Spring_事件通知实例_进程内异步

ゞ浴缸里的玫瑰 2022-01-17 03:15 206阅读 0赞

Spring事件监听实现了观察者模式。

主要有三个类：事件类、监听器类、事件发布类（入口）

### 1、事件类 ###

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、监听类 ###

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、事件发布类\_测试类 ###

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));
        }
    
    }

### ![20190612190202681.png][] ###

### 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/> 
        </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>

[20190612190202681.png]: /images/20220117/fa05de2569fa446d854078c1c10a049f.png