由于一直忙于公司产品的开发工作，企业搜索引擎的连接器分析及constellio源码分析因此长时间没有更新，本次继续这项未竟事业
连接器管理都是通过servlet对外提供通信接口，由此从连接器管理提供的servlet着手，寻求分析连接器的入口
该系统提供的servlet的uml模型图如下
这些servlet主要提供连接器的管理，诸如连接器的配置、修改、移除、重启、设置定时调度等功能;其中StartUp跟随应用同时启动，负责初始化一些bean及相关参数等，其源码如下：
/** * The main purpose of this servlet is to have its "init" method called when the * container starts up. This is by done by means of the web.xml file. But I also * gave it a get and post that do the same thing. * */ public class StartUp extends HttpServlet { private static final Logger LOGGER = Logger.getLogger(StartUp.class.getName()); @Override public void init() { NDC.push("Init"); try { LOGGER.info("init"); ServletContext servletContext = this.getServletContext(); doConnectorManagerStartup(servletContext); LOGGER.info("init done"); } finally { NDC.remove(); } } @Override public void destroy() { NDC.push("Shutdown"); try { LOGGER.info("destroy"); Context.getInstance().shutdown(true); } finally { NDC.remove(); } } @Override protected void doGet(HttpServletRequest req, HttpServletResponse res) throws IOException { doPost(req, res); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse res) throws IOException { ServletContext servletContext = this.getServletContext(); doConnectorManagerStartup(servletContext); res.setContentType(ServletUtil.MIMETYPE_HTML); PrintWriter out = res.getWriter(); out.println("<HTML><HEAD><TITLE>Connector Manager Started</TITLE></HEAD>" + "<BODY>Connector manager has been successfully started.</BODY>" + "</HTML>"); out.close(); LOGGER.info("Connector Manager started."); } private void doConnectorManagerStartup(ServletContext servletContext) { LOGGER.info(ServletUtil.getManagerSplash()); // read in and set initialization parameters String kp = servletContext.getInitParameter("keystore_passwd_file"); EncryptedPropertyPlaceholderConfigurer.setKeyStorePasswdPath(kp); String ks = servletContext.getInitParameter("keystore_file"); String realks = servletContext.getRealPath("/WEB-INF/" + ks); if (null == realks) { // Servlet container cannot translated the virtual path to a // real path, so use the given path. EncryptedPropertyPlaceholderConfigurer.setKeyStorePath(ks); } else { EncryptedPropertyPlaceholderConfigurer.setKeyStorePath(realks); } String kt = servletContext.getInitParameter("keystore_type"); EncryptedPropertyPlaceholderConfigurer.setKeyStoreType(kt); String ka = servletContext.getInitParameter("keystore_crypto_algo"); EncryptedPropertyPlaceholderConfigurer.setKeyStoreCryptoAlgo(ka); // Note: default context location is /WEB-INF/applicationContext.xml LOGGER.info("Making an XmlWebApplicationContext"); XmlWebApplicationContext ac = new XmlWebApplicationContext(); ac.setServletContext(servletContext); ac.refresh(); Context context = Context.getInstance(); context.setServletContext(ac, servletContext.getRealPath("/WEB-INF")); context.start(); } }
这里的关键方法是void doConnectorManagerStartup(ServletContext servletContext)
前面部分用于证书生成，后面部分是获取spring容器并初始化Context上下文对象
接下来分析Context的源码：
/** * Static services for establishing the application context. This consists of * configuration, instantiating singletons, start up, etc. * This code supports two context types: servlet (as a web application within * an application server) and standalone. * When we run junit tests, we use a standalone context. * Use the methods setStandaloneContext and setServletContext to select the * context type. * <p> * Also the interface used for event publishing. Wraps the event publishing * functionality of the established context. */ public class Context { public static final String GSA_FEED_HOST_PROPERTY_KEY = "gsa.feed.host"; public static final String GSA_FEED_PORT_PROPERTY_KEY = "gsa.feed.port"; public static final String GSA_FEED_PORT_DEFAULT = "19900"; public static final String GSA_ADMIN_REQUIRES_PREFIX_KEY = "gsa.admin.requiresPrefix"; public static final String TEED_FEED_FILE_PROPERTY_KEY = "teedFeedFile"; public static final String MANAGER_LOCKED_PROPERTY_KEY = "manager.locked"; public static final Boolean GSA_ADMIN_REQUIRES_PREFIX_DEFAULT = Boolean.FALSE; public static final String DEFAULT_JUNIT_CONTEXT_LOCATION = "testdata/mocktestdata/applicationContext.xml"; public static final String DEFAULT_JUNIT_COMMON_DIR_PATH = "testdata/mocktestdata/"; /** * Id of the Spring Bean used to declare the order services are to be loaded. */ public static final String ORDERED_SERVICES_BEAN_NAME = "OrderedServices"; private static final String APPLICATION_CONTEXT_PROPERTIES_BEAN_NAME = "ApplicationContextProperties"; // This is the comment written to the ApplicationContextProperties file. private static final String CONNECTOR_MANGER_CONFIG_HEADER = " Google Search Appliance Connector Manager Configuration\n" + "\n" + " The 'gsa.feed.host' property specifies the host name or IP address\n" + " for the feed host on the GSA.\n" + " For example:\n" + " gsa.feed.host=172.24.2.0\n" + "\n" + " The 'gsa.feed.port' property specifies the host port for the feed\n" + " host on the GSA.\n" + " For example:\n" + " gsa.feed.port=19900\n" + "\n" + " The 'manager.locked' property is used to lock out the Admin Servlet\n" + " and prevent it from making changes to this configuration file.\n" + " Specifically, the ability to set the FeedConnection properties will\n" + " be locked out. If it is set to 'true' or missing the Servlet will\n" + " not be allowed to update this file.\n" + " NOTE: This property will automatically be changed to 'true' upon\n" + " successful update of the file by the Servlet. Therefore, once the\n" + " FeedConnection properties are successfully updated by the Servlet\n" + " subsequent updates will be locked out until the flag is manually\n" + " reset to 'false'.\n" + " For example:\n" + " manager.locked=false\n" + "\n" + " The 'feedLoggingLevel' property controls the logging of the feed\n" + " record to a log file. The log record will contain the feed XML\n" + " without the content data. Set this property to 'ALL' to enable feed\n" + " logging, 'OFF' to disable. Customers and developers can use this\n" + " functionality to observe the feed record and metadata information\n" + " the connector manager sends to the GSA.\n" + " For example:\n" + " feedLoggingLevel=OFF\n" + "\n" + " If you set the 'teedFeedFile' property to the name of an existing\n" + " file, whenever the connector manager feeds content to the GSA, it\n" + " will write a duplicate copy of the feed XML to the file specified by\n" + " the teedFeedFile property. GSA customers and third-party developers\n" + " can use this functionality to observe the content the connector\n" + " manager sends to the GSA and reproduce any issue which may arise.\n" + " NOTE: The teedFeedFile will contain all feed data sent to the GSA,\n" + " including document content and metadata. The teedFeedFile can\n" + " therefore grow quite large very quickly.\n" + " For example:\n" + " teedFeedFile=/tmp/CMTeedFeedFile" + "\n" + " The 'feed.timezone' property defines the default time zone used\n" + " for Date metadata values for Documents. A null or empty string\n" + " indicates that the system timezone of the machine running the\n" + " Connector Manager should be used. Standard TimeZone identifiers\n" + " may be used. For example:\n" + " feed.timezone=America/Los_Angeles\n" + " If a standard TimeZone identifier is unavailable, then a custom\n" + " TimeZone identifier can be constructed as +/-hours[minutes] offset\n" + " from GMT. For example:\n" + " feed.timezone=GMT+10 # GMT + 10 hours\n" + " feed.timezone=GMT+0630 # GMT + 6 hours, 30 minutes\n" + " feed.timezone=GMT-0800 # GMT - 8 hours, 0 minutes\n" + "\n" + " The 'feed.file.size' property sets the target size, in bytes, of\n" + " an accumulated feed file. The Connector Manager tries to collect\n" + " many feed Documents into a single feed file to improve the\n" + " efficiency of sending feed data to the GSA. Specifying too small\n" + " a value may result in many small feeds which might overrun the\n" + " GSA's feed processor. However, specifying too large a feed size\n" + " reduces concurrency and may result in OutOfMemory errors in the\n" + " Java VM, especially if using multiple Connector Instances.\n" + " The default target feed size is 10MB.\n" + " For example:\n" + " feed.file.size=10485760\n" + "\n" + " The 'feed.document.size.limit' property defines the maximum\n" + " allowed size, in bytes, of a Document's content. Documents whose\n" + " content exceeds this size will still have metadata indexed,\n" + " however the content itself will not be fed. The default value\n" + " is 30MB, the maximum file size accepted by the GSA.\n" + " For example:\n" + " feed.document.size.limit=31457280\n" + "\n" + " The 'feed.backlog.*' properties are used to throttle back the\n" + " document feed if the GSA has fallen behind processing outstanding\n" + " feed items. The Connector Manager periodically polls the GSA,\n" + " fetching the count of unprocessed feed items (the backlog count).\n" + " If the backlog count exceeds the ceiling value, feeding is paused.\n" + " Once the backlog count drops down below the floor value, feeding\n" + " resumes.\n For example:\n" + " Stop feeding the GSA if its backlog exceeds this value.\n" + " feed.backlog.ceiling=10000\n" + " Resume feeding the GSA if its backlog falls below this value.\n" + " feed.backlog.floor=1000\n" + " How often to check for feed backlog (in seconds).\n" + " feed.backlog.interval=900\n" + "\n" + " The 'traversal.batch.size' property defines the optimal number\n" + " of items to return in each repository traversal batch. The batch\n" + " size represents the size of the roll-back that occurs during a\n" + " failure condition. Batch sizes that are too small may incur\n" + " excessive processing overhead. Batch sizes that are too large\n" + " may produce OutOfMemory conditions within a Connector or result\n" + " in early termination of the batch if processing time exceeds the\n" + " travesal.time.limit. For example:\n" + " traversal.batch.size=500\n" + "\n" + " The 'traversal.poll.interval' property defines the number of\n" + " seconds to wait after a traversal of the repository finds no new\n" + " content before looking again. Short intervals allow new content\n" + " to be readily available for search, at the cost of increased\n" + " repository access. Long intervals add latency before new\n" + " content becomes available for search. By default, the Connector\n" + " Manager waits 5 minutes (300 seconds) before retraversing the\n" + " repository if no new content was found on the last traversal.\n" + " For example:\n" + " traversal.poll.interval=300\n" + "\n" + " The 'traversal.time.limit' property defines the number of\n" + " seconds a traversal batch should run before gracefully exiting.\n" + " Traversals that exceed this time period risk cancelation.\n" + " The default time limit is 30 minutes (1800 seconds).\n" + " For example:\n" + " traversal.time.limit=1800\n" + "\n" + " The 'traversal.enabled' property is used to enable or disable\n" + " Traversals and Feeds for all connector instances in this\n" + " Connector Manager. Disabling Traversal would be desirable if\n" + " configuring a Connector Manager deployment that only authorizes\n" + " search results. Traversals are enabled by default.\n" + " traversal.enabled=false\n" + "\n"; private static final Logger LOGGER = Logger.getLogger(Context.class.getName()); private static final GenericApplicationContext genericApplicationContext = new GenericApplicationContext(); private static Context INSTANCE = new Context(); private boolean started = false; private boolean isServletContext = false; private boolean isFeeding = true; private String commonDirPath = null; // singletons private Manager manager = null; private TraversalScheduler traversalScheduler = null; private TraversalContext traversalContext = null; private SpringInstantiator instantiator = null; // control variables for turning off normal functionality - testing only private String standaloneContextLocation; private Boolean gsaAdminRequiresPrefix = null; private boolean isTeedFeedFileInitialized = false; private String teedFeedFile = null; private boolean isGsaFeedHostInitialized = false; private String gsaFeedHost = null; private int propertiesVersion = 0; /** * @param feeding to feed or not to feed */ public void setFeeding(boolean feeding) { LOGGER.config("Traversal and Feeds are " + ((feeding) ? "enabled." : "disabled.")); this.isFeeding = feeding; } public static Context getInstance() { return INSTANCE; } ApplicationContext applicationContext = null; private Context() { // Private to ensure singleton. } private void initializeStandaloneApplicationContext() { if (applicationContext != null) { // too late - someone else already established a context. this might // happen with multiple junit tests that each want to establish a context. // so long as they use the same context location, it's ok. if they want a // different context location, they should refresh() - see below return; } applicationContext = genericApplicationContext; // avoid recursion if (standaloneContextLocation == null) { standaloneContextLocation = DEFAULT_JUNIT_CONTEXT_LOCATION; } if (commonDirPath == null) { commonDirPath = DEFAULT_JUNIT_COMMON_DIR_PATH; } LOGGER.info("context file: " + standaloneContextLocation); LOGGER.info("common dir path: " + commonDirPath); applicationContext = new FileSystemXmlApplicationContext(standaloneContextLocation); } /** * Establishes that we are operating within the standalone context. In * this case, we use a FileSystemApplicationContext. * @param contextLocation the name of the context XML file used for * instantiation. * @param commonDirPath the location of the common directory which contains * ConnectorType and Connector instantiation configuration data. */ public void setStandaloneContext(String contextLocation, String commonDirPath) { this.standaloneContextLocation = contextLocation; this.commonDirPath = commonDirPath; initializeStandaloneApplicationContext(); } /** * Establishes that we are operating from a servlet context. In this case, we * use an XmlWebApplicationContext, which finds its config from the servlet * context - WEB-INF/applicationContext.xml. */ public void setServletContext(ApplicationContext servletApplicationContext, String commonDirPath) { this.applicationContext = servletApplicationContext; this.commonDirPath = commonDirPath; isServletContext = true; } /* * Choose a default context, if it wasn't specified in any other way. For now, * we choose servlet context by default. */ private void initApplicationContext() { if (applicationContext == null) { initializeStandaloneApplicationContext(); } if (applicationContext == null) { throw new IllegalStateException("Spring failure - no application context"); } } /** * Start up the Scheduler. */ private void startScheduler() { traversalScheduler = (TraversalScheduler) getRequiredBean("TraversalScheduler", TraversalScheduler.class); if (traversalScheduler != null) { traversalScheduler.init(); } } /** * Start up the Instantiator. */ private void startInstantiator() { instantiator = (SpringInstantiator) getBean("Instantiator", SpringInstantiator.class); if (instantiator != null) { instantiator.init(); } } /** * Do everything necessary to start up the application. */ public void start() { if (started) { return; } initApplicationContext(); startInstantiator(); if (isFeeding) { startScheduler(); } startServices(); started = true; } /** * Starts any services declared as part of the application. */ private void startServices() { for (ContextService service : getServices()) { service.start(); } } /** * Gets a service by name. Returns a matching bean if found or null * otherwise. * * @param serviceName the name of the service to find. * @return if there is a single bean with the given name it will be returned. * If there are multiple beans with the same name, the first one found * will be returned. If there are no beans with the given name, null * will be returned. */ public ContextService findService(String serviceName) { return (ContextService) getBean(serviceName, null); } /** * Returns an ordered list of services attached to the context. Collection is * ordered according to the startup order of the services. * <p> * To get the list in reverse order use {@link Collections#reverse(List)}. * * @return an ordered list of ContextService objects. If no services are * registered an empty list will be returned. */ public List<ContextService> getServices() { // TODO: Investigate the use of the GenericBeanFactoryAccessor here. Map<?, ?> orderedServices = (Map<?, ?>) getBean(ORDERED_SERVICES_BEAN_NAME, null); Map<?, ?> services = applicationContext.getBeansOfType(ContextService.class); List<ContextService> result = new ArrayList<ContextService>(); if (orderedServices != null) { for (Iterator<?> iter = orderedServices.keySet().iterator(); iter.hasNext(); ) { ContextService service = (ContextService) orderedServices.get(iter.next()); result.add(service); } } for (Iterator<?> iter = services.values().iterator(); iter.hasNext(); ) { ContextService service = (ContextService) iter.next(); if (!result.contains(service)) { result.add(service); } } return result; } /** * Get a bean from the application context that we MUST have to operate. * * @param beanName the name of the bean we're looking for. Typically, the same * as its most general interface. * @param clazz the class of the bean we're looking for. * @return if there is a single bean of the required type, we return it, * regardless of name. If there are multiple beans of the required * type, we return the one with the required name, if present, or the * first one we find, if there is none of the right name. * @throws IllegalStateException if there are no beans of the right type, or * if there is an instantiation problem. */ public Object getRequiredBean(String beanName, Class<?> clazz) { try { Object object = getBean(beanName, clazz); if (object != null) { return object; } throw new IllegalStateException("The context has no " + beanName); } catch (BeansException e) { throw new IllegalStateException("Spring failure - can't instantiate " + beanName + ": (" + e.toString() + ")"); } } /** * Get an optional bean from the application context. * * @param beanName the name of the bean we're looking for. Typically, * the same as its most general interface. * @param clazz the class of the bean we're looking for. * @return if there is a single bean of the required type, we return it, * regardless of name. If there are multiple beans of the required * type, we return the one with the required name, if present, or the * first one we find, if there is none of the right name. Returns * null if no bean of the appropriate name or type is found. * @throws BeansException if there is an instantiation problem. */ public Object getBean(String beanName, Class<?> clazz) throws BeansException { initApplicationContext(); return getBean(applicationContext, beanName, clazz); } /** * Get a bean from the supplied BeanFactory. First look for a bean with * the given name and type. If none is found, look for the first bean * of the specified type. * * @param factory a ListableBeanFactory * @param beanName the name of the bean we're looking for. Typically, the same * as its most general interface. If null, return the first bean * of the requested type. * @param clazz the class of the bean we're looking for. If null, return * any bean of the specified name. * @return if there is a single bean of the required type, we return it, * regardless of name. If there are multiple beans of the required * type, we return the one with the required name, if present, or the * first one we find, if there is none of the right name. Returns * null if no bean of the appropriate name or type is found. * @throws BeansException if there is an instantiation problem. */ public Object getBean(ListableBeanFactory factory, String beanName, Class<?> clazz) throws BeansException { Object result = null; // First, look for a bean with the specified name and type. try { if (beanName != null && beanName.length() > 0) { result = factory.getBean(beanName, clazz); if (result != null) { return result; } } } catch (NoSuchBeanDefinitionException e) { // Not a problem yet. Look for any bean of the appropriate type. } // If no bean type was specified, we are done. if (clazz == null) { return null; } // Get the list of beans defined in the bean factory of the required type. String[] beanList = factory.getBeanNamesForType(clazz); // Make sure there is at least one if (beanList.length < 1) { return null; } // If more beans were found issue a warning. if (beanList.length > 1) { StringBuilder buf = new StringBuilder(); for (int i = 1; i < beanList.length; i++) { buf.append(" "); buf.append(beanList[i]); } LOGGER.warning("Resource contains multiple " + clazz.getName() + " definitions. Using the first: " + beanList[0] + ". Skipping: " + buf); } return factory.getBean(beanList[0]); } /** * Gets the singleton Manager. * * @return the Manager */ public Manager getManager() { if (manager != null) { return manager; } manager = (Manager) getRequiredBean("Manager", Manager.class); return manager; } /** * Gets the singleton TraversalContext. * * @return the TraversalContext */ public TraversalContext getTraversalContext() { if (traversalContext != null) { return traversalContext; } try { traversalContext = (TraversalContext) getRequiredBean("TraversalContext", TraversalContext.class); } catch (IllegalStateException e) { LOGGER.warning("Can't find suitable " + TraversalContext.class.getName() + " bean in context, using default."); traversalContext = new ProductionTraversalContext(); } return traversalContext; } /** * Throws out the current context instance and gets another one. For testing * only. This could really boolux things up if it were used in production! * */ public static void refresh() { INSTANCE = new Context(); } /** * Gets the applicationContext. For testing only. * * @return the applicationContext */ public ApplicationContext getApplicationContext() { initApplicationContext(); return applicationContext; } public synchronized void shutdown(boolean force) { LOGGER.info("Shutdown initiated..."); stopServices(force); if (null != traversalScheduler) { traversalScheduler.shutdown(); traversalScheduler = null; } if (null != instantiator) { instantiator.shutdown(force, ThreadPool.DEFAULT_SHUTDOWN_TIMEOUT_MILLIS); instantiator = null; } started = false; } /** * Stops any services declared as part of the application. */ private void stopServices(boolean force) { initApplicationContext(); List<ContextService> services = getServices(); Collections.reverse(services); for (ContextService service : services) { service.stop(force); } } /** * Retrieves the prefix for the Common directory file depending on whether * it is a standalone context or servlet context. * * @return prefix for the Repository file. */ public String getCommonDirPath() { initApplicationContext(); return commonDirPath; } private String getPropFileName() throws InstantiatorException { String propFileName = null; try { propFileName = (String) applicationContext.getBean( APPLICATION_CONTEXT_PROPERTIES_BEAN_NAME, java.lang.String.class); } catch (BeansException e) { throw new InstantiatorException("Spring exception while getting " + APPLICATION_CONTEXT_PROPERTIES_BEAN_NAME + " bean", e); } if (propFileName == null || propFileName.length() < 1) { throw new InstantiatorException("Null or empty file name returned from " + "Spring while getting " + APPLICATION_CONTEXT_PROPERTIES_BEAN_NAME + " bean"); } return propFileName; } private File getPropFile(String propFileName) throws InstantiatorException { Resource propResource = applicationContext.getResource(propFileName); File propFile; try { propFile = propResource.getFile(); } catch (IOException e) { throw new InstantiatorException(e); } return propFile; } public Properties getConnectorManagerConfig() throws InstantiatorException { initApplicationContext(); Properties result = new Properties(); // Get the properties out of the CM properties file if present. String propFileName = getPropFileName(); File propFile = getPropFile(propFileName); try { Properties props = PropertiesUtils.loadFromFile(propFile); result.setProperty(GSA_FEED_HOST_PROPERTY_KEY, props.getProperty(GSA_FEED_HOST_PROPERTY_KEY)); result.setProperty(GSA_FEED_PORT_PROPERTY_KEY, props.getProperty(GSA_FEED_PORT_PROPERTY_KEY, GSA_FEED_PORT_DEFAULT)); } catch (PropertiesException e) { LOGGER.log(Level.WARNING, "Unable to read application context properties" + " file " + propFileName, e); } return result; } public void setConnectorManagerConfig(String feederGateHost, int feederGatePort) throws InstantiatorException { initApplicationContext(); // Update the feed host and port in the CM properties file. String propFileName = getPropFileName(); File propFile = getPropFile(propFileName); Properties props; try { props = PropertiesUtils.loadFromFile(propFile); } catch (PropertiesException e) { LOGGER.log(Level.WARNING, "Unable to read application context properties" + " file "+ propFileName + "; attempting instantiation stand-alone.", e); props = new Properties(); } props.put(GSA_FEED_HOST_PROPERTY_KEY, feederGateHost); props.put(GSA_FEED_PORT_PROPERTY_KEY, Integer.toString(feederGatePort)); // Lock down the manager at this point. props.put(MANAGER_LOCKED_PROPERTY_KEY, Boolean.TRUE.toString()); try { PropertiesUtils.storeToFile(props, propFile, CONNECTOR_MANGER_CONFIG_HEADER); } catch (PropertiesException e) { LOGGER.log(Level.WARNING, "Unable to save application context properties" + " file " + propFileName + ". ", e); throw new InstantiatorException(e); } LOGGER.info("Updated Connector Manager Config: " + GSA_FEED_HOST_PROPERTY_KEY + "=" + feederGateHost + "; " + GSA_FEED_PORT_PROPERTY_KEY + "=" + feederGatePort + ";" + MANAGER_LOCKED_PROPERTY_KEY + "=" + props.getProperty(MANAGER_LOCKED_PROPERTY_KEY)); // Update our local cached feed host. gsaFeedHost = feederGateHost; isGsaFeedHostInitialized = true; // Notify the GsaFeedConnection of new host and port. try { GsaFeedConnection feeder = (GsaFeedConnection) applicationContext.getBean("FeedConnection", GsaFeedConnection.class); feeder.setFeedHostAndPort(feederGateHost, feederGatePort); } catch (BeansException be) { // The configured FeedConnection isn't a GSA, so it doesn't care // about the GSA host and port. } catch (MalformedURLException e) { throw new InstantiatorException("Invalid GSA Feed specification", e); } } /** * Whether or not the GSA requires the connector manager to prepend a * connector-manager-specific prefix to connector configuration * property names. Older GSA require the prefix, and newer GSAs do not. * This value is read from the <code>gsa.admin.requiresPrefix</code> * property in the application context properties file. * If the <code>gsa.admin.requiresPrefix</code> property is not defined, the * default value is <code>false</code>. */ public boolean gsaAdminRequiresPrefix() { initApplicationContext(); if (gsaAdminRequiresPrefix == null) { String prop = getProperty( GSA_ADMIN_REQUIRES_PREFIX_KEY, GSA_ADMIN_REQUIRES_PREFIX_DEFAULT.toString()); gsaAdminRequiresPrefix = Boolean.valueOf(prop); } return gsaAdminRequiresPrefix; } /** * Reads <code>teedFeedFile</code> from the application context properties file. * See google-enterprise-connector-manager/projects/connector-manager/etc/applicationContext.properties * for additional documentation. */ public String getTeedFeedFile() { initApplicationContext(); if (!isTeedFeedFileInitialized) { teedFeedFile = getProperty(TEED_FEED_FILE_PROPERTY_KEY, null); isTeedFeedFileInitialized = true; } return teedFeedFile; } /** * Reads <code>gsa.feed.host</code> from the application context properties file. * See google-enterprise-connector-manager/projects/connector-manager/etc/applicationContext.properties * for additional documentation. */ public String getGsaFeedHost() { initApplicationContext(); if (!isGsaFeedHostInitialized) { gsaFeedHost = getProperty(GSA_FEED_HOST_PROPERTY_KEY, null); isGsaFeedHostInitialized = true; } return gsaFeedHost; } /** * Reads <code>manager.locked</code> property from the application context * properties file. * * @return true if the property does not exist. Returns true if the property * is set to 'true', ignoring case. Returns false otherwise. */ public boolean getIsManagerLocked() { initApplicationContext(); String isManagerLocked = getProperty(MANAGER_LOCKED_PROPERTY_KEY, null); if (isManagerLocked != null) { return Boolean.valueOf(isManagerLocked).booleanValue(); } // Consider older, but uninitialized properties files to be unlocked. if (propertiesVersion < 2 && "localhost".equals(getGsaFeedHost())) { return false; } return true; } /** * Reads a property from the application context properties file. * * @param key the property name * @param defaultValue if property does not exist */ private String getProperty(String key, String defaultValue) { try { String propFileName = getPropFileName(); File propFile = getPropFile(propFileName); try { Properties props = PropertiesUtils.loadFromFile(propFile); propertiesVersion = PropertiesUtils.getPropertiesVersion(props); return props.getProperty(key, defaultValue); } catch (PropertiesException e) { LOGGER.log(Level.WARNING, "Unable to read application context " + "properties file " + propFileName, e); } } catch (InstantiatorException ie) { LOGGER.log(Level.WARNING, "Unable to read application context " + "properties file.", ie); } return defaultValue; } /** * Notify all listeners registered with this context of an application event. * Events may be framework events or application-specific events. * * @param event the event to publish. */ public void publishEvent(ApplicationEvent event) { initApplicationContext(); applicationContext.publishEvent(event); } }
这里可以看到，Context上下文对象支持两种方式初始化，作为web应用方式（部署在应用服务器内）和以独立方式
如果以独立方式初始化，则我们可以如下调用：
public static void main(String[] args) throws ConnectorNotFoundException, InstantiatorException { // TODO Auto-generated method stub Context.refresh(); Context.getInstance().setStandaloneContext("/WebRoot/WEB-INF/applicationContext.xml", "D:/googlework/app"); Context.getInstance().setFeeding(false); Context.getInstance().start(); SpringInstantiator instantiator = (SpringInstantiator) Context.getInstance().getBean("Instantiator", SpringInstantiator.class); //instantiator.init(); //Manager manager=Context.getInstance().getManager(); for( String str:instantiator.getConnectorTypeNames()) { System.out.println("ConnectorTypeName:"+str); } for( String str:instantiator.getConnectorNames()) { System.out.println("ConnectorName:"+str); } ConfigureResponse cr = instantiator.getConfigFormForConnector("default_huilan_http-connector_1363539625968", "http-connector", Locale.ENGLISH); System.out.println(cr.getFormSnippet()); Map<String, String> map =instantiator.getConnectorConfig("default_huilan_http-connector_1363539625968"); Iterator<String> it=map.keySet().iterator(); while(it.hasNext()){ String key= (String) it.next(); System.out.println("key:"+key+"||value:"+map.get(key)); } System.out.println("ConnectorSchedule:"+instantiator.getConnectorSchedule("default_huilan_http-connector_1363539625968")); ConnectorCoordinator coordinator = instantiator.getConnectorCoordinator("default_huilan_http-connector_1363539625968"); Context.getInstance().shutdown(true); Context.refresh(); }
需要注意的是以独立方式初始化需要修改applicationContext.xml文件里面applicationContext.properties的路径，并且在applicationContext.properties文件里面指定catalina.base变量（如果是tomcat容器，默认为tomcat的安装路径，如我的是C:/apache-tomcat-7.0.33）
Context上下文对象对外提供spring容器里面的bean，并负责初始化相关bean，它的启动方法如下
/** * Do everything necessary to start up the application. */ public void start() { if (started) { return; } initApplicationContext(); startInstantiator(); if (isFeeding) { startScheduler(); } startServices(); started = true; } /** * Start up the Instantiator. */ private void startInstantiator() { instantiator = (SpringInstantiator) getBean("Instantiator", SpringInstantiator.class); if (instantiator != null) { instantiator.init(); } } /** * Start up the Scheduler. */ private void startScheduler() { traversalScheduler = (TraversalScheduler) getRequiredBean("TraversalScheduler", TraversalScheduler.class); if (traversalScheduler != null) { traversalScheduler.init(); } }
这里的start方法启动实例化对象和定时调度对象，这两个对象的类源码及功能待下文分析吧