tomcat(12)org.apache.catalina.core.StandardContext源码剖析

public StandardContext() { // org.apache.catalina.core.StandardContext.StandardContext().
        super();
        pipeline.setBasic(new StandardContextValve());
        namingResources.setContainer(this);
    }

public void invoke(Request request, Response response)  throws IOException, ServletException { 
        // Wait if we are reloading
        while (getPaused()) {  // 返回 paused属性的值，当paused为true时，表明应用程序正在重载；
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                ;
            }
        }
        // Normal request processing
        if (swallowOutput) {
            try {
                SystemLogHandler.startCapture();
                super.invoke(request, response);
            } finally {
                String log = SystemLogHandler.stopCapture();
                if (log != null && log.length() > 0) {
                    log(log);
                }
            }
        } else {
            super.invoke(request, response);
        }
    }

protected void addDefaultMapper(String mapperClass) { // org.apache.catalina.core.ContainerBase.addDefaultMapper() method.
        // Do we need a default Mapper?
        if (mapperClass == null)
            return;
        if (mappers.size() >= 1)
            return;

        // Instantiate and add a default Mapper
        try {
            Class clazz = Class.forName(mapperClass);
            Mapper mapper = (Mapper) clazz.newInstance();
            mapper.setProtocol("http");
            addMapper(mapper);
        } catch (Exception e) {
            log(sm.getString("containerBase.addDefaultMapper", mapperClass),
                e);
        }
    }

public synchronized void start() throws LifecycleException {
        // ......
        if (ok) {
            try {
                addDefaultMapper(this.mapperClass);
                started = true;
        } //......
// private String mapperClass =  "org.apache.catalina.core.StandardContextMapper";

public void setContainer(Container container) { // org.apche.catalina.core.StandardContextMapper.setContainer().
        if (!(container instanceof StandardContext))
            throw new IllegalArgumentException
                (sm.getString("httpContextMapper.container"));
        context = (StandardContext) container;
    }
 public StandardContext() { // 而在StandardContext构造中调用setContainer().
        super();
        pipeline.setBasic(new StandardContextValve());
        namingResources.setContainer(this);
    }

public Container map(Request request, boolean update) { // org.apache.catalina.core.StandardContextMapper.map().
        int debug = context.getDebug();

        // Has this request already been mapped?
        if (update && (request.getWrapper() != null))
            return (request.getWrapper());

        // Identify the context-relative URI to be mapped
        String contextPath =
            ((HttpServletRequest) request.getRequest()).getContextPath();
        String requestURI = ((HttpRequest) request).getDecodedRequestURI();
        String relativeURI = requestURI.substring(contextPath.length());
       
        // Apply the standard request URI mapping rules from the specification
       Wrapper wrapper = null;
        String servletPath = relativeURI;
        String pathInfo = null;
        String name = null;
        // Rule 1 -- Exact Match      
        // Rule 2 -- Prefix Match       
         // Rule 3 -- Extension Match 
         // Rule 4 -- Default Match       
        // Update the Request (if requested) and return this Wrapper 
        if ((debug >= 1) && (wrapper != null))
            context.log(" Mapped to servlet '" + wrapper.getName() +
                        "' with servlet path '" + servletPath +
                        "' and path info '" + pathInfo +
                        "' and update=" + update);
        if (update) {
            request.setWrapper(wrapper);
            ((HttpRequest) request).setServletPath(servletPath);
            ((HttpRequest) request).setPathInfo(pathInfo);
        }
        return (wrapper);
    }
}

public void invoke(Request request, Response response,  ValveContext valveContext) 
        throws IOException, ServletException { <span style="font-family: Arial, Helvetica, sans-serif;">//org.apche.catalina.core.StandardContextValve.invoke().</span>
        // .....        
        // Disallow any direct access to resources under WEB-INF or META-INF
        HttpServletRequest hreq = (HttpServletRequest) request.getRequest();
        String contextPath = hreq.getContextPath();
        String requestURI = ((HttpRequest) request).getDecodedRequestURI();
        String relativeURI =
            requestURI.substring(contextPath.length()).toUpperCase();
       //......
        Context context = (Context) getContainer();
        Wrapper wrapper = null;
        try {
            wrapper = (Wrapper) context.map(request, true); // highlight line.->ContainerBase.map().
        } //......
        // Ask this Wrapper to process this Request
        response.setContext(context);
        wrapper.invoke(request, response);  
    }

public Container map(Request request, boolean update) {
        // Select the Mapper we will use
        Mapper mapper = findMapper(request.getRequest().getProtocol());
        if (mapper == null)
            return (null);
        // Use this Mapper to perform this mapping
        return (mapper.map(request, update));
}
 public Mapper findMapper(String protocol) {
        if (mapper != null)
            return (mapper); // mapper == StandardContextMapper
        else
            synchronized (mappers) {
                return ((Mapper) mappers.get(protocol));
            }
     }

// step1 begins.    
public Container map(Request request, boolean update) { // org.apache.catalina.core.StandardContextMapper.map().
        int debug = context.getDebug();
        // Has this request already been mapped?
        if (update && (request.getWrapper() != null))
            return (request.getWrapper());
        // Identify the context-relative URI to be mapped
        String contextPath =
            ((HttpServletRequest) request.getRequest()).getContextPath();
        String requestURI = ((HttpRequest) request).getDecodedRequestURI();
        String relativeURI = requestURI.substring(contextPath.length());
        if (debug >= 1)
            context.log("Mapping contextPath='" + contextPath +
                        "' with requestURI='" + requestURI +
                        "' and relativeURI='" + relativeURI + "'");
// step1 ends.
// step2 begins.
// Apply the standard request URI mapping rules from the specification
        Wrapper wrapper = null;
        String servletPath = relativeURI;
        String pathInfo = null;
        String name = null;
        // Rule 1 -- Exact Match
        if (wrapper == null) {
            if (debug >= 2)
                context.log("  Trying exact match");
            if (!(relativeURI.equals("/")))
                name = context.findServletMapping(relativeURI);
            if (name != null)
                wrapper = (Wrapper) context.findChild(name); //highlight line.
            if (wrapper != null) {
                servletPath = relativeURI;
                pathInfo = null;
            }
        }
        // Rule 2 -- Prefix Match
        if (wrapper == null) {
            if (debug >= 2)
                context.log("  Trying prefix match");
            servletPath = relativeURI;
            while (true) {
                name = context.findServletMapping(servletPath + "/*");
                if (name != null)
                    wrapper = (Wrapper) context.findChild(name); // highlight line.
                if (wrapper != null) {
                    pathInfo = relativeURI.substring(servletPath.length());
                    if (pathInfo.length() == 0)
                        pathInfo = null;
                    break;
                }
                int slash = servletPath.lastIndexOf('/');
                if (slash < 0)
                    break;
                servletPath = servletPath.substring(0, slash);
            }
        }
        // Rule 3 -- Extension Match
        if (wrapper == null) {
            if (debug >= 2)
                context.log("  Trying extension match");
            int slash = relativeURI.lastIndexOf('/');
            if (slash >= 0) {
                String last = relativeURI.substring(slash);
                int period = last.lastIndexOf('.');
                if (period >= 0) {
                    String pattern = "*" + last.substring(period);
                    name = context.findServletMapping(pattern); // highlight line.
                    if (name != null)
                        wrapper = (Wrapper) context.findChild(name);
                    if (wrapper != null) {
                        servletPath = relativeURI;
                        pathInfo = null;
                    }
                }
            }
        }
        // Rule 4 -- Default Match
        if (wrapper == null) {
            if (debug >= 2)
                context.log("  Trying default match");
            name = context.findServletMapping("/");
            if (name != null)
                wrapper = (Wrapper) context.findChild(name); //highlight line.
            if (wrapper != null) {
                servletPath = relativeURI;
                pathInfo = null;
            }
        }
// step2 ends.
// step3 begins.
        // Update the Request (if requested) and return this Wrapper
        if ((debug >= 1) && (wrapper != null))
            context.log(" Mapped to servlet '" + wrapper.getName() +
                        "' with servlet path '" + servletPath +
                        "' and path info '" + pathInfo +
                        "' and update=" + update);
        if (update) {
            request.setWrapper(wrapper);
            ((HttpRequest) request).setServletPath(servletPath);
            ((HttpRequest) request).setPathInfo(pathInfo);
        }
        return (wrapper);
    }

public synchronized void reload() { //org.apache.catalina.core.StandardContext.reload().
        // Validate our current component state
        if (!started)
            throw new IllegalStateException
                (sm.getString("containerBase.notStarted", logName()));

        // Make sure reloading is enabled
        //      if (!reloadable)
        //          throw new IllegalStateException
        //              (sm.getString("standardContext.notReloadable"));
        log(sm.getString("standardContext.reloadingStarted"));

        // Stop accepting requests temporarily
        setPaused(true);

        // Binding thread
        ClassLoader oldCCL = bindThread();

        // Shut down our session manager
        if ((manager != null) && (manager instanceof Lifecycle)) {
            try {
                ((Lifecycle) manager).stop();
            } catch (LifecycleException e) {
                log(sm.getString("standardContext.stoppingManager"), e);
            }
        }

        // Shut down the current version of all active servlets
        Container children[] = findChildren();
        for (int i = 0; i < children.length; i++) {
            Wrapper wrapper = (Wrapper) children[i];
            if (wrapper instanceof Lifecycle) {
                try {
                    ((Lifecycle) wrapper).stop();
                } catch (LifecycleException e) {
                    log(sm.getString("standardContext.stoppingWrapper",
                                     wrapper.getName()),
                        e);
                }
            }
        }

        // Shut down application event listeners
        listenerStop();

        // Clear all application-originated servlet context attributes
        if (context != null)
            context.clearAttributes();

        // Shut down filters
        filterStop();

        if (isUseNaming()) {
            // Start
            namingContextListener.lifecycleEvent
                (new LifecycleEvent(this, Lifecycle.STOP_EVENT));
        }

        // Binding thread
        unbindThread(oldCCL);

        // Shut down our application class loader
        if ((loader != null) && (loader instanceof Lifecycle)) {
            try {
                ((Lifecycle) loader).stop();
            } catch (LifecycleException e) {
                log(sm.getString("standardContext.stoppingLoader"), e);
            }
        }

        // Binding thread
        oldCCL = bindThread();

        // Restart our application class loader
        if ((loader != null) && (loader instanceof Lifecycle)) {
            try {
                ((Lifecycle) loader).start();
            } catch (LifecycleException e) {
                log(sm.getString("standardContext.startingLoader"), e);
            }
        }

        // Binding thread
        unbindThread(oldCCL);

        // Create and register the associated naming context, if internal
        // naming is used
        boolean ok = true;
        if (isUseNaming()) {
            // Start
            namingContextListener.lifecycleEvent
                (new LifecycleEvent(this, Lifecycle.START_EVENT));
        }

        // Binding thread
        oldCCL = bindThread();

        // Restart our application event listeners and filters
        if (ok) {
            if (!listenerStart()) {
                log(sm.getString("standardContext.listenerStartFailed"));
                ok = false;
            }
        }
        if (ok) {
            if (!filterStart()) {
                log(sm.getString("standardContext.filterStartFailed"));
                ok = false;
            }
        }

        // Restore the "Welcome Files" and "Resources" context attributes
        postResources();
        postWelcomeFiles();

        // Restart our currently defined servlets
        for (int i = 0; i < children.length; i++) {
            if (!ok)
                break;
            Wrapper wrapper = (Wrapper) children[i];
            if (wrapper instanceof Lifecycle) {
                try {
                    ((Lifecycle) wrapper).start();
                } catch (LifecycleException e) {
                    log(sm.getString("standardContext.startingWrapper",
                                     wrapper.getName()),
                        e);
                    ok = false;
                }
            }
        }

        // Reinitialize all load on startup servlets
        loadOnStartup(children);

        // Restart our session manager (AFTER naming context recreated/bound)
        if ((manager != null) && (manager instanceof Lifecycle)) {
            try {
                ((Lifecycle) manager).start();
            } catch (LifecycleException e) {
                log(sm.getString("standardContext.startingManager"), e);
            }
        }

        // Unbinding thread
        unbindThread(oldCCL);
        // Start accepting requests again
        if (ok) {
            log(sm.getString("standardContext.reloadingCompleted"));
        } else {
            setAvailable(false);
            log(sm.getString("standardContext.reloadingFailed"));
        }
        setPaused(false);
        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(Context.RELOAD_EVENT, null);

    }

public void setContainer(Container container) { // org.apache.catalina.loader.WebappLoader.setContainer().
        // Deregister from the old Container (if any)
        if ((this.container != null) && (this.container instanceof Context))
            ((Context) this.container).removePropertyChangeListener(this);
        // Process this property change
        Container oldContainer = this.container;
        this.container = container;
        support.firePropertyChange("container", oldContainer, this.container);
        // Register with the new Container (if any)
        if ((this.container != null) && (this.container instanceof Context)) {
            setReloadable( ((Context) this.container).getReloadable() );
            ((Context) this.container).addPropertyChangeListener(this);
        }
    }

 public void setReloadable(boolean reloadable) {  // org.apache.catalina.loader.WebappLoader.setContainer(). setReloadable()
        // Process this property change
        boolean oldReloadable = this.reloadable;
        this.reloadable = reloadable;
        support.firePropertyChange("reloadable",
                                   new Boolean(oldReloadable),
                                   new Boolean(this.reloadable));
        // Start or stop our background thread if required
        if (!started)
            return;
        if (!oldReloadable && this.reloadable)
            threadStart();
        else if (oldReloadable && !this.reloadable)
            threadStop();
    }

public synchronized void start() throws LifecycleException { //org.apache.catalina.core.ContainerBase.start() in tomcat5.
        // Validate and update our current component state
        if (started) {
            log.info(sm.getString("containerBase.alreadyStarted", logName()));
            return;
        }        
        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(BEFORE_START_EVENT, null);

        started = true;

        // Start our subordinate components, if any
        if ((loader != null) && (loader instanceof Lifecycle))
            ((Lifecycle) loader).start();
        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
        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
        if (pipeline instanceof Lifecycle)
            ((Lifecycle) pipeline).start();

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

        // Start our thread
        threadStart(); //highlight line.

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

    }

protected void threadStart() { //org.apache.catalina.core.ContainerBase.threadStart() in tomcat5.

        if (thread != null)
            return;
        if (backgroundProcessorDelay <= 0)
            return;

        threadDone = false;
        String threadName = "ContainerBackgroundProcessor[" + toString() + "]";
        thread = new Thread(new ContainerBackgroundProcessor(), threadName); //highlight line.
        thread.setDaemon(true);
        thread.start();
    }

protected class ContainerBackgroundProcessor implements Runnable { //org.apache.catalina.core.ContainerBase.ContainerBackroundProcessor class defined in tomcat 5, which is a inner class in ContainerBase

        public void run() {
            while (!threadDone) {
                try {
                    Thread.sleep(backgroundProcessorDelay * 1000L);
                } catch (InterruptedException e) {
                    ;
                }
                if (!threadDone) {
                    Container parent = (Container) getMappingObject();
                    ClassLoader cl = 
                        Thread.currentThread().getContextClassLoader();
                    if (parent.getLoader() != null) {
                        cl = parent.getLoader().getClassLoader();
                    }
                    processChildren(parent, cl); // highlight line.
                }
            }
        }

        protected void processChildren(Container container, ClassLoader cl) {
            try {
                if (container.getLoader() != null) {
                    Thread.currentThread().setContextClassLoader
                        (container.getLoader().getClassLoader());
                }
                container.backgroundProcess(); // highlight line.
            } catch (Throwable t) {
                log.error("Exception invoking periodic operation: ", t);
            } finally {
                Thread.currentThread().setContextClassLoader(cl);
            }
            Container[] children = container.findChildren();
            for (int i = 0; i < children.length; i++) {
                if (children[i].getBackgroundProcessorDelay() <= 0) {
                    processChildren(children[i], cl);
                }
            }
        }
    }