定时执行任务

@EnableScheduling //开启定时执行任务的功能 (在主启动类中添加)

package com.Google;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.annotation.EnableScheduling;

@SpringBootApplication
@EnableAsync//开启异步功能
@EnableScheduling //开启定时执行任务的功能
public class SpringBoot07MailTestApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBoot07MailTestApplication.class, args);
    }

}

@Scheduled(cron="0/1 * * * * ?") (设置预定的时间),在类上添加注解就可以运行

package com.Google.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSenderImpl;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;

import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;
import java.io.File;

@Service
public class TimeService {

    @Autowired
    JavaMailSenderImpl senderMail;  //需要先配置 邮件配置文件，才能自动注入

    @Async //告诉spring这是一个异步方法
    public void timeSleep() throws InterruptedException {
        Thread.sleep(3000);
        System.out.println("邮件正在发送");
    }
    @Async
    @Scheduled(cron="0/1 * * * * ?") //每隔三秒执行一次任务  17879535823
    public void sendMail(){  //简单邮箱
        SimpleMailMessage message = new SimpleMailMessage();
        message.setSubject("这是lzl通过java程序发送的测试邮件");
        message.setText("这是正文");
        message.setTo("2034281742@qq.com");
        message.setFrom("2034281742@qq.com");
        senderMail.send(message);
        System.out.println("邮件已发送");
    }

    @Async
    public void sendMimeMail() throws MessagingException { //发送复杂邮件
        MimeMessage mimeMessage = senderMail.createMimeMessage();
        MimeMessageHelper messageHelper = new MimeMessageHelper(mimeMessage,true); //开启multipart，以实现发送附件
        messageHelper.setSubject("这是lzl通过java程序发送的测试邮件");
        messageHelper.setText("<p style='color:yellow'>这是正文</p>",true);
        //附件
        messageHelper.addAttachment("图片1",new File("D:\\Instalaltion package\\sunDowm.jpg"));
        messageHelper.addAttachment("图片2",new File("D:\\Instalaltion package\\sunDowm.jpg"));
        messageHelper.setTo("2034281742@qq.com");
        messageHelper.setFrom("2034281742@qq.com");
        senderMail.send(mimeMessage);
    }

}