Spring boot execution process sorting

注：本文梳理启动流程使用的Spring版本：4.0.2.RELEASE
To use spring configuration, you need to configure a spring listener and startup parameter (context-param) in web.xml, as follows:

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            classpath:spring-*.xml
        </param-value>
    </context-param>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

When the web container starts, the following steps are executed for spring loading:

1. Execute the ContextLoaderListener listener in web.xml
2. Initialize the contextInitialized method in ContextLoaderListener
   
3. The initWebApplicationContext method of the parent class (ContextLoader) is called in the contextInitialized method
   
4. Three tasks are performed in the initWebApplicationContext method
   
   • Create the WebApplicationContext container
     
   • Load the spring configuration file configured in context-param
   • Initialize the bean in the configuration file and create the bean in the configuration file
     
     

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When the web container stops, the contextDestroyed method of ContextLoaderListener will be executed to destroy the context container