2）ServletContextAttributeListener:

ServletContextAttributeListener能監測到有人正在往ServletContext裡新增屬性。你可以採取相應的措施。

例 2.2.2.1

web.xml當中再加入一段話：

  <listener>
    <listener-class>com.MyServletContextAttributeListener</listener-class>
  </listener>

package com;
import javax.servlet.ServletContextAttributeEvent;
import javax.servlet.ServletContextAttributeListener;
public class MyServletContextAttributeListener implements ServletContextAttributeListener  {
    public void attributeAdded(ServletContextAttributeEvent arg0) {
        System.out.println("增加了" + arg0.getName() + " " +
                arg0.getValue() );
    }
    public void attributeRemoved(ServletContextAttributeEvent arg0) {
        System.out.println("去除了" + arg0.getName() + " " +
                arg0.getValue() );
    }
    public void attributeReplaced(ServletContextAttributeEvent arg0) {
        System.out.println("取代了" + arg0.getName() + " " +

詳情請見：http://www.mark-to-win.com/index.html?content=Jsp/jspUrl.html&chapter=Jsp/jsp6_web.html#ServletContextAttributeListener