getUsername() {
    		return username;
    	}
    	public void setUsername(String username) {
    		this.username = username;
    	}
    	public String getPassword() {
    		return password;
    	}
    	public void setPassword(String password) {
    		this.password = password;
    	}
    	public String getRealname() {
    		return realname;
    	}
    	public void setRealname(String realname) {
    		this.realname = realname;
    	}
    	public String getBirthday() {
    		return birthday;
    	}
    	public void setBirthday(String birthday) {
    		this.birthday = birthday;
    	}
    	public String getEmail() {
    		return email;
    	}
    	public void setEmail(String email) {
    		this.email = email;
    	}
    	@Override
    	public String toString() {
    		return "Customer [id=" + id + ", username=" + username + ", password=" + password + ", realname=" + realname
    				+ ", birthday=" + birthday + ", email=" + email + "]";
    	}
    	
    	
    	
    }

编写类继承ServletContextListener，覆盖监听器的方法

package web;
    
    import java.sql.SQLException;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    import java.util.List;
    import java.util.Timer;
    import java.util.TimerTask;
    
    import javax.mail.MessagingException;
    import javax.servlet.ServletContextEvent;
    import javax.servlet.ServletContextListener;
    
    import Utils.MailUtils;
    import domain.Customer;
    import service.birthdayService;
    
    public class SendBirthday implements ServletContextListener{
    
    	@Override
    	public void contextDestroyed(ServletContextEvent sce) {
    		System.out.println("销毁。。。。");
    	}
    
    	@Override
    	public void contextInitialized(ServletContextEvent sce) {
    		Timer timer = new Timer();
    		timer.scheduleAtFixedRate(new TimerTask() {
    			
    			@Override
    			public void run() {
    				SimpleDateFormat format = new SimpleDateFormat("MM-dd");
    				String currentDate = format.format(new Date());
    				System.out.println("currentDate:"+currentDate);
    				birthdayService birthdayService = new birthdayService();
    				List<Customer> allCustomer = null;
    				try {
                        //传入当前时间，获取list集合，此步为从数据库获取Customer集合
    					allCustomer = birthdayService.getCustomer(currentDate);
    				} catch (SQLException e) {
    					e.printStackTrace();
    				}
    				if(allCustomer!=null&&allCustomer.size()>0) {
    					for(Customer c:allCustomer) {
    						System.out.println("C:"+c.toString());
    						String emailMsg = "dear"+c.getRealname()+"hello birthday";
    						try {
    							MailUtils.sendMail(c.getEmail(), "test02", emailMsg);
    							System.out.println("ok");
    						} catch (MessagingException e) {
    							// TODO Auto-generated catch block
    							System.out.println("NO");
    							e.printStackTrace();
    						}
    					}
    				}
    				
    			}
    		}, new Date(), 1000*20);
    		
    	}
    
    }

web.xml

listener-class   包名+类名   web.SendBirthday

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
      
      <listener>
      	<listener-class>web.SendBirthday</listener-class>
      </listener>
      <display-name>webTest</display-name>
      
      
      <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
      </welcome-file-list>
      <servlet>
        <description></description>
        <display-name>Birthday</display-name>
        <servlet-name>Birthday</servlet-name>
        <servlet-class>web.Birthday</servlet-class>
      </servlet>
      <servlet-mapping>
        <servlet-name>Birthday</servlet-name>
        <url-pattern>/birthday</url-pattern>
      </servlet-mapping>
    </web-app>

MailUtils是发送邮件工具类

package Utils;
    
    import java.util.Properties;
    
    import javax.mail.Authenticator;
    import javax.mail.Message;
    import javax.mail.MessagingException;
    import javax.mail.PasswordAuthentication;
    import javax.mail.Session;
    import javax.mail.Transport;
    import javax.mail.internet.AddressException;
    import javax.mail.internet.InternetAddress;
    import javax.mail.internet.MimeMessage;
    import javax.mail.internet.MimeMessage.RecipientType;
    /*
     * email:邮件发给谁
     *  subject:主题
     *  emailMsg：邮件的内容
     */
    public class MailUtils {
    
    	
    	public static void sendMail(String email, String subject, 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");//发邮件的协议
    		props.setProperty("mail.host", "localhost");//发送邮件的服务器地址   外网发邮件需要修改mail.host如 SMTP服务器: smtp.163.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("jack", "123");//发邮件的账号的验证jack@jack.com   填入用户名和授权码   注意是授权码
    			}
    		};
    
    		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("jack@jack.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(subject);//邮件的主题
    
    		message.setContent(emailMsg, "text/html;charset=utf-8");
    
    		// 3.创建 Transport用于将邮件发送
    		Transport.send(message);
    	}
    	
    	
    }