使用监听器实现邮件自动定时发送

首先找到已经封装好的邮件发送API文件，放入包中即可，使用不同邮件将下面对应处修改即可：此例使用的是一个本地发送。

package com.sicau.mail;

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;

public class MailUtils {

	//email:邮件发给谁  subject:主题  emailMsg：邮件的内容
	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
		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("tom", "123456");//发邮件的账号的验证
			}
		};

		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);
	}
}

要添加一个mail.jar包，需要自己去网上下载

然后写一个监听器实现有生日祝福的发送

package com.sicau.birthday;

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 org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;

import com.sicau.mail.MailUtils;

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 customerList = null;
				try {
					customerList = runner.query(sql, new BeanListHandler(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，这里为了方便演示
		//实际开发中间隔时间是1天
	}

	@Override
	public void contextDestroyed(ServletContextEvent sce) {
		
	}

}

下面是这里用到的实体类文件

package com.itheima.birthday;

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;
	}
	
	
	
}

这是进行数据库连接的工具类，使用C3P0进行数据库交互：

package com.itheima.birthday;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class DataSourceUtils {

	private static DataSource dataSource = new ComboPooledDataSource();

	private static ThreadLocal tl = new ThreadLocal();

	// 直接可以获取一个连接池
	public static DataSource getDataSource() {
		return dataSource;
	}
	
	public static Connection getConnection() throws SQLException{
		return dataSource.getConnection();
	}

	// 获取连接对象
	public static Connection getCurrentConnection() throws SQLException {

		Connection con = tl.get();
		if (con == null) {
			con = dataSource.getConnection();
			tl.set(con);
		}
		return con;
	}

	// 开启事务
	public static void startTransaction() throws SQLException {
		Connection con = getCurrentConnection();
		if (con != null) {
			con.setAutoCommit(false);
		}
	}

	// 事务回滚
	public static void rollback() throws SQLException {
		Connection con = getCurrentConnection();
		if (con != null) {
			con.rollback();
		}
	}

	// 提交并且 关闭资源及从ThreadLocall中释放
	public static void commitAndRelease() throws SQLException {
		Connection con = getCurrentConnection();
		if (con != null) {
			con.commit(); // 事务提交
			con.close();// 关闭资源
			tl.remove();// 从线程绑定中移除
		}
	}

	// 关闭资源方法
	public static void closeConnection() throws SQLException {
		Connection con = getCurrentConnection();
		if (con != null) {
			con.close();
		}
	}

	public static void closeStatement(Statement st) throws SQLException {
		if (st != null) {
			st.close();
		}
	}

	public static void closeResultSet(ResultSet rs) throws SQLException {
		if (rs != null) {
			rs.close();
		}
	}

}

放于SRC下的配置文件：

	
		root
		root
		com.mysql.jdbc.Driver
		jdbc:mysql:///Database
	 
 

 

WEB-INF下的配置文件中一定要对监听器进行配置

  
  	com.sicau.birthday.BirthdayListener