Tomcat源码---容器启动六(2)

  super.start()--->org.apache.catalina.core.ContainerBase#start()

 

/**
     * Prepare for active use of the public methods of this Component.
     *
     * @exception LifecycleException if this component detects a fatal error
     *  that prevents it from being started
     */
    public synchronized void start() throws LifecycleException {

        // Validate and update our current component state
        if (started) {
            if(log.isInfoEnabled())
                log.info(sm.getString("containerBase.alreadyStarted", logName()));
            return;
        }
        
        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(BEFORE_START_EVENT, null);

        started = true;
	
   	//这些为server.xml中配置应用组件的启动,如果要了解的话
	//可根据自己的配置进行查看
        // Start our subordinate components, if any
        if ((loader != null) && (loader instanceof Lifecycle))
            ((Lifecycle) loader).start();
        logger = null;
        getLogger();
        if ((logger != null) && (logger instanceof Lifecycle))
            ((Lifecycle) logger).start();
        if ((manager != null) && (manager instanceof Lifecycle))
            ((Lifecycle) manager).start();
        if ((cluster != null) && (cluster instanceof Lifecycle))
            ((Lifecycle) cluster).start();
        if ((realm != null) && (realm instanceof Lifecycle))
            ((Lifecycle) realm).start();
        if ((resources != null) && (resources instanceof Lifecycle))
            ((Lifecycle) resources).start();

        // Start our child containers, if any
 	//StandardHost容器的启动,
        Container children[] = findChildren();
        for (int i = 0; i < children.length; i++) {
            if (children[i] instanceof Lifecycle)
                ((Lifecycle) children[i]).start();
        }

        // Start the Valves in our pipeline (including the basic), if any
 	//StandardPipeline的启动(容器与容器间的管道)
        if (pipeline instanceof Lifecycle)
            ((Lifecycle) pipeline).start();

        // Notify our interested LifecycleListeners（里面将会对HostConfig进行启动,并且部暑webapps）
        lifecycle.fireLifecycleEvent(START_EVENT, null);

        // Start our thread
        threadStart();

        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(AFTER_START_EVENT, null);

    }

  StandardHost#start

  /**

     * Start this host.
     *
     * @exception LifecycleException if this component detects a fatal error
     *  that prevents it from being started
     */
    public synchronized void start() throws LifecycleException {
        if( started ) {
            return;
        }
        if( ! initialized )
            init();

        // Look for a realm - that may have been configured earlier. 
        // If the realm is added after context - it'll set itself.
        if( realm == null ) {
            ObjectName realmName=null;
            try {
                realmName=new ObjectName( domain + ":type=Realm,host=" + getName());
                if( mserver.isRegistered(realmName ) ) {
                    mserver.invoke(realmName, "init", 
                            new Object[] {},
                            new String[] {}
                    );            
                }
            } catch( Throwable t ) {
                log.debug("No realm for this host " + realmName);
            }
        }
            
        // Set error report valve
        if ((errorReportValveClass != null)
            && (!errorReportValveClass.equals(""))) {
            try {
                boolean found = false;
                if(errorReportValveObjectName != null) {
                    ObjectName[] names = 
                        ((StandardPipeline)pipeline).getValveObjectNames();
                    for (int i=0; !found && i<names.length; i++)
                        if(errorReportValveObjectName.equals(names[i]))
                            found = true ;
                    }
                    if(!found) { 
			//添加阀门,在接收消息时,进行过滤消息         	
                        Valve valve = (Valve) Class.forName(errorReportValveClass)
                        .newInstance();
                        addValve(valve);
                        errorReportValveObjectName = ((ValveBase)valve).getObjectName() ;
                    }
            } catch (Throwable t) {
                log.error(sm.getString
                    ("standardHost.invalidErrorReportValveClass", 
                     errorReportValveClass), t);
            }
        }
        if(log.isDebugEnabled()) {
            if (xmlValidation)
                log.debug(sm.getString("standardHost.validationEnabled"));
            else
                log.debug(sm.getString("standardHost.validationDisabled"));
        }
 	//返回到以上的containerBase#start执行pipeline
	//pipeline是容器与容器间的桥梁(管道),在每一个容器中执行这一步,都为自己的容器添加相应的valve
        super.start();

    }

 StandardPipeline#start

 

 /**
     * Prepare for active use of the public methods of this Component.
     *
     * @exception LifecycleException if this component detects a fatal error
     *  that prevents it from being started
     */
    public synchronized void start() throws LifecycleException {

        // Validate and update our current component state
        if (started)
            throw new LifecycleException
                (sm.getString("standardPipeline.alreadyStarted"));

        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(BEFORE_START_EVENT, null);

        started = true;

        // Start the Valves in our pipeline (including the basic), if any
        Valve current = first;
        if (current == null) {
        	current = basic;
        }
        while (current != null) {
            //ErrorReportValve StandardHostValve两个阀门
            if (current instanceof Lifecycle)
                ((Lifecycle) current).start();
	    //注册阀门,
            registerValve(current);
        	current = current.getNext();
        }

        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(START_EVENT, null);

        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(AFTER_START_EVENT, null);

    }

   HostConfig#lifecycleEvent方法下的start方法

 

  /**
     * Process a "start" event for this Host.
     */
    public void start() {

        if (log.isDebugEnabled())
            log.debug(sm.getString("hostConfig.start"));

        try {
            ObjectName hostON = new ObjectName(host.getObjectName());
            oname = new ObjectName
                (hostON.getDomain() + ":type=Deployer,host=" + host.getName());
            Registry.getRegistry(null, null).registerComponent
                (this, oname, this.getClass().getName());
        } catch (Exception e) {
            log.error(sm.getString("hostConfig.jmx.register", oname), e);
        }
        //StandardHost判断
        if (host.getDeployOnStartup())
            //部暑webapps
            deployApps();
        
    }

 HostConfig#deployApps

 

 /**
     * Deploy applications for any directories or WAR files that are found
     * in our "application root" directory.
     */
    protected void deployApps() {
	//webapps,以下方法见名知义
        File appBase = appBase();
        File configBase = configBase();
        // Deploy XML descriptors from configBase
        deployDescriptors(configBase, configBase.list());
        // Deploy WARs, and loop if additional descriptors are found
        deployWARs(appBase, appBase.list());
        // Deploy expanded folders
        deployDirectories(appBase, appBase.list());
        
    }