struts2.2.1关于sitemesh和freemarker整合的细节

http://nighty.iteye.com/blog/788241

有段时间没有使用struts2了，上了官网发现已经更新到2.2.1版本，没有细看note，照着以前老的方式配置web.xml，发现装饰器sitemesh对freemarker不起作用，折腾了一整天。最后还是老老实实看官方的文档，发现以前书上推荐的配置已经过时。老的一般配置如下：

Xml代码  

1. <filter>  
2.    <filter-name>ActionContextCleanUp</filter-name>  
3.    <filter-class>org.apache.struts2.dispatcher.ActionContextCleanUp</filter-class>  
4. </filter>  
5. <filter>  
6.    <filter-name>sitemesh</filter-name>  
7.    <filter-class>com.opensymphony.module.sitemesh.filter.PageFilter</filter-class>  
8. </filter>  
9. <filter>  
10.    <filter-name>struts2</filter-name>  
11.    <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>  
12. </filter>  

      从struts2.1.3开始ActionContextCleanUp 和 FilterDispatcher过滤器，已经不建议使用了。将使用StrutsPrepareFilter 和StrutsExecuteFilter拦截器替代。正确的配置方式如下：

Xml代码  

1. <filter>  
2.         <filter-name>struts-prepare</filter-name>  
3.         <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareFilter</filter-class>  
4.     </filter>  
5.     <filter>  
6.         <filter-name>sitemesh</filter-name>  
7.         <filter-class>com.opensymphony.sitemesh.webapp.SiteMeshFilter</filter-class>  
8.     </filter>  
9.     <filter>  
10.         <filter-name>struts-execute</filter-name>  
11.         <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsExecuteFilter</filter-class>  
12.     </filter>  
13.       
14.     <filter-mapping>  
15.         <filter-name>struts-prepare</filter-name>  
16.         <url-pattern>/*</url-pattern>  
17.     </filter-mapping>  
18.     <filter-mapping>  
19.         <filter-name>sitemesh</filter-name>  
20.         <url-pattern>/*</url-pattern>  
21.         <dispatcher>REQUEST</dispatcher>  
22.         <dispatcher>FORWARD</dispatcher>  
23.         <dispatcher>INCLUDE</dispatcher>  
24.     </filter-mapping>  
25.     <filter-mapping>  
26.         <filter-name>struts-execute</filter-name>  
27.         <url-pattern>/*</url-pattern>  
28.     </filter-mapping>  
29.       
30.     <servlet>  
31.         <servlet-name>sitemesh-freemarker</servlet-name>  
32.         <servlet-class>org.apache.struts2.sitemesh.FreemarkerDecoratorServlet</servlet-class>  
33.         <init-param>  
34.             <param-name>default_encoding</param-name>  
35.             <param-value>UTF-8</param-value>  
36.         </init-param>  
37.         <load-on-startup>1</load-on-startup>  
38.     </servlet>  
39.     <servlet-mapping>  
40.         <servlet-name>sitemesh-freemarker</servlet-name>  
41.         <url-pattern>*.ftl</url-pattern>  
42.     </servlet-mapping>  
43.     <listener>  
44.         <listener-class>org.apache.struts2.dispatcher.ng.listener.StrutsListener</listener-class>  
45.     </listener>  

    注意：

    1. com.opensymphony.sitemesh.webapp.SiteMeshFilter这个过滤器是必需的，否则装饰不起作用

    2. 为了支持FreeMaker或Velocity，必须添加org.apache.struts2.sitemesh.FreemarkerDecoratorServlet这个Servlet，官方原话：

写道

From 2.2+ the recommended way to use Freemarker with Sitemesh is through the org.apache.struts2.sitemesh.FreemarkerDecoratorServlet servlet

    3. 而已从2.2.x开始，必须添加org.apache.struts2.dispatcher.ng.listener.StrutsListener这个监听器

写道

From 2.2+ the new com.opensymphony.sitemesh.webapp.SiteMeshFilter filter and Struts org.apache.struts2.dispatcher.ng.listener.StrutsListener context listener must be added to web.xml,

    4. 这样sitemesh装饰器才能在freemarker模板中起作用。