digester.addRuleSet(new HostRuleSet("Server/Service/Engine/"));

public void addRuleInstances(Digester digester) { //org.apache.catalina.startup.HosRuleSet.addRuleInstances().digester.addObjectCreate(prefix + "Host","org.apache.catalina.core.StandardHost","className");digester.addSetProperties(prefix + "Host");digester.addRule(prefix + "Host",new CopyParentClassLoaderRule(digester));digester.addRule(prefix + "Host",new LifecycleListenerRule(digester,"org.apache.catalina.startup.HostConfig", // highlight line."hostConfigClass"));//......}

 public void lifecycleEvent(LifecycleEvent event) { //org.apache.catalina.startup.HostConfig.lifecycleEvent().// Identify the host we are associated withtry {host = (Host) event.getLifecycle();if (host instanceof StandardHost) {int hostDebug = ((StandardHost) host).getDebug();if (hostDebug > this.debug) {this.debug = hostDebug;}setDeployXML(((StandardHost) host).isDeployXML());setLiveDeploy(((StandardHost) host).getLiveDeploy());setUnpackWARs(((StandardHost) host).isUnpackWARs());}} catch (ClassCastException e) {log(sm.getString("hostConfig.cce", event.getLifecycle()), e);return;}// Process the event that has occurredif (event.getType().equals(Lifecycle.START_EVENT))start(); // highlight line.else if (event.getType().equals(Lifecycle.STOP_EVENT))stop(); // highlight line.}

protected void deployApps() {  //org.apache.catalina.startup.HostConfig.deployApps().if (!(host instanceof Deployer))return;if (debug >= 1)log(sm.getString("hostConfig.deploying"));File appBase = appBase();if (!appBase.exists() || !appBase.isDirectory())return;String files[] = appBase.list();deployDescriptors(appBase, files); //highlight line.deployWARs(appBase, files); //highlight line.deployDirectories(appBase, files); //highlight line.}

<!-- tomcat4下的admin.xml 文件(\container\webapps\admin)-->
<Context path="/admin" docBase="../server/webapps/admin"debug="0" privileged="true"><!-- Uncomment this Valve to limit access to the Admin app to localhostfor obvious security reasons. Allow may be a comma-separated list ofhosts (or even regular expressions).<Valve className="org.apache.catalina.valves.RemoteAddrValve"allow="127.0.0.1"/>--><Logger className="org.apache.catalina.logger.FileLogger"prefix="localhost_admin_log." suffix=".txt"timestamp="true"/>
</Context>
<!-- tomcat5下的 manager.xml 文件(\container\webapps\manager -->
<Context docBase="${catalina.home}/server/webapps/manager"privileged="true" antiResourceLocking="false" antiJARLocking="false" useHttpOnly="true"><!-- Link to the user database we will get roles from --><ResourceLink name="users" global="UserDatabase"type="org.apache.catalina.UserDatabase"/>
</Context>

protected void deployWARs(File appBase, String[] files) {for (int i = 0; i < files.length; i++) {if (files[i].equalsIgnoreCase("META-INF"))continue;if (files[i].equalsIgnoreCase("WEB-INF"))continue;if (deployed.contains(files[i]))continue;File dir = new File(appBase, files[i]);if (files[i].toLowerCase().endsWith(".war")) {deployed.add(files[i]);// Calculate the context path and make sure it is uniqueString contextPath = "/" + files[i];int period = contextPath.lastIndexOf(".");if (period >= 0)contextPath = contextPath.substring(0, period);if (contextPath.equals("/ROOT"))contextPath = "";if (host.findChild(contextPath) != null)continue;if (isUnpackWARs()) {// Expand and deploy this application as a directorylog(sm.getString("hostConfig.expand", files[i]));try {URL url = new URL("jar:file:" +dir.getCanonicalPath() + "!/");String path = ExpandWar.expand(host,url);url = new URL("file:" + path);((Deployer) host).install(contextPath, url);} catch (Throwable t) {log(sm.getString("hostConfig.expand.error", files[i]),t);}} else {// Deploy the application in this WAR filelog(sm.getString("hostConfig.deployJar", files[i]));try {URL url = new URL("file", null,dir.getCanonicalPath());url = new URL("jar:" + url.toString() + "!/");((Deployer) host).install(contextPath, url);} catch (Throwable t) {log(sm.getString("hostConfig.deployJar.error",files[i]), t);}}}}}

protected void deployDirectories(File appBase, String[] files) {for (int i = 0; i < files.length; i++) {if (files[i].equalsIgnoreCase("META-INF"))continue;if (files[i].equalsIgnoreCase("WEB-INF"))continue;if (deployed.contains(files[i]))continue;File dir = new File(appBase, files[i]);if (dir.isDirectory()) {deployed.add(files[i]);// Make sure there is an application configuration directory// This is needed if the Context appBase is the same as the// web server document root to make sure only web applications// are deployed and not directories for web space.File webInf = new File(dir, "/WEB-INF");if (!webInf.exists() || !webInf.isDirectory() ||!webInf.canRead())continue;// Calculate the context path and make sure it is uniqueString contextPath = "/" + files[i];if (files[i].equals("ROOT"))contextPath = "";if (host.findChild(contextPath) != null)continue;// Deploy the application in this directorylog(sm.getString("hostConfig.deployDir", files[i]));try {URL url = new URL("file", null, dir.getCanonicalPath());((Deployer) host).install(contextPath, url);} catch (Throwable t) {log(sm.getString("hostConfig.deployDir.error", files[i]),t);}}}}

protected void start() {  // org.apache.catalina.startup.HostConfig.start().if (debug >= 1)log(sm.getString("hostConfig.start"));if (host.getAutoDeploy()) {deployApps();}if (isLiveDeploy()) { //highlight line.threadStart();}}

protected void threadStart() {  // org.apache.catalina.startup.HostConfig.threadStart().// Has the background thread already been started?if (thread != null)return;// Start the background threadif (debug >= 1)log(" Starting background thread");threadDone = false;threadName = "HostConfig[" + host.getName() + "]";thread = new Thread(this, threadName);thread.setDaemon(true);thread.start();}
public void run() {  //org.apache.catalina.startup.HostConfig.run().if (debug >= 1)log("BACKGROUND THREAD Starting");// Loop until the termination semaphore is setwhile (!threadDone) {// Wait for our check intervalthreadSleep();// Deploy apps if the Host allows auto deployingdeployApps();// Check for web.xml modificationcheckWebXmlLastModified();}if (debug >= 1)log("BACKGROUND THREAD Stopping");}

 protected void threadSleep() {try {Thread.sleep(checkInterval * 1000L);}  // ......}

public void backgroundProcess() {lifecycle.fireLifecycleEvent("check", null);
}

public void lifecycleEvent(LifecycleEvent event) { //org.apache.catalina.startup.HostConfig.lifecycleEvent().if (event.getType().equals(Lifecycle.PERIODIC_EVENT))check(); // highlight line.// Identify the host we are associated withtry {host = (Host) event.getLifecycle();if (host instanceof StandardHost) {setDeployXML(((StandardHost) host).isDeployXML());setUnpackWARs(((StandardHost) host).isUnpackWARs());setXmlNamespaceAware(((StandardHost) host).getXmlNamespaceAware());setXmlValidation(((StandardHost) host).getXmlValidation());}} catch (ClassCastException e) {log.error(sm.getString("hostConfig.cce", event.getLifecycle()), e);return;}// Process the event that has occurredif (event.getType().equals(Lifecycle.START_EVENT))start();else if (event.getType().equals(Lifecycle.STOP_EVENT))stop();}

protected void check() {  //org.apache.catalina.startup.HostConfig.check().if (host.getAutoDeploy()) {// Check for resources modification to trigger redeploymentDeployedApplication[] apps =(DeployedApplication[]) deployed.values().toArray(new DeployedApplication[0]);for (int i = 0; i < apps.length; i++) {if (!isServiced(apps[i].name))checkResources(apps[i]);}// Hotdeploy applicationsdeployApps();// ......checkContextLastModified();}}

public class StandardHost  extends ContainerBase implements Deployer, Host {
//......

public interface Deployer  {  //org.apache.catalina.Deployer.public static final String PRE_INSTALL_EVENT = "pre-install";public static final String INSTALL_EVENT = "install"; public static final String REMOVE_EVENT = "remove";  public String getName();    public void install(String contextPath, URL war) throws IOException; public void install(URL config, URL war) throws IOException;   public Context findDeployedApp(String contextPath); public String[] findDeployedApps();  public void remove(String contextPath) throws IOException;public void remove(String contextPath, boolean undeploy) throws IOException; public void start(String contextPath) throws IOException;    public void stop(String contextPath) throws IOException;
}

// the follwing code is defined in org.apache.catalina.core.StandardHostpublic void install(String contextPath, URL war) throws IOException {deployer.install(contextPath, war);}public synchronized void install(URL config, URL war) throws IOException {deployer.install(config, war);}public Context findDeployedApp(String contextPath) {return (deployer.findDeployedApp(contextPath));}public String[] findDeployedApps() {return (deployer.findDeployedApps());}public void remove(String contextPath) throws IOException {deployer.remove(contextPath);}public void remove(String contextPath, boolean undeploy) throws IOException {deployer.remove(contextPath,undeploy);}public void start(String contextPath) throws IOException { deployer.start(contextPath);}public void stop(String contextPath) throws IOException { deployer.stop(contextPath);}protected void addDefaultMapper(String mapperClass) {super.addDefaultMapper(this.mapperClass);}

public StandardHostDeployer(StandardHost host) {super();this.host = host;}

 protected void deployDescriptors(File appBase, String[] files) { // org.apache.catalina.startup.HostConfig.deployDescriptors()if (!deployXML)return;for (int i = 0; i < files.length; i++) {if (files[i].equalsIgnoreCase("META-INF"))continue;if (files[i].equalsIgnoreCase("WEB-INF"))continue;if (deployed.contains(files[i]))continue;File dir = new File(appBase, files[i]);if (files[i].toLowerCase().endsWith(".xml")) {deployed.add(files[i]);// Calculate the context path and make sure it is uniqueString file = files[i].substring(0, files[i].length() - 4);String contextPath = "/" + file;if (file.equals("ROOT")) {contextPath = "";}if (host.findChild(contextPath) != null) {continue;}// Assume this is a configuration descriptor and deploy itlog(sm.getString("hostConfig.deployDescriptor", files[i]));try {URL config =new URL("file", null, dir.getCanonicalPath());((Deployer) host).install(config, null); // highlight line.} catch (Throwable t) {log(sm.getString("hostConfig.deployDescriptor.error",files[i]), t);}}}}

public synchronized void install(URL config, URL war) throws IOException { // org.apache.catalina.core.StandardHost.install().deployer.install(config, war); // highlight line.}

 public synchronized void install(URL config, URL war) throws IOException { // org.apache.catalina.core.StandardHostDeployer.install().// Validate the format and state of our argumentsif (config == null)throw new IllegalArgumentException(sm.getString("standardHost.configRequired"));if (!host.isDeployXML())throw new IllegalArgumentException(sm.getString("standardHost.configNotAllowed"));// Calculate the document base for the new web application (if needed)String docBase = null; // Optional override for value in config fileif (war != null) {String url = war.toString();host.log(sm.getString("standardHost.installingWAR", url));// Calculate the WAR file absolute pathnameif (url.startsWith("jar:")) {url = url.substring(4, url.length() - 2);}if (url.startsWith("file://"))docBase = url.substring(7);else if (url.startsWith("file:"))docBase = url.substring(5);elsethrow new IllegalArgumentException(sm.getString("standardHost.warURL", url));}// Install the new web applicationthis.context = null;this.overrideDocBase = docBase;InputStream stream = null;try {stream = config.openStream();Digester digester = createDigester();digester.setDebug(host.getDebug());digester.clear();digester.push(this);digester.parse(stream);stream.close();stream = null;} catch (Exception e) {host.log(sm.getString("standardHost.installError", docBase), e);throw new IOException(e.toString());} finally {if (stream != null) {try {stream.close();} catch (Throwable t) {;}}}}

public void start(String contextPath) throws IOException {// Validate the format and state of our argumentsif (contextPath == null)throw new IllegalArgumentException(sm.getString("standardHost.pathRequired"));if (!contextPath.equals("") && !contextPath.startsWith("/"))throw new IllegalArgumentException(sm.getString("standardHost.pathFormat", contextPath));Context context = findDeployedApp(contextPath);if (context == null)throw new IllegalArgumentException(sm.getString("standardHost.pathMissing", contextPath));host.log("standardHost.start " + contextPath);try {((Lifecycle) context).start();} catch (LifecycleException e) {host.log("standardHost.start " + contextPath + ": ", e);throw new IllegalStateException("standardHost.start " + contextPath + ": " + e);}}

public void stop(String contextPath) throws IOException {// Validate the format and state of our argumentsif (contextPath == null)throw new IllegalArgumentException(sm.getString("standardHost.pathRequired"));if (!contextPath.equals("") && !contextPath.startsWith("/"))throw new IllegalArgumentException(sm.getString("standardHost.pathFormat", contextPath));Context context = findDeployedApp(contextPath);if (context == null)throw new IllegalArgumentException(sm.getString("standardHost.pathMissing", contextPath));host.log("standardHost.stop " + contextPath);try {((Lifecycle) context).stop();} catch (LifecycleException e) {host.log("standardHost.stop " + contextPath + ": ", e);throw new IllegalStateException("standardHost.stop " + contextPath + ": " + e);}}