SPRing的入口配置在web.xml中。以監聽器的形式來實現。

	<listener>		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>	</listener>	<!-- 指定Spring Bean的配置文件所在目錄。默認配置在WEB-INF目錄下 -->	<context-param>		<param-name>contextConfigLocation</param-name>		<param-value>			classpath:config/applicationContext.xml			<!-- classpath:config/applicationContext-security.xml  -->		</param-value>	</context-param>
ContextLoaderListener實現了接口ServletContextListener,也就是說他必須實現contextDestroyed, contextInitialized這兩個方法
public class ContextLoaderListener extends ContextLoader implements ServletContextListener {		public ContextLoaderListener() {	}		public ContextLoaderListener(WebApplicationContext context) {		super(context);	}	/**	 * Initialize the root web application context.	 */	@Override	public void contextInitialized(ServletContextEvent event) {		initWebApplicationContext(event.getServletContext());	}	/**	 * Close the root web application context.	 */	@Override	public void contextDestroyed(ServletContextEvent event) {		closeWebApplicationContext(event.getServletContext());		ContextCleanupListener.cleanupAttributes(event.getServletContext());	}}
這個入口非常簡單,所有實現都隱藏在ContextLoader類里。
參考： http://solodu.iteye.com/blog/695980