package org.apache.turbine;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.FileReader;
  import java.io.IOException;
  import java.io.Reader;
  import java.io.UnsupportedEncodingException;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.Map;
  import java.util.Properties;
  
  import javax.servlet.ServletConfig;
  import javax.servlet.ServletContext;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import javax.xml.parsers.FactoryConfigurationError;
  
  import org.apache.commons.configuration.Configuration;
  import org.apache.commons.configuration.DefaultConfigurationBuilder;
  import org.apache.commons.configuration.PropertiesConfiguration;
  import org.apache.commons.lang.StringUtils;
  import org.apache.commons.lang.exception.ExceptionUtils;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.log4j.PropertyConfigurator;
  import org.apache.log4j.xml.DOMConfigurator;
  import org.apache.turbine.modules.PageLoader;
  import org.apache.turbine.pipeline.Pipeline;
  import org.apache.turbine.pipeline.PipelineData;
  import org.apache.turbine.pipeline.TurbinePipeline;
  import org.apache.turbine.services.Initable;
  import org.apache.turbine.services.InitializationException;
  import org.apache.turbine.services.ServiceManager;
  import org.apache.turbine.services.TurbineServices;
  import org.apache.turbine.services.rundata.RunDataService;
  import org.apache.turbine.services.template.TemplateService;
  import org.apache.turbine.services.template.TurbineTemplate;
  import org.apache.turbine.util.RunData;
  import org.apache.turbine.util.ServerData;
  import org.apache.turbine.util.TurbineConfig;
  import org.apache.turbine.util.TurbineException;
  import org.apache.turbine.util.uri.URIConstants;
  
  import com.thoughtworks.xstream.XStream;
  import com.thoughtworks.xstream.io.xml.StaxDriver;
  
  /**
   * Turbine is the main servlet for the entire system. It is <code>final</code>
   * because you should <i>not</i> ever need to subclass this servlet.  If you
   * need to perform initialization of a service, then you should implement the
   * Services API and let your code be initialized by it.
   * If you need to override something in the <code>doGet()</code> or
   * <code>doPost()</code> methods, edit the TurbineResources.properties file and
   * specify your own classes there.
   * <p>
   * Turbine servlet recognizes the following initialization parameters.
   * <ul>
   * <li><code>properties</code> the path to TurbineResources.properties file
   * used by the default implementation of <code>ResourceService</code>, relative
   * to the application root.</li>
   * <li><code>basedir</code> this parameter is used <strong>only</strong> if your
   * application server does not support web applications, or the or does not
   * support <code>ServletContext.getRealPath(String)</code> method correctly.
   * You can use this parameter to specify the directory within the server's
   * filesystem, that is the base of your web application.</li>
   * </ul>
   *
   * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
   * @author <a href="mailto:bmclaugh@algx.net">Brett McLaughlin</a>
   * @author <a href="mailto:greg@shwoop.com">Greg Ritter</a>
   * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
   * @author <a href="mailto:frank.kim@clearink.com">Frank Y. Kim</a>
   * @author <a href="mailto:krzewski@e-point.pl">Rafal Krzewski</a>
   * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
  * @author <a href="mailto:sean@informage.net">Sean Legassick</a>
  * @author <a href="mailto:mpoeschl@marmot.at">Martin Poeschl</a>
  * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
  * @author <a href="mailto:quintonm@bellsouth.net">Quinton McCombs</a>
  * @author <a href="mailto:epugh@upstate.com">Eric Pugh</a>
  * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
  * @author <a href="mailto:tv@apache.org">Thomas Vandahl</a>
  * @version $Id: Turbine.java 1709648 2015-10-20 17:08:10Z tv $
  */
 public class Turbine
         extends HttpServlet
 {
     /** Serialversion */
     private static final long serialVersionUID = -6317118078613623990L;
 
     /**
      * Name of path info parameter used to indicate the redirected stage of
      * a given user's initial Turbine request
      */
     public static final String REDIRECTED_PATHINFO_NAME = "redirected";
 
     /** The base directory key */
     public static final String BASEDIR_KEY = "basedir";
 
     /**
      * In certain situations the init() method is called more than once,
      * sometimes even concurrently. This causes bad things to happen,
      * so we use this flag to prevent it.
      */
     private static boolean firstInit = true;
 
     /**
      * The pipeline to use when processing requests.
      */
     private static Pipeline pipeline = null;
 
     /** Whether init succeeded or not. */
     private static Throwable initFailure = null;
 
     /**
      * Should initialization activities be performed during doGet() execution?
      */
     private static boolean firstDoGet = true;
 
     /**
      * Keep all the properties of the web server in a convenient data
      * structure
      */
     private static ServerData serverData = null;
 
     /** The base from which the Turbine application will operate. */
     private static String applicationRoot;
 
     /** Servlet config for this Turbine webapp. */
     private static ServletConfig servletConfig;
 
     /** Servlet context for this Turbine webapp. */
     private static ServletContext servletContext;
 
     /**
      * The webapp root where the Turbine application
      * is running in the servlet container.
      * This might differ from the application root.
      */
     private static String webappRoot;
 
     /** Our internal configuration object */
     private static Configuration configuration = null;
 
     /** Default Input encoding if the servlet container does not report an encoding */
     private String inputEncoding = null;
 
     /** Logging class from commons.logging */
     private static Log log = LogFactory.getLog(Turbine.class);
 
     /**
      * This init method will load the default resources from a
      * properties file.
      *
      * This method is called by init(ServletConfig config)
      *
      * @exception ServletException a servlet exception.
      */
     @Override
     public void init() throws ServletException
     {
         synchronized (Turbine.class)
         {
             super.init();
             ServletConfig config = getServletConfig();
 
             if (!firstInit)
             {
                 log.info("Double initialization of Turbine was attempted!");
                 return;
             }
             // executing init will trigger some static initializers, so we have
             // only one chance.
             firstInit = false;
 
             try
             {
                 ServletContext context = config.getServletContext();
 
                 configure(config, context);
 
                 TemplateService templateService = TurbineTemplate.getService();
                 if (templateService == null)
                 {
                     throw new TurbineException(
                             "No Template Service configured!");
                 }
 
                 if (getRunDataService() == null)
                 {
                     throw new TurbineException(
                             "No RunData Service configured!");
                 }
 
             }
             catch (Exception e)
             {
                 // save the exception to complain loudly later :-)
                 initFailure = e;
                 log.fatal("Turbine: init() failed: ", e);
                 throw new ServletException("Turbine: init() failed", e);
             }
 
             log.info("Turbine: init() Ready to Rumble!");
         }
     }
 
     /**
      * Read the master configuration file in, configure logging
      * and start up any early services.
      *
      * @param config The Servlet Configuration supplied by the container
      * @param context The Servlet Context supplied by the container
      *
      * @throws Exception A problem occurred while reading the configuration or performing early startup
      */
 
     protected void configure(ServletConfig config, ServletContext context)
             throws Exception
     {
 
         // Set the application root. This defaults to the webapp
         // context if not otherwise set. This is to allow 2.1 apps
         // to be developed from CVS. This feature will carry over
         // into 3.0.
         applicationRoot = findInitParameter(context, config,
                 TurbineConstants.APPLICATION_ROOT_KEY,
                 TurbineConstants.APPLICATION_ROOT_DEFAULT);
 
         webappRoot = config.getServletContext().getRealPath("/");
         // log.info("Web Application root is " + webappRoot);
         // log.info("Application root is "     + applicationRoot);
 
         if (applicationRoot == null || applicationRoot.equals(TurbineConstants.WEB_CONTEXT))
         {
             applicationRoot = webappRoot;
             // log.info("got empty or 'webContext' Application root. Application root now: " + applicationRoot);
         }
 
         // Set the applicationRoot for this webapp.
         setApplicationRoot(applicationRoot);
 
         // Create any directories that need to be setup for
         // a running Turbine application.
         createRuntimeDirectories(context, config);
 
         //
         // Now we run the Turbine configuration code. There are two ways
         // to configure Turbine:
         //
         // a) By supplying an web.xml init parameter called "configuration"
         //
         // <init-param>
         //   <param-name>configuration</param-name>
         //   <param-value>/WEB-INF/conf/turbine.xml</param-value>
         // </init-param>
         //
         // This loads an XML based configuration file.
         //
         // b) By supplying an web.xml init parameter called "properties"
         //
         // <init-param>
         //   <param-name>properties</param-name>
         //   <param-value>/WEB-INF/conf/TurbineResources.properties</param-value>
         // </init-param>
         //
         // This loads a Properties based configuration file. Actually, these are
         // extended properties as provided by commons-configuration
         //
         // If neither a) nor b) is supplied, Turbine will fall back to the
         // known behaviour of loading a properties file called
         // /WEB-INF/conf/TurbineResources.properties relative to the
         // web application root.
 
         String confStyle = "unset";
         String confPath= null;
         // first test
         String confFile= findInitParameter(context, config,
                 TurbineConfig.CONFIGURATION_PATH_KEY,
                 null);
         if (StringUtils.isNotEmpty(confFile))
         {
             confStyle = "XML";
         } else // // second test
         {
             confFile = findInitParameter(context, config,
                     TurbineConfig.PROPERTIES_PATH_KEY,
                                          null);
             if (StringUtils.isNotEmpty((confFile)) )
             {
                 confStyle = "Properties";
             }
         }
         // more tests ..
         // last test
         if (confStyle.equals( "unset" ))
         {  // last resort
              confFile = findInitParameter(context, config,
                     TurbineConfig.PROPERTIES_PATH_KEY,
                     TurbineConfig.PROPERTIES_PATH_DEFAULT);
              confStyle = "Properties";
         }
         // now begin loading
         if (!confStyle.equals( "unset" ))
         {
              if (confStyle.equals( "XML" )) {
                  if (confFile.startsWith( "/" ))
                  {
                      confFile = confFile.substring( 1 ); // cft. RFC2396 should not start with a slash, if not absolute path
                  }
                  DefaultConfigurationBuilder configurationBuilder = new DefaultConfigurationBuilder(confFile);
                  confPath = new File(applicationRoot).toURI().toString();// relative base path used for this and child configuration files
                  configurationBuilder.setBasePath(confPath);
                  configuration = configurationBuilder.getConfiguration();
              } else {
                  confPath = getRealPath(confFile);
                  //configurationBuilder.setBasePath(getRealPath(getApplicationRoot()));
                  configuration = new PropertiesConfiguration(confPath);
              }
         }
         //
         // Set up logging as soon as possible
         //
         configureLogging();
 
         // Now report our successful configuration to the world
         log.info("Loaded configuration (" + confStyle + ") from " + confFile + " (" + confPath + ") style: "+ configuration.toString());
 
         setTurbineServletConfig(config);
         setTurbineServletContext(context);
 
         getServiceManager().setApplicationRoot(applicationRoot);
 
         // We want to set a few values in the configuration so
         // that ${variable} interpolation will work for
         //
         // ${applicationRoot}
         // ${webappRoot}
         configuration.setProperty(TurbineConstants.APPLICATION_ROOT_KEY, applicationRoot);
         configuration.setProperty(TurbineConstants.WEBAPP_ROOT_KEY, webappRoot);
 
         // Get the default input encoding
         inputEncoding = configuration.getString(
                 TurbineConstants.PARAMETER_ENCODING_KEY,
                 TurbineConstants.PARAMETER_ENCODING_DEFAULT);
 
         if (log.isDebugEnabled())
         {
             log.debug("Input Encoding has been set to " + inputEncoding);
         }
 
         getServiceManager().setConfiguration(configuration);
 
         // Initialize the service manager. Services
         // that have its 'earlyInit' property set to
         // a value of 'true' will be started when
         // the service manager is initialized.
         getServiceManager().init();
 
         // Retrieve the pipeline class and then initialize it.  The pipeline
         // handles the processing of a webrequest/response cycle.
 
 	    String descriptorPath =
 		  	configuration.getString(
 			  "pipeline.default.descriptor",
 					  TurbinePipeline.CLASSIC_PIPELINE);
 
         descriptorPath = getRealPath(descriptorPath);
 
   		log.debug("Using descriptor path: " + descriptorPath);
         Reader reader = new BufferedReader(new FileReader(descriptorPath));
         XStream pipelineMapper = new XStream(new StaxDriver()); // does not require XPP3 library
         pipeline = (Pipeline) pipelineMapper.fromXML(reader);
 
 	  	log.debug("Initializing pipeline");
 
 	  	pipeline.initialize();
     }
 
     /**
      * Configure the logging facilities of Turbine
      *
      * @throws IOException if the configuration file handling fails.
      */
     protected void configureLogging() throws IOException
     {
         String log4jFile = configuration.getString(TurbineConstants.LOG4J_CONFIG_FILE,
                 TurbineConstants.LOG4J_CONFIG_FILE_DEFAULT);
 
         if (StringUtils.isNotEmpty(log4jFile) &&
                 !log4jFile.equalsIgnoreCase("none"))
         {
             log4jFile = getRealPath(log4jFile);
             boolean success = false;
 
             if (log4jFile.endsWith(".xml"))
             {
                 // load XML type configuration
                 // NOTE: Only system property expansion available
                 try
                 {
                     DOMConfigurator.configure(log4jFile);
                     success = true;
                 }
                 catch (FactoryConfigurationError e)
                 {
                     System.err.println("Could not configure Log4J from configuration file "
                             + log4jFile + ": ");
                     e.printStackTrace();
                 }
             }
             else
             {
                 //
                 // Load the config file above into a Properties object and
                 // fix up the Application root
                 //
                 Properties p = new Properties();
                 FileInputStream fis = null;
 
                 try
                 {
                     fis = new FileInputStream(log4jFile);
                     p.load(fis);
                     p.setProperty(TurbineConstants.APPLICATION_ROOT_KEY, getApplicationRoot());
                     PropertyConfigurator.configure(p);
                     success = true;
                 }
                 catch (FileNotFoundException fnf)
                 {
                     System.err.println("Could not open Log4J configuration file "
                             + log4jFile + ": ");
                     fnf.printStackTrace();
                 }
                 finally
                 {
                     if (fis != null)
                     {
                         fis.close();
                     }
                 }
             }
 
             if (success)
             {
                 // Rebuild our log object with a configured commons-logging
                 log = LogFactory.getLog(this.getClass());
                 log.info("Configured log4j from " + log4jFile);
             }
         }
     }
     /**
      * Create any directories that might be needed during
      * runtime. Right now this includes:
      *
      * <ul>
      *
      * <li>The directory to write the log files to (relative to the
      * web application root), or <code>null</code> for the default of
      * <code>/logs</code>.  The directory is specified via the {@link
      * TurbineConstants#LOGGING_ROOT_KEY} parameter.</li>
      *
      * </ul>
      *
      * @param context Global initialization parameters.
      * @param config Initialization parameters specific to the Turbine
      * servlet.
      */
     protected void createRuntimeDirectories(ServletContext context,
                                                  ServletConfig config)
     {
         String path = findInitParameter(context, config,
                                         TurbineConstants.LOGGING_ROOT_KEY,
                                         TurbineConstants.LOGGING_ROOT_DEFAULT);
 
         File logDir = new File(getRealPath(path));
         if (!logDir.exists())
         {
             // Create the logging directory
             if (!logDir.mkdirs())
             {
                 System.err.println("Cannot create directory for logs!");
             }
         }
     }
 
     /**
      * Finds the specified servlet configuration/initialization
      * parameter, looking first for a servlet-specific parameter, then
      * for a global parameter, and using the provided default if not
      * found.
      */
     protected String findInitParameter(ServletContext context,
             ServletConfig config, String name, String defaultValue)
     {
         String path = null;
 
         // Try the name as provided first.
         boolean usingNamespace = name.startsWith(TurbineConstants.CONFIG_NAMESPACE);
         while (true)
         {
             path = config.getInitParameter(name);
             if (StringUtils.isEmpty(path))
             {
                 path = context.getInitParameter(name);
                 if (StringUtils.isEmpty(path))
                 {
                     // The named parameter didn't yield a value.
                     if (usingNamespace)
                     {
                         path = defaultValue;
                     }
                     else
                     {
                         // Try again using Turbine's namespace.
                         name = TurbineConstants.CONFIG_NAMESPACE + '.' + name;
                         usingNamespace = true;
                         continue;
                     }
                 }
             }
             break;
         }
 
         return path;
     }
 
     /**
      * Initializes the services which need <code>PipelineData</code> to
      * initialize themselves (post startup).
      *
      * @param data The first <code>GET</code> request.
      */
     public void init(PipelineData data)
     {
         synchronized (Turbine.class)
         {
             if (firstDoGet)
             {
                 // All we want to do here is save some servlet
                 // information so that services and processes
                 // that don't have direct access to a RunData
                 // object can still know something about
                 // the servlet environment.
                 saveServletInfo(data);
 
                 // Initialize services with the PipelineData instance
                 TurbineServices services = (TurbineServices)TurbineServices.getInstance();
 
                 for (Iterator<String> i = services.getServiceNames(); i.hasNext();)
                 {
                 	String serviceName = i.next();
                 	Object service = services.getService(serviceName);
 
                 	if (service instanceof Initable)
                 	{
                 		try
                 		{
 							((Initable)service).init(data);
 						}
                 		catch (InitializationException e)
                 		{
                 			log.warn("Could not initialize Initable " + serviceName + " with PipelineData", e);
 						}
                 	}
                 }
 
                 // Mark that we're done.
                 firstDoGet = false;
                 log.info("Turbine: first Request successful");
             }
         }
     }
 
     /**
      * Return the current configuration with all keys included
      *
      * @return a Configuration Object
      */
     public static Configuration getConfiguration()
     {
         return configuration;
     }
 
     /**
      * Return the server name.
      *
      * @return String server name
      */
     public static String getServerName()
     {
         return getDefaultServerData().getServerName();
     }
 
     /**
      * Return the server scheme.
      *
      * @return String server scheme
      */
     public static String getServerScheme()
     {
         return getDefaultServerData().getServerScheme();
     }
 
     /**
      * Return the server port.
      *
      * @return String server port
      */
     public static String getServerPort()
     {
         return Integer.toString(getDefaultServerData().getServerPort());
     }
 
     /**
      * Get the script name. This is the initial script name.
      * Actually this is probably not needed any more. I'll
      * check. jvz.
      *
      * @return String initial script name.
      */
     public static String getScriptName()
     {
         return getDefaultServerData().getScriptName();
     }
 
     /**
      * Return the context path.
      *
      * @return String context path
      */
     public static String getContextPath()
     {
         return getDefaultServerData().getContextPath();
     }
 
     /**
      * Return all the Turbine Servlet information (Server Name, Port,
      * Scheme in a ServerData structure. This is generated from the
      * values set when initializing the Turbine and may not be correct
      * if you're running in a clustered structure. You can provide default
      * values in your configuration for cases where access is requied before
      * your application is first accessed by a user.  This might be used
      * if you need a DataURI and have no RunData object handy.
      *
      * @return An initialized ServerData object
      */
     public static ServerData getDefaultServerData()
     {
         if (serverData == null)
         {
             String serverName
                     = configuration.getString(TurbineConstants.DEFAULT_SERVER_NAME_KEY);
             if (serverName == null)
             {
                 log.error("ServerData Information requested from Turbine before first request!");
             }
             else
             {
                 log.info("ServerData Information retrieved from configuration.");
             }
             // Will be overwritten once the first request is run;
             serverData = new ServerData(serverName,
                     configuration.getInt(TurbineConstants.DEFAULT_SERVER_PORT_KEY,
                             URIConstants.HTTP_PORT),
                     configuration.getString(TurbineConstants.DEFAULT_SERVER_SCHEME_KEY,
                             URIConstants.HTTP),
                     configuration.getString(TurbineConstants.DEFAULT_SCRIPT_NAME_KEY),
                     configuration.getString(TurbineConstants.DEFAULT_CONTEXT_PATH_KEY));
         }
         return serverData;
     }
 
     /**
      * Set the servlet config for this turbine webapp.
      *
      * @param config New servlet config
      */
     public static void setTurbineServletConfig(ServletConfig config)
     {
         servletConfig = config;
     }
 
     /**
      * Get the servlet config for this turbine webapp.
      *
      * @return ServletConfig
      */
     public static ServletConfig getTurbineServletConfig()
     {
         return servletConfig;
     }
 
     /**
      * Set the servlet context for this turbine webapp.
      *
      * @param context New servlet context.
      */
     public static void setTurbineServletContext(ServletContext context)
     {
         servletContext = context;
     }
 
     /**
      * Get the servlet context for this turbine webapp.
      *
      * @return ServletContext
      */
     public static ServletContext getTurbineServletContext()
     {
         return servletContext;
     }
 
     /**
      * The <code>Servlet</code> destroy method.  Invokes
      * <code>ServiceBroker</code> tear down method.
      */
     @Override
     public void destroy()
     {
         // Shut down all Turbine Services.
         getServiceManager().shutdownServices();
 
         firstInit = true;
         firstDoGet = true;
         log.info("Turbine: Done shutting down!");
     }
 
     /**
      * The primary method invoked when the Turbine servlet is executed.
      *
      * @param req Servlet request.
      * @param res Servlet response.
      * @exception IOException a servlet exception.
      * @exception ServletException a servlet exception.
      */
     @Override
     public void doGet(HttpServletRequest req, HttpServletResponse res)
             throws IOException, ServletException
     {
         PipelineData pipelineData = null;
 
         try
         {
             // Check to make sure that we started up properly.
             if (initFailure != null)
             {
                 throw initFailure;
             }
 
             //
             // If the servlet container gives us no clear indication about the
             // Encoding of the contents, set it to our default value.
             if (req.getCharacterEncoding() == null)
             {
                 if (log.isDebugEnabled())
                 {
                     log.debug("Changing Input Encoding to " + inputEncoding);
                 }
 
                 try
                 {
                     req.setCharacterEncoding(inputEncoding);
                 }
                 catch (UnsupportedEncodingException uee)
                 {
                     log.warn("Could not change request encoding to " + inputEncoding, uee);
                 }
             }
 
             // Get general RunData here...
             // Perform turbine specific initialization below.
             pipelineData = getRunDataService().getRunData(req, res, getServletConfig());
             Map<Class<?>, Object> runDataMap = new HashMap<Class<?>, Object>();
             runDataMap.put(RunData.class, pipelineData);
             // put the data into the pipeline
             pipelineData.put(RunData.class, runDataMap);
 
             // If this is the first invocation, perform some
             // initialization.  Certain services need RunData to initialize
             // themselves.
             if (firstDoGet)
             {
                 init(pipelineData);
             }
 
             // Stages of Pipeline implementation execution
 			// configurable via attached Valve implementations in a
 			// XML properties file.
 			pipeline.invoke(pipelineData);
 
         }
         catch (Exception e)
         {
             handleException(pipelineData, res, e);
         }
         catch (Throwable t)
         {
             handleException(pipelineData, res, t);
         }
         finally
         {
             // Return the used RunData to the factory for recycling.
             getRunDataService().putRunData((RunData)pipelineData);
         }
     }
 
     /**
      * In this application doGet and doPost are the same thing.
      *
      * @param req Servlet request.
      * @param res Servlet response.
      * @exception IOException a servlet exception.
      * @exception ServletException a servlet exception.
      */
     @Override
     public void doPost(HttpServletRequest req, HttpServletResponse res)
             throws IOException, ServletException
     {
         doGet(req, res);
     }
 
     /**
      * Return the servlet info.
      *
      * @return a string with the servlet information.
      */
     @Override
     public String getServletInfo()
     {
         return "Turbine Servlet";
     }
 
     /**
      * This method is about making sure that we catch and display
      * errors to the screen in one fashion or another. What happens is
      * that it will attempt to show the error using your user defined
      * Error Screen. If that fails, then it will resort to just
      * displaying the error and logging it all over the place
      * including the servlet engine log file, the Turbine log file and
      * on the screen.
      *
      * @param pipelineData A Turbine PipelineData object.
      * @param res Servlet response.
      * @param t The exception to report.
      */
     protected void handleException(PipelineData pipelineData, HttpServletResponse res,
                                        Throwable t)
     {
         RunData data = getRunData(pipelineData);
         // make sure that the stack trace makes it the log
         log.error("Turbine.handleException: ", t);
 
         String mimeType = "text/plain";
         try
         {
             // This is where we capture all exceptions and show the
             // Error Screen.
             data.setStackTrace(ExceptionUtils.getStackTrace(t), t);
 
             // setup the screen
             data.setScreen(configuration.getString(
                     TurbineConstants.SCREEN_ERROR_KEY,
                     TurbineConstants.SCREEN_ERROR_DEFAULT));
 
             // do more screen setup for template execution if needed
             if (data.getTemplateInfo() != null)
             {
                 data.getTemplateInfo()
                     .setScreenTemplate(configuration.getString(
                             TurbineConstants.TEMPLATE_ERROR_KEY,
                             TurbineConstants.TEMPLATE_ERROR_VM));
             }
 
             // Make sure to not execute an action.
             data.setAction("");
 
             PageLoader.getInstance().exec(pipelineData,
                     configuration.getString(TurbineConstants.PAGE_DEFAULT_KEY,
                             TurbineConstants.PAGE_DEFAULT_DEFAULT));
 
             data.getResponse().setContentType(data.getContentType());
             data.getResponse().setStatus(data.getStatusCode());
         }
         // Catch this one because it occurs if some code hasn't been
         // completely re-compiled after a change..
         catch (java.lang.NoSuchFieldError e)
         {
             try
             {
                 data.getResponse().setContentType(mimeType);
                 data.getResponse().setStatus(200);
             }
             catch (Exception ignored)
             {
                 // ignore
             }
 
             try
             {
 				data.getResponse().getWriter().print("java.lang.NoSuchFieldError: "
                         + "Please recompile all of your source code.");
             }
             catch (IOException ignored)
             {
                 // ignore
             }
 
             log.error(data.getStackTrace(), e);
         }
         // Attempt to do *something* at this point...
         catch (Throwable reallyScrewedNow)
         {
             StringBuilder msg = new StringBuilder();
             msg.append("Horrible Exception: ");
             if (data != null)
             {
                 msg.append(data.getStackTrace());
             }
             else
             {
                 msg.append(t);
             }
             try
             {
                 res.setContentType(mimeType);
                 res.setStatus(200);
                 res.getWriter().print(msg.toString());
             }
             catch (Exception ignored)
             {
                 // ignore
             }
 
             log.error(reallyScrewedNow.getMessage(), reallyScrewedNow);
         }
     }
 
     /**
      * Save some information about this servlet so that
      * it can be utilized by object instances that do not
      * have direct access to PipelineData.
      *
      * @param data Turbine request data
      */
     public static synchronized void saveServletInfo(PipelineData data)
     {
         // Store the context path for tools like ContentURI and
         // the UIManager that use webapp context path information
         // for constructing URLs.
 
         //
         // Bundle all the information above up into a convenient structure
         //
         ServerData requestServerData = data.get(Turbine.class, ServerData.class);
         serverData = (ServerData) requestServerData.clone();
     }
 
     /**
      * Set the application root for the webapp.
      *
      * @param val New app root.
      */
     public static void setApplicationRoot(String val)
     {
         applicationRoot = val;
     }
 
     /**
      * Get the application root for this Turbine webapp. This
      * concept was started in 3.0 and will allow an app to be
      * developed from a standard CVS layout. With a simple
      * switch the app will work fully within the servlet
      * container for deployment.
      *
      * @return String applicationRoot
      */
     public static String getApplicationRoot()
     {
         return applicationRoot;
     }
 
     /**
      * Used to get the real path of configuration and resource
      * information. This can be used by an app being
      * developed in a standard CVS layout.
      *
      * @param path path translated to the application root
      * @return the real path
      */
     public static String getRealPath(String path)
     {
         if (path.startsWith("/"))
         {
             return new File(getApplicationRoot(), path.substring(1)).getAbsolutePath();
         }
 
         return new File(getApplicationRoot(), path).getAbsolutePath();
     }
 
     /**
      * Return an instance of the currently configured Service Manager
      *
      * @return A service Manager instance
      */
     private ServiceManager getServiceManager()
     {
         return TurbineServices.getInstance();
     }
 
     /**
      * Get a RunData from the pipelineData. Once RunData is fully replaced
      * by PipelineData this should not be required.
      * @param pipelineData
      * @return
      */
     private RunData getRunData(PipelineData pipelineData)
     {
         RunData data = null;
         data = (RunData)pipelineData;
         return data;
     }
 
 
     /**
      * Returns the default input encoding for the servlet.
      *
      * @return the default input encoding.
      */
     public String getDefaultInputEncoding()
     {
         return inputEncoding;
     }
 
     /**
      * Static Helper method for looking up the RunDataService
      * @return A RunDataService
      */
     private RunDataService getRunDataService()
     {
         return (RunDataService) TurbineServices
             .getInstance().getService(RunDataService.SERVICE_NAME);
     }
 }