sitemesh2.xml解析
  <sitemesh>
       <!--默认情况下，
           sitemesh 只对 HTTP 响应头中 Content-Type 为 text/html 的类型进行拦截和装饰，
          我们可以添加更多的 mime 类型-->
    <mime-type>text/html</mime-type>
    <mime-type>application/vnd.wap.xhtml+xml</mime-type>
    <mime-type>application/xhtml+xml</mime-type>
    ...
    
   <!-- 默认装饰器，当下面的路径都不匹配时，启用该装饰器进行装饰 -->
   <mapping decorator="/default-decorator.html"/>
   
   <!-- 对不同的路径，启用不同的装饰器 -->
   <mapping path="/admin/*" decorator="/another-decorator.html"/>
   <mapping path="/*.special.jsp" decorator="/special-decorator.html"/>
 
   <!-- 对同一路径，启用多个装饰器 -->
   <mapping>
     <path>/articles/*</path>
     <decorator>/decorators/article.html</decorator>
     <decorator>/decorators/two-page-layout.html</decorator>
     <decorator>/decorators/common.html</decorator>
   </mapping>
 
   <!-- 排除，不进行装饰的路径 -->
   <mapping path="/javadoc/*" exclue="true"/>
   <mapping path="/brochures/*" exclue="true"/>
   
   <!-- 自定义 tag 规则 -->
   <content-processor>
     <tag-rule-bundle class="com.something.CssCompressingBundle" />
     <tag-rule-bundle class="com.something.LinkRewritingBundle"/>
   </content-processor>
   ...
 
 </sitemesh>