Spring 之事件发布与监听

1.同步处理

　　a.引入Spring的pom依赖（略）

　　b.创建Event事件类

public class TestEvent1 extends ApplicationEvent {

    private String message;

    public TestEvent1(Object source, String message) {
        super(source);
        this.message = message;
    }

    public String getMessage() {
        return message;
    }
}

public class TestEvent2 extends ApplicationEvent {

    private String message;

    public TestEvent2(Object source, String message) {
        super(source);
        this.message = message;
    }

    public String getMessage() {
        return message;
    }
}

 

　　c.创建Listener监听类

@Component
public class TestListener1 implements ApplicationListener<TestEvent1> {

    @Override
    public void onApplicationEvent(TestEvent1 event) {
        System.out.println("[TestListener1] start ......");
        try {
            Thread.sleep(2000);
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("[TestListener1] receive event: " + event.getMessage());
        System.out.println("[TestListener1] end ......");
    }

}

@Component
public class TestListener2 implements ApplicationListener<TestEvent2> {

    @Override
    public void onApplicationEvent(TestEvent2 event) {
        System.out.println("[TestListener2] start ......");
        try {
            Thread.sleep(2000);
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("[TestListener2] receive event: " + event.getMessage());
        System.out.println("[TestListener2] end ......");
    }

}

 

　　d.使用

@Component
public class CommonEventHandler {

    @Autowired
    private ApplicationEventPublisher applicationEventPublisher;

    public void sendEvent1(String msg){
        ApplicationEvent event = new TestEvent1(this,msg);
        applicationEventPublisher.publishEvent(event);
    }

    public void sendEvent2(String msg){
        ApplicationEvent event = new TestEvent2(this,msg);
        applicationEventPublisher.publishEvent(event);
    }

}

 

　　e.测试

public class App 
{
    public static void main( String[] args )
    {
        ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
        CommonEventHandler handler = (CommonEventHandler) context.getBean("commonEventHandler");

        for (int i = 0; i < 20; i++) {
            if(i % 3 == 0){
                handler.sendEvent1("[Event1]count: " + i);
                continue;
            }
            handler.sendEvent2("[Event2]count: " + i);
        }
    }
}

 

 

2.异步处理

　　a.在spring.xml中加入线程池相关配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:task="http://www.springframework.org/schema/task"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-4.1.xsd">

    <!-- 自动扫描的包名 -->
    <context:component-scan base-package="com.wode" />

    <!-- 开启AOP代理 -->
    <aop:aspectj-autoproxy proxy-target-class="true" />

    <!--开启注解处理器 -->
    <context:annotation-config>
    </context:annotation-config>

    <!-- 线程池异步任务 -->
    <task:annotation-driven executor="executor"/>
    <task:executor id="executor" pool-size="10" queue-capacity="100"/>

</beans>

 

　　b.在 Listener 的 onApplicationEvent 方法上加上 @Async 注解

@Component
public class TestListener1 implements ApplicationListener<TestEvent1> {

    @Async
    @Override
    public void onApplicationEvent(TestEvent1 event) {
        System.out.println("[TestListener1] start ......");
        try {
            Thread.sleep(2000);
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("[TestListener1] receive event: " + event.getMessage());
        System.out.println("[TestListener1] end ......");
    }

}

@Component
public class TestListener2 implements ApplicationListener<TestEvent2> {

    @Async
    @Override
    public void onApplicationEvent(TestEvent2 event) {
        System.out.println("[TestListener2] start ......");
        try {
            Thread.sleep(2000);
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("[TestListener2] receive event: " + event.getMessage());
        System.out.println("[TestListener2] end ......");
    }

}