Spring_ event notification process within an instance _ asynchronous

Spring event listener implements the observer pattern.

There are three main categories: event class listener class event publishing class (entrance)

1 Event Class

package com.listen.demo.event.msg;

import lombok.Data;

@Data
public class ProductEvent {

    private Long productId;

    public ProductEvent() {
    }

    public ProductEvent(Long productId) {
        this.productId = productId;
    }
}

2, the class monitor

package com.listen.demo.event;

import com.listen.demo.event.msg.ProductEvent;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.event.EventListener;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Component;

/**
 * 服务内事件处理
 */
@Slf4j
@Component
public class AllEventListener {

    /**
     * 新产品上线，通知事件
     */
    @Async
    @EventListener(classes = ProductEvent.class)
    public void handleProductPutAwayEvent(ProductEvent event) {

        log.info("产品 {} 上线事件处理", event.getProductId());

        if (event.getProductId() == null) {
            return;
        }

        log.info("产品上线业务处理...");

    }
}

3, event publishing test class class _

package com.listen.demo;

import com.listen.demo.event.msg.ProductEvent;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.ApplicationContext;
import org.springframework.test.context.junit4.SpringRunner;

import javax.annotation.Resource;

@RunWith(SpringRunner.class)
@SpringBootTest
public class DemoApplicationTests {


    @Resource
    private ApplicationContext applicationContext;

    @Test
    public void contextLoads() {
    }

    @Test
    public void testHandleProductPutAwayEvent(){
        applicationContext.publishEvent(new ProductEvent(99L));
    }

}

4, 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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.listen</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <lombok.version>1.18.4</lombok.version>
    </properties>

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

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

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
            <scope>provided</scope>
        </dependency>

    </dependencies>

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

</project>