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[email protected] 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("[email protected]")); // 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);
}
}