springMVC源码阅读-容器初始化

1.传统spring mvc配置

<!-- 省略非关键的配置 -->

<!-- [1] Spring配置 -->
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 指定Spring Bean的配置文件所在目录。默认配置在WEB-INF目录下 -->
<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:config/applicationContext.xml</param-value>
</context-param>

<!-- ====================================== -->

<!-- [2] Spring MVC配置 -->
<servlet>
    <servlet-name>spring</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!-- 可以自定义servlet.xml配置文件的位置和名称，默认为WEB-INF目录下，名称为[<servlet-name>]-servlet.xml，如spring-servlet.xml
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/spring-servlet.xml</param-value> // 默认
    </init-param>
    -->
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>spring</servlet-name>
    <url-pattern>*.do</url-pattern>
</servlet-mapping>

现在spring boot已经不需要配置了。通过自动配置代替了手动配置。但是这些配置还是存在

ContextLoaderListener

作用是在启动tomcat 或者jetty服务器的时候初始化一个Root Spring WebApplicationContext 

public class ContextLoaderListener extends ContextLoader implements ServletContextListener {
    public ContextLoaderListener() {
    }

    public ContextLoaderListener(WebApplicationContext context) {
        super(context);
    }

    //负责初始化容器
    public void contextInitialized(ServletContextEvent event) {
        this.initWebApplicationContext(event.getServletContext());
    }

    //负责销毁容器
    public void contextDestroyed(ServletContextEvent event) {
        this.closeWebApplicationContext(event.getServletContext());
        ContextCleanupListener.cleanupAttributes(event.getServletContext());
    }
}

initWebApplicationContext

<4>

text.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
    <bean id="remoteOssClient" class="com.bozhi.wemall.SimepleBeanFactory">
    </bean>
</beans>

web.xml

<context-param>
    <param-name>locatorFactorySelector</param-name>
    <param-value>classpath:test.xml</param-value>
  </context-param>
  <context-param>
    <param-name>parentContextKey</param-name>
    <param-value>remoteOssClient</param-value>
  </context-param>