tomcat解析(九)StandardServer.initialize.start

在前幾篇文章中已說到整個服務器的啓動已託管給該類的initialize及start方法，下面我們來看一下這兩個方法的內容
一.initialize
 /** * Invoke a pre-startup initialization. This is used to allow connectors * to bind to restricted ports under Unix operating environments. */ public void initialize() throws LifecycleException { if (initialized) { log.info(sm.getString("standardServer.initialize.initialized")); return; } lifecycle.fireLifecycleEvent(INIT_EVENT, null); initialized = true; if( oname==null ) { try { oname=new ObjectName( "Catalina:type=Server"); Registry.getRegistry(null, null) .registerComponent(this, oname, null ); } catch (Exception e) { log.error("Error registering ",e); } } // Register global String cache try { ObjectName oname2 = new ObjectName(oname.getDomain() + ":type=StringCache"); Registry.getRegistry(null, null) .registerComponent(new StringCache(), oname2, null ); } catch (Exception e) { log.error("Error registering ",e); } // Initialize our defined Services for (int i = 0; i < services.length; i++) { services[i].initialize(); } }

內容有三
1.lifecycle.fireLifecycleEvent(INIT_EVENT, null);
 觸發Lifecycle事件,將調用其LifecycleListener的相應方法，這裏需要在XML文件裏有配置，這裏不細講了
2.Registry.getRegistry(null, null).registerComponent(this, oname, null );
將該實例註冊到MBeanFactory
3.services[i].initialize()

這裏又將初始化的動作妥託給StandardService類的initialize進行

二.start()
 /** * Prepare for the beginning of active use of the public methods of this * component. This method should be called before any of the public * methods of this component are utilized. It should also send a * LifecycleEvent of type START_EVENT to any registered listeners. * * @exception LifecycleException if this component detects a fatal error * that prevents this component from being used */ public void start() throws LifecycleException { // Validate and update our current component state if (started) { log.debug(sm.getString("standardServer.start.started")); return; } // Notify our interested LifecycleListeners lifecycle.fireLifecycleEvent(BEFORE_START_EVENT, null); lifecycle.fireLifecycleEvent(START_EVENT, null); started = true; // Start our defined Services synchronized (services) { for (int i = 0; i < services.length; i++) { if (services[i] instanceof Lifecycle) ((Lifecycle) services[i]).start(); } } // Notify our interested LifecycleListeners lifecycle.fireLifecycleEvent(AFTER_START_EVENT, null); }

內容有三
1.lifecycle.fireLifecycleEvent
觸發Lifecycle.BEFORE_START_EVENT及Lifecycle.START_EVENT
2.((Lifecycle) services[i]).start();
妥拒給StandardService.start
3.lifecycle.fireLifecycleEvent
觸發Lifecycle.AFTER_START_EVENT
StandardServer的默認Listener有如下幾個
org.apache.catalina.core.AprLifecycleListener
org.apache.catalina.core.JasperListener
org.apache.catalina.mbeans.ServerLifecycleListener
org.apache.catalina.mbeans.GlobalResourcesLifecycleListener
這幾個監聽器的工作無非就是初化一些類如JspRuntimeContext,將之前解析XML得到的對象以MBean方式進行註冊及取消註冊等
下一篇我們分別來看StandardService.initialize,start