Springboot+异步任务简单入门

介绍

在Java应用中，绝大多数情况下都是通过同步的方式来实现交互处理的；但是在
处理与第三方系统交互的时候，容易造成响应迟缓的情况，之前大部分都是使用
多线程来完成此类任务，其实，在Spring 3.x之后，就已经内置了@Async来完
美解决这个问题。

涉及两个注解：
@EnableAysnc、@Aysnc

 public void hello(){
        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("处理数据中...");
    }

注意： 原来这样的方法会等待三秒后控制台打印数据。

springboot异步处理demo代码

pom.xml

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.atguigu</groupId>
	<artifactId>springboot-04-task</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>springboot-04-task</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.2.5.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<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-mail</artifactId>
		</dependency>

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

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>


</project>

Service

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

@Service
public class AsyncService {

    //告诉Spring这是一个异步方法
    @Async
    public void hello(){
        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("处理数据中...");
    }
}

注意：@Async //告诉Spring这是一个异步方法

Controller

import com.atguigu.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";
    }
}

Application

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

@EnableAsync  //开启异步注解功能
@SpringBootApplication
public class Springboot04TaskApplication {

	public static void main(String[] args) {
		SpringApplication.run(Springboot04TaskApplication.class, args);
	}
}

注意：需要加@EnableAsync //开启异步注解功能

测试

1. 运行main方法
2. 打开浏览器输入http://localhost/8080/hello
3. 立即响应success则成功。

有用可以关注一下