定时发邮件

GmailSender.java


 


package test;


import java.security.Security;
import java.util.Date;
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;




public class GmailSender {


public void gmailSend(){
   Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
   final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
   // Get a Properties object
   Properties props = System.getProperties();
   props.setProperty("mail.smtp.host", "smtp.gmail.com");
   props.setProperty("mail.smtp.socketFactory.class", SSL_FACTORY);
   props.setProperty("mail.smtp.socketFactory.fallback", "false");
   props.setProperty("mail.smtp.port", "465");
   props.setProperty("mail.smtp.socketFactory.port", "465");
   props.put("mail.smtp.auth", "true");
   final String username = "用户名@gmail.com";//发件人用户名
   final String password = "密码";
   Session session = Session.getDefaultInstance(props, new Authenticator(){
       protected PasswordAuthentication getPasswordAuthentication() {
           return new PasswordAuthentication(username, password);
       }});


        // -- Create a new message --
   Message msg = new MimeMessage(session);


   // -- Set the FROM and TO fields --
//   msg.setFrom(new InternetAddress("用户名@hotmail.com"));//收件人用户名
 try {
  msg.setRecipients(Message.RecipientType.TO,
       InternetAddress.parse("用户名@hotmail.com",false));//收件人用户名
  msg.setSubject("Hello");
     msg.setText("How are you");
     msg.setSentDate(new Date());
     Transport.send(msg);
 } catch (AddressException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 } catch (MessagingException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 }
 
  
 
   System.out.println("Message sent.");
}
}


 


 


MyListener.java


 


package test;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Timer;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
public class MyListener implements ServletContextListener{


 private Timer timer = null;
 public void contextDestroyed(ServletContextEvent arg0) {
  timer.cancel();
 }


 public void contextInitialized(ServletContextEvent arg0) {
  timer = new Timer(true);
  Calendar calendar = Calendar.getInstance();
  Date date = new Date();
  SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-M-d HH:mm:ss");
  String nowTime = dateFormat.format(date);
  int year = Integer.parseInt(nowTime.substring(0, 4));
  int month = Integer.parseInt(nowTime.substring(nowTime.indexOf("-") + 1, nowTime.lastIndexOf("-"))) - 1;
  int day = Integer.parseInt(nowTime.substring(nowTime.lastIndexOf("-") + 1, nowTime.indexOf(" ")));
  //每天中午 12 点定时发邮件
  int hour = 12;
  int minute = 0;
  int second= 0;
  calendar.set(year, month, day, hour, minute, second);//第二个参数是实际月份减一，比如一月份是 0
  if(date.after(calendar.getTime())){
   day = day + 1;
   calendar.set(year, month, day, hour, minute, second);
  }
  date = calendar.getTime();
  timer.schedule(new MyTask(), date, 86400000);//每隔 24 小时发一次
 }


}




 


MyTask.java


 


package test;


import java.util.TimerTask;




public class MyTask extends TimerTask{


 @Override
 public void run() {
  new GmailSender().gmailSend();
 }


}




 


web.xml


 


<listener>
  <listener-class>test.MyListener</listener-class>
</listener>