SiteMesh3整合SpringMVC+FreeMarker

时间:2022-04-30 18:34:39

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整合SpringMVC+FreeMarker

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>

SiteMesh3整合SpringMVC+FreeMarker

  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, 0this.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);
    }