中文设计网站,wordpress退出登录,大学网站 作风建设专题,zac博客seo1.springboot内嵌的tomcat的pom坐标 启动后可以看到tomcat版本为9.0.46 2.springboot 内嵌tomcat启动流程
点击进入SpringApplication.run()方法里面 看这次tomcat启动相关的核心代码refreshContext(context);刷新上下文方法
public ConfigurableApplicationContext run(Stri…1.springboot内嵌的tomcat的pom坐标 启动后可以看到tomcat版本为9.0.46 2.springboot 内嵌tomcat启动流程
点击进入SpringApplication.run()方法里面 看这次tomcat启动相关的核心代码refreshContext(context);刷新上下文方法
public ConfigurableApplicationContext run(String... args) {StopWatch stopWatch new StopWatch();stopWatch.start();ConfigurableApplicationContext context null;configureHeadlessProperty();SpringApplicationRunListeners listeners getRunListeners(args);listeners.starting();try {ApplicationArguments applicationArguments new DefaultApplicationArguments(args);ConfigurableEnvironment environment prepareEnvironment(listeners, applicationArguments);configureIgnoreBeanInfo(environment);Banner printedBanner printBanner(environment);context createApplicationContext();prepareContext(context, environment, listeners, applicationArguments, printedBanner);// 此次的核心代码是刷新上下文方法refreshContext(context);afterRefresh(context, applicationArguments);stopWatch.stop();if (this.logStartupInfo) {new StartupInfoLogger(this.mainApplicationClass).logStarted(getApplicationLog(), stopWatch);}listeners.started(context);callRunners(context, applicationArguments);}catch (Throwable ex) {handleRunFailure(context, ex, listeners);throw new IllegalStateException(ex);}try {listeners.running(context);}catch (Throwable ex) {handleRunFailure(context, ex, null);throw new IllegalStateException(ex);}return context;
}
进入 私有方法refreshContext
private void refreshContext(ConfigurableApplicationContext context) {if (this.registerShutdownHook) {try {context.registerShutdownHook();}catch (AccessControlException ex) {// Not allowed in some environments.}}// 核心方法继续进入refresh((ApplicationContext) context);
}
Deprecated
protected void refresh(ApplicationContext applicationContext) {Assert.isInstanceOf(ConfigurableApplicationContext.class, applicationContext);// 核心代码继续进入方法refresh((ConfigurableApplicationContext) applicationContext);
}
进入refresh方法
protected void refresh(ConfigurableApplicationContext applicationContext) {// 核心方法查看调用的方法refresh()applicationContext.refresh();
}
查看refresh方法有三个实现类进入默认的实现类ServletWebServerApplicationContext定位到实现方法 Override
public final void refresh() throws BeansException, IllegalStateException {try {// 进入父类refreshsuper.refresh();}catch (RuntimeException ex) {WebServer webServer this.webServer;if (webServer ! null) {webServer.stop();}throw ex;}
} 看onRefresh()方法
Override
public void refresh() throws BeansException, IllegalStateException {synchronized (this.startupShutdownMonitor) {// Prepare this context for refreshing.prepareRefresh();// Tell the subclass to refresh the internal bean factory.ConfigurableListableBeanFactory beanFactory obtainFreshBeanFactory();// Prepare the bean factory for use in this context.prepareBeanFactory(beanFactory);try {// Allows post-processing of the bean factory in context subclasses.postProcessBeanFactory(beanFactory);// Invoke factory processors registered as beans in the context.invokeBeanFactoryPostProcessors(beanFactory);// Register bean processors that intercept bean creation.registerBeanPostProcessors(beanFactory);// Initialize message source for this context.initMessageSource();// Initialize event multicaster for this context.initApplicationEventMulticaster();// 我们进入这个方法// Initialize other special beans in specific context subclasses.onRefresh();// Check for listener beans and register them.registerListeners();// Instantiate all remaining (non-lazy-init) singletons.finishBeanFactoryInitialization(beanFactory);// Last step: publish corresponding event.finishRefresh();}catch (BeansException ex) {if (logger.isWarnEnabled()) {logger.warn(Exception encountered during context initialization - cancelling refresh attempt: ex);}// Destroy already created singletons to avoid dangling resources.destroyBeans();// Reset active flag.cancelRefresh(ex);// Propagate exception to caller.throw ex;}finally {// Reset common introspection caches in Springs core, since we// might not ever need metadata for singleton beans anymore...resetCommonCaches();}}
} 找到子类的实现方法 Override
protected void onRefresh() {super.onRefresh();try {// 核心代码创建web服务器createWebServer();}catch (Throwable ex) {throw new ApplicationContextException(Unable to start web server, ex);}
}
进入createWebServer方法ServletContext、WebServer在tomcat启动的时候一定为空还没有初始化完成会进入if代码块执行
private void createWebServer() {WebServer webServer this.webServer;// tomcat启动servletContext才进行创建ServletContext servletContext getServletContext();if (webServer null servletContext null) {ServletWebServerFactory factory getWebServerFactory();// 核心代码通过工厂获取一个WebServer实例this.webServer factory.getWebServer(getSelfInitializer());getBeanFactory().registerSingleton(webServerGracefulShutdown,new WebServerGracefulShutdownLifecycle(this.webServer));getBeanFactory().registerSingleton(webServerStartStop,new WebServerStartStopLifecycle(this, this.webServer));}else if (servletContext ! null) {try {getSelfInitializer().onStartup(servletContext);}catch (ServletException ex) {throw new ApplicationContextException(Cannot initialize servlet context, ex);}}initPropertySources();
} getWebServer方法需要参数该参数是一个方法getSelfInitializer()找到
private org.springframework.boot.web.servlet.ServletContextInitializer getSelfInitializer() {// 方法引用ServletContextInitializer是一个函数是接口通过方法引用返回一个实现 // ServletContextInitializer的一个实现子类,作用同匿名内部类。return this::selfInitialize;
}
函数式接口
FunctionalInterface
public interface ServletContextInitializer {/*** Configure the given {link ServletContext} with any servlets, filters, listeners* context-params and attributes necessary for initialization.* param servletContext the {code ServletContext} to initialize* throws ServletException if any call against the given {code ServletContext}* throws a {code ServletException}*/void onStartup(ServletContext servletContext) throws ServletException;}
this::selfInitialize就是实例::方法名调用方式this代表当前对象selfInitialize是this(ServletWebServerApplicationContext)对象的一个私有方法
private void selfInitialize(ServletContext servletContext) throws ServletException {prepareWebApplicationContext(servletContext);registerApplicationScope(servletContext);WebApplicationContextUtils.registerEnvironmentBeans(getBeanFactory(), servletContext);for (ServletContextInitializer beans : getServletContextInitializerBeans()) {beans.onStartup(servletContext);}
}
继续进入getWebServer发现是一个接口有三个实现类Jetty、Tomcat、UnderTow我们是Tomcat服务器进入TomcatServletWebServerFactory中的实现方法 Override
public WebServer getWebServer(ServletContextInitializer... initializers) {if (this.disableMBeanRegistry) {Registry.disableRegistry();}Tomcat tomcat new Tomcat();File baseDir (this.baseDirectory ! null) ? this.baseDirectory : createTempDir(tomcat);// 用于设置临时文件的目录这些目录用于存放JSP生成的源代码及Class文件xtomcat.setBaseDir(baseDir.getAbsolutePath());Connector connector new Connector(this.protocol);connector.setThrowOnFailure(true);tomcat.getService().addConnector(connector);customizeConnector(connector);// 用于设置链接器包括协议、I/0、端口、压缩、加密等等tomcat.setConnector(connector);// 是否自动部署tomcat.getHost().setAutoDeploy(false);configureEngine(tomcat.getEngine());for (Connector additionalConnector : this.additionalTomcatConnectors) {tomcat.getService().addConnector(additionalConnector);}prepareContext(tomcat.getHost(), initializers);// 核心代码return getTomcatWebServer(tomcat);
}
protected TomcatWebServer getTomcatWebServer(Tomcat tomcat) {return new TomcatWebServer(tomcat, getPort() 0, getShutdown());
}
进入TomcatWebServer构造方法
public TomcatWebServer(Tomcat tomcat, boolean autoStart, Shutdown shutdown) {Assert.notNull(tomcat, Tomcat Server must not be null);this.tomcat tomcat;this.autoStart autoStart;this.gracefulShutdown (shutdown Shutdown.GRACEFUL) ? new GracefulShutdown(tomcat) : null;// 核心代码initialize();
} 进入initialize()方法
private void initialize() throws WebServerException {logger.info(Tomcat initialized with port(s): getPortsDescription(false));synchronized (this.monitor) {try {addInstanceIdToEngineName();Context context findContext();context.addLifecycleListener((event) - {if (context.equals(event.getSource()) Lifecycle.START_EVENT.equals(event.getType())) {// Remove service connectors so that protocol binding doesnt// happen when the service is started.removeServiceConnectors();}});// 核心代码// Start the server to trigger initialization listenersthis.tomcat.start();// We can re-throw failure exception directly in the main threadrethrowDeferredStartupExceptions();try {ContextBindings.bindClassLoader(context, context.getNamingToken(), getClass().getClassLoader());}catch (NamingException ex) {// Naming is not enabled. Continue}// Unlike Jetty, all Tomcat threads are daemon threads. We create a// blocking non-daemon to stop immediate shutdownstartDaemonAwaitThread();}catch (Exception ex) {stopSilently();destroySilently();throw new WebServerException(Unable to start embedded Tomcat, ex);}}
}
public void start() throws LifecycleException {getServer();// 核心代码server.start();
}
进入start()方法找到LifecycleBase实现类方法 LifecycleBase类中init();startInternal();两个核心方法 Override
public final synchronized void start() throws LifecycleException {if (LifecycleState.STARTING_PREP.equals(state) || LifecycleState.STARTING.equals(state) ||LifecycleState.STARTED.equals(state)) {if (log.isDebugEnabled()) {Exception e new LifecycleException();log.debug(sm.getString(lifecycleBase.alreadyStarted, toString()), e);} else if (log.isInfoEnabled()) {log.info(sm.getString(lifecycleBase.alreadyStarted, toString()));}return;}if (state.equals(LifecycleState.NEW)) {// 核心代码1init();} else if (state.equals(LifecycleState.FAILED)) {stop();} else if (!state.equals(LifecycleState.INITIALIZED) !state.equals(LifecycleState.STOPPED)) {invalidTransition(Lifecycle.BEFORE_START_EVENT);}try {setStateInternal(LifecycleState.STARTING_PREP, null, false);// 核心代码2startInternal();if (state.equals(LifecycleState.FAILED)) {// This is a controlled failure. The component put itself into the// FAILED state so call stop() to complete the clean-up.stop();} else if (!state.equals(LifecycleState.STARTING)) {// Shouldnt be necessary but acts as a check that sub-classes are// doing what they are supposed to.invalidTransition(Lifecycle.AFTER_START_EVENT);} else {setStateInternal(LifecycleState.STARTED, null, false);}} catch (Throwable t) {// This is an uncontrolled failure so put the component into the// FAILED state and throw an exception.handleSubClassException(t, lifecycleBase.startFail, toString());}
} init()方法 Override
public final synchronized void init() throws LifecycleException {if (!state.equals(LifecycleState.NEW)) {invalidTransition(Lifecycle.BEFORE_INIT_EVENT);}try {setStateInternal(LifecycleState.INITIALIZING, null, false);// 核心代码initInternal();setStateInternal(LifecycleState.INITIALIZED, null, false);} catch (Throwable t) {handleSubClassException(t, lifecycleBase.initFail, toString());}
}
initInternal有很多实现类看组件Connector中的实现方法 组件Connector类型方法
Override
protected void initInternal() throws LifecycleException {super.initInternal();if (protocolHandler null) {throw new LifecycleException(sm.getString(coyoteConnector.protocolHandlerInstantiationFailed));}// Initialize adapteradapter new CoyoteAdapter(this);protocolHandler.setAdapter(adapter);if (service ! null) {protocolHandler.setUtilityExecutor(service.getServer().getUtilityExecutor());}// Make sure parseBodyMethodsSet has a defaultif (null parseBodyMethodsSet) {setParseBodyMethods(getParseBodyMethods());}if (protocolHandler.isAprRequired() !AprStatus.isInstanceCreated()) {throw new LifecycleException(sm.getString(coyoteConnector.protocolHandlerNoAprListener,getProtocolHandlerClassName()));}if (protocolHandler.isAprRequired() !AprStatus.isAprAvailable()) {throw new LifecycleException(sm.getString(coyoteConnector.protocolHandlerNoAprLibrary,getProtocolHandlerClassName()));}if (AprStatus.isAprAvailable() AprStatus.getUseOpenSSL() protocolHandler instanceof AbstractHttp11JsseProtocol) {AbstractHttp11JsseProtocol? jsseProtocolHandler (AbstractHttp11JsseProtocol?) protocolHandler;if (jsseProtocolHandler.isSSLEnabled() jsseProtocolHandler.getSslImplementationName() null) {// OpenSSL is compatible with the JSSE configuration, so use it if APR is availablejsseProtocolHandler.setSslImplementationName(OpenSSLImplementation.class.getName());}}try {// 核心方法protocolHandler.init();} catch (Exception e) {throw new LifecycleException(sm.getString(coyoteConnector.protocolHandlerInitializationFailed), e);}
}
进入实现类AbstractProtocol中init()方法
Override
public void init() throws Exception {if (getLog().isInfoEnabled()) {getLog().info(sm.getString(abstractProtocolHandler.init, getName()));logPortOffset();}if (oname null) {// Component not pre-registered so register itoname createObjectName();if (oname ! null) {Registry.getRegistry(null, null).registerComponent(this, oname, null);}}if (this.domain ! null) {ObjectName rgOname new ObjectName(domain :typeGlobalRequestProcessor,name getName());this.rgOname rgOname;Registry.getRegistry(null, null).registerComponent(getHandler().getGlobal(), rgOname, null);}String endpointName getName();endpoint.setName(endpointName.substring(1, endpointName.length()-1));endpoint.setDomain(domain);// 核心代码endpoint.init();
}
进入endpoint.init()方法
public final void init() throws Exception {if (bindOnInit) {// 核心代码bindWithCleanup();bindState BindState.BOUND_ON_INIT;}if (this.domain ! null) {// Register endpoint (as ThreadPool - historical name)oname new ObjectName(domain :typeThreadPool,name\ getName() \);Registry.getRegistry(null, null).registerComponent(this, oname, null);ObjectName socketPropertiesOname new ObjectName(domain :typeSocketProperties,name\ getName() \);socketProperties.setObjectName(socketPropertiesOname);Registry.getRegistry(null, null).registerComponent(socketProperties, socketPropertiesOname, null);for (SSLHostConfig sslHostConfig : findSslHostConfigs()) {registerJmx(sslHostConfig);}}
}进入bindWithCleanup方法里面
private void bindWithCleanup() throws Exception {try {// 核心代码bind();} catch (Throwable t) {// Ensure open sockets etc. are cleaned up if something goes// wrong during bindExceptionUtils.handleThrowable(t);unbind();throw t;}
}
Override
public void bind() throws Exception {// 核心代码initServerSocket();setStopLatch(new CountDownLatch(1));// Initialize SSL if neededinitialiseSsl();selectorPool.open(getName());
}
初始化Socket
protected void initServerSocket() throws Exception {if (getUseInheritedChannel()) {// Retrieve the channel provided by the OSChannel ic System.inheritedChannel();if (ic instanceof ServerSocketChannel) {serverSock (ServerSocketChannel) ic;}if (serverSock null) {throw new IllegalArgumentException(sm.getString(endpoint.init.bind.inherited));}} else if (getUnixDomainSocketPath() ! null) {SocketAddress sa JreCompat.getInstance().getUnixDomainSocketAddress(getUnixDomainSocketPath());serverSock JreCompat.getInstance().openUnixDomainServerSocketChannel();serverSock.bind(sa, getAcceptCount());if (getUnixDomainSocketPathPermissions() ! null) {Path path Paths.get(getUnixDomainSocketPath());SetPosixFilePermission permissions PosixFilePermissions.fromString(getUnixDomainSocketPathPermissions());if (path.getFileSystem().supportedFileAttributeViews().contains(posix)) {FileAttributeSetPosixFilePermission attrs PosixFilePermissions.asFileAttribute(permissions);Files.setAttribute(path, attrs.name(), attrs.value());} else {java.io.File file path.toFile();if (permissions.contains(PosixFilePermission.OTHERS_READ) !file.setReadable(true, false)) {log.warn(sm.getString(endpoint.nio.perms.readFail, file.getPath()));}if (permissions.contains(PosixFilePermission.OTHERS_WRITE) !file.setWritable(true, false)) {log.warn(sm.getString(endpoint.nio.perms.writeFail, file.getPath()));}}}} else {serverSock ServerSocketChannel.open();socketProperties.setProperties(serverSock.socket());InetSocketAddress addr new InetSocketAddress(getAddress(), getPortWithOffset());serverSock.bind(addr, getAcceptCount());}serverSock.configureBlocking(true); //mimic APR behavior
}
startInternal();
看下这个方法找到Connector里面的startInternal()方法实现 Override
protected void startInternal() throws LifecycleException {// Validate settings before startingString id (protocolHandler ! null) ? protocolHandler.getId() : null;if (id null getPortWithOffset() 0) {throw new LifecycleException(sm.getString(coyoteConnector.invalidPort, Integer.valueOf(getPortWithOffset())));}setState(LifecycleState.STARTING);try {// 核心代码protocolHandler.start();} catch (Exception e) {throw new LifecycleException(sm.getString(coyoteConnector.protocolHandlerStartFailed), e);}
}
进入protocolHandler.start();方法里面。进入AbstractProtocol里面的实现方法 Override
public void start() throws Exception {if (getLog().isInfoEnabled()) {getLog().info(sm.getString(abstractProtocolHandler.start, getName()));logPortOffset();}// 核心代码endpoint.start();monitorFuture getUtilityExecutor().scheduleWithFixedDelay(() - {if (!isPaused()) {startAsyncTimeout();}}, 0, 60, TimeUnit.SECONDS);
}
找到endpoint.start()方法
public final void start() throws Exception {if (bindState BindState.UNBOUND) {bindWithCleanup();bindState BindState.BOUND_ON_START;}// 核心代码startInternal();
}
进入这个实现类里找到实现方法 Overridepublic void startInternal() throws Exception {if (!running) {running true;paused false;if (socketProperties.getProcessorCache() ! 0) {processorCache new SynchronizedStack(SynchronizedStack.DEFAULT_SIZE,socketProperties.getProcessorCache());}if (socketProperties.getEventCache() ! 0) {eventCache new SynchronizedStack(SynchronizedStack.DEFAULT_SIZE,socketProperties.getEventCache());}if (socketProperties.getBufferPool() ! 0) {nioChannels new SynchronizedStack(SynchronizedStack.DEFAULT_SIZE,socketProperties.getBufferPool());}// Create worker collectionif (getExecutor() null) {createExecutor();}initializeConnectionLatch();// 核心代码 *******// Start poller threadpoller new Poller();Thread pollerThread new Thread(poller, getName() -ClientPoller);// 设置进程的优先级pollerThread.setPriority(threadPriority);// 守护线程:当非守护线程销毁的时候守护线程跟着销毁。当运行的唯一线程是守护线程时 // Java虚拟机将退出pollerThread.setDaemon(true);// 开启线程pollerThread.start();startAcceptorThread();}}
Poller类是什么 Poller里面的run方法
Override
public void run() {// Loop until destroy() is called// 核心代码1 轮询while (true) {boolean hasEvents false;try {if (!close) {hasEvents events();if (wakeupCounter.getAndSet(-1) 0) {// If we are here, means we have other stuff to do// Do a non blocking selectkeyCount selector.selectNow();} else {keyCount selector.select(selectorTimeout);}wakeupCounter.set(0);}if (close) {events();timeout(0, false);try {selector.close();} catch (IOException ioe) {log.error(sm.getString(endpoint.nio.selectorCloseFail), ioe);}break;}// Either we timed out or we woke up, process events firstif (keyCount 0) {hasEvents (hasEvents | events());}} catch (Throwable x) {ExceptionUtils.handleThrowable(x);log.error(sm.getString(endpoint.nio.selectorLoopError), x);continue;}IteratorSelectionKey iterator keyCount 0 ? selector.selectedKeys().iterator() : null;// Walk through the collection of ready keys and dispatch// any active event.while (iterator ! null iterator.hasNext()) {SelectionKey sk iterator.next();iterator.remove();NioSocketWrapper socketWrapper (NioSocketWrapper) sk.attachment();// Attachment may be null if another thread has called// cancelledKey()if (socketWrapper ! null) {// 核心代码2processKey(sk, socketWrapper);}}// Process timeoutstimeout(keyCount,hasEvents);}getStopLatch().countDown();
}
启动一个Poller线程轮询监听NIO接收的请求直到执行核心代码2processKey(sk, socketWrapper);Poller类会轮询监听Socket连接到这里tomcat算启动成功啦。
springboot嵌入tomcat处理请求的过程
主要看下Poller类中的processKey方法我们发起一个请求怎么处理的呢
processKey方法
protected void processKey(SelectionKey sk, NioSocketWrapper socketWrapper) {try {if (close) {cancelledKey(sk, socketWrapper);} else if (sk.isValid() socketWrapper ! null) {if (sk.isReadable() || sk.isWritable()) {if (socketWrapper.getSendfileData() ! null) {processSendfile(sk, socketWrapper, false);} else {unreg(sk, socketWrapper, sk.readyOps());boolean closeSocket false;// Read goes before writeif (sk.isReadable()) {if (socketWrapper.readOperation ! null) {// 核心代码if (!socketWrapper.readOperation.process()) {closeSocket true;}// 核心代码} else if (!processSocket(socketWrapper, SocketEvent.OPEN_READ, true)) {closeSocket true;}}if (!closeSocket sk.isWritable()) {if (socketWrapper.writeOperation ! null) {if (!socketWrapper.writeOperation.process()) {closeSocket true;}} else if (!processSocket(socketWrapper, SocketEvent.OPEN_WRITE, true)) {closeSocket true;}}if (closeSocket) {cancelledKey(sk, socketWrapper);}}}} else {// Invalid keycancelledKey(sk, socketWrapper);}} catch (CancelledKeyException ckx) {cancelledKey(sk, socketWrapper);} catch (Throwable t) {ExceptionUtils.handleThrowable(t);log.error(sm.getString(endpoint.nio.keyProcessingError), t);}
}
进入processSocket方法
public boolean processSocket(SocketWrapperBaseS socketWrapper,SocketEvent event, boolean dispatch) {try {if (socketWrapper null) {return false;}// 核心代码 线程SocketProcessorBaseS sc null;if (processorCache ! null) {sc processorCache.pop();}if (sc null) {sc createSocketProcessor(socketWrapper, event);} else {sc.reset(socketWrapper, event);}// 核心代码 获取线程池通过线程池执行Executor executor getExecutor();if (dispatch executor ! null) {executor.execute(sc);} else {sc.run();}} catch (RejectedExecutionException ree) {getLog().warn(sm.getString(endpoint.executor.fail, socketWrapper) , ree);return false;} catch (Throwable t) {ExceptionUtils.handleThrowable(t);// This means we got an OOM or similar creating a thread, or that// the pool and its queue are fullgetLog().error(sm.getString(endpoint.process.fail), t);return false;}return true;
}看看SocketProcessBase是什么 实现了Runnable接口 看下SocketProcessBase的run()方法 Overridepublic final void run() {synchronized (socketWrapper) {// It is possible that processing may be triggered for read and// write at the same time. The sync above makes sure that processing// does not occur in parallel. The test below ensures that if the// first event to be processed results in the socket being closed,// the subsequent events are not processed.if (socketWrapper.isClosed()) {return;}// 核心代码doRun();}}
看下doRun()方法 找到过滤器链ApplicationFilterChain找到doFilter()方法
Override
public void doFilter(ServletRequest request, ServletResponse response)throws IOException, ServletException {if( Globals.IS_SECURITY_ENABLED ) {final ServletRequest req request;final ServletResponse res response;try {java.security.AccessController.doPrivileged((java.security.PrivilegedExceptionActionVoid) () - {// 核心代码internalDoFilter(req,res);return null;});} catch( PrivilegedActionException pe) {Exception e pe.getException();if (e instanceof ServletException)throw (ServletException) e;else if (e instanceof IOException)throw (IOException) e;else if (e instanceof RuntimeException)throw (RuntimeException) e;elsethrow new ServletException(e.getMessage(), e);}} else {internalDoFilter(request,response);}
}
定位到internalDoFilter()方法
private void internalDoFilter(ServletRequest request,ServletResponse response)throws IOException, ServletException {// Call the next filter if there is oneif (pos n) {ApplicationFilterConfig filterConfig filters[pos];try {Filter filter filterConfig.getFilter();if (request.isAsyncSupported() false.equalsIgnoreCase(filterConfig.getFilterDef().getAsyncSupported())) {request.setAttribute(Globals.ASYNC_SUPPORTED_ATTR, Boolean.FALSE);}if( Globals.IS_SECURITY_ENABLED ) {final ServletRequest req request;final ServletResponse res response;Principal principal ((HttpServletRequest) req).getUserPrincipal();Object[] args new Object[]{req, res, this};SecurityUtil.doAsPrivilege (doFilter, filter, classType, args, principal);} else {filter.doFilter(request, response, this);}} catch (IOException | ServletException | RuntimeException e) {throw e;} catch (Throwable e) {e ExceptionUtils.unwrapInvocationTargetException(e);ExceptionUtils.handleThrowable(e);throw new ServletException(sm.getString(filterChain.filter), e);}return;}// We fell off the end of the chain -- call the servlet instancetry {if (ApplicationDispatcher.WRAP_SAME_OBJECT) {lastServicedRequest.set(request);lastServicedResponse.set(response);}if (request.isAsyncSupported() !servletSupportsAsync) {request.setAttribute(Globals.ASYNC_SUPPORTED_ATTR,Boolean.FALSE);}// Use potentially wrapped request from this pointif ((request instanceof HttpServletRequest) (response instanceof HttpServletResponse) Globals.IS_SECURITY_ENABLED ) {final ServletRequest req request;final ServletResponse res response;Principal principal ((HttpServletRequest) req).getUserPrincipal();Object[] args new Object[]{req, res};SecurityUtil.doAsPrivilege(service,servlet,classTypeUsedInService,args,principal);} else {// 核心代码servlet.service(request, response);}} catch (IOException | ServletException | RuntimeException e) {throw e;} catch (Throwable e) {e ExceptionUtils.unwrapInvocationTargetException(e);ExceptionUtils.handleThrowable(e);throw new ServletException(sm.getString(filterChain.servlet), e);} finally {if (ApplicationDispatcher.WRAP_SAME_OBJECT) {lastServicedRequest.set(null);lastServicedResponse.set(null);}}
}定位到service()方法的实现类HttpServlet中的service()方法中
Overridepublic void service(ServletRequest req, ServletResponse res)throws ServletException, IOException {HttpServletRequest request;HttpServletResponse response;try {request (HttpServletRequest) req;response (HttpServletResponse) res;} catch (ClassCastException e) {throw new ServletException(lStrings.getString(http.non_http));}// 核心代码service(request, response);}
继续进入到service()方法中 protected final void processRequest(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {long startTime System.currentTimeMillis();Throwable failureCause null;LocaleContext previousLocaleContext LocaleContextHolder.getLocaleContext();LocaleContext localeContext buildLocaleContext(request);RequestAttributes previousAttributes RequestContextHolder.getRequestAttributes();ServletRequestAttributes requestAttributes buildRequestAttributes(request, response, previousAttributes);WebAsyncManager asyncManager WebAsyncUtils.getAsyncManager(request);asyncManager.registerCallableInterceptor(FrameworkServlet.class.getName(), new RequestBindingInterceptor());initContextHolders(request, localeContext, requestAttributes);try {// 核心代码doService(request, response);}catch (ServletException | IOException ex) {failureCause ex;throw ex;}catch (Throwable ex) {failureCause ex;throw new NestedServletException(Request processing failed, ex);}finally {resetContextHolders(request, previousLocaleContext, previousAttributes);if (requestAttributes ! null) {requestAttributes.requestCompleted();}logResult(request, response, failureCause, asyncManager);publishRequestHandledEvent(request, response, startTime, failureCause);}
} 进入doService()方法 https://blog.csdn.net/z69183787/article/details/129240218 https://blog.csdn.net/sunshinezx8023/article/details/128630710
