springboot之异步任务、邮件任务、定时任务

springboot之异步任务

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>springboot-task</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-task</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>


</project>

package com.example.task;

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

@SpringBootApplication
@EnableAsync // 开启异步注解功能
public class SpringbootTaskApplication {
    

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

}

package com.example.task.service;

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(); // 停止3s
        return "ok";
    }
}




package com.example.task.service;

import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;

@Service
public class AsyncService {
    

    // 告诉spring这是一个异步的方法
    // 如果不是异步任务，controller会等待3s，才返回ok
    // 异步任务的话，controller会直接返回ok，service会正常执行
    @Async
    public void hello(){
    

        System.out.println("========数据开始处理============");

        try {
    
            Thread.sleep(3000);
        } catch (InterruptedException e) {
    
            e.printStackTrace();
        }

        System.out.println("===========数据处理完成=========");
    }
}

springboot之邮件发送

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>springboot-task</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-task</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

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

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


</project>

spring:
  mail:
    host: smtp.qq.com
    username: 你的qq号
    password: qq邮箱的授权码，当然这些东西用网易、移动那些也可以
    # 开启加密验证
    properties.mail.smtl.ssl.enable: true

package com.example.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.JavaMailSender;
import org.springframework.mail.javamail.JavaMailSenderImpl;
import org.springframework.mail.javamail.MimeMessageHelper;

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

@SpringBootTest
class SpringbootTaskApplicationTests {
    

    @Autowired
    JavaMailSenderImpl javaMailSender;

    // 发送一个简单的邮件
    @Test
    void contextLoads() {
    
        SimpleMailMessage simpleMailMessage = new SimpleMailMessage();
        simpleMailMessage.setSubject("这是邮件的主题");
        simpleMailMessage.setText("这是邮件的内容");

        // 接收者
        simpleMailMessage.setTo("[email protected]");
        // 发送者
        simpleMailMessage.setFrom("[email protected]");


        javaMailSender.send(simpleMailMessage);

    }





    // 发送一个复杂的邮件
    @Test
    void contextLoads2() throws MessagingException {
    

        MimeMessage mimeMessage = javaMailSender.createMimeMessage();
        // 组装
        // 第二个参数为 多文件
        MimeMessageHelper mimeMessageHelper = new MimeMessageHelper(mimeMessage,true);

        mimeMessageHelper.setSubject("这是邮件的主题");
        // true 会解析html，否则是纯文本
        mimeMessageHelper.setText("<h1 style='color:red'>这是邮件的内容</h1>",true);

        // 附件
        mimeMessageHelper.addAttachment("1.txt",new File("C:\\Users\\EDY\\Desktop\\新文件 1.txt"));


        // 接收者
        mimeMessageHelper.setTo("[email protected]");
        // 发送者
        mimeMessageHelper.setFrom("[email protected]");


        javaMailSender.send(mimeMessage);

    }

}

springboot之定时任务

@SpringBootApplication
// 开启使用定时任务，使用spring自带的定时任务
@EnableScheduling
public class CrawlerApplication {
    

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

	// 这两个不是在同一个类中，用spring定时任务的这个类需要交给spring管理
 	// 添加定时任务配置，这里一般是用corn表达式
    // initialDelay，项目启动成功后，多久执行任务，单位毫秒
    // fixedDelay，任务执行完成后，间隔多久下一次任务执行，单位毫秒
    @Scheduled(initialDelay = 1000, fixedDelay = 10000)
    public void run(){
    
    }


/** cron：cron表达式，指定任务在特定时间执行； fixedDelay：上一次任务执行完后多久再执行，参数类型为long，单位ms fixedDelayString：与fixedDelay含义一样，只是参数类型变为String fixedRate：按一定的频率执行任务，参数类型为long，单位ms fixedRateString: 与fixedRate的含义一样，只是将参数类型变为String initialDelay：延迟多久再第一次执行任务，参数类型为long，单位ms initialDelayString：与initialDelay的含义一样，只是将参数类型变为String zone：时区，默认为当前时区，一般没有用到 */

// 使用cron表达式
package com.example.task.service;

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
public class TaskScheduling {
    

    @Scheduled(cron = "0/10 * * * * ?")
    public void testScheduling(){
    
        System.out.println("testScheduling");
    }

}

部分内容转载自：
https://bilibili.com/video/BV1PE411i7CV/?p=52&spm_id_from=pageDriver&vd_source=64c73c596c59837e620fed47fa27ada7

世界是复杂的，但又不是随机的，知识也应当如此。求知的道路，意味着永恒的疲倦以及偶尔的惊喜。

可能性的艺术:比较政治学30讲
刘瑜