Filter总结

1、多个Filter的执行顺序

Fileter的执行顺序与在web.xml中声明的顺序一致，先声明的先执行。

1. <filter> 
2.         <filter-name>MyServlet1</filter-name> 
3.         <filter-class>com.alibaba.exchange.MyServlet1</filter-class> 
4.     </filter> 
5.     <filter-mapping> 
6.         <filter-name>MyServlet1</filter-name> 
7.         <url-pattern>/*</url-pattern> 
8.     </filter-mapping> 
9.     <filter> 
10.         <filter-name>MyServlet2</filter-name> 
11.         <filter-class>com.alibaba.exchange.MyServlet2</filter-class> 
12.     </filter> 
13.     <filter-mapping> 
14.         <filter-name>MyServlet2</filter-name> 
15.         <url-pattern>/*</url-pattern> 
16.     </filter-mapping> 

在Filter中代码如下：

1. @Override 
2. public void doFilter(ServletRequest request, ServletResponse response, 
3.         FilterChain chain) throws IOException, ServletException { 
4.     // TODO Auto-generated method stub 
5.     System.out.println("MyServlet1 doFilter before"); 
6.     chain.doFilter(request, response); 
7.     System.out.println("MyServlet1 doFilter after"); 
8. } 

过滤链执行结果如下：

1. MyServlet1 doFilter before 
2. MyServlet2 doFilter before 
3. zhangsan, hello123
4. MyServlet2 doFilter after 
5. MyServlet1 doFilter after 

 本文转自 tianya23 51CTO博客，原文链接：http://blog.51cto.com/tianya23/678234，如需转载请自行联系原作者