使用sitemesh替换tiles2，spring mvc+spring web flow+sitemsh
之 前改写的spring web flow发行包中的booking-mvc应用(参见 http://clongjava.iteye.com/blog/1314108 )，采用的是 tiles2来统一整个站点页面风格，spring web flow提供了一个ViewResolver为 org.springframework.js.ajax.AjaxUrlBasedViewResolver，它结合了spring-js，提供了 ajax内置的支持，可以使我们局部加载某个tiles的put-attribute中的内容。可是每次都要写tiles配置文件，感觉不爽，由于之前使 用过sitemesh感觉不错，就想替换掉tiles，由于tiles和sitemesh采用统一页面风格的理念不一样，sitemesh采用的是装饰 (decorator)通过filter来过滤所有请求生成的页面。而tiles是采用的模板方法。二者目的都是一样的，统一风格 。
sitemesh配置很简单：首先在web.xml中添加一个sitemesh filter,代码如下：
<filter>
<filter-name>sitemesh</filter-name>
<filter-class>com.opensymphony.sitemesh.webapp.SiteMeshFilter</filter-class>
</filter>
<!-- note:sitemesh filter mapping must appear after springSecurityFilterChain filter mapping -->
<filter-mapping>
<filter-name>sitemesh</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
这里有个注意点要提下：当我们也配置了spring security filter的时候，sitemesh的filter mapping应该在spring security filter mapping之后，不然sitemesh对于使用spring security jsp tag的页面显示不出来，这也可以理解，sitemesh已经装饰完成了，而spring security filter还没结束，当然显示不出来。
第二步，在WEB-INF目录下，新建一个名为decorators.xml文件即可，内容如下：
<?xml version="1.0" encoding="UTF-8" ?>
<decorators defaultDir="/WEB-INF/layout">
<excludes>
<pattern>/resources/*</pattern>
</excludes>
<decorator name="main" page="main.jsp">
<pattern>/*</pattern>
</decorator>
</decorators>
第三步，开始编写我们的装饰者页面，这里展示一下我的页面：
<%@ page contentType="text/html;charset=UTF-8" language="java" pageEncoding="UTF-8" %>
<%@ taglib prefix="s" uri="http://www.springframework.org/tags" %>
<%@ taglib prefix="decorator" uri="http://www.opensymphony.com/sitemesh/decorator" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="sec" uri="http://www.springframework.org/security/tags" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title><decorator:title default="Spring Travel: Spring MVC and Web Flow Reference Application" /></title>
<link type="text/css" rel="stylesheet" href="<c:url value="/resources/dijit/themes/tundra/tundra.css" />" />
<link rel="stylesheet" type="text/css" href="<s:url value="/resources/css/main.css" />" />
<!--[if lte IE 6]>
<link rel="stylesheet" type="text/css" href="<s:url value="/resources/css/ie6.css" />" />
<![endif]-->
<script type="text/javascript" src="<c:url value="/resources/dojo/dojo.js" />"></script>
<script type="text/javascript" src="<c:url value="/resources/spring/Spring.js" />"></script>
<script type="text/javascript" src="<c:url value="/resources/spring/Spring-Dojo.js" />"></script>
<script type="text/javascript" src="<s:url value="/resources/js/jquery-1.7.1.min.js" />"></script>
<script type="text/javascript" src="<s:url value="/resources/js/jquery.validate.min.js" />"></script>
<decorator:head />
</head>
<body class="tundra">
<div id="wrapper">
<div id="header">
<div id="topbar">
<p>
<sec:authorize access="hasRole('ROLE_USER')">
<c:if test="${pageContext.request.userPrincipal != null}">
Welcome, ${pageContext.request.userPrincipal.name} |
</c:if>
<a href="<c:url value="/logout" />">Logout</a> |
<a href="<c:url value="/sec/users/changePassword" />">Change Password</a>
</sec:authorize>
<sec:authorize access="anonymous">
<a href="<c:url value="/login" />">Login</a>
</sec:authorize>
</p>
</div>
<div id="logo">
<p>
<a href="<s:url value="/" />"><img src="<s:url value="/resources/images/header.jpg" />" alt="generic hotel" /></a>
</p>
</div>
</div>
<div id="content">
<div id="primary">
<decorator:body />
</div>
<div id="secondary">
<p>
<a href="http://www.thespringexperience.com">
<img src="<s:url value="/resources/images/myDog.jpg" />" width="208px" height="300px" alt="generic hotel" />
</a>
</p>
<p class="center">
<a href="http://www.thespringexperience.com">
<img src="<s:url value="/resources/images/springone2gx.jpeg" />" alt="SpringOne 2GX" />
</a>
</p>
</div>
</div>
<div id="footer">
<a href="http://www.springframework.org">
<img src="<s:url value="/resources/images/powered-by-spring.png" />" alt="Powered by Spring" />
</a>
</div>
</div>
</body>
</html>
这里充分显示你的前端水平，规划好整个风格后，后面开发起来就轻松多了。
传几张图片看看效果图吧，图中的dog是我养的，非常棒。
本来打算使用sitemesh3的，它里面有些新的东西，对返回的MIME不是text/html的响应也能进行装饰，可是发现sitemesh3有一个问题，当第一次访问页面的时候没有问题，可是一刷新页面就会出现页面加载缓慢，并抛出一个异常，异常如下：
[DEBUG,FlowHandlerMapping,qtp1056001-20 - /SpringWebFlowTutorial/resources/js/jquery.validate.min.js] No flow mapping found for request with URI '/SpringWebFlowTutorial/resources/js/jquery.validate.min.js' [DEBUG,RequestMappingHandlerMapping,qtp1056001-20 - /SpringWebFlowTutorial/resources/js/jquery.validate.min.js] Looking up handler method for path /resources/js/jquery.validate.min.js [DEBUG,DispatcherServlet,qtp1056001-24 - /SpringWebFlowTutorial/resources/js/jquery-1.7.1.min.js] Could not complete request java.lang.IllegalStateException: NO CONTENT at org.eclipse.jetty.http.HttpGenerator.addContent(HttpGenerator.java:156) at org.eclipse.jetty.server.HttpOutput.write(HttpOutput.java:167) at org.eclipse.jetty.server.HttpOutput.write(HttpOutput.java:101) at org.sitemesh.webapp.contentfilter.io.RoutableServletOutputStream.write(RoutableServletOutputStream.java:133) at org.springframework.util.FileCopyUtils.copy(FileCopyUtils.java:113) at org.springframework.web.servlet.resource.ResourceHttpRequestHandler.writeContent(ResourceHttpRequestHandler.java:240) at org.springframework.web.servlet.resource.ResourceHttpRequestHandler.handleRequest(ResourceHttpRequestHandler.java:141) at org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter.handle(HttpRequestHandlerAdapter.java:49) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:900) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:827) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778) at javax.servlet.http.HttpServlet.service(HttpServlet.java:705) at javax.servlet.http.HttpServlet.service(HttpServlet.java:814) at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:547) at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1359) at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1330) at org.sitemesh.webapp.contentfilter.ContentBufferingFilter.bufferAndPostProcess(ContentBufferingFilter.java:169) at org.sitemesh.webapp.contentfilter.ContentBufferingFilter.doFilter(ContentBufferingFilter.java:126) at org.sitemesh.config.ConfigurableSiteMeshFilter.doFilter(ConfigurableSiteMeshFilter.java:163) at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1330) at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:167) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:259) at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1330) at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:478) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119) at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:520) at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:227) at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:941) at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:409) at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:186) at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:875) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117) at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:250) at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:149) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:110) at org.eclipse.jetty.server.Server.handle(Server.java:345) at org.eclipse.jetty.server.HttpConnection.handleRequest(HttpConnection.java:441) at org.eclipse.jetty.server.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:919) at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:582) at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:218) at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:51) at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:586) at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:44) at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:598) at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:533) at java.lang.Thread.run(Thread.java:662)
这个只有在刷新当前页面的时候才会出现，我想就是在加载静态资源文件时会出错，可能是sitemesh3的一个bug，毕竟sitemesh3还是alpha版本，不知道有没有高人遇到过这个问题，帮小弟解答一下。
sitemesh3配置更简单，只需在WEB-INF下放置sitemesh3.xml即可。
<?xml version="1.0" encoding="UTF-8"?>
<sitemesh>
<!-- Map default decorator. This shall be applied to all paths if no other paths match. -->
<mapping path="/*" decorator="/WEB-INF/layout/main.jsp" exclue="false"/>
<!-- Exclude path from decoration. -->
<mapping path="/resources/*" exclue="true"/>
</sitemesh>
web.xml过滤器配置如下：
<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>
当然了应该把sitemesh3的maven依赖加进去。pom.xml
<dependency> <groupId>org.sitemesh</groupId> <artifactId>sitemesh</artifactId> <version>3.0-alpha-2</version> </dependency>
对于使用maven作为项目管理工具的，应该拥有自己的一台私服，比如nexus，这样构件搜索起来比较快速,便于管理。
