spring学习之配置文件

在编写spring web项目中遇到的一些问题。DispatcherServlet 和ContextLoaderListener的关系。

加载顺序 ContextLoaderListener -> DispatcherServlet

DispatcherServlet :负责加载controller对象，视图解析器等。
ContextLoaderListener : 负责加载service,dao,component以及开启定时任务，注册数据库配置等等。

为了避免controller被初始化两次的问题，一定要注意这几个配置文件的编写。将controller的自动扫描至配置在dispatcher.xml的文件当中

<context-param>    <param-name>contextConfigLocation</param-name>    <param-value>        classpath:conf/spring-context.xml;classpath:conf/spring-mybatis.xml;    </param-value></context-param><listener>    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener><!-- springMVC核心配置 --><servlet>    <servlet-name>spring</servlet-name>    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>    <init-param>        <param-name>contextConfigLocation</param-name>        <param-value>classpath:conf/spring-mvc.xml</param-value>    </init-param>    <load-on-startup>1</load-on-startup>    <async-supported>true</async-supported></servlet><servlet-mapping>    <servlet-name>spring</servlet-name>    <url-pattern>/</url-pattern></servlet-mapping>

spring加载过程中加载了两个容器。

2017-09-19 11:54:12.069:INFO:oejs.Server:main: jetty-9.2.6.v201412052017-09-19 11:54:15.468:INFO:/route:main: No Spring WebApplicationInitializer types detected on classpath2017-09-19 11:54:15.993:INFO:/route:main: Set web app root system property: 'topo' = [F:\zhongyingProject-websocket\toposerver\webapp]2017-09-19 11:54:16.010:INFO:/route:main: Initializing log4j from [classpath:conf/log4j.properties]2017-09-19 11:54:16.014:INFO:/route:main: Initializing Spring root WebApplicationContext启动topoServer程序2017-09-19 11:54:17.005:INFO:/route:main: $Id: GZIPFilter.java,v 1.15 2005/03/12 01:52:29 mike Exp $2017-09-19 11:54:17.005:INFO:/route:main: [ERROR] Could not locate the filter config file: tk-filters.properties2017-09-19 11:54:17.005:INFO:/route:main: ?GZIPFilter.Enabled: false2017-09-19 11:54:17.005:INFO:/route:main: ?GZIPFilter.LogStats: false2017-09-19 11:54:17.006:INFO:/route:main: $Id: CacheHeaderFilter.java,v 1.10 2005/03/12 01:52:28 mike Exp $2017-09-19 11:54:17.006:INFO:/route:main: [ERROR] Could not locate the filter config file: tk-filters.properties2017-09-19 11:54:17.006:INFO:/route:main: ?CacheFilter: false2017-09-19 11:54:17.006:INFO:/route:main: ?CacheFilter.ExpirationMinutes: -12017-09-19 11:54:17.056:INFO:/route:main: Initializing Spring FrameworkServlet 'spring'

由上面可见，加载了Spring root WebApplicationContext和Spring FrameworkServlet ‘spring’。。
对于以下代码

public class TopoServerStart implements ApplicationListener<ContextRefreshedEvent> {    /**    * 监听，servlet容器启动完成之后就可以起动数据进行缓存数据     */    public void onApplicationEvent(ContextRefreshedEvent event) {        if(event.getApplicationContext().getParent() == null){            //root application context 没有parent，他就是老大.           //需要执行的逻辑代码，当spring容器初始化完成后就会执行该方法。            System.out.println("启动topoServer程序");        }    }}

这段代码是在初始化完Spring root WebApplicationContext之后执行的。。
因此会导致这段代码执行之后，spring还在初始化controller。如果要在controller中操作一些方法，则需要考虑清楚在进行。