1.程序入口

Bootstrap.java的main方法
关键语句：

    public static void main(String args[]) {

        if (daemon == null) {
            // Don't set daemon until init() has completed
            //创建对象
            Bootstrap bootstrap = new Bootstrap();
            try {
                //初始化bootstrap
                bootstrap.init();
            } catch (Throwable t) {
                handleThrowable(t);
                t.printStackTrace();
                return;
            }
            daemon = bootstrap;
        } else {
            // When running as a service the call to stop will be on a new
            // thread so make sure the correct class loader is used to prevent
            // a range of class not found exceptions.
            Thread.currentThread().setContextClassLoader(daemon.catalinaLoader);
        }

        try {
            String command = "start";
            if (args.length > 0) {
                command = args[args.length - 1];
            }

            if (command.equals("startd")) {
                args[args.length - 1] = "start";
                daemon.load(args);
                daemon.start();
            } else if (command.equals("stopd")) {
                args[args.length - 1] = "stop";
                daemon.stop();
            } else if (command.equals("start")) {
                daemon.setAwait(true);
                //装在参数
                daemon.load(args);
                //开始启动
                daemon.start();
                if (null == daemon.getServer()) {
                    System.exit(1);
                }
            } else if (command.equals("stop")) {
                daemon.stopServer(args);
            } else if (command.equals("configtest")) {
                daemon.load(args);
                if (null == daemon.getServer()) {
                    System.exit(1);
                }
                System.exit(0);
            } else {
                log.warn("Bootstrap: command \"" + command + "\" does not exist.");
            }
        } catch (Throwable t) {
            // Unwrap the Exception for clearer error reporting
            if (t instanceof InvocationTargetException &&
                    t.getCause() != null) {
                t = t.getCause();
            }
            handleThrowable(t);
            t.printStackTrace();
            System.exit(1);
        }

    }

2.程序分析

--------------------------设置环境变量----------------------------------
>Bootstrap下的静态代码块;//定义Globals.CATALINA_HOME_PROP和Globals.CATALINA_BASE_PROP环境变量
>Bootstrap bootstrap = new Bootstrap();

--------------------------init()----------------------------------
>bootstrap.init();
>initClassLoaders();
>commonLoader = createClassLoader("common", null);
>CatalinaProperties.getProperty(name + ".loader");//装载.loader文件
>loadProperties();//CatalinaProperties静态代码块，主要是解析装载/conf/catalina.properties文件
>ClassLoaderFactory.createClassLoader(repositories, parent);//创建类加载器
>return new URLClassLoader(array);//array是lib文件夹下的jar的url

--------------------------load()----------------------------------
>daemon.load(args);
>method.invoke(catalinaDaemon, param);//调用catalina的load方法
>Digester digester = createStartDigester(); //创建和执行破壳器
>digester.addObjectCreate("Server","org.apache.catalina.core.StandardServer","className");//基于StandardServer创建Server对象
>digester.addSetProperties("Server");//设置属性
>digester.addSetNext("Server","setServer","org.apache.catalina.Server");//执行setServer方法
>digester.parse(inputSource); //使用破壳器解析server.xml，**重要**

--------------------------初始化容器----------------------------------
>getServer().init(); //初始化server
>LefecycleBase.initInternal();//调用基类的initInternal方法
>StanderServer.initInternal();//调用StanderServer的initInternal方法
>services[i].init(); //调用services的init方法

>LefecycleBase.initInternal();//调用基类的initInternal方法
>StanderService.initInternal();//调用StanderService的initInternal方法
>engine.init();//调用engine的init方法

>LefecycleBase.initInternal();//调用基类的initInternal方法
>StanderEngine.initInternal();//调用StanderEngine的initInternal方法
>super.initInternal();
>startStopExecutor = new ThreadPoolExecutor(getStartStopThreadsInternal(),getStartStopThreadsInternal(), 10, TimeUnit.SECONDS,startStopQueue,new StartStopThreadFactory(getName() + "-startStop-"));//创建线程池

--------------------------初始化executor----------------------------------
>executor.init();//执行器初始化

--------------------------初始化mapperListener----------------------------------
>mapperListener.init();//映射监听器初始化
>LifecycleMBeanBase.initInternal()；

--------------------------初始化connector----------------------------------
>connector.init();//连接器初始化
>Connector.initInternal()；
>adapter = new CoyoteAdapter(this);//适配器
>protocolHandler.setAdapter(adapter);//协议适配器
>protocolHandler.init();
>AbstractHttp11Protocol.init();
>endpoint.init(); //端点初始化

--------------------------start()----------------------------------
>daemon.start();//启动
>method.invoke(catalinaDaemon, (Object [])null); //调用catalina的start方法
>start();
>getServer().start();//启动server
>LefecycleBase.start();//
>startInternal();//
>StandardServer.startInternal()//调用StandardServer启动
>globalNamingResources.start();
>services[i].start();//启动service
>LefecycleBase.start();
>startInternal();
>stanardservice.startInternal();//调用stanardservice启动

--------------------------启动engine----------------------------------
>engine.start();//启动engine
>results.add(startStopExecutor.submit(new StartChild(children[i])));
>child.start();
>StandardHost.startInternal()
>setState(LifecycleState.STARTING);//ContainerBase.java
>fireLifecycleEvent(lifecycleEvent, data);
>lifecycleEvent()//HostConfig
>start();
>deployApps();   //部署webapp  

--------------------------启动executor----------------------------------
>executor.start();//启动执行器

--------------------------启动connector----------------------------------
>connector.start();//启动连接器
>lefcycleBase.start();
>Connector.startInternal();
>protocolHandler.start();//协议处理器启动
>AbstractProtocol.start();
>endpoint.start();//端点启动
>AbstractEndpoint.start();
>startInternal();
>NioEndpoint.startInternal();//NioEndpoint启动
>pollerThread.start();//poller线程启动
>poller.run();
>processKey(sk, attachment);//接收到请求进入此方法
>processSocket(attachment, SocketEvent.OPEN_READ, true);
>createSocketProcessor(socketWrapper, event);//创建SocketProcessor
>return new SocketProcessor(socketWrapper, event);
>SocketProcessorBase.run();
>SocketProcessor.doRun();//运行SocketProcessor
>state = getHandler().process(socketWrapper, SocketEvent.OPEN_READ);//
>state = processor.process(wrapper, status);
>state = service(socketWrapper);
>http11Processor.service();//http11Processor 
>getAdapter().service(request, response);//
>CoyoteAdapter.service(request, response);//适配器执行service方法
>postParseSuccess = postParseRequest(req, request, res, response);//解析请求
>connector.getService().getMapper().map(serverName, decodedURI,version, request.getMappingData());//请求路径映射
>connector.getService().getContainer().getPipeline().getFirst().invoke(request, response);//调用第一个container的valve
>StandardEngineValve.invoke(request, response);
>host.getPipeline().getFirst().invoke(request, response);//调用host容器
>StandardHostValve.invoke(request, response);
>context.getPipeline().getFirst().invoke(request, response);//调用context容器
>StandardContextValve.invoke(request, response);
>wrapper.getPipeline().getFirst().invoke(request, response);//调用wrapper
>StandardWrapperValve.invoke(request, response);
>servlet = wrapper.allocate();
>ApplicationFilterChain filterChain =ApplicationFilterFactory.createFilterChain(request, wrapper, servlet);//创建过滤器链
>filterChain.doFilter(request.getRequest(), response.getResponse());
>internalDoFilter(request,response);
>filter.doFilter(request, response, this);
>chain.doFilter(request, response);
>internalDoFilter(request,response);
>servlet.service(request, response);//servlet执行service方法

>filterChain.release();//释放filterChain
>wrapper.deallocate(servlet);//释放wrapper

--------------------------阻塞等待----------------------------------
>await();
>StandardServer.await();
>awaitSocket = new ServerSocket(port, 1,InetAddress.getByName(address));//port 8005
>socket = serverSocket.accept();//阻塞等待
>