SiteMesh3整合SpringMVC+FreeMarker

• SiteMesh3配置
  • 添加maven依赖
  • 添加filter
  • 配置servlet
  • 添加sitemesh配置文件 
  • decorator示例
  • SpringMVC、FreeMarker配置（404问题处理）
  • decorate源码

 

SiteMesh3文档 http://wiki.sitemesh.org/wiki/pages/viewpage.action?pageId=1081348

重新搭建项目偶然发现SiteMesh有了新版本SiteMesh3，本着用新不用旧原则果断升级，多少遇了点坑，顺便记录下

 

 

 

SiteMesh3配置

 

1. 添加maven依赖

   <dependency>
       <groupId>org.sitemesh</groupId>
       <artifactId>sitemesh</artifactId>
       <version> 3.0 . 1 </version>
   </dependency>

2. 添加filter

   在web.xml中添加filter

   <filter>
       <filter-name>sitemesh</filter-name>
       <filter- class >org.sitemesh.config.ConfigurableSiteMeshFilter</filter- class >
   </filter>
   <filter-mapping>
       <filter-name>sitemesh</filter-name>
       <url-pattern>/*</url-pattern>
   </filter-mapping>

3. 配置servlet

   <servlet-mapping>
       <servlet-name> default </servlet-name>
       <url-pattern>*.ftl</url-pattern>
   </servlet-mapping>

4. 添加sitemesh配置文件 

   1. 添加配置文件 sitemesh3.xml
      默认配置文件路径为：/WEB-INF/sitemesh3.xml 

      sitemesh3.xml

      < sitemesh >
          <!--
          By default, SiteMesh will only intercept responses that set the Content-Type HTTP header to text/html
          This can be altered to allow SiteMesh to intercept responses for other types.
          默认 SiteMesh 只对HTTP响应头中Content-Type为 text/html 的类型进行拦截和装饰，若需要处理其它mime类型需要自行添加配置
          -->
          < mime-type >text/html</ mime-type >
          <!--
          Map default decorator. This shall be applied to all paths if no other paths match.
          配置装饰器，仅设置decorator参数时表示为默认的装饰器，当没有任何路径被匹配时会使用默认装饰器装配
           -->
          < mapping  decorator = "/WEB-INF/decorators/decorator.ftl" />
          <!--对不同的路径指定特定的装饰器-->
          <!--<mapping path="/admin/*" decorator="/WEB-INF/decorators/admin-decorator.ftl"/>-->
          <!--
          Alternative convention. This is more verbose but allows multiple decorators to be applied to a single path.
          对同一路径可以同时使用多个装饰器
          -->
          < mapping >
              < path >/category/*</ path >
              < decorator >/WEB-INF/decorators/common-decorator.ftl</ decorator >
              < decorator >/WEB-INF/decorators/menu-decorator.ftl</ decorator >
              < decorator >/WEB-INF/decorators/category-decorator.ftl</ decorator >
          </ mapping >
          <!--
          Exclude path from decoration.
          排除路径，只需将exclue设置为true即可
          -->
          < mapping  path = "/static/*"  exclue = "true" />
          <!--
          An advanced feature of SiteMesh is the ability to define custom rules that manipulate tags on a page.
          These are classes that implement org.sitemesh.content.tagrules.TagRuleBundle.
          默认SiteMesh仅支持title、head、meta、body等tag,可以自定义tag，实现TagRuleBundle接口即可
          -->
          < content-processor >
              < tag-rule-bundle  class = "com.sankuai.shangchao.util.HtmlTagRuleBundle" />
          </ content-processor >
      </ sitemesh >

   2. 修改配置文件路径
      默认配置文件路径为：/WEB-INF/sitemesh3.xml 若需要修改配置文件路径需要在filter里配置configFile参数 

      <filter>
          <filter-name>sitemesh</filter-name>
          <filter- class >org.sitemesh.config.ConfigurableSiteMeshFilter</filter- class >
          <init-param>
              <param-name>configFile</param-name>
              <param-value>/WEB-INF/sitemesh3.xml</param-value>
          </init-param>
      </filter>

   3. 自定义tag

      HtmlTagRuleBundle.java

      import  org.sitemesh.SiteMeshContext;
      import  org.sitemesh.content.ContentProperty;
      import  org.sitemesh.content.tagrules.TagRuleBundle;
      import  org.sitemesh.content.tagrules.html.ExportTagToContentRule;
      import  org.sitemesh.tagprocessor.State;
      
      /**
       * Description: FootTagRuleBundle
       * Author: liuzhao
       * Create: 2015-08-22 09:21
       */
      public  class  HtmlTagRuleBundle  implements  TagRuleBundle {
          @Override
          public  void  install(State defaultState, ContentProperty contentProperty, SiteMeshContext siteMeshContext) {
              defaultState.addRule( "foot" ,  new  ExportTagToContentRule(siteMeshContext, contentProperty.getChild( "foot" ),  false ));
          }
      
          @Override
          public  void  cleanUp(State defaultState, ContentProperty contentProperty, SiteMeshContext siteMeshContext) {
      
          }
      }

5. decorator示例

   decorator配置页面布局layout，对应的tag会被进行装饰替换

   decorator.ftl

   <!DOCTYPE html>
   < html >
   < head >
       < title >
           < sitemesh:write  property = "title" />
       </ title >
       < sitemesh:write  property = 'head' />
   </ head >
   < body >
   < h1 >啦拉拉，我是卖报的小行家</ h1 >
   < sitemesh:write  property = 'body' />
   < sitemesh:write  property = "foot" />
   </ body >
   </ html >

6. SpringMVC、FreeMarker配置（404问题处理）

   sitemesh3是完全独立的，不和任何框架进行偶合，因此SpringMVC、FreeMarker配置完全不需要考虑sitemesh3的兼容问题
   在加载装饰器的时候，会出现404问题，可能的原因是找不到ftl文件的解析器，所以需要配置下ftl使用默认的Servlet解析，在web.xml中添加如下配置

   <servlet-mapping>
       <servlet-name> default </servlet-name>
       <url-pattern>*.ftl</url-pattern>
   </servlet-mapping>

    

1. decorate源码

   @Override
   protected  boolean  postProcess(String contentType, CharBuffer buffer,
                                 HttpServletRequest request, HttpServletResponse response,
                                 ResponseMetaData metaData)
           throws  IOException, ServletException {
       WebAppContext context = createContext(contentType, request, response, metaData);
       Content content = contentProcessor.build(buffer, context);
       if  (content ==  null ) {
           return  false ;
       }
   
       String[] decoratorPaths = decoratorSelector.selectDecoratorPaths(content, context);
       //遍历装饰器进行装饰
       for  (String decoratorPath : decoratorPaths) {
           content = context.decorate(decoratorPath, content);
       }
   
       if  (content ==  null ) {
           return  false ;
       }
       try  {
           content.getData().writeValueTo(response.getWriter());
       }  catch  (IllegalStateException ise) {   // If getOutputStream() has already been called
           content.getData().writeValueTo( new  PrintStream(response.getOutputStream()));
       }
       return  true ;
   }
   
   public  Content decorate(String decoratorName, Content content)  throws  IOException {
       if  (decoratorName ==  null ) {
           return  null ;
       }
   
       class  CharBufferWriter  extends  CharArrayWriter {
           public  CharBuffer toCharBuffer() {
               return  CharBuffer.wrap( this .buf,  0 ,  this .count);
           }
       }
       CharBufferWriter out =  new  CharBufferWriter();
       decorate(decoratorName, content, out);
   
       CharBuffer decorated = out.toCharBuffer();
   
       Content lastContent = currentContent;
       currentContent = content;
       try  {
           return  contentProcessor.build(decorated,  this );
       }  finally  {
           currentContent = lastContent;
       }
   }
   
   @Override
   protected  void  decorate(String decoratorPath, Content content, Writer out)  throws  IOException {
       HttpServletRequest filterableRequest =  new  HttpServletRequestFilterable(request);
       // Wrap response so output gets buffered.
       HttpServletResponseBuffer responseBuffer =  new  HttpServletResponseBuffer(response, metaData,  new  BasicSelector( new  PathMapper<Boolean>(), includeErrorPages) {
           @Override
           public  boolean  shouldBufferForContentType(String contentType, String mimeType, String encoding) {
               return  true ;  // We know we should buffer.
           }
       });
       responseBuffer.setContentType(response.getContentType());  // Trigger buffering.
   
       // It's possible that this is reentrant, so we need to take a copy
       // of additional request attributes so we can restore them afterwards.
       Object oldContent = request.getAttribute(CONTENT_KEY);
       Object oldContext = request.getAttribute(CONTEXT_KEY);
   
       request.setAttribute(CONTENT_KEY, content);
       request.setAttribute(CONTEXT_KEY,  this );
   
       try  {
           // Main dispatch.
           dispatch(filterableRequest, responseBuffer, decoratorPath);
   
           // Write out the buffered output.
           CharBuffer buffer = responseBuffer.getBuffer();
           out.append(buffer);
       }  catch  (ServletException e) {
           //noinspection ThrowableInstanceNeverThrown
           throw  (IOException)  new  IOException( "Could not dispatch to decorator" ).initCause(e);
       }  finally  {
           // Restore previous state.
           request.setAttribute(CONTENT_KEY, oldContent);
           request.setAttribute(CONTEXT_KEY, oldContext);
       }
   }
   
   protected  void  dispatch(HttpServletRequest request, HttpServletResponse response, String path)
           throws  ServletException, IOException {
       //这里调用加载文件会出现404错误 /WEB-INF/decorators/decorator.ftl
       RequestDispatcher dispatcher = servletContext.getRequestDispatcher(path);
       if  (dispatcher ==  null ) {
           throw  new  ServletException( "Not found: "  + path);
       }
       dispatcher.forward(request, response);
   }