大致步骤
* ApplicationListener：监听容器中发布的事件,事件驱动模型开发
* public interface ApplicationListener<E extends ApplicationEvent> extends EventListener
* 步骤：
* 1、写一个监听器来监听某个事件（ApplicationEvent及其子类）
* 2、把监听器放入容器中
* 3、只有容器中有响应类型的事件发布，我们就能监听到这个事件
* ContextRefreshedEvent：容器刷新完成
* ContextClosedEvent：关闭容器发布这个事件
* 4、自己来发布一个事件
配置类
@ComponentScan("com.dwd.snail.testspring.test.ext")
@Configuration
public class ExtConfig {
}
实现ApplicationListener接口并注册到容器中
@Component
public class MyApplicationListener implements ApplicationListener<ApplicationEvent> {
//当容器中发布此事件后，方法会得到触发
@Override
public void onApplicationEvent(ApplicationEvent event) {
System.out.println("收到事件...");
System.out.println(event);
}
}
测试类
public class IocTest_ext {
@Test
public void test01(){
AnnotationConfigApplicationContext applicationContext=new AnnotationConfigApplicationContext(ExtConfig.class);
applicationContext.publishEvent(new ApplicationEvent(new String("发布事件snail")) {
});
applicationContext.close();
}
测试结果
收到事件...
org.springframework.context.event.ContextRefreshedEvent[source=org.springframework.context.annotation.AnnotationConfigApplicationContext@62043840: startup date [Thu Aug 29 15:13:23 CST 2019]; root of context hierarchy]
收到事件...
com.dwd.snail.testspring.IocTest_ext$1[source=发布事件snail]
15:13:25.235 [main] INFO org.springframework.context.annotation.AnnotationConfigApplicationContext - Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@62043840: startup date [Thu Aug 29 15:13:23 CST 2019]; root of context hierarchy
收到事件...
org.springframework.context.event.ContextClosedEvent[source=org.springframework.context.annotation.AnnotationConfigApplicationContext@62043840: startup date [Thu Aug 29 15:13:23 CST 2019]; root of context hierarchy]
