spring web项目加载过程

监听容器初始化tomcat web.xml 中配置

<listener>  
     <listener-class>org.springframework.web.context.ContextLoaderListener
     </listener-class>  
</listener> 
<context-param>  
    <param-name>contextConfigLocation</param-name>  
    <param-value>classpath:applicationContext.xml</param-value>  
</context-param>

在contextInitialized时候调用初始化web应用context

/**
* Initialize the root web application context.
*/
@Override
public void contextInitialized(ServletContextEvent event) {
initWebApplicationContext(event.getServletContext());
}

2 然后创建创建context

this.context = createWebApplicationContext(servletContext);

3 配置和刷新context

configureAndRefreshWebApplicationContext(cwac, servletContext);

4在AbstractApplicationContext.refresh 接口中会初始化容器中的bean

// Instantiate all remaining (non-lazy-init) singletons.
finishBeanFactoryInitialization(beanFactory);

参考文件
https://juejin.im/post/6844903492977442823
https://blog.csdn.net/hl_java/article/details/79698775