1、ApplicationListener在使用过程中可以监听某一事件的发生，可以做出相应的处理，这个方式不常用，但是在特殊情况下面还是有用的。
2、导包pom.xml
<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>
<groupId>com.troy</groupId>
<artifactId>springInit</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>3.2.8.RELEASE</version>
</dependency>
</dependencies>
</project>
3、web.xml配置
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
<display-name>springInit</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/spring-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/</url-pattern>
</filter-mapping>
</web-app>
4、spring-mvc.xml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:context="http://www.springframework.org/schema/context"
xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:jee="http://www.springframework.org/schema/jee"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:util="http://www.springframework.org/schema/util"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd"> <mvc:annotation-driven/>
<context:component-scan base-package="com.troy"/>
<bean class="com.troy.springInit.SpringListenerEvent"/>
<bean class="com.troy.springInit.SpringListener"/>
<bean id="initApplicationContext" class="com.troy.springInit.InitApplicationContext"/>
</beans>
5、<bean class="com.troy.springInit.SpringListener"/>在spring的作用是为了在bean加载完成过后进行初始化加载
这里可以参考：http://www.cnblogs.com/ll409546297/p/6903357.html
6、目录结构，因为我用初始化加载来实现某一个事件的监听，自己可以根据相应事件触发来实现
7、触发方式
1）第一步：因为事件触发需要用到ApplicationContext的publishEvent来触发事件，我这里没有ClassPathXmlApplicationContext的方式来加载配置文件，而是实现ApplicationContextAware这个接口来实现ApplicationContext的加载
public class InitApplicationContext implements ApplicationContextAware{
public static ApplicationContext ac;
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.ac = applicationContext;
}
}
2）第二步编写事件：继承ApplicationEvent类会要求重写一个构造方法
public class InitEvent extends ApplicationEvent{
public String data;
public InitEvent(Object source) {
super(source);
}
public InitEvent(Object source,String data) {
super(source);
this.data = data;
}
public String getData() {
return data;
}
public void setData(String data) {
this.data = data;
}
//这里我是利用spring初始化来实现方法的加载
public static void execute(){
ApplicationContext ac = InitApplicationContext.ac;
System.out.println("test==================test");
InitEvent ie = new InitEvent("test", "test");
ac.publishEvent(ie);
}
}
3）通过初始化的方式来触发这个事件，这个可以通过其他方式，比如servlet等方式来触发
public class SpringListener implements ApplicationListener<ContextRefreshedEvent>{
public void onApplicationEvent(ContextRefreshedEvent event) {
System.out.println(event.getApplicationContext());
//判断spring容器是否加载完成
if (event.getApplicationContext().getParent() == null) {
Init.init();
InitEvent.execute();
}
}
}
4）上面的方式也可以触发事件，但是写出来比较繁琐。我们一般通过ApplicationListener接口来实现事件的监听，这样来触发事件的产生。通过ApplicationListener的泛型机制，来监听事件的发生，这里可以针对于时间做相对处理，实现对事件的监听
public class SpringListenerEvent implements ApplicationListener<InitEvent>{
public void onApplicationEvent(InitEvent event) {
System.out.println("事件处理==================事件处理");
System.out.println(event.getData());
}
}
8、总体来说：ApplicationListener是对相应应用的监听，只是对于不同方式，通过不同方式来呈现！