ContextLoaderListener

Tomcat 在进行最终调用 listener.contextInitialized，从而掉用到 ContextLoaderListener

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"  
  3.          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
  4.          xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> 
  6.         <listener>  
  7.         <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>  
  8.     </listener>
  10.       <context-param>  
  11.         <param-name>contextConfigLocation</param-name>  
  12.         <param-value>classpath:spring/spring.xml</param-value>  
  13.     </context-param>
  15.     <servlet>
  16.           <servlet-name>DispatcherServlet</servlet-name>
  17.         <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  18.         <init-param>
  19.             <param-name>contextConfigLocation</param-name>
  20.             <param-value>classpath:spring-servlet.xml</param-value>
  21.         </init-param>
  22.           <load-on-startup>1</load-on-startup>
  23.     </servlet>
  25.     <servlet-mapping>
  26.         <servlet-name>DispatcherServlet</servlet-name>
  27.         <url-pattern>*.do</url-pattern>
  28.     </servlet-mapping>
  30. </web-app>

ContextLoaderListener 主要是为了创建并刷新父容器（IOC），其实现类是 XmlWebApplicationContext

DispatcherServlet

init()：创建子容器

DispatcherServlet => FrameworkServlet => HttpServletBean.init()，完成创建子容器

onRefresh()：初始化九大组件

初始化九大组件