8、Spring Boot任務

1.異步任務

  Java應用中,絕大多數情況下都是通過同步的方式來實現交互處理的;但是在處理與第三方系統交互的時候,容易造成響應遲緩的情況,之前大部分都是使用多線程來完成此類任務,其實,在Spring 3.x之後,就已經內置了@Async來完美解決這個問題。

  主要使用兩個註解完成,@EnableAysnc、@Aysnc

(1).Springboot04TaskApplication.java

@EnableAsync    //開啟異步註解功能

@SpringBootApplication

public class Springboot04TaskApplication {

 

   public static void main(String[] args) {

      SpringApplication.run(Springboot04TaskApplication.class, args);

   }

 

}

(2).AsyncController.java

package com.hosystem.task.controller;

 

import com.hosystem.task.service.AsyncService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.RestController;

 

@RestController

public class AsyncController {

 

    @Autowired

    AsyncService asyncService;

 

    @GetMapping(“/hello”)

    public String hello(){

        asyncService.hello();

        return “success”;

    }

}

(3).AsyncService.java

package com.hosystem.task.service;

 

import org.springframework.scheduling.annotation.Async;

import org.springframework.stereotype.Service;

 

@Service

public class AsyncService {

 

    //通知spring這是一個異步方法

    @Async

    public void hello(){

        try {

            Thread.sleep(3000);

        } catch (InterruptedException e) {

            e.printStackTrace();

        }

        System.out.println(處理數據….”);

    }

}

 

2.定時任務

  開發中經常需要執行一些定時任務,比如需要在每天凌晨時候,分析一次前一天的日誌信息。Spring為我們提供了異步執行任務調度的方式,提供TaskExecutor 、TaskScheduler 接口。

  使用到的註解有兩個,@EnableScheduling、@Scheduled

  Cron表達式:

 

(1).ScheduledService.java

package com.hosystem.task.service;

 

import org.springframework.scheduling.annotation.Scheduled;

import org.springframework.stereotype.Service;

 

@Service

public class ScheduledService {

 

    /**

     *  second(), minute(分), hour(時), day of month(日), month(月), day of week(周幾).

     *  0 * * * * MON-FRI

     * [0 0/5 14,18 * * ?]:每天14點整,和18點整,每隔5分鐘執行一次

     * [0 15 10 ? * 1-6]:每個月的周一至周六10:15分執行一次

     * [0 0 2 ? * 6L]:每個月的最後一個周六凌晨2點執行一次

     * [0 0 2 LW * ?]:每個月的最後一個工作日凌晨2點執行一次

     * [0 0 2-4 ? * 1#1]:每個月的第一個周一凌晨2點到4點期間,每個整點都執行一次;

     */

    // @Scheduled(cron = “0 * * * * MON-SAT”)

    //@Scheduled(cron = “0,1,2,3,4 * * * * MON-SAT”)

    // @Scheduled(cron = “0-4 * * * * MON-SAT”)

    @Scheduled(cron = “0/4 * * * * 0-7”)  //4秒執行一次

    public void hello() {

        System.out.println(“hello …”);

    }

}

(2).Springboot04TaskApplication.java

package com.hosystem.task;

 

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.scheduling.annotation.EnableAsync;

import org.springframework.scheduling.annotation.EnableScheduling;

import org.springframework.scheduling.annotation.Scheduled;

 

@EnableScheduling //開啟基於註解定時任務

@SpringBootApplication

public class Springboot04TaskApplication {

 

   public static void main(String[] args) {

      SpringApplication.run(Springboot04TaskApplication.class, args);

   }

 

}

3.郵件任務

 

 

(1).導入pom.xml

<!–mail–>

<dependency>

   <groupId>org.springframework.boot</groupId>

   <artifactId>spring-boot-starter-mail</artifactId>

</dependency>

(2).開啟POP3/SMTP

 

(3).開啟IMAP/SMTP

 

(4).生成授權碼

 

(5).applicaiton.properties

server.port=80

 

#配置郵箱信息

spring.mail.username=[email protected]

#授權碼

spring.mail.password=password

#smtp地址

spring.mail.host=smtp.qq.com

spring.mail.protocol=smtp

spring.mail.properties.mail.smtp.ssl.enable=true

(6).Springboot04TaskApplicationTests.java

  SendMailTest測試郵箱發送,一定要在mail中開啟SMTP

package com.hosystem.task;

 

import org.junit.jupiter.api.Test;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.test.context.SpringBootTest;

import org.springframework.mail.SimpleMailMessage;

import org.springframework.mail.javamail.JavaMailSenderImpl;

import org.springframework.mail.javamail.MimeMessageHelper;

 

import javax.mail.internet.MimeMessage;

import java.io.File;

 

@SpringBootTest

class Springboot04TaskApplicationTests {

 

   @Autowired

   JavaMailSenderImpl mailSender;

 

   @Test

   public void contextLoads() {

      SimpleMailMessage simpleMailMessage = new SimpleMailMessage();

      //郵件設置

      simpleMailMessage.setSubject(通知—–“);

      simpleMailMessage.setText(學習java”);

  //setTo:目的郵件地址  setFrom:發送郵件地址

      simpleMailMessage.setTo([email protected]);

      simpleMailMessage.setFrom(username@qq.com”);

      mailSender.send(simpleMailMessage);

   }

 

   @Test

   public void test01() throws Exception{

      //1.創建一個複雜的消息郵件

      MimeMessage mimeMessage = mailSender.createMimeMessage();

      MimeMessageHelper helper = new MimeMessageHelper(mimeMessage, true);

 

      //郵件設置

      helper.setSubject(通知—–“);

 

      /**

       *     public void setText(String text) throws MessagingException {this.setText(text, false);

       }

       */

      helper.setText(“<b style=’color:red’>學習java</b>”,true);

  //setTo:目的郵件地址  setFrom:發送郵件地址

      helper.setTo(username@163.com”);

      helper.setFrom(username@qq.com”);

 

      //上傳文件

      helper.addAttachment(“8a92681cb892bf78ec83af62f2b6a82.jpg”,new File(“E:\\Users\\Asuna\\Desktop\\html\\8a92681cb892bf78ec83af62f2b6a82.jpg”));

      helper.addAttachment(“8f82df421233241732db6ec6baed07e.jpg”,new File(“E:\\Users\\Asuna\\Desktop\\html\\8f82df421233241732db6ec6baed07e.jpg”));

 

 

      mailSender.send(mimeMessage);

   }

 

}

  

參考文檔:

//github.com/spring-projects/spring-boot/tree/v2.1.0.RELEASE/spring-boot-project/spring-boot-starters