//
   //  ========================================================================
   //  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  All rights reserved. This program and the accompanying materials
   //  are made available under the terms of the Eclipse Public License v1.0
   //  and Apache License v2.0 which accompanies this distribution.
   //
   //      The Eclipse Public License is available at
  //      http://www.eclipse.org/legal/epl-v10.html
  //
  //      The Apache License v2.0 is available at
  //      http://www.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.webapp;
  
  import java.io.File;
  import java.io.IOException;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.security.PermissionCollection;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.EventListener;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import javax.servlet.ServletContext;
  import javax.servlet.ServletRegistration.Dynamic;
  import javax.servlet.ServletSecurityElement;
  import javax.servlet.http.HttpSessionActivationListener;
  import javax.servlet.http.HttpSessionAttributeListener;
  import javax.servlet.http.HttpSessionBindingListener;
  import javax.servlet.http.HttpSessionIdListener;
  import javax.servlet.http.HttpSessionListener;
  
  import org.eclipse.jetty.security.ConstraintAware;
  import org.eclipse.jetty.security.ConstraintMapping;
  import org.eclipse.jetty.security.ConstraintSecurityHandler;
  import org.eclipse.jetty.security.SecurityHandler;
  import org.eclipse.jetty.server.Connector;
  import org.eclipse.jetty.server.HandlerContainer;
  import org.eclipse.jetty.server.Server;
  import org.eclipse.jetty.server.handler.ContextHandler;
  import org.eclipse.jetty.server.handler.ErrorHandler;
  import org.eclipse.jetty.server.session.SessionHandler;
  import org.eclipse.jetty.servlet.ErrorPageErrorHandler;
  import org.eclipse.jetty.servlet.ServletContextHandler;
  import org.eclipse.jetty.servlet.ServletHandler;
  import org.eclipse.jetty.util.Loader;
  import org.eclipse.jetty.util.MultiException;
  import org.eclipse.jetty.util.URIUtil;
  import org.eclipse.jetty.util.annotation.ManagedAttribute;
  import org.eclipse.jetty.util.annotation.ManagedObject;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  import org.eclipse.jetty.util.resource.Resource;
  import org.eclipse.jetty.util.resource.ResourceCollection;
  
  /* ------------------------------------------------------------ */
  /** Web Application Context Handler.
   * The WebAppContext handler is an extension of ContextHandler that
   * coordinates the construction and configuration of nested handlers:
   * {@link org.eclipse.jetty.security.ConstraintSecurityHandler}, {@link org.eclipse.jetty.server.session.SessionHandler}
   * and {@link org.eclipse.jetty.servlet.ServletHandler}.
   * The handlers are configured by pluggable configuration classes, with
   * the default being  {@link org.eclipse.jetty.webapp.WebXmlConfiguration} and
   * {@link org.eclipse.jetty.webapp.JettyWebXmlConfiguration}.
   *
   * @org.apache.xbean.XBean description="Creates a servlet web application at a given context from a resource base"
   *
   */
  @ManagedObject("Web Application ContextHandler")
  public class WebAppContext extends ServletContextHandler implements WebAppClassLoader.Context
  {
      private static final Logger LOG = Log.getLogger(WebAppContext.class);
  
      public static final String TEMPDIR = "javax.servlet.context.tempdir";
      public static final String BASETEMPDIR = "org.eclipse.jetty.webapp.basetempdir";
      public final static String WEB_DEFAULTS_XML="org/eclipse/jetty/webapp/webdefault.xml";
      public final static String ERROR_PAGE="org.eclipse.jetty.server.error_page";
      public final static String SERVER_SYS_CLASSES = "org.eclipse.jetty.webapp.systemClasses";
      public final static String SERVER_SRV_CLASSES = "org.eclipse.jetty.webapp.serverClasses";
  
      private String[] __dftProtectedTargets = {"/web-inf", "/meta-inf"};
  
      public static final String[] DEFAULT_CONFIGURATION_CLASSES =
      {
          "org.eclipse.jetty.webapp.WebInfConfiguration",
          "org.eclipse.jetty.webapp.WebXmlConfiguration",
         "org.eclipse.jetty.webapp.MetaInfConfiguration",
         "org.eclipse.jetty.webapp.FragmentConfiguration",
         "org.eclipse.jetty.webapp.JettyWebXmlConfiguration"
     } ;
 
     // System classes are classes that cannot be replaced by
     // the web application, and they are *always* loaded via
     // system classloader.
     public final static String[] __dftSystemClasses =
     {
         "java.",                            // Java SE classes (per servlet spec v2.5 / SRV.9.7.2)
         "javax.",                           // Java SE classes (per servlet spec v2.5 / SRV.9.7.2)
         "org.xml.",                         // needed by javax.xml
         "org.w3c.",                         // needed by javax.xml
         "org.eclipse.jetty.continuation.",  // webapp cannot change continuation classes
         "org.eclipse.jetty.jndi.",          // webapp cannot change naming classes
         "org.eclipse.jetty.jaas.",          // webapp cannot change jaas classes
         "org.eclipse.jetty.websocket.",     // webapp cannot change / replace websocket classes
         "org.eclipse.jetty.util.log.",      // webapp should use server log
         "org.eclipse.jetty.servlet.ServletContextHandler.Decorator", // for CDI / weld use
         "org.eclipse.jetty.servlet.DefaultServlet", // webapp cannot change default servlets
         "org.eclipse.jetty.servlets.AsyncGzipFilter" // special case for AsyncGzipFilter
     } ;
 
     // Server classes are classes that are hidden from being
     // loaded by the web application using system classloader,
     // so if web application needs to load any of such classes,
     // it has to include them in its distribution.
     public final static String[] __dftServerClasses =
     {
         "-org.eclipse.jetty.continuation.", // don't hide continuation classes
         "-org.eclipse.jetty.jndi.",         // don't hide naming classes
         "-org.eclipse.jetty.jaas.",         // don't hide jaas classes
         "-org.eclipse.jetty.servlets.",     // don't hide jetty servlets
         "-org.eclipse.jetty.servlet.DefaultServlet", // don't hide default servlet
         "-org.eclipse.jetty.servlet.listener.", // don't hide useful listeners
         "-org.eclipse.jetty.websocket.",    // don't hide websocket classes from webapps (allow webapp to use ones from system classloader)
         "-org.eclipse.jetty.apache.",       // don't hide jetty apache impls
         "-org.eclipse.jetty.util.log.",     // don't hide server log 
         "-org.eclipse.jetty.servlet.ServletContextHandler.Decorator", // don't hide CDI / weld interface  
         "org.objectweb.asm.",               // hide asm used by jetty
         "org.eclipse.jdt.",                 // hide jdt used by jetty
         "org.eclipse.jetty."                // hide other jetty classes
     } ;
 
     private final List<String> _configurationClasses = new ArrayList<>();
     private ClasspathPattern _systemClasses = null;
     private ClasspathPattern _serverClasses = null;
 
     private final List<Configuration> _configurations = new ArrayList<>();
     private String _defaultsDescriptor=WEB_DEFAULTS_XML;
     private String _descriptor=null;
     private final List<String> _overrideDescriptors = new ArrayList<>();
     private boolean _distributable=false;
     private boolean _extractWAR=true;
     private boolean _copyDir=false;
     private boolean _copyWebInf=false;
     private boolean _logUrlOnStart =false;
     private boolean _parentLoaderPriority= Boolean.getBoolean("org.eclipse.jetty.server.webapp.parentLoaderPriority");
     private PermissionCollection _permissions;
 
     private String[] _contextWhiteList = null;
 
     private File _tmpDir;
     private boolean _persistTmpDir = false;
  
     private String _war;
     private String _extraClasspath;
     private Throwable _unavailableException;
 
     private Map<String, String> _resourceAliases;
     private boolean _ownClassLoader=false;
     private boolean _configurationDiscovered=true;
     private boolean _allowDuplicateFragmentNames = false;
     private boolean _throwUnavailableOnStartupException = false;
 
 
 
     private MetaData _metadata=new MetaData();
 
     public static WebAppContext getCurrentWebAppContext()
     {
         ContextHandler.Context context=ContextHandler.getCurrentContext();
         if (context!=null)
         {
             ContextHandler handler = context.getContextHandler();
             if (handler instanceof WebAppContext)
                 return (WebAppContext)handler;
         }
         return null;
     }
 
     /* ------------------------------------------------------------ */
     public WebAppContext()
     {
         this(null,null,null,null,null,new ErrorPageErrorHandler(),SESSIONS|SECURITY);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param contextPath The context path
      * @param webApp The URL or filename of the webapp directory or war file.
      */
     public WebAppContext(String webApp,String contextPath)
     {
         this(null,contextPath,null,null,null,new ErrorPageErrorHandler(),SESSIONS|SECURITY);
         setWar(webApp);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param parent The parent HandlerContainer.
      * @param contextPath The context path
      * @param webApp The URL or filename of the webapp directory or war file.
      */
     public WebAppContext(HandlerContainer parent, String webApp, String contextPath)
     {
         this(parent,contextPath,null,null,null,new ErrorPageErrorHandler(),SESSIONS|SECURITY);
         setWar(webApp);
     }
 
     /* ------------------------------------------------------------ */
 
     /**
      * This constructor is used in the geronimo integration.
      *
      * @param sessionHandler SessionHandler for this web app
      * @param securityHandler SecurityHandler for this web app
      * @param servletHandler ServletHandler for this web app
      * @param errorHandler ErrorHandler for this web app
      */
     public WebAppContext(SessionHandler sessionHandler, SecurityHandler securityHandler, ServletHandler servletHandler, ErrorHandler errorHandler) 
     {
         this(null, null, sessionHandler, securityHandler, servletHandler, errorHandler,0);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * This constructor is used in the geronimo integration.
      *
      * @param sessionHandler SessionHandler for this web app
      * @param securityHandler SecurityHandler for this web app
      * @param servletHandler ServletHandler for this web app
      * @param errorHandler ErrorHandler for this web app
      */
     public WebAppContext(HandlerContainer parent, String contextPath, SessionHandler sessionHandler, SecurityHandler securityHandler, ServletHandler servletHandler, ErrorHandler errorHandler,int options) 
     {
         super(parent, contextPath,sessionHandler, securityHandler, servletHandler, errorHandler,options);
         _scontext = new Context();
         setErrorHandler(errorHandler != null ? errorHandler : new ErrorPageErrorHandler());
         setProtectedTargets(__dftProtectedTargets);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param servletContextName The servletContextName to set.
      */
     @Override
     public void setDisplayName(String servletContextName)
     {
         super.setDisplayName(servletContextName);
         ClassLoader cl = getClassLoader();
         if (cl!=null && cl instanceof WebAppClassLoader && servletContextName!=null)
             ((WebAppClassLoader)cl).setName(servletContextName);
     }
 
     /* ------------------------------------------------------------ */
     /** Get an exception that caused the webapp to be unavailable
      * @return A throwable if the webapp is unavailable or null
      */
     public Throwable getUnavailableException()
     {
         return _unavailableException;
     }
 
 
     /* ------------------------------------------------------------ */
     /** Set Resource Alias.
      * Resource aliases map resource uri's within a context.
      * They may optionally be used by a handler when looking for
      * a resource.
      * @param alias
      * @param uri
      */
     public void setResourceAlias(String alias, String uri)
     {
         if (_resourceAliases == null)
             _resourceAliases= new HashMap<String, String>(5);
         _resourceAliases.put(alias, uri);
     }
 
     /* ------------------------------------------------------------ */
     public Map<String, String> getResourceAliases()
     {
         if (_resourceAliases == null)
             return null;
         return _resourceAliases;
     }
 
     /* ------------------------------------------------------------ */
     public void setResourceAliases(Map<String, String> map)
     {
         _resourceAliases = map;
     }
 
     /* ------------------------------------------------------------ */
     public String getResourceAlias(String path)
     {
         if (_resourceAliases == null)
             return null;
         String alias = _resourceAliases.get(path);
 
         int slash=path.length();
         while (alias==null)
         {
             slash=path.lastIndexOf("/",slash-1);
             if (slash<0)
                 break;
             String match=_resourceAliases.get(path.substring(0,slash+1));
             if (match!=null)
                 alias=match+path.substring(slash+1);
         }
         return alias;
     }
 
     /* ------------------------------------------------------------ */
     public String removeResourceAlias(String alias)
     {
         if (_resourceAliases == null)
             return null;
         return _resourceAliases.remove(alias);
     }
 
     /* ------------------------------------------------------------ */
     /* (non-Javadoc)
      * @see org.eclipse.jetty.server.server.handler.ContextHandler#setClassLoader(java.lang.ClassLoader)
      */
     @Override
     public void setClassLoader(ClassLoader classLoader)
     {
         super.setClassLoader(classLoader);
 
 //        if ( !(classLoader instanceof WebAppClassLoader) )
 //        {
 //            LOG.info("NOTE: detected a classloader which is not an instance of WebAppClassLoader being set on WebAppContext, some typical class and resource locations may be missing on: " + toString() );
 //        }
 
         if (classLoader!=null && classLoader instanceof WebAppClassLoader && getDisplayName()!=null)
             ((WebAppClassLoader)classLoader).setName(getDisplayName());
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public Resource getResource(String uriInContext) throws MalformedURLException
     {
         if (uriInContext==null || !uriInContext.startsWith(URIUtil.SLASH))
             throw new MalformedURLException(uriInContext);
 
         IOException ioe= null;
         Resource resource= null;
         int loop=0;
         while (uriInContext!=null && loop++<100)
         {
             try
             {
                 resource= super.getResource(uriInContext);
                 if (resource != null && resource.exists())
                     return resource;
 
                 uriInContext = getResourceAlias(uriInContext);
             }
             catch (IOException e)
             {
                 LOG.ignore(e);
                 if (ioe==null)
                     ioe= e;
             }
         }
 
         if (ioe != null && ioe instanceof MalformedURLException)
             throw (MalformedURLException)ioe;
 
         return resource;
     }
 
 
     /* ------------------------------------------------------------ */
     /** Is the context Automatically configured.
      *
      * @return true if configuration discovery.
      */
     public boolean isConfigurationDiscovered()
     {
         return _configurationDiscovered;
     }
 
     /* ------------------------------------------------------------ */
     /** Set the configuration discovery mode.
      * If configuration discovery is set to true, then the JSR315
      * servlet 3.0 discovered configuration features are enabled.
      * These are:<ul>
      * <li>Web Fragments</li>
      * <li>META-INF/resource directories</li>
      * </ul>
      * @param discovered true if configuration discovery is enabled for automatic configuration from the context
      */
     public void setConfigurationDiscovered(boolean discovered)
     {
         _configurationDiscovered = discovered;
     }
 
     /* ------------------------------------------------------------ */
     /** Pre configure the web application.
      * <p>
      * The method is normally called from {@link #start()}. It performs
      * the discovery of the configurations to be applied to this context,
      * specifically:<ul>
      * <li>Instantiate the {@link Configuration} instances with a call to {@link #loadConfigurations()}.
      * <li>Setup the default System classes by calling {@link #loadSystemClasses()}
      * <li>Setup the default Server classes by calling <code>loadServerClasses()</code>
      * <li>Instantiates a classload (if one is not already set)
      * <li>Calls the {@link Configuration#preConfigure(WebAppContext)} method of all
      * Configuration instances.
      * </ul>
      * @throws Exception
      */
     public void preConfigure() throws Exception
     {
         // Setup configurations
         loadConfigurations();
 
         // Setup system classes
         loadSystemClasses();
 
         // Setup server classes
         loadServerClasses();
 
         // Configure classloader
         _ownClassLoader=false;
         if (getClassLoader()==null)
         {
             WebAppClassLoader classLoader = new WebAppClassLoader(this);
             setClassLoader(classLoader);
             _ownClassLoader=true;
         }
 
         if (LOG.isDebugEnabled())
         {
             ClassLoader loader = getClassLoader();
             LOG.debug("Thread Context classloader {}",loader);
             loader=loader.getParent();
             while(loader!=null)
             {
                 LOG.debug("Parent class loader: {} ",loader);
                 loader=loader.getParent();
             }
         }
 
         // Prepare for configuration
         for (Configuration configuration : _configurations)
         {
             LOG.debug("preConfigure {} with {}",this,configuration);
             configuration.preConfigure(this);
         }
     }
 
     /* ------------------------------------------------------------ */
     public void configure() throws Exception
     {
         // Configure webapp
         for (Configuration configuration : _configurations)
         {
             LOG.debug("configure {} with {}",this,configuration);
             configuration.configure(this);
         }
     }
 
     /* ------------------------------------------------------------ */
     public void postConfigure() throws Exception
     {
         // Clean up after configuration
         for (Configuration configuration : _configurations)
         {
             LOG.debug("postConfigure {} with {}",this,configuration);
             configuration.postConfigure(this);
         }
     }
 
     /* ------------------------------------------------------------ */
     /*
      * @see org.eclipse.thread.AbstractLifeCycle#doStart()
      */
     @Override
     protected void doStart() throws Exception
     {
         try
         {
             _metadata.setAllowDuplicateFragmentNames(isAllowDuplicateFragmentNames());
             preConfigure();
             super.doStart();
             postConfigure();
 
             if (isLogUrlOnStart())
                 dumpUrl();
         }
         catch (Exception e)
         {
             //start up of the webapp context failed, make sure it is not started
             LOG.warn("Failed startup of context "+this, e);
             _unavailableException=e;
             setAvailable(false);
             if (isThrowUnavailableOnStartupException())
                 throw e;
         }
     }
 
     /* ------------------------------------------------------------ */
     /*
      * @see org.eclipse.thread.AbstractLifeCycle#doStop()
      */
     @Override
     protected void doStop() throws Exception
     {
         super.doStop();
 
         try
         {
             for (int i=_configurations.size();i-->0;)
                 _configurations.get(i).deconfigure(this);
 
             if (_metadata != null)
                 _metadata.clear();
             _metadata=new MetaData();
 
         }
         finally
         {
             if (_ownClassLoader)
                 setClassLoader(null);
 
             setAvailable(true);
             _unavailableException=null;
         }
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public void destroy()
     {
         // Prepare for configuration
         MultiException mx=new MultiException();
         if (_configurations!=null)
         {
             for (int i=_configurations.size();i-->0;)
             {
                 try
                 {
                     _configurations.get(i).destroy(this);
                 }
                 catch(Exception e)
                 {
                     mx.add(e);
                 }
             }
         }
         _configurations.clear();
         super.destroy();
         mx.ifExceptionThrowRuntime();
     }
 
 
     /* ------------------------------------------------------------ */
     /*
      * Dumps the current web app name and URL to the log
      */
     private void dumpUrl()
     {
         Connector[] connectors = getServer().getConnectors();
         for (int i=0;i<connectors.length;i++)
         {
             String displayName = getDisplayName();
             if (displayName == null)
                 displayName = "WebApp@"+connectors.hashCode();
 
             LOG.info(displayName + " at http://" + connectors[i].toString() + getContextPath());
         }
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return Returns the configurations.
      */
     @ManagedAttribute(value="configuration classes used to configure webapp", readonly=true)
     public String[] getConfigurationClasses()
     {
         return _configurationClasses.toArray(new String[_configurationClasses.size()]);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return Returns the configurations.
      */
     public Configuration[] getConfigurations()
     {
         return _configurations.toArray(new Configuration[_configurations.size()]);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * The default descriptor is a web.xml format file that is applied to the context before the standard WEB-INF/web.xml
      * @return Returns the defaultsDescriptor.
      */
     @ManagedAttribute(value="default web.xml deascriptor applied before standard web.xml", readonly=true)
     public String getDefaultsDescriptor()
     {
         return _defaultsDescriptor;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * The override descriptor is a web.xml format file that is applied to the context after the standard WEB-INF/web.xml
      * @return Returns the Override Descriptor.
      */
     public String getOverrideDescriptor()
     {
         if (_overrideDescriptors.size()!=1)
             return null;
         return _overrideDescriptors.get(0);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * An override descriptor is a web.xml format file that is applied to the context after the standard WEB-INF/web.xml
      * @return Returns the Override Descriptor list
      */
     @ManagedAttribute(value="web.xml deascriptors applied after standard web.xml", readonly=true)
     public List<String> getOverrideDescriptors()
     {
         return Collections.unmodifiableList(_overrideDescriptors);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return Returns the permissions.
      */
     @Override
     public PermissionCollection getPermissions()
     {
         return _permissions;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @see #setServerClasses(String[])
      * @return Returns the serverClasses.
      */
     @ManagedAttribute(value="classes and packages hidden by the context classloader", readonly=true)
     public String[] getServerClasses()
     {
         if (_serverClasses == null)
             loadServerClasses();
 
         return _serverClasses.getPatterns();
     }
 
     /* ------------------------------------------------------------ */
     /** Add to the list of Server classes.
      * @param classOrPackage A fully qualified class name (eg com.foo.MyClass) 
      * or a qualified package name ending with '.' (eg com.foo.).  If the class 
      * or package has '-' it is excluded from the server classes and order is thus
      * important when added system class patterns. This argument may also be a comma 
      * separated list of classOrPackage patterns.
      * @see #setServerClasses(String[])
      * @see <a href="http://www.eclipse.org/jetty/documentation/current/jetty-classloading.html">Jetty Documentation: Classloading</a>
      */
     public void addServerClass(String classOrPackage)
     {
         if (_serverClasses == null)
             loadServerClasses();
 
         _serverClasses.addPattern(classOrPackage);
     }
 
     /* ------------------------------------------------------------ */
     /** Prepend to the list of Server classes.
      * @param classOrPackage A fully qualified class name (eg com.foo.MyClass) 
      * or a qualified package name ending with '.' (eg com.foo.).  If the class 
      * or package has '-' it is excluded from the server classes and order is thus
      * important when added system class patterns. This argument may also be a comma 
      * separated list of classOrPackage patterns.
      * @see #setServerClasses(String[])
      * @see <a href="http://www.eclipse.org/jetty/documentation/current/jetty-classloading.html">Jetty Documentation: Classloading</a>
      */
     public void prependServerClass(String classOrPackage)
     {
         if (_serverClasses == null)
             loadServerClasses();
 
         _serverClasses.prependPattern(classOrPackage);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @see #setSystemClasses(String[])
      * @return Returns the systemClasses.
      */
     @ManagedAttribute(value="classes and packages given priority by context classloader", readonly=true)
     public String[] getSystemClasses()
     {
         if (_systemClasses == null)
             loadSystemClasses();
 
         return _systemClasses.getPatterns();
     }
 
     /* ------------------------------------------------------------ */
     /** Add to the list of System classes.
      * @param classOrPackage A fully qualified class name (eg com.foo.MyClass) 
      * or a qualified package name ending with '.' (eg com.foo.).  If the class 
      * or package has '-' it is excluded from the system classes and order is thus
      * important when added system class patterns.  This argument may also be a comma 
      * separated list of classOrPackage patterns.
      * @see #setSystemClasses(String[])
      * @see <a href="http://www.eclipse.org/jetty/documentation/current/jetty-classloading.html">Jetty Documentation: Classloading</a>
      */
     public void addSystemClass(String classOrPackage)
     {
         if (_systemClasses == null)
             loadSystemClasses();
 
         _systemClasses.addPattern(classOrPackage);
     }
 
 
     /* ------------------------------------------------------------ */
     /** Prepend to the list of System classes.
      * @param classOrPackage A fully qualified class name (eg com.foo.MyClass) 
      * or a qualified package name ending with '.' (eg com.foo.).  If the class 
      * or package has '-' it is excluded from the system classes and order is thus
      * important when added system class patterns.This argument may also be a comma 
      * separated list of classOrPackage patterns.
      * @see #setSystemClasses(String[])
      * @see <a href="http://www.eclipse.org/jetty/documentation/current/jetty-classloading.html">Jetty Documentation: Classloading</a>
      */
     public void prependSystemClass(String classOrPackage)
     {
         if (_systemClasses == null)
             loadSystemClasses();
 
         _systemClasses.prependPattern(classOrPackage);
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public boolean isServerClass(String name)
     {
         if (_serverClasses == null)
             loadServerClasses();
 
         return _serverClasses.match(name);
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public boolean isSystemClass(String name)
     {
         if (_systemClasses == null)
             loadSystemClasses();
 
         return _systemClasses.match(name);
     }
 
     /* ------------------------------------------------------------ */
     protected void loadSystemClasses()
     {
         if (_systemClasses != null)
             return;
 
         //look for a Server attribute with the list of System classes
         //to apply to every web application. If not present, use our defaults.
         Server server = getServer();
         if (server != null)
         {
             Object systemClasses = server.getAttribute(SERVER_SYS_CLASSES);
             if (systemClasses != null && systemClasses instanceof String[])
                 _systemClasses = new ClasspathPattern((String[])systemClasses);
         }
 
         if (_systemClasses == null)
             _systemClasses = new ClasspathPattern(__dftSystemClasses);
     }
 
     /* ------------------------------------------------------------ */
     private void loadServerClasses()
     {
         if (_serverClasses != null)
         {
             return;
         }
 
         // look for a Server attribute with the list of Server classes
         // to apply to every web application. If not present, use our defaults.
         Server server = getServer();
         if (server != null)
         {
             Object serverClasses = server.getAttribute(SERVER_SRV_CLASSES);
             if (serverClasses != null && serverClasses instanceof String[])
             {
                 _serverClasses = new ClasspathPattern((String[])serverClasses);
             }
         }
 
         if (_serverClasses == null)
         {
             _serverClasses = new ClasspathPattern(__dftServerClasses);
         }
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return Returns the war as a file or URL string (Resource)
      */
     @ManagedAttribute(value="war file location", readonly=true)
     public String getWar()
     {
         if (_war==null)
             _war=getResourceBase();
         return _war;
     }
 
     /* ------------------------------------------------------------ */
     public Resource getWebInf() throws IOException
     {
         if (super.getBaseResource() == null)
             return null;
 
         // Iw there a WEB-INF directory?
         Resource web_inf= super.getBaseResource().addPath("WEB-INF/");
         if (!web_inf.exists() || !web_inf.isDirectory())
             return null;
 
         return web_inf;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return Returns the distributable.
      */
     @ManagedAttribute("web application distributable")
     public boolean isDistributable()
     {
         return _distributable;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return Returns the extractWAR.
      */
     @ManagedAttribute(value="extract war", readonly=true)
     public boolean isExtractWAR()
     {
         return _extractWAR;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return True if the webdir is copied (to allow hot replacement of jars on windows)
      */
     @ManagedAttribute(value="webdir copied on deploy (allows hot replacement on windows)", readonly=true)
     public boolean isCopyWebDir()
     {
         return _copyDir;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return True if the web-inf lib and classes directories are copied (to allow hot replacement of jars on windows)
      */
     public boolean isCopyWebInf()
     {
         return _copyWebInf;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return True if the classloader should delegate first to the parent
      * classloader (standard java behaviour) or false if the classloader
      * should first try to load from WEB-INF/lib or WEB-INF/classes (servlet
      * spec recommendation). Default is false or can be set by the system 
      * property org.eclipse.jetty.server.webapp.parentLoaderPriority
      */
     @Override
     @ManagedAttribute(value="parent classloader given priority", readonly=true)
     public boolean isParentLoaderPriority()
     {
         return _parentLoaderPriority;
     }
 
 
     /* ------------------------------------------------------------ */
     public static String[] getDefaultConfigurationClasses ()
     {
         return DEFAULT_CONFIGURATION_CLASSES;
     }
 
     /* ------------------------------------------------------------ */
     public String[] getDefaultServerClasses ()
     {
         return __dftServerClasses;
     }
 
     /* ------------------------------------------------------------ */
     public String[] getDefaultSystemClasses ()
     {
         return __dftSystemClasses;
     }
 
     /* ------------------------------------------------------------ */
     protected void loadConfigurations()
         throws Exception
     {
         //if the configuration instances have been set explicitly, use them
         if (_configurations.size()>0)
             return;
         
         if (_configurationClasses.size()==0)
             _configurationClasses.addAll(Configuration.ClassList.serverDefault(getServer()));
         for (String configClass : _configurationClasses)
             _configurations.add((Configuration)Loader.loadClass(this.getClass(), configClass).newInstance());
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public String toString()
     {
         if (_war!=null)
         {
             String war=_war;
             if (war.indexOf("/webapps/")>=0)
                 war=war.substring(war.indexOf("/webapps/")+8);
             return super.toString()+"{"+war+"}";
         }
         return super.toString();
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param configurations The configuration class names.  If setConfigurations is not called
      * these classes are used to create a configurations array.
      */
     public void setConfigurationClasses(String[] configurations)
     {
         if (isStarted())
             throw new IllegalStateException();
         _configurationClasses.clear();
         if (configurations!=null)
             _configurationClasses.addAll(Arrays.asList(configurations));
         _configurations.clear();
     }
 
     public void setConfigurationClasses(List<String> configurations)
     {
         setConfigurationClasses(configurations.toArray(new String[configurations.size()]));
     }
     
     /* ------------------------------------------------------------ */
     /**
      * @param configurations The configurations to set.
      */
     public void setConfigurations(Configuration[] configurations)
     {
         if (isStarted())
             throw new IllegalStateException();
         _configurations.clear();
         if (configurations!=null)
             _configurations.addAll(Arrays.asList(configurations));
     }
 
     /* ------------------------------------------------------------ */
     /**
      * The default descriptor is a web.xml format file that is applied to the context before the standard WEB-INF/web.xml
      * @param defaultsDescriptor The defaultsDescriptor to set.
      */
     public void setDefaultsDescriptor(String defaultsDescriptor)
     {
         _defaultsDescriptor = defaultsDescriptor;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * The override descriptor is a web.xml format file that is applied to the context after the standard WEB-INF/web.xml
      * @param overrideDescriptor The overrideDescritpor to set.
      */
     public void setOverrideDescriptor(String overrideDescriptor)
     {
         _overrideDescriptors.clear();
         _overrideDescriptors.add(overrideDescriptor);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * The override descriptor is a web.xml format file that is applied to the context after the standard WEB-INF/web.xml
      * @param overrideDescriptors The overrideDescriptors (file or URL) to set.
      */
     public void setOverrideDescriptors(List<String> overrideDescriptors)
     {
         _overrideDescriptors.clear();
         _overrideDescriptors.addAll(overrideDescriptors);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * The override descriptor is a web.xml format file that is applied to the context after the standard WEB-INF/web.xml
      * @param overrideDescriptor The overrideDescriptor (file or URL) to add.
      */
     public void addOverrideDescriptor(String overrideDescriptor)
     {
         _overrideDescriptors.add(overrideDescriptor);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return the web.xml descriptor to use. If set to null, WEB-INF/web.xml is used if it exists.
      */
     @ManagedAttribute(value="standard web.xml descriptor", readonly=true)
     public String getDescriptor()
     {
         return _descriptor;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param descriptor the web.xml descriptor to use. If set to null, WEB-INF/web.xml is used if it exists.
      */
     public void setDescriptor(String descriptor)
     {
         _descriptor=descriptor;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param distributable The distributable to set.
      */
     public void setDistributable(boolean distributable)
     {
         this._distributable = distributable;
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public void setEventListeners(EventListener[] eventListeners)
     {
         if (_sessionHandler!=null)
             _sessionHandler.clearEventListeners();
 
         super.setEventListeners(eventListeners);
     }
 
     /* ------------------------------------------------------------ */
     /** Add EventListener
      * Convenience method that calls {@link #setEventListeners(EventListener[])}
      * @param listener
      */
     @Override
     public void addEventListener(EventListener listener)
     {
         super.addEventListener(listener);
         if ((listener instanceof HttpSessionActivationListener)
             || (listener instanceof HttpSessionAttributeListener)
             || (listener instanceof HttpSessionBindingListener)
             || (listener instanceof HttpSessionListener)
             || (listener instanceof HttpSessionIdListener))
         {
             if (_sessionHandler!=null)
                 _sessionHandler.addEventListener(listener);
         }
     }
     
     @Override
     public void removeEventListener(EventListener listener)
     {
         super.removeEventListener(listener);
         if ((listener instanceof HttpSessionActivationListener)
             || (listener instanceof HttpSessionAttributeListener)
             || (listener instanceof HttpSessionBindingListener)
             || (listener instanceof HttpSessionListener)
             || (listener instanceof HttpSessionIdListener))
         {
             if (_sessionHandler!=null)
                 _sessionHandler.removeEventListener(listener);
         }
         
     }
 
 
     /* ------------------------------------------------------------ */
     /**
      * @param extractWAR True if war files are extracted
      */
     public void setExtractWAR(boolean extractWAR)
     {
         _extractWAR = extractWAR;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param copy True if the webdir is copied (to allow hot replacement of jars)
      */
     public void setCopyWebDir(boolean copy)
     {
         _copyDir = copy;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param copyWebInf True if the web-inf lib and classes directories are copied (to allow hot replacement of jars on windows)
      */
     public void setCopyWebInf(boolean copyWebInf)
     {
         _copyWebInf = copyWebInf;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param java2compliant True if the classloader should delegate first to the parent
      * classloader (standard java behaviour) or false if the classloader
      * should first try to load from WEB-INF/lib or WEB-INF/classes (servlet
      * spec recommendation).  Default is false or can be set by the system 
      * property org.eclipse.jetty.server.webapp.parentLoaderPriority
      */
     public void setParentLoaderPriority(boolean java2compliant)
     {
         _parentLoaderPriority = java2compliant;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param permissions The permissions to set.
      */
     public void setPermissions(PermissionCollection permissions)
     {
         _permissions = permissions;
     }
 
     /**
      * Set the context white list
      *
      * In certain circumstances you want may want to deny access of one webapp from another
      * when you may not fully trust the webapp.  Setting this white list will enable a
      * check when a servlet called getContext(String), validating that the uriInPath
      * for the given webapp has been declaratively allows access to the context.
      * @param contextWhiteList
      */
     public void setContextWhiteList(String[] contextWhiteList)
     {
         _contextWhiteList = contextWhiteList;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * Set the server classes patterns.
      * <p>
      * Server classes/packages are classes used to implement the server and are hidden
      * from the context.  If the context needs to load these classes, it must have its
      * own copy of them in WEB-INF/lib or WEB-INF/classes.
      * A class pattern is a string of one of the forms:<dl>
      * <dt>org.package.Classname</dt><dd>Match a specific class</dd>
      * <dt>org.package.</dt><dd>Match a specific package hierarchy</dd>
      * <dt>-org.package.Classname</dt><dd>Exclude a specific class</dd>
      * <dt>-org.package.</dt><dd>Exclude a specific package hierarchy</dd>
      * </dl>
      * @param serverClasses The serverClasses to set.
      */
     public void setServerClasses(String[] serverClasses)
     {
         _serverClasses = new ClasspathPattern(serverClasses);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * Set the system classes patterns.
      * <p>
      * System classes/packages are classes provided by the JVM and that
      * cannot be replaced by classes of the same name from WEB-INF,
      * regardless of the value of {@link #setParentLoaderPriority(boolean)}.
      * A class pattern is a string of one of the forms:<dl>
      * <dt>org.package.Classname</dt><dd>Match a specific class</dd>
      * <dt>org.package.</dt><dd>Match a specific package hierarchy</dd>
      * <dt>-org.package.Classname</dt><dd>Exclude a specific class</dd>
      * <dt>-org.package.</dt><dd>Exclude a specific package hierarchy</dd>
      * </dl>
      * @param systemClasses The systemClasses to set.
      */
     public void setSystemClasses(String[] systemClasses)
     {
         _systemClasses = new ClasspathPattern(systemClasses);
     }
 
 
     /* ------------------------------------------------------------ */
     /** Set temporary directory for context.
      * The javax.servlet.context.tempdir attribute is also set.
      * @param dir Writable temporary directory.
      */
     public void setTempDirectory(File dir)
     {
         if (isStarted())
             throw new IllegalStateException("Started");
 
         if (dir!=null)
         {
             try{dir=new File(dir.getCanonicalPath());}
             catch (IOException e){LOG.warn(Log.EXCEPTION,e);}
         }
 
         _tmpDir=dir;
         setAttribute(TEMPDIR,_tmpDir);            
     }
 
     /* ------------------------------------------------------------ */
     @ManagedAttribute(value="temporary directory location", readonly=true)
     public File getTempDirectory ()
     {
         return _tmpDir;
     }
 
     /**
      * If true the temp directory for this 
      * webapp will be kept when the webapp stops. Otherwise,
      * it will be deleted.
      * 
      * @param delete
      */
     public void setPersistTempDirectory(boolean persist)
     {
         _persistTmpDir = persist;
     }
     
     /**
      * @return
      */
     public boolean isPersistTempDirectory()
     {
         return _persistTmpDir;
     }
     
     
     /* ------------------------------------------------------------ */
     /**
      * @param war The war to set as a file name or URL
      */
     public void setWar(String war)
     {
         _war = war;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return Comma or semicolon separated path of filenames or URLs
      * pointing to directories or jar files. Directories should end
      * with '/'.
      */
     @Override
     @ManagedAttribute(value="extra classpath for context classloader", readonly=true)
     public String getExtraClasspath()
     {
         return _extraClasspath;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param extraClasspath Comma or semicolon separated path of filenames or URLs
      * pointing to directories or jar files. Directories should end
      * with '/'.
      */
     public void setExtraClasspath(String extraClasspath)
     {
         _extraClasspath=extraClasspath;
     }
 
     /* ------------------------------------------------------------ */
     public boolean isLogUrlOnStart()
     {
         return _logUrlOnStart;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * Sets whether or not the web app name and URL is logged on startup
      *
      * @param logOnStart whether or not the log message is created
      */
     public void setLogUrlOnStart(boolean logOnStart)
     {
         this._logUrlOnStart = logOnStart;
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public void setServer(Server server)
     {
         super.setServer(server);
     }
 
     /* ------------------------------------------------------------ */
     public boolean isAllowDuplicateFragmentNames()
     {
         return _allowDuplicateFragmentNames;
     }
 
     /* ------------------------------------------------------------ */
     public void setAllowDuplicateFragmentNames(boolean allowDuplicateFragmentNames)
     {
         _allowDuplicateFragmentNames = allowDuplicateFragmentNames;
     }
 
     /* ------------------------------------------------------------ */
     public void setThrowUnavailableOnStartupException (boolean throwIfStartupException) {
         _throwUnavailableOnStartupException = throwIfStartupException;
     }
 
     /* ------------------------------------------------------------ */
     public boolean isThrowUnavailableOnStartupException () {
         return _throwUnavailableOnStartupException;
     }
 
     /* ------------------------------------------------------------ */
     @Override
     protected void startContext()
         throws Exception
     {
         configure();
 
         //resolve the metadata
         _metadata.resolve(this);
 
         startWebapp();
     }
 
     /* ------------------------------------------------------------ */
     protected void startWebapp()
         throws Exception
     {
         super.startContext();
     }
     
     /* ------------------------------------------------------------ */    
     @Override
     public Set<String> setServletSecurity(Dynamic registration, ServletSecurityElement servletSecurityElement)
     {
         Set<String> unchangedURLMappings = new HashSet<String>();
         //From javadoc for ServletSecurityElement:
         /*
         If a URL pattern of this ServletRegistration is an exact target of a security-constraint that 
         was established via the portable deployment descriptor, then this method does not change the 
         security-constraint for that pattern, and the pattern will be included in the return value.
 
         If a URL pattern of this ServletRegistration is an exact target of a security constraint 
         that was established via the ServletSecurity annotation or a previous call to this method, 
         then this method replaces the security constraint for that pattern.
 
         If a URL pattern of this ServletRegistration is neither the exact target of a security constraint 
         that was established via the ServletSecurity annotation or a previous call to this method, 
         nor the exact target of a security-constraint in the portable deployment descriptor, then 
         this method establishes the security constraint for that pattern from the argument ServletSecurityElement. 
          */
 
         Collection<String> pathMappings = registration.getMappings();
         if (pathMappings != null)
         {
             ConstraintSecurityHandler.createConstraint(registration.getName(), servletSecurityElement);
 
             for (String pathSpec:pathMappings)
             {
                 Origin origin = getMetaData().getOrigin("constraint.url."+pathSpec);
                
                 switch (origin)
                 {
                     case NotSet:
                     {
                         //No mapping for this url already established
                         List<ConstraintMapping> mappings = ConstraintSecurityHandler.createConstraintsWithMappingsForPath(registration.getName(), pathSpec, servletSecurityElement);
                         for (ConstraintMapping m:mappings)
                             ((ConstraintAware)getSecurityHandler()).addConstraintMapping(m);
                         ((ConstraintAware)getSecurityHandler()).checkPathsWithUncoveredHttpMethods();
                         getMetaData().setOriginAPI("constraint.url."+pathSpec);
                         break;
                     }
                     case WebXml:
                     case WebDefaults:
                     case WebOverride:
                     case WebFragment:
                     {
                         //a mapping for this url was created in a descriptor, which overrides everything
                         unchangedURLMappings.add(pathSpec);
                         break;
                     }
                     case Annotation:
                     case API:
                     {
                         //mapping established via an annotation or by previous call to this method,
                         //replace the security constraint for this pattern
                         List<ConstraintMapping> constraintMappings = ConstraintSecurityHandler.removeConstraintMappingsForPath(pathSpec, ((ConstraintAware)getSecurityHandler()).getConstraintMappings());
                        
                         List<ConstraintMapping> freshMappings = ConstraintSecurityHandler.createConstraintsWithMappingsForPath(registration.getName(), pathSpec, servletSecurityElement);
                         constraintMappings.addAll(freshMappings);
                            
                         ((ConstraintSecurityHandler)getSecurityHandler()).setConstraintMappings(constraintMappings);
                         ((ConstraintAware)getSecurityHandler()).checkPathsWithUncoveredHttpMethods();
                         break;
                     }
                 }
             }
         }
         
         return unchangedURLMappings;
     }
 
 
 
     /* ------------------------------------------------------------ */
     public class Context extends ServletContextHandler.Context
     {
        
         /* ------------------------------------------------------------ */
         @Override
         public void checkListener(Class<? extends EventListener> listener) throws IllegalStateException
         {
             try
             {
                 super.checkListener(listener);
             }
             catch (IllegalArgumentException e)
             {
                 //not one of the standard servlet listeners, check our extended session listener types
                 boolean ok = false;
                 for (Class l:SessionHandler.SESSION_LISTENER_TYPES)
                 {
                     if (l.isAssignableFrom(listener))
                     {
                         ok = true;
                         break;
                     }
                 }
                 if (!ok)
                     throw new IllegalArgumentException("Inappropriate listener type "+listener.getName());
             }
         }
 
         /* ------------------------------------------------------------ */
         @Override
         public URL getResource(String path) throws MalformedURLException
         {
             Resource resource=WebAppContext.this.getResource(path);
             if (resource==null || !resource.exists())
                 return null;
 
             // Should we go to the original war?
             if (resource.isDirectory() && resource instanceof ResourceCollection && !WebAppContext.this.isExtractWAR())
             {
                 Resource[] resources = ((ResourceCollection)resource).getResources();
                 for (int i=resources.length;i-->0;)
                 {
                     if (resources[i].getName().startsWith("jar:file"))
                         return resources[i].getURL();
                 }
             }
 
             return resource.getURL();
         }
 
         /* ------------------------------------------------------------ */
         @Override
         public ServletContext getContext(String uripath)
         {
             ServletContext servletContext = super.getContext(uripath);
 
             if ( servletContext != null && _contextWhiteList != null )
             {
                 for ( String context : _contextWhiteList )
                 {
                     if ( context.equals(uripath) )
                     {
                         return servletContext;
                     }
                 }
 
                 return null;
             }
             else
             {
                 return servletContext;
             }
         }
         
     }
 
     /* ------------------------------------------------------------ */
     public MetaData getMetaData()
     {
         return _metadata;
     }
 }