Spring Boot's personal notes from 0 to learn 10 - tasks

One, asynchronous processing

• @Async: Written before the service method, it means that this method needs to be processed asynchronously
• @EnableAsync: Write before the spring boot startup class to enable the function of asynchronous processing

AsynService：

@Service
public class AsynService {
    
    

    @Async
    public void hello(){
    
    
        try {
    
    
            Thread.sleep(3000);
        } catch (InterruptedException e) {
    
    
            e.printStackTrace();
        }
        System.out.println("数据处理中");
    }
}

AsynController：

@RestController
public class AsynController {
    
    
    @Autowired
    AsynService asynService;

    @GetMapping("/hello")
    public String hello(){
    
    
        asynService.hello();
        return "success";
    }
}

SpringBootTaskApplication：

@EnableAsync
@SpringBootApplication
public class SpringBootTaskApplication {
    
    

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

}

Originally, there was no + asynchronous processing. Every time you visit http://localhost:8080/hello, you have to wait 3 seconds for the result. Added this, the result in seconds

Two, timed tasks

• @EnableScheduling: Before writing in the spring boot startup class, turn on the timing task function
• @Scheduled: Used before the method in the service class, used to set up timing tasks
  • @Scheduled(cron = "xxx")This xxx has grammatical rules
  • The attribute value of cron is specified as a string. This string specifies 6 times, which areSeconds, minutes, hours, day of month, month, day of week, Each time period is separated by a space. For example
    "0 * * * * 1-7", it means that during any time period from Monday to Sunday, when the second is 0, the function will be executed once

2. Some examples

• @Scheduled(cron = "0,1,2,3,4 * * * * 1-5"): From Monday to Friday, when the second is 0, 1, 2, 3, 4, execute the code once
• @Scheduled(cron = "0-5 * * * * 1,2,3,4,5"): Same as above
• @Scheduled(cron = "0/4 * * * * 1,2,3,4,5"): From Monday to Friday, when the second is 0, it will be executed every 4 seconds
• 0 0/5 14,18 ? * ?: Every day at 14 o'clock, 18 o'clock, once every 5 minutes
• 0 0 2 ? * 6L: Executed at 2 AM on the last Saturday of every month

Three, send email

Spring boot comes with the function of sending mailboxes, I didn't expect it

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-mail</artifactId>
</dependency>

1. Simple mail

application.yml ：

spring:
  mail:
    username: [email protected]
    password: xxxxxxxxxxxxxxx(这个密码，下面有说是什么)
    host: smtp.qq.com
    profiles:
      mail:
        smtp:
          ssl:
            enable: true

• The password is not your QQ password, but
  
  this authorization code

Test in the test class:

@SpringBootTest
class SpringBootTaskApplicationTests {
    
    

    @Autowired
    JavaMailSenderImpl mailSender;

    //简单的发送邮件
    @Test
    void contextLoads() {
    
    
        SimpleMailMessage message = new SimpleMailMessage();
        message.setSubject("今晚打老虎");//发送邮件标题
        message.setText("多谢乌蝇哥");//正文
        message.setTo("[email protected]");//发给谁
        message.setFrom("[email protected]");//发送者
        this.mailSender.send(message);
    }

}

2. Complex mail

    //复杂的邮件
    @Test
    public void test02() throws Exception {
    
    
        MimeMessage mimeMessage = this.mailSender.createMimeMessage();//要用MimeMessage类型
        MimeMessageHelper helper = new MimeMessageHelper(mimeMessage, true);//然后用helper操作
        helper.setSubject("今晚打老虎");//标题
        helper.setText("<b style='color:red'>多谢乌蝇哥</b>", true);//内容，第二个参数为true就开启html格式
        helper.setTo("[email protected]");//发给谁
        helper.setFrom("[email protected]");//发送者
        helper.addAttachment("1.jpg", new File("D:\\壁纸\\59e06a3543101.png"));
        helper.addAttachment("2.jpg", new File("D:\\壁纸\\336-160G2110S6.png"));
        this.mailSender.send(mimeMessage);
    }