Java彻底 - WEB容器的侦听具体解释 ServletContextListener

WEB容器的侦听器ServletContextListener主要用于监测容器启动和 当破坏需要做一些操作，听众将能够使用此做。

ServletContextListener在Spring开始，然后再开始。

们实现一个简单的监听器，须要继承接口ServletContextListener：

* 一个測试的监听器样例
* @author zhuli
* @date 2014-7-26
*/
public class TestContextLister implements ServletContextListener {

@Override
public void contextInitialized(ServletContextEvent sce) {
System.out.println("==============================容器装载");

}

@Override
public void contextDestroyed(ServletContextEvent sce) {
System.out.println("==============================容器销毁");
}

}

ServletContextListener 实现两个接口，一个是容器启动的时候，一个是容器销毁的时候：

public interface ServletContextListener extends EventListener {
/**
** Notification that the web application initialization
** process is starting.
** All ServletContextListeners are notified of context
** initialization before any filter or servlet in the web
** application is initialized.
*/

public void contextInitialized ( ServletContextEvent sce );

/**
** Notification that the servlet context is about to be shut down.
** All servlets and filters have been destroy()ed before any
** ServletContextListeners are notified of context
** destruction.
*/
public void contextDestroyed ( ServletContextEvent sce );
}

在web.xml中的配置：

<listener>
<listener-class>com.xxx.controller.web.TestContextLister</listener-class>
</listener>

容器启动后，会在容器启动的日志中看到：

==============================容器装载
2014-07-26 08:54:01.302:INFO:/:Initializing Spring FrameworkServlet 'apiServlet'