spring中已经内置的几种事件:
ContextClosedEvent 、ContextRefreshedEvent 、ContextStartedEvent 、ContextStoppedEvent 、RequestHandleEvent
首先自定义 2 种事件:
package com.tch.test.ssh.spring.event;
import org.springframework.context.ApplicationEvent;
/**
* 降价通知
* @author Administrator
*
*/
public class PriceDecrease extends ApplicationEvent {
private static final long serialVersionUID = 1L;
public PriceDecrease(Object source) {
super(source);
}
public PriceDecrease(String description) {
super(description);
}
}
package com.tch.test.ssh.spring.event;
import org.springframework.context.ApplicationEvent;
/**
* 涨价通知
* @author Administrator
*
*/
public class PriceIncrease extends ApplicationEvent {
private static final long serialVersionUID = 1L;
public PriceIncrease(Object source) {
super(source);
}
public PriceIncrease(String description) {
super(description);
}
}
然后定义监听器,并交给spring管理:
package com.tch.test.ssh.spring.listener;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;
import com.tch.test.ssh.spring.event.PriceDecrease;
import com.tch.test.ssh.spring.event.PriceIncrease;
/**
* 价格监听器
* @author Administrator
*
*/
@Component
public class PriceListener implements ApplicationListener {
@Override
public void onApplicationEvent(ApplicationEvent event) {
if(event instanceof PriceDecrease){
System.out.println("PriceListener监听到PriceDecrease事件:"+event.getSource());
}else if(event instanceof PriceIncrease){
System.out.println("PriceListener监听到PriceIncrease事件:"+event.getSource());
}
}
}
接下来定义发布事件的组件(可以使用下面两种方法之一):
1:实现ApplicationEventPublisherAware 接口
package com.tch.test.ssh.spring.event;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.stereotype.Component;
@Component
public class EventPublisher implements ApplicationEventPublisherAware {
private static ApplicationEventPublisher eventPublisher;
@Override
public void setApplicationEventPublisher(ApplicationEventPublisher eventPublisher) {
System.out.println("注入属性:ApplicationEventPublisher");
EventPublisher.eventPublisher = eventPublisher;
}
public static void publishEvent(ApplicationEvent event){
System.out.println("EventPublisher发布了一个事件");
eventPublisher.publishEvent(event);
}
}
2:实现ApplicationContextAware 接口:
package com.tch.test.ssh.spring.event;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationEvent;
import org.springframework.stereotype.Component;
@Component
public class GlobalEventPublisher implements ApplicationContextAware {
private static ApplicationContext context;
@Override
public void setApplicationContext(ApplicationContext context)
throws BeansException {
GlobalEventPublisher.context = context;
}
public static void publishApplicationEvent(ApplicationEvent event){
System.out.println("通过GlobalEventPublisher发布了一个事件");
context.publishEvent(event);
}
}
下面是spring的配置文件:
<?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:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd"> <context:annotation-config></context:annotation-config> <context:component-scan base-package="com.tch.test.ssh.spring"></context:component-scan> </beans>
最后测试:
package test;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tch.test.ssh.spring.event.EventPublisher;
import com.tch.test.ssh.spring.event.GlobalEventPublisher;
import com.tch.test.ssh.spring.event.PriceDecrease;
import com.tch.test.ssh.spring.event.PriceIncrease;
public class TestSpring {
public static void main(String[] args) throws Exception {
new ClassPathXmlApplicationContext("applicationContext.xml");
PriceDecrease decrease = new PriceDecrease("降价通知");
PriceIncrease increase = new PriceIncrease("涨价通知");
EventPublisher.publishEvent(decrease);
GlobalEventPublisher.publishApplicationEvent(increase);
}
}
输出结果:
EventPublisher发布了一个事件
PriceListener监听到PriceDecrease事件:降价通知
通过GlobalEventPublisher发布了一个事件
PriceListener监听到PriceIncrease事件:涨价通知