Spring实战——使用ApplicationContext的事件机制

我就是我 2021-07-24 22:29 402阅读 0赞

**一 配置**

<?xml version="1.0" encoding="GBK"?>
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://www.springframework.org/schema/beans"
         xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-4.0.xsd">
         
         <bean class="org.crazyit.app.listener.EmailNotifier"/>
    </beans>

**二 事件**

package org.crazyit.app.event;
    import org.springframework.context.ApplicationEvent;
    
    public class EmailEvent extends ApplicationEvent
    {
         private String address;
         private String text;
         public EmailEvent(Object source)
         {
               super(source);
         }
         // 初始化全部成员变量的构造器
         public EmailEvent(Object source , String address , String  text)
         {
               super(source);
               this.address = address;
               this.text = text;
         }
         // address的setter和getter方法
         public void setAddress(String address)
         {
               this.address = address;
         }
         public String getAddress()
         {
               return this.address;
         }
         // text的setter和getter方法
         public void setText(String text)
         {
               this.text = text;
         }
         public String getText()
         {
               return this.text;
         }
    }

**三 监听器**

package org.crazyit.app.listener;
    
    import org.springframework.context.ApplicationListener;
    import org.springframework.context.ApplicationEvent;
    
    import org.crazyit.app.event.*;
    
    public class EmailNotifier implements ApplicationListener
    {
        // 该方法会在容器发生事件时自动触发
        public void onApplicationEvent(ApplicationEvent evt)
        {
            // 只处理EmailEvent，模拟发送email通知...
            if (evt instanceof EmailEvent)
            {
                EmailEvent emailEvent = (EmailEvent)evt;
                System.out.println("需要发送邮件的接收地址  "
                    + emailEvent.getAddress());
                System.out.println("需要发送邮件的邮件正文  "
                    + emailEvent.getText());
            }
            else
            {
                // 其他事件不作任何处理
                System.out.println("其他事件：" + evt);
            }
        }
    }

**四 测试类**

package lee;
    import org.springframework.context.ApplicationContext;
    import  org.springframework.context.support.ClassPathXmlApplicationContext;
    import org.crazyit.app.event.*;
    
    public class SpringTest
    {
         public static void main(String[] args)
         {
               ApplicationContext ctx = new
                    ClassPathXmlApplicationContext("beans.xml");
               // 创建一个ApplicationEvent对象
               EmailEvent ele = new EmailEvent("test" ,
                    "spring_test@163.com" , "this is a test");
               // 发布容器事件
               ctx.publishEvent(ele);
         }
    }

**五 测试**

其他事件：org.springframework.context.event.ContextRefreshedEvent[source=org.springframework.context.support.ClassPathXmlApplicationContext@21b8d17c: startup date [Thu Sep 19 20:12:54 CST  2019]; root of context hierarchy]
    需要发送邮件的接收地址  spring_test@163.com
    需要发送邮件的邮件正文  this is a test