上一篇講到當用戶在瀏覽器地址欄上輸入http://localhost:8080/后，經過幾次迭代，服務器最終處理的是http://localhost:8080/c/portal/update，那當服務器收到/c/portal/update的請求后做了什么動作，最后是怎么向瀏覽器發送網頁信息呢？
1. 首先MainServlet接收這個請求，然后傳遞到LayoutAction。（具體怎么傳遞后續會介紹到）
在struts-config.xml中有定義，表明有關"/portal/layout"的請求是由LayoutAction來處理的。而在tiles-def.xml中定義"/portal/layout"最終傳遞到"/portal/layout.jsp"。
struts-config.xml
------------------------
<action path="/portal/layout" type="com.liferay.portal.action.LayoutAction">
<forward name="portal.layout" path="portal.layout" />
</action>
tiles-def.xml
------------------
<definition name="portal.layout" extends="portal">
<put name="content" value="/portal/layout.jsp" />
<put name="selectable" value="true" />
</definition>
2. 下面分析LayoutAction的簡要流程
LayoutAction.execute()
--------------------------------
ThemeDisplay themeDisplay = (ThemeDisplay)req.getAttribute(WebKeys.THEME_DISPLAY);
Layout layout = themeDisplay.getLayout();
/* 加入/html/portal/layout/view/portlet.jsp 到網頁*/
incluldeLayoutContent(req, res, themeDisplay, layout);
/* 加入/html/portal/layout.jsp 到網頁，先portlet.jsp，后layout.jsp*/
return mapping.findForward("portal.layout");
LayoutAction.includeLayoutContent()
-----------------------------------------------------
String path = StrutsUtil.TEXT_HTML_DIR;
/* path = "/html" */
path += PortalUtil.getLayoutViewPage(layout);
/* path = "/html/portal/layout/view/portlet.jsp" */
RequestDispatcher rd = ctx.getRequestDispatcher(path);
rd.include(req, stringServletRes);
可見兩個jsp文件是頁面的關鍵所在。
/portal/layout/view/portlet.jsp
-----------------------------------------
<%
String content = LayoutTemplateLocalUtil.getContent(layoutTypePortlet.getLayoutTemplateId(),
false, theme.getThemeId());
%>
<%= RuntimePortletUtil.processTemplate(application, request, response, pageContext, content) %>
/*****************************************************
其中content的內容通過斷點調試可以知道（是什么時候生成的呢？）
<div class="columns-2" id="content-wrapper">
<table id="layout-grid">
<tr>
<td class="lfr-column thirty" id="column-1" valign="top">
$processor.processColumn("column-1")
</td>
<td class="lfr-column seventy" id="column-2" valign="top">
$processor.processColumn("column-2")
</td>
</tr>
</table>
</div>
*****************************************************/
/* RuntimePortletUtil.processTemplate()函數返回的是一個很長很長的字符串，就是最終用于顯示頁面上各個portlet的代碼，下面有分析 */
RuntimePortletUtil.processTemplate()
------------------------------------------------------
TemplateProcessor processor = new TemplateProcessor(ctx, req, res, portletId);
VelocityContext vc = new VelocityContext();
vc.put("processor", processor);
// Velocity variables
VelocityVariables.insertVariables(vc, req);
vc.put("taglibLiferay", velocityTaglib);
vc.put("theme", velocityTaglib);
StringWriter sw = new StringWriter();
Velocity.evaluate(vc, sw, RuntimePortletUtil.class.getName(), content);
String output = sw.toString();
/*****************************************************
output的初始內容為：
<div class="columns-3" id="content-wrapper">
<table id="layout-grid">
<tr>
<td class="lfr-column thirty" id="column-1" valign="top">
[$TEMPLATE_COLUMN_column-1$]
</td>
<td class="lfr-column thirty" id="column-2" valign="top">
[$TEMPLATE_COLUMN_column-2$]
</td>
<td class="lfr-column thirty" id="column-3" valign="top">
[$TEMPLATE_COLUMN_column-3$]
</td>
</tr>
</table>
</div>
*****************************************************/
Map columnsMap = processor.getColumnsMap();
while (itr.hasNext()) {
Map.Entry entry = (Map.Entry)itr.next();
String key = (String)entry.getKey();
String value = (String)entry.getValue();
output = StringUtil.replace(output, key, value);
}
/*****************************************************
如果首頁面上有四個portlet，名字為A，B，C，D，其中A在左邊一列上，B，C同在中間一列，D在右邊一列。則output的內容為：
<div class="columns-3" id="content-wrapper">
<table id="layout-grid">
<tr>
<td class="lfr-column thirty" id="column-1" valign="top">
<div class="lfr-portlet-column" id="layout-column_column-1">
[$TEMPLATE_PORTLET_A$]
</div>
</td>
<td class="lfr-column thirty" id="column-2" valign="top">
<div class="lfr-portlet-column" id="layout-column_column-2">
[$TEMPLATE_PORTLET_B$]
[$TEMPLATE_PORTLET_C$]
</div>
</td>
<td class="lfr-column thirty" id="column-3" valign="top">
<div class="lfr-portlet-column" id="layout-column_column-3">
[$TEMPLATE_PORTLET_D$]
</div>
</td>
</tr>
</table>
</div>
*****************************************************/
Map portletsMap = processor.getPortletsMap();
itr = portletsMap.entrySet().iterator();
while (itr.hasNext()) {
StringMaker sm = new StringMaker();
processPortlet(sm, ctx, req, res, portlet, queryString, columnId, columnPos,columnCount, null);
output = StringUtil.replace(output, "[$TEMPLATE_PORTLET_" + portlet.getPortletId() + "$]", sm.toString());
/*****************************************************
這里每迭代一個portlet，output的內容中就添加了該portlet的view.jsp代碼段落，而且還會增加portlet的標準頭部和邊框，如最小化，關閉等按鈕及其對應的JavaScript代碼。
*****************************************************/
}
return output;
/* 這個output就是在portlet.jsp中要顯示的內容 */
portal.jsp
------------
<c:choose>
<c:when test="<%= themeDisplay.isStateExclusive() %>">
<%= request.getAttribute(WebKeys.LAYOUT_CONTENT) %>
</c:when>
<c:when test="<%= themeDisplay.isStatePopUp() %>">
<liferay-theme:include page="portal_pop_up.jsp" />
</c:when>
<c:otherwise>
<liferay-theme:include page="portal_normal.jsp" />
</c:otherwise>
</c:choose>
在Liferay中沒有發現portal_normal.jsp的蹤影，發現portal_normal.vm似乎有點相關。portal_normal粉墨登場。
portal_normal.vm
-------------------------
#parse ($init)
<html dir="#language ("lang.dir")">
<head>
<title>$company_name - $the_title</title>
$theme.include($top_head_include)
#css ($css_main_file)
#js ($js_main_file)
#if ($company_logo != "")
<style type="text/css">
#banner .logo {background: url($company_logo) no-repeat;
height: ${company_logo_height}px;
width: ${company_logo_width}px; }
</style>
#end
</head>
<body class="$css_class">
$theme.include($top_messages_include)
<div id="wrapper">
<div id="banner">
<div id="banner-inner">
<h1 class="logo">
<a href="$company_url">$company_name</a>
</h1>
<div id="page-search">
$theme.journalContentSearch()
</div>
#parse ("$full_templates_path/dock.vm")
#if ($update_available_url)
<div class="popup-alert-notice">
<a class="update-available" href="$update_available_url">#language("updates-are-available-for-liferay")</a>
</div>
#end
#if ($has_navigation)
#parse ("$full_templates_path/navigation.vm")
#end
</div>
</div>
#if ($selectable)
$theme.include($content_include)
#else
<div id="content-wrapper" class="login">
$portletDisplay.recycle()
$portletDisplay.setTitle($the_title)
$theme.wrapPortlet("portlet.vm", $content_include)
</div>
#end
<div id="footer">
<p class="language">$theme.language()</p>
</div>
</div>
$theme.include($bottom_ext_include)
$theme.include($session_timeout_include)
$theme.include($sound_alerts_include)
</body>
</html>
可見關鍵是一些Velocity變量的值，例如$top_head_include。
init.vm
----------
#set ($bottom_ext_include = "$dir_include/common/themes/bottom.jsp")
#set ($content_include = "$dir_include$tilesContent")
#set ($session_timeout_include = "$dir_include/common/themes/session_timeout.jsp")
#set ($sound_alerts_include = "$dir_include/common/themes/sound_alerts.jsp")
#set ($top_head_include = "$dir_include/common/themes/top_head.jsp")
#set ($top_messages_include = "$dir_include/common/themes/top_messages.jsp")
可見$top_head_include就是top_head.jsp。
top_head.jsp
-------------------
<%@ include file="/html/common/themes/top_js.jspf" %>
<%@ include file="/html/common/themes/top_js-ext.jsp" %>
portal/portal-web/docroot/html/common/themes/top_js.jspf
<%
String[] javaScriptFiles = PropsUtil.getArray(PropsUtil.JAVASCRIPT_FILES);
for (int i = 0; i < javaScriptFiles.length; i++) {
%>
<script src="<%= themeDisplay.getPathJavaScript() %>/<%= javaScriptFiles[i] %>" type="text/javascript"></script>
<%
}
%>
那javascriptFiles又如何得到的呢？
portal.properties
------------------------
javascript.files=\
jquery/jquery.js,\
jquery/cookie.js,\
jquery/tabs.js,\
\
liferay/liferay.js,\
liferay/browser.js,\
liferay/util.js,\
liferay/language.js,\
liferay/layout.js,\
\
liferay/ajax.js,\
liferay/animate.js,\
liferay/auto_fields.js,\
liferay/color_picker.js,\
liferay/columns.js,\
liferay/dock.js,\
liferay/dynamic_select.js,\
liferay/freeform.js,\
liferay/layout_configuration.js,......
另外還有一個很重要的properties文件值得關注：language.properties。好累啊，還有很多細節可以繼續挖掘，還涉及到Velocity的一些變量的操作，休息下先。
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