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.

 

 

 

posted on 2013-03-22 15:56  一天不进步,就是退步  阅读(588)  评论(0编辑  收藏  举报