引用网址：
http://tomcat.apache.org/tomcat-6.0-doc/architecture/startup/serverStartup.txt
http://tomcat.apache.org/tomcat-6.0-doc/architecture/startup/serverStartup.pdf
Tomcat启动时序 第一步：初始化
类: org.apache.catalina.startup.Bootstrap
1 /** 2 * Initialize daemon. 3 */ 4 public void init() 5 throws Exception 6 { 7 8 // Set Catalina path,home and base value is set to system.getProperties("user.dir"),把程序当前目录设置为catalina home和base的值。 9 setCatalinaHome(); 10 setCatalinaBase(); 11 12 initClassLoaders(); 13 14 Thread.currentThread().setContextClassLoader(catalinaLoader); 15 16 SecurityClassLoad.securityClassLoad(catalinaLoader); 17 18 // Load our startup class and call its process() method 19 if (log.isDebugEnabled()) 20 log.debug("Loading startup class"); 21 Class startupClass = 22 catalinaLoader.loadClass 23 ("org.apache.catalina.startup.Catalina"); 24 Object startupInstance = startupClass.newInstance(); 25 26 // Set the shared extensions class loader 27 if (log.isDebugEnabled()) 28 log.debug("Setting startup class properties"); 29 String methodName = "setParentClassLoader"; 30 Class paramTypes[] = new Class[1]; 31 paramTypes[0] = Class.forName("java.lang.ClassLoader"); 32 Object paramValues[] = new Object[1]; 33 paramValues[0] = sharedLoader; 34 Method method = 35 startupInstance.getClass().getMethod(methodName, paramTypes); 36 method.invoke(startupInstance, paramValues); 37 38 catalinaDaemon = startupInstance; 39 40 }
工作流程如下: a) Set up classloaders commonLoader (common)-> System Loader sharedLoader (shared)-> commonLoader -> System Loader catalinaLoader(server) -> commonLoader -> System Loader b) Load startup class (reflection) org.apache.catalina.startup.Catalina setParentClassloader -> sharedLoader Thread.contextClassloader -> catalinaLoader c) Bootstrap.daemon.init() complete 第二步： 处理命令行参数 (start, startd, stop, stopd) 类: org.apache.catalina.startup.Bootstrap (假定命令为start)
try { String command = "start"; if (args.length > 0) { command = args[args.length - 1]; } if (command.equals("startd")) { args[0] = "start"; daemon.load(args); daemon.start(); } else if (command.equals("stopd")) { args[0] = "stop"; daemon.stop(); } else if (command.equals("start")) { daemon.setAwait(true); daemon.load(args); daemon.start(); } else if (command.equals("stop")) { daemon.stopServer(args); } else { log.warn("Bootstrap: command \"" + command + "\" does not exist."); } } catch (Throwable t) { t.printStackTrace(); }
工作流程如下: a) Catalina.setAwait(true); b) Catalina.load()
1 public void load() { 2 3 long t1 = System.nanoTime(); 4 5 initDirs(); 6 7 // Before digester - it may be needed 8 9 initNaming(); 10 11 // Create and execute our Digester 12 Digester digester = createStartDigester(); 13 14 InputSource inputSource = null; 15 InputStream inputStream = null; 16 File file = null; 17 try { 18 file = configFile(); 19 inputStream = new FileInputStream(file); 20 inputSource = new InputSource("file://" + file.getAbsolutePath()); 21 } catch (Exception e) { 22 ; 23 } 24 if (inputStream == null) { 25 try { 26 inputStream = getClass().getClassLoader() 27 .getResourceAsStream(getConfigFile()); 28 inputSource = new InputSource 29 (getClass().getClassLoader() 30 .getResource(getConfigFile()).toString()); 31 } catch (Exception e) { 32 ; 33 } 34 } 35 36 // This should be included in catalina.jar 37 // Alternative: don't bother with xml, just create it manually. 38 if( inputStream==null ) { 39 try { 40 inputStream = getClass().getClassLoader() 41 .getResourceAsStream("server-embed.xml"); 42 inputSource = new InputSource 43 (getClass().getClassLoader() 44 .getResource("server-embed.xml").toString()); 45 } catch (Exception e) { 46 ; 47 } 48 } 49 50 51 if ((inputStream == null) && (file != null)) { 52 log.warn("Can't load server.xml from " + file.getAbsolutePath()); 53 return; 54 } 55 56 try { 57 inputSource.setByteStream(inputStream); 58 digester.push(this); 59 digester.parse(inputSource); 60 inputStream.close(); 61 } catch (Exception e) { 62 log.warn("Catalina.start using " 63 + getConfigFile() + ": " , e); 64 return; 65 } 66 67 // Stream redirection 68 initStreams(); 69 70 // Start the new server 71 if (server instanceof Lifecycle) { 72 try { 73 server.initialize(); 74 } catch (LifecycleException e) { 75 log.error("Catalina.start", e); 76 } 77 } 78 79 long t2 = System.nanoTime(); 80 if(log.isInfoEnabled()) 81 log.info("Initialization processed in " + ((t2 - t1) / 1000000) + " ms"); 82 83 }
standardServer.java
1 public void initialize() 2 throws LifecycleException 3 { 4 if (initialized) { 5 log.info(sm.getString("standardServer.initialize.initialized")); 6 return; 7 } 8 lifecycle.fireLifecycleEvent(INIT_EVENT, null); 9 initialized = true; 10 11 if( oname==null ) { 12 try { 13 oname=new ObjectName( "Catalina:type=Server"); 14 Registry.getRegistry(null, null) 15 .registerComponent(this, oname, null ); 16 } catch (Exception e) { 17 log.error("Error registering ",e); 18 } 19 } 20 21 // Register global String cache 22 try { 23 ObjectName oname2 = 24 new ObjectName(oname.getDomain() + ":type=StringCache"); 25 Registry.getRegistry(null, null) 26 .registerComponent(new StringCache(), oname2, null ); 27 } catch (Exception e) { 28 log.error("Error registering ",e); 29 } 30 31 // Initialize our defined Services 32 for (int i = 0; i < services.length; i++) { 33 services[i].initialize(); 34 } 35 }
standardService.java
public void initialize() throws LifecycleException { // Service shouldn't be used with embeded, so it doesn't matter if (initialized) { if(log.isInfoEnabled()) log.info(sm.getString("standardService.initialize.initialized")); return; } initialized = true; if( oname==null ) { try { // Hack - Server should be deprecated... Container engine=this.getContainer(); domain=engine.getName(); oname=new ObjectName(domain + ":type=Service,serviceName="+name); this.controller=oname; Registry.getRegistry(null, null) .registerComponent(this, oname, null); Executor[] executors = findExecutors(); for (int i = 0; i < executors.length; i++) { ObjectName executorObjectName = new ObjectName(domain + ":type=Executor,name=" + executors[i].getName()); Registry.getRegistry(null, null) .registerComponent(executors[i], executorObjectName, null); } } catch (Exception e) { log.error(sm.getString("standardService.register.failed",domain),e); } } if( server==null ) { // Register with the server // HACK: ServerFactory should be removed... ServerFactory.getServer().addService(this); } // Initialize our defined Connectors synchronized (connectors) { for (int i = 0; i < connectors.length; i++) { connectors[i].initialize(); } } }
connector.java
1 public void initialize() 2 throws LifecycleException 3 { 4 if (initialized) { 5 if(log.isInfoEnabled()) 6 log.info(sm.getString("coyoteConnector.alreadyInitialized")); 7 return; 8 } 9 10 this.initialized = true; 11 12 if( oname == null && (container instanceof StandardEngine)) { 13 try { 14 // we are loaded directly, via API - and no name was given to us 15 StandardEngine cb=(StandardEngine)container; 16 oname = createObjectName(cb.getName(), "Connector"); 17 Registry.getRegistry(null, null) 18 .registerComponent(this, oname, null); 19 controller=oname; 20 } catch (Exception e) { 21 log.error( "Error registering connector ", e); 22 } 23 if(log.isDebugEnabled()) 24 log.debug("Creating name for connector " + oname); 25 } 26 27 // Initializa adapter 28 adapter = new CoyoteAdapter(this); 29 protocolHandler.setAdapter(adapter); 30 31 IntrospectionUtils.setProperty(protocolHandler, "jkHome", 32 System.getProperty("catalina.base")); 33 34 try { 35 protocolHandler.init(); 36 } catch (Exception e) { 37 throw new LifecycleException 38 (sm.getString 39 ("coyoteConnector.protocolHandlerInitializationFailed", e)); 40 } 41 }
Http11Protocol.java初始化
1 public void init() throws Exception { 2 endpoint.setName(getName()); 3 endpoint.setHandler(cHandler); 4 5 // Verify the validity of the configured socket factory 6 try { 7 if (isSSLEnabled()) { 8 sslImplementation = 9 SSLImplementation.getInstance(sslImplementationName); 10 socketFactory = sslImplementation.getServerSocketFactory(); 11 endpoint.setServerSocketFactory(socketFactory); 12 } else if (socketFactoryName != null) { 13 socketFactory = (ServerSocketFactory) Class.forName(socketFactoryName).newInstance(); 14 endpoint.setServerSocketFactory(socketFactory); 15 } 16 } catch (Exception ex) { 17 log.error(sm.getString("http11protocol.socketfactory.initerror"), 18 ex); 19 throw ex; 20 } 21 22 if (socketFactory!=null) { 23 Iterator<String> attE = attributes.keySet().iterator(); 24 while( attE.hasNext() ) { 25 String key = attE.next(); 26 Object v=attributes.get(key); 27 socketFactory.setAttribute(key, v); 28 } 29 } 30 31 try { 32 endpoint.init(); 33 } catch (Exception ex) { 34 log.error(sm.getString("http11protocol.endpoint.initerror"), ex); 35 throw ex; 36 } 37 if (log.isInfoEnabled()) 38 log.info(sm.getString("http11protocol.init", getName())); 39 40 }
JIoEndpoint.java
* Handle incoming TCP connections.
*
* This class implement a simple server model: one listener thread accepts on a socket and
* creates a new worker thread for each incoming connection.
*
* More advanced Endpoints will reuse the threads, use queues, etc.
1 public void init() 2 throws Exception { 3 4 if (initialized) 5 return; 6 7 // Initialize thread count defaults for acceptor 8 if (acceptorThreadCount == 0) { 9 acceptorThreadCount = 1; 10 } 11 if (serverSocketFactory == null) { 12 serverSocketFactory = ServerSocketFactory.getDefault(); 13 } 14 if (serverSocket == null) { 15 try { 16 if (address == null) { 17 serverSocket = serverSocketFactory.createSocket(port, backlog); 18 } else { 19 serverSocket = serverSocketFactory.createSocket(port, backlog, address); 20 } 21 } catch (BindException be) { 22 if (address == null) 23 throw new BindException(be.getMessage() + "<null>:" + port); 24 else 25 throw new BindException(be.getMessage() + " " + 26 address.toString() + ":" + port); 27 } 28 } 29 //if( serverTimeout >= 0 ) 30 // serverSocket.setSoTimeout( serverTimeout ); 31 32 initialized = true; 33 34 }
b1) initDirs() -> set properties like catalina.home catalina.base == catalina.home (most cases) b2) initNaming setProperty(javax.naming.Context.INITIAL_CONTEXT_FACTORY, org.apache.naming.java.javaURLContextFactory ->default) b3) createStartDigester() Configures a digester for the main server.xml elements like org.apache.catalina.core.StandardServer (can change of course :) org.apache.catalina.deploy.NamingResources Stores naming resources in the J2EE JNDI tree org.apache.catalina.LifecycleListener implements events for start/stop of major components org.apache.catalina.core.StandardService The single entry for a set of connectors, so that a container can listen to multiple connectors ie, single entry org.apache.coyote.tomcat5.CoyoteConnector Connectors to listen for incoming requests only It also adds the following rulesets to the digester NamingRuleSet EngineRuleSet HostRuleSet ContextRuleSet b4) Load the server.xml and parse it using the digester Parsing the server.xml using the digester is an automatic XML-object mapping tool, that will create the objects defined in server.xml Startup of the actual container has not started yet. b5) Assigns System.out and System.err to the SystemLogHandler class b6) Calls initialize on all components, this makes each object register itself with the JMX agent. During the process call the Connectors also initialize the adapters. The adapters are the components that do the request pre-processing. Typical adapters are HTTP1.1 (default if no protocol is specified, org.apache.coyote.http11.Http11Protocol) AJP1.3 for mod_jk etc.
