JavaEE企业应用实战学习记录MyGetAttributeListener

Posted 2020-08-12

 1 package sanglp.servlet;
 2 
 3 import javax.servlet.ServletContext;
 4 import javax.servlet.ServletContextAttributeEvent;
 5 import javax.servlet.ServletContextAttributeListener;
 6 import javax.servlet.annotation.WebListener;
 7 
 8 /**
 9  * Created by Administrator on 2016/10/5.
10  * 监听ServletContext范围内属性改变的Listener
11  */
12 @WebListener
13 public class MyServletContextAttributeListener implements ServletContextAttributeListener {
14 
15     @Override
16     public void attributeAdded(ServletContextAttributeEvent servletContextAttributeEvent) {
17         ServletContext application=servletContextAttributeEvent.getServletContext();
18         //获取添加的属性名和属性值
19         String name=servletContextAttributeEvent.getName();
20         Object value=servletContextAttributeEvent.getValue();
21         System.out.println(application+"范围内添加了"+name+"值为"+value+"的属性");
22 
23 
24     }
25 
26     @Override
27     public void attributeRemoved(ServletContextAttributeEvent servletContextAttributeEvent) {
28         ServletContext application=servletContextAttributeEvent.getServletContext();
29         //获取添加的属性名和属性值
30         String name=servletContextAttributeEvent.getName();
31         Object value=servletContextAttributeEvent.getValue();
32         System.out.println(application+"范围内删除了"+name+"值为"+value+"的属性");
33     }
34 
35 
36     @Override
37     public void attributeReplaced(ServletContextAttributeEvent servletContextAttributeEvent) {
38         ServletContext application=servletContextAttributeEvent.getServletContext();
39         //获取添加的属性名和属性值
40         String name=servletContextAttributeEvent.getName();
41         Object value=servletContextAttributeEvent.getValue();
42         System.out.println(application+"范围内替换了"+name+"值为"+value+"的属性");
43 
44     }
45 }