Liferay 启动过程分析6-初始化Portlets

 在MainServlet中，初始化插件包之后，就开始初始化Portlets:

对应的代码是：

if (_log.isDebugEnabled()) {
            _log.debug("Initialize portlets");
        }

        List<Portlet> portlets = null;

        try {
            portlets = initPortlets(pluginPackage);
        }
...

 

它会去调用initPortlets方法，并且传入一个我们上一步刚初始化的核心pluginPackage,我们来细看它究竟做了哪些事情:

 

读取配置文件：

首先，它去取得servletContext,然后获取一组xml配置文件：

protected List<Portlet> initPortlets(PluginPackage pluginPackage)
        throws Exception {

        ServletContext servletContext = getServletContext();

        String[] xmls = new String[] {
            HttpUtil.URLtoString(
                servletContext.getResource(
                    "/WEB-INF/" + Portal.PORTLET_XML_FILE_NAME_CUSTOM)),
            HttpUtil.URLtoString(
                servletContext.getResource("/WEB-INF/portlet-ext.xml")),
            HttpUtil.URLtoString(
                servletContext.getResource("/WEB-INF/liferay-portlet.xml")),
            HttpUtil.URLtoString(
                servletContext.getResource("/WEB-INF/liferay-portlet-ext.xml")),
            HttpUtil.URLtoString(
                servletContext.getResource("/WEB-INF/web.xml"))
        };
....

这些xml配置文件中，我研究了下，大概是提供如下的功能。

portlet_custom.xml可以用来根据请求的p_p_id字段，到这个文件中找到相应的portlet的<init-param>的<view-action>元素，然后去struts-config.xml中找到action的配置信息，最终到tiles-config.xml中找到对应的页面信息。

portlet-ext.xml,定义了portlet的初始化信息。

liferay-portlet.xml，定义了portlet在liferay框架中的一般外观信息

liferay-portlet-ext.xml,定义了portlet在liferay框架中的模板和是否允许重复。

 

初始化EAR:

然后，调用以下代码来初始化：

PortletLocalServiceUtil.initEAR(servletContext, xmls, pluginPackage);

它最终会调用PortletLocalServiceImpl的initEAR方法：

public void initEAR(
        ServletContext servletContext, String[] xmls,
        PluginPackage pluginPackage) {

        // Clear pools every time initEAR is called. See LEP-5452.

        portletLocalService.clearCompanyPortletsPool();

        _portletAppsPool.clear();
        _portletsPool.clear();
        _portletIdsByStrutsPath.clear();
        _friendlyURLMapperPortlets.clear();

        Map<String, Portlet> portletsPool = _getPortletsPool();

        try {
            Set<String> servletURLPatterns = _readWebXML(xmls[4]);

            Set<String> portletIds = _readPortletXML(
                servletContext, xmls[0], portletsPool, servletURLPatterns,
                pluginPackage);

            portletIds.addAll(
                _readPortletXML(
                    servletContext, xmls[1], portletsPool, servletURLPatterns,
                    pluginPackage));

            Set<String> liferayPortletIds =
                _readLiferayPortletXML(xmls[2], portletsPool);

            liferayPortletIds.addAll(
                _readLiferayPortletXML(xmls[3], portletsPool));

            // Check for missing entries in liferay-portlet.xml

            for (String portletId : portletIds) {
                if (_log.isWarnEnabled() &&
                    !liferayPortletIds.contains(portletId)) {

                    _log.warn(
                        "Portlet with the name " + portletId +
                            " is described in portlet.xml but does not " +
                                "have a matching entry in liferay-portlet.xml");
                }
            }

            // Check for missing entries in portlet.xml

            for (String portletId : liferayPortletIds) {
                if (_log.isWarnEnabled() && !portletIds.contains(portletId)) {
                    _log.warn(
                        "Portlet with the name " + portletId +
                            " is described in liferay-portlet.xml but does " +
                                "not have a matching entry in portlet.xml");
                }
            }

            // Remove portlets that should not be included

            Iterator<Map.Entry<String, Portlet>> portletPoolsItr =
                portletsPool.entrySet().iterator();

            while (portletPoolsItr.hasNext()) {
                Map.Entry<String, Portlet> entry = portletPoolsItr.next();

                Portlet portletModel = entry.getValue();

                if (!portletModel.getPortletId().equals(PortletKeys.ADMIN) &&
                    !portletModel.getPortletId().equals(
                        PortletKeys.MY_ACCOUNT) &&
                    !portletModel.isInclude()) {

                    portletPoolsItr.remove();

                    _friendlyURLMapperPortlets.remove(
                        portletModel.getPortletId());
                }
            }

            // Sprite images

            PortletApp portletApp = _getPortletApp(StringPool.BLANK);

            _setSpriteImages(servletContext, portletApp, "/html/icons/");
        }
        catch (Exception e) {
            _log.error(e, e);
        }
    }

这里可以看出.它先去做一些清理工作（05-12行），然后它再去依次读取这些xml文件（所以，参数传递过来的xml文件的顺序不能错，17-32行），最终获取的是servletURLPattern的集合，portletId的集合，liferayPortletId的集合。然后检查portletId与liferayPortletId是否一一匹配（见第34-56行）。然后遍历Portlet池，吧PortletId=9(Admin Portlet),PortletId=2(My Account Portlet)和所有被标注为不应该include的Portlet从Portlet池和friendlyURLMapperPortlets中移除（见第58-78行），最后第80-87行，会sprite图片，它会在ROOT/html/icons/目录下递归的去找所有.png扩展名的文件，然后吧这些图片拼接成一张大图/html/icons/_sprite.png,然后把这些小图标在大图上的位置都写入/html/icons/_sprite.properties文件中。

 

封装每个Portlet到PortletBag中并且初始化这些Portlet:

PortletBagFactory portletBagFactory = new PortletBagFactory();

        portletBagFactory.setClassLoader(
            PortalClassLoaderUtil.getClassLoader());
        portletBagFactory.setServletContext(servletContext);
        portletBagFactory.setWARFile(false);

        List<Portlet> portlets = PortletLocalServiceUtil.getPortlets();

        for (int i = 0; i < portlets.size(); i++) {
            Portlet portlet = portlets.get(i);

            portletBagFactory.create(portlet);

            if (i == 0) {
                initPortletApp(portlet, servletContext);
            }
        }

        return portlets;

从这段代码看，它会遍历上一步的得到的所有portlet(除了admin,my account,以及必须排除的portlet),然后把每一个Portlet放入PortletBag中。

 

其中第13行会调用portletBagFactory.create()方法：

它首先会指定这个Portlet的类加载器：

if (!portletApp.isWARFile() && _warFile) {
        String contextPath = PortalUtil.getPathContext();

        _servletContext = ServletContextPool.get(contextPath);

        _classLoader = PortalClassLoaderUtil.getClassLoader();
    }

    Class<?> portletClass = null;

    try {
        portletClass = _classLoader.loadClass(portlet.getPortletClass());
    }
    catch (Throwable e) {
    ...

然后吧Portlet与整个Liferay的环境进行绑定，绑定信息填充到PortletBag中，绑定完之后，吧PortletBag添加到PortletPool中

javax.portlet.Portlet portletInstance =
        (javax.portlet.Portlet)portletClass.newInstance();

...

    PortletBag portletBag = new PortletBagImpl(
        portlet.getPortletId(), _servletContext, portletInstance,
        configurationActionInstance, indexerInstances, openSearchInstance,
        friendlyURLMapperInstance, urlEncoderInstance,
        portletDataHandlerInstance, portletLayoutListenerInstance,
        pollerProcessorInstance, popMessageListenerInstance,
        socialActivityInterpreterInstance, socialRequestInterpreterInstance,
        webDAVStorageInstance, xmlRpcMethodInstance,
        controlPanelEntryInstance, assetRendererFactoryInstances,
        atomCollectionAdapterInstances, customAttributesDisplayInstances,
        permissionPropagatorInstance, workflowHandlerInstances,
        preferencesValidatorInstance, resourceBundles);

    PortletBagPool.put(portlet.getRootPortletId(), portletBag);

最后让PortletInstanceFactory吧这个Portlet实例创建出来并且关联到servleetContext:

try {
            PortletInstanceFactoryUtil.create(portlet, _servletContext);
        }

而第16行，则是为PortletApp做一些初始化工作，他们在MainServlet的initApp()方法中：

protected void initPortletApp(
            Portlet portlet, ServletContext servletContext)
        throws PortletException {

        PortletApp portletApp = portlet.getPortletApp();

        PortletConfig portletConfig = PortletConfigFactoryUtil.create(
            portlet, servletContext);

        PortletContext portletContext = portletConfig.getPortletContext();

        Set<PortletFilter> portletFilters = portletApp.getPortletFilters();

        for (PortletFilter portletFilter : portletFilters) {
            PortletFilterFactory.create(portletFilter, portletContext);
        }

        Set<PortletURLListener> portletURLListeners =
            portletApp.getPortletURLListeners();

        for (PortletURLListener portletURLListener : portletURLListeners) {
            PortletURLListenerFactory.create(portletURLListener);
        }
    }

很显然，这里就是做一些Portlet环境配置工作，并且为Portlet添加一些监听器和过滤器。

 

现在，这些Portlet实例就都在Liferay服务器的内存中并且可用了。