liferay加载过程详解 转

当用户在浏览器地址栏上输入http://localhost:8080/ 后，经过几次迭代，服务器最终处理的是http://localhost:8080/c/portal/update ，那当服务器收到/c/portal/update的请求后做了什么动作，最后是怎么向浏览器发送网页信息呢？

 

1. 首先MainServlet接收这个请求，然后传递到LayoutAction。（具体怎么传递后续会介绍到）
在struts-config.xml中有定义，表明有关"/portal/layout"的请求是由LayoutAction来处理的。而在tiles-def.xml中定义"/portal/layout"最终传递到"/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的简要流程

LayoutAction.execute()
--------------------------------
ThemeDisplay themeDisplay = (ThemeDisplay)req.getAttribute(WebKeys.THEME_DISPLAY);
Layout layout = themeDisplay.getLayout();

/* 加入/html/portal/layout/view/portlet.jsp 到网页*/
incluldeLayoutContent (req, res, themeDisplay, layout);

/* 加入/html/portal/layout.jsp 到网页，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);

可见两个jsp文件是页面的关键所在。

/portal/layout/view/portlet.jsp
-----------------------------------------
<%
String content = LayoutTemplateLocalUtil.getContent(layoutTypePortlet.getLayoutTemplateId(),
   false, theme.getThemeId());
%>
<%= RuntimePortletUtil.processTemplate (application, request, response, pageContext, content) %>

/*****************************************************
其中content的内容通过断点调试可以知道（是什么时候生成的呢？）
<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()函数返回的是一个很长很长的字符串，就是最终用于显示页面上各个portlet的代码，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的初始内容为：
<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);
}

/ *****************************************************
如果首页面上有四个portlet，名字为A，B，C，D，其中A在左边一列上，B，C同在中间一列，D在右边一列。则output的内容为：
<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());

/*****************************************************
  这里每迭代一个portlet，output的内容中就添加了该portlet的view.jsp代码段落，而且还会增加portlet的标准头部和边框，如最小化，关闭等按钮及其对应的JavaScript代码。
*****************************************************/
}

return output;
/* 这个output就是在portlet.jsp中要显示的内容 */

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中没有发现portal_normal.jsp的踪影，发现portal_normal.vm似乎有点相关。portal_normal粉墨登场。

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>

可见关键是一些Velocity变量的值，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")

可见$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,......

另外还有一个很重要的properties文件值得关注：language.properties。好累啊，还有很多细节可以继续挖掘，还涉及到Velocity的一些变量的操作，休息下先。