trunk/core/src/main/java/org/apache/struts2/views/freemarker/FreemarkerManager.java - struts - Git at Google

 /*
  * $Id$
  *
  * Copyright 2006 The Apache Software Foundation.
  *
  * Licensed 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.
  */
 package org.apache.struts2.views.freemarker;

 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Map;
 import java.util.Properties;

 import javax.servlet.GenericServlet;
 import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpSession;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.struts2.StrutsConstants;
 import org.apache.struts2.config.Settings;
 import org.apache.struts2.views.JspSupportServlet;
 import org.apache.struts2.views.freemarker.tags.StrutsModels;
 import org.apache.struts2.views.util.ContextUtil;

 import com.opensymphony.xwork2.util.FileManager;
 import com.opensymphony.xwork2.ObjectFactory;
 import com.opensymphony.xwork2.util.OgnlValueStack;

 import freemarker.cache.FileTemplateLoader;
 import freemarker.cache.MultiTemplateLoader;
 import freemarker.cache.TemplateLoader;
 import freemarker.cache.WebappTemplateLoader;
 import freemarker.ext.beans.BeansWrapper;
 import freemarker.ext.jsp.TaglibFactory;
 import freemarker.ext.servlet.HttpRequestHashModel;
 import freemarker.ext.servlet.HttpRequestParametersHashModel;
 import freemarker.ext.servlet.HttpSessionHashModel;
 import freemarker.ext.servlet.ServletContextHashModel;
 import freemarker.template.ObjectWrapper;
 import freemarker.template.SimpleHash;
 import freemarker.template.TemplateException;
 import freemarker.template.TemplateExceptionHandler;
 import freemarker.template.TemplateModel;


 /**
  * Static Configuration Manager for the FreemarkerResult's configuration
  *
  * <p/>
  *
  * Possible extension points are :-
  * <ul>
  *   <li>createConfiguration method</li>
  *   <li>loadSettings method</li>
  *   <li>getTemplateLoader method</li>
  *   <li>populateContext method</li>
  * </ul>
  *
  * <p/>
  * <b> createConfiguration method </b><br/>
  * Create a freemarker Configuration.
  * <p/>
  *
  * <b> loadSettings method </b><br/>
  * Load freemarker settings, default to freemarker.properties (if found in classpath)
  * <p/>
  *
  * <b> getTemplateLoader method</b><br/>
  * create a freemarker TemplateLoader that loads freemarker template in the following order :-
  * <ol>
  *   <li>path defined in ServletContext init parameter named 'templatePath' or 'TemplatePath' (must be an absolute path)</li>
  *   <li>webapp classpath</li>
  *   <li>struts's static folder (under [STRUT2_SOURCE]/org/apache/struts2/static/</li>
  * </ol>
  * <p/>
  *
  * <b> populateContext method</b><br/>
  * populate the created model.
  *
  */
 public class FreemarkerManager {

     private static final Log log = LogFactory.getLog(FreemarkerManager.class);
     public static final String CONFIG_SERVLET_CONTEXT_KEY = "freemarker.Configuration";
     public static final String KEY_EXCEPTION = "exception";

     // coppied from freemarker servlet - since they are private
     private static final String ATTR_APPLICATION_MODEL = ".freemarker.Application";
     private static final String ATTR_JSP_TAGLIBS_MODEL = ".freemarker.JspTaglibs";
     private static final String ATTR_REQUEST_MODEL = ".freemarker.Request";
     private static final String ATTR_REQUEST_PARAMETERS_MODEL = ".freemarker.RequestParameters";

     // coppied from freemarker servlet - so that there is no dependency on it
     public static final String KEY_APPLICATION = "Application";
     public static final String KEY_REQUEST_MODEL = "Request";
     public static final String KEY_SESSION_MODEL = "Session";
     public static final String KEY_JSP_TAGLIBS = "JspTaglibs";
     public static final String KEY_REQUEST_PARAMETER_MODEL = "Parameters";
     private static FreemarkerManager instance = null;


     /**
      * To allow for custom configuration of freemarker, sublcass this class "ConfigManager" and
      * set the Struts configuration property
      * <b>struts.freemarker.configmanager.classname</b> to the fully qualified classname.
      * <p/>
      * This allows you to override the protected methods in the ConfigMangaer
      * to programatically create your own Configuration instance
      */
     public final static synchronized FreemarkerManager getInstance() {
         if (instance == null) {
             String classname = FreemarkerManager.class.getName();

             if (Settings.isSet(StrutsConstants.STRUTS_FREEMARKER_MANAGER_CLASSNAME)) {
                 classname = Settings.get(StrutsConstants.STRUTS_FREEMARKER_MANAGER_CLASSNAME).trim();
             }

             try {
                 log.info("Instantiating Freemarker ConfigManager!, " + classname);
                 // singleton instances shouldn't be built accessing request or session-specific context data
                 instance = (FreemarkerManager) ObjectFactory.getObjectFactory().buildBean(classname, null);
             } catch (Exception e) {
                 log.fatal("Fatal exception occurred while trying to instantiate a Freemarker ConfigManager instance, " + classname, e);
             }
         }

         // if the instance creation failed, make sure there is a default instance
         if (instance == null) {
             instance = new FreemarkerManager();
         }

         return instance;
     }

     public final synchronized freemarker.template.Configuration getConfiguration(ServletContext servletContext) throws TemplateException {
         freemarker.template.Configuration config = (freemarker.template.Configuration) servletContext.getAttribute(CONFIG_SERVLET_CONTEXT_KEY);

         if (config == null) {
             config = createConfiguration(servletContext);

             // store this configuration in the servlet context
             servletContext.setAttribute(CONFIG_SERVLET_CONTEXT_KEY, config);
         }

         config.setWhitespaceStripping(true);

         return config;
     }

     protected ScopesHashModel buildScopesHashModel(ServletContext servletContext, HttpServletRequest request, HttpServletResponse response, ObjectWrapper wrapper, OgnlValueStack stack) {
         ScopesHashModel model = new ScopesHashModel(wrapper, servletContext, request, stack);

         // Create hash model wrapper for servlet context (the application)
         // only need one thread to do this once, per servlet context
         synchronized (servletContext) {
             ServletContextHashModel servletContextModel = (ServletContextHashModel) servletContext.getAttribute(ATTR_APPLICATION_MODEL);

             if (servletContextModel == null) {

                 GenericServlet servlet = JspSupportServlet.jspSupportServlet;
                 // TODO if the jsp support  servlet isn't load-on-startup then it won't exist
                 // if it hasn't been accessed, and a JSP page is accessed
                 if (servlet != null) {
                     servletContextModel = new ServletContextHashModel(servlet, wrapper);
                     servletContext.setAttribute(ATTR_APPLICATION_MODEL, servletContextModel);
                     TaglibFactory taglibs = new TaglibFactory(servletContext);
                     servletContext.setAttribute(ATTR_JSP_TAGLIBS_MODEL, taglibs);
                 }

             }

             model.put(KEY_APPLICATION, servletContextModel);
             model.put(KEY_JSP_TAGLIBS, (TemplateModel) servletContext.getAttribute(ATTR_JSP_TAGLIBS_MODEL));
         }

         // Create hash model wrapper for session
         HttpSession session = request.getSession(false);
         if (session != null) {
             model.put(KEY_SESSION_MODEL, new HttpSessionHashModel(session, wrapper));
         } else {
             // no session means no attributes ???
             //            model.put(KEY_SESSION_MODEL, new SimpleHash());
         }

         // Create hash model wrapper for the request attributes
         HttpRequestHashModel requestModel = (HttpRequestHashModel) request.getAttribute(ATTR_REQUEST_MODEL);

         if ((requestModel == null) || (requestModel.getRequest() != request)) {
             requestModel = new HttpRequestHashModel(request, response, wrapper);
             request.setAttribute(ATTR_REQUEST_MODEL, requestModel);
         }

         model.put(KEY_REQUEST_MODEL, requestModel);


         // Create hash model wrapper for request parameters
         HttpRequestParametersHashModel reqParametersModel = (HttpRequestParametersHashModel) request.getAttribute(ATTR_REQUEST_PARAMETERS_MODEL);
         if (reqParametersModel == null || requestModel.getRequest() != request) {
         	reqParametersModel = new HttpRequestParametersHashModel(request);
         	request.setAttribute(ATTR_REQUEST_PARAMETERS_MODEL, reqParametersModel);
         }
         model.put(KEY_REQUEST_PARAMETER_MODEL, reqParametersModel);

         return model;
     }

     protected void populateContext(ScopesHashModel model, OgnlValueStack stack, Object action, HttpServletRequest request, HttpServletResponse response) {
         // put the same objects into the context that the velocity result uses
         Map standard = ContextUtil.getStandardContext(stack, request, response);
         model.putAll(standard);

         // support for JSP exception pages, exposing the servlet or JSP exception
         Throwable exception = (Throwable) request.getAttribute("javax.servlet.error.exception");

         if (exception == null) {
             exception = (Throwable) request.getAttribute("javax.servlet.error.JspException");
         }

         if (exception != null) {
             model.put(KEY_EXCEPTION, exception);
         }
     }

     protected BeansWrapper getObjectWrapper() {
         return new StrutsBeanWrapper();
     }

     /**
      * The default template loader is a MultiTemplateLoader which includes
      * a ClassTemplateLoader and a WebappTemplateLoader (and a FileTemplateLoader depending on
      * the init-parameter 'TemplatePath').
      * <p/>
      * The ClassTemplateLoader will resolve fully qualified template includes
      * that begin with a slash. for example /com/company/template/common.ftl
      * <p/>
      * The WebappTemplateLoader attempts to resolve templates relative to the web root folder
      */
     protected TemplateLoader getTemplateLoader(ServletContext servletContext) {
         // construct a FileTemplateLoader for the init-param 'TemplatePath'
         FileTemplateLoader templatePathLoader = null;

         String templatePath = servletContext.getInitParameter("TemplatePath");
         if (templatePath == null) {
             templatePath = servletContext.getInitParameter("templatePath");
         }

         if (templatePath != null) {
             try {
                 templatePathLoader = new FileTemplateLoader(new File(templatePath));
             } catch (IOException e) {
                 log.error("Invalid template path specified: " + e.getMessage(), e);
             }
         }

         // presume that most apps will require the class and webapp template loader
         // if people wish to
         return templatePathLoader != null ?
                 new MultiTemplateLoader(new TemplateLoader[]{
                         templatePathLoader,
                         new WebappTemplateLoader(servletContext),
                         new StrutsClassTemplateLoader()
                 })
                 : new MultiTemplateLoader(new TemplateLoader[]{
                 new WebappTemplateLoader(servletContext),
                 new StrutsClassTemplateLoader()
         });
     }

     /**
      * Create the instance of the freemarker Configuration object.
      * <p/>
      * this implementation
      * <ul>
      * <li>obtains the default configuration from Configuration.getDefaultConfiguration()
      * <li>sets up template loading from a ClassTemplateLoader and a WebappTemplateLoader
      * <li>sets up the object wrapper to be the BeansWrapper
      * <li>loads settings from the classpath file /freemarker.properties
      * </ul>
      *
      * @param servletContext
      */
     protected freemarker.template.Configuration createConfiguration(ServletContext servletContext) throws TemplateException {
     	freemarker.template.Configuration configuration = new freemarker.template.Configuration();

         configuration.setTemplateLoader(getTemplateLoader(servletContext));

         configuration.setTemplateExceptionHandler(TemplateExceptionHandler.HTML_DEBUG_HANDLER);

         configuration.setObjectWrapper(getObjectWrapper());

         if (Settings.isSet(StrutsConstants.STRUTS_I18N_ENCODING)) {
         	configuration.setDefaultEncoding(Settings.get(StrutsConstants.STRUTS_I18N_ENCODING));
         }

         loadSettings(servletContext, configuration);

         return configuration;
     }

     /**
      * Load the settings from the /freemarker.properties file on the classpath
      *
      * @see freemarker.template.Configuration#setSettings for the definition of valid settings
      */
     protected void loadSettings(ServletContext servletContext, freemarker.template.Configuration configuration) {
         try {
             InputStream in = FileManager.loadFile("freemarker.properties", FreemarkerManager.class);

             if (in != null) {
                 Properties p = new Properties();
                 p.load(in);
                 configuration.setSettings(p);
             }
         } catch (IOException e) {
             log.error("Error while loading freemarker settings from /freemarker.properties", e);
         } catch (TemplateException e) {
             log.error("Error while loading freemarker settings from /freemarker.properties", e);
         }
     }

     public SimpleHash buildTemplateModel(OgnlValueStack stack, Object action, ServletContext servletContext, HttpServletRequest request, HttpServletResponse response, ObjectWrapper wrapper) {
         ScopesHashModel model = buildScopesHashModel(servletContext, request, response, wrapper, stack);
         populateContext(model, stack, action, request, response);
         model.put("s", new StrutsModels(stack, request, response));
         return model;
     }
 }
	/*
	* $Id$
	*
	* Copyright 2006 The Apache Software Foundation.
	*
	* Licensed 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.
	*/
	package org.apache.struts2.views.freemarker;

	import java.io.File;
	import java.io.IOException;
	import java.io.InputStream;
	import java.util.Map;
	import java.util.Properties;

	import javax.servlet.GenericServlet;
	import javax.servlet.ServletContext;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;
	import javax.servlet.http.HttpSession;

	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;
	import org.apache.struts2.StrutsConstants;
	import org.apache.struts2.config.Settings;
	import org.apache.struts2.views.JspSupportServlet;
	import org.apache.struts2.views.freemarker.tags.StrutsModels;
	import org.apache.struts2.views.util.ContextUtil;

	import com.opensymphony.xwork2.util.FileManager;
	import com.opensymphony.xwork2.ObjectFactory;
	import com.opensymphony.xwork2.util.OgnlValueStack;

	import freemarker.cache.FileTemplateLoader;
	import freemarker.cache.MultiTemplateLoader;
	import freemarker.cache.TemplateLoader;
	import freemarker.cache.WebappTemplateLoader;
	import freemarker.ext.beans.BeansWrapper;
	import freemarker.ext.jsp.TaglibFactory;
	import freemarker.ext.servlet.HttpRequestHashModel;
	import freemarker.ext.servlet.HttpRequestParametersHashModel;
	import freemarker.ext.servlet.HttpSessionHashModel;
	import freemarker.ext.servlet.ServletContextHashModel;
	import freemarker.template.ObjectWrapper;
	import freemarker.template.SimpleHash;
	import freemarker.template.TemplateException;
	import freemarker.template.TemplateExceptionHandler;
	import freemarker.template.TemplateModel;


	/**
	* Static Configuration Manager for the FreemarkerResult's configuration
	*
	* <p/>
	*
	* Possible extension points are :-
	* <ul>
	* <li>createConfiguration method</li>
	* <li>loadSettings method</li>
	* <li>getTemplateLoader method</li>
	* <li>populateContext method</li>
	* </ul>
	*
	* <p/>
	* <b> createConfiguration method </b><br/>
	* Create a freemarker Configuration.
	* <p/>
	*
	* <b> loadSettings method </b><br/>
	* Load freemarker settings, default to freemarker.properties (if found in classpath)
	* <p/>
	*
	* <b> getTemplateLoader method</b><br/>
	* create a freemarker TemplateLoader that loads freemarker template in the following order :-
	* <ol>
	* <li>path defined in ServletContext init parameter named 'templatePath' or 'TemplatePath' (must be an absolute path)</li>
	* <li>webapp classpath</li>
	* <li>struts's static folder (under [STRUT2_SOURCE]/org/apache/struts2/static/</li>
	* </ol>
	* <p/>
	*
	* <b> populateContext method</b><br/>
	* populate the created model.
	*
	*/
	public class FreemarkerManager {

	private static final Log log = LogFactory.getLog(FreemarkerManager.class);
	public static final String CONFIG_SERVLET_CONTEXT_KEY = "freemarker.Configuration";
	public static final String KEY_EXCEPTION = "exception";

	// coppied from freemarker servlet - since they are private
	private static final String ATTR_APPLICATION_MODEL = ".freemarker.Application";
	private static final String ATTR_JSP_TAGLIBS_MODEL = ".freemarker.JspTaglibs";
	private static final String ATTR_REQUEST_MODEL = ".freemarker.Request";
	private static final String ATTR_REQUEST_PARAMETERS_MODEL = ".freemarker.RequestParameters";

	// coppied from freemarker servlet - so that there is no dependency on it
	public static final String KEY_APPLICATION = "Application";
	public static final String KEY_REQUEST_MODEL = "Request";
	public static final String KEY_SESSION_MODEL = "Session";
	public static final String KEY_JSP_TAGLIBS = "JspTaglibs";
	public static final String KEY_REQUEST_PARAMETER_MODEL = "Parameters";
	private static FreemarkerManager instance = null;


	/**
	* To allow for custom configuration of freemarker, sublcass this class "ConfigManager" and
	* set the Struts configuration property
	* <b>struts.freemarker.configmanager.classname</b> to the fully qualified classname.
	* <p/>
	* This allows you to override the protected methods in the ConfigMangaer
	* to programatically create your own Configuration instance
	*/
	public final static synchronized FreemarkerManager getInstance() {
	if (instance == null) {
	String classname = FreemarkerManager.class.getName();

	if (Settings.isSet(StrutsConstants.STRUTS_FREEMARKER_MANAGER_CLASSNAME)) {
	classname = Settings.get(StrutsConstants.STRUTS_FREEMARKER_MANAGER_CLASSNAME).trim();
	}

	try {
	log.info("Instantiating Freemarker ConfigManager!, " + classname);
	// singleton instances shouldn't be built accessing request or session-specific context data
	instance = (FreemarkerManager) ObjectFactory.getObjectFactory().buildBean(classname, null);
	} catch (Exception e) {
	log.fatal("Fatal exception occurred while trying to instantiate a Freemarker ConfigManager instance, " + classname, e);
	}
	}

	// if the instance creation failed, make sure there is a default instance
	if (instance == null) {
	instance = new FreemarkerManager();
	}

	return instance;
	}

	public final synchronized freemarker.template.Configuration getConfiguration(ServletContext servletContext) throws TemplateException {
	freemarker.template.Configuration config = (freemarker.template.Configuration) servletContext.getAttribute(CONFIG_SERVLET_CONTEXT_KEY);

	if (config == null) {
	config = createConfiguration(servletContext);

	// store this configuration in the servlet context
	servletContext.setAttribute(CONFIG_SERVLET_CONTEXT_KEY, config);
	}

	config.setWhitespaceStripping(true);

	return config;
	}

	protected ScopesHashModel buildScopesHashModel(ServletContext servletContext, HttpServletRequest request, HttpServletResponse response, ObjectWrapper wrapper, OgnlValueStack stack) {
	ScopesHashModel model = new ScopesHashModel(wrapper, servletContext, request, stack);

	// Create hash model wrapper for servlet context (the application)
	// only need one thread to do this once, per servlet context
	synchronized (servletContext) {
	ServletContextHashModel servletContextModel = (ServletContextHashModel) servletContext.getAttribute(ATTR_APPLICATION_MODEL);

	if (servletContextModel == null) {

	GenericServlet servlet = JspSupportServlet.jspSupportServlet;
	// TODO if the jsp support servlet isn't load-on-startup then it won't exist
	// if it hasn't been accessed, and a JSP page is accessed
	if (servlet != null) {
	servletContextModel = new ServletContextHashModel(servlet, wrapper);
	servletContext.setAttribute(ATTR_APPLICATION_MODEL, servletContextModel);
	TaglibFactory taglibs = new TaglibFactory(servletContext);
	servletContext.setAttribute(ATTR_JSP_TAGLIBS_MODEL, taglibs);
	}

	}

	model.put(KEY_APPLICATION, servletContextModel);
	model.put(KEY_JSP_TAGLIBS, (TemplateModel) servletContext.getAttribute(ATTR_JSP_TAGLIBS_MODEL));
	}

	// Create hash model wrapper for session
	HttpSession session = request.getSession(false);
	if (session != null) {
	model.put(KEY_SESSION_MODEL, new HttpSessionHashModel(session, wrapper));
	} else {
	// no session means no attributes ???
	// model.put(KEY_SESSION_MODEL, new SimpleHash());
	}

	// Create hash model wrapper for the request attributes
	HttpRequestHashModel requestModel = (HttpRequestHashModel) request.getAttribute(ATTR_REQUEST_MODEL);

	if ((requestModel == null) \|\| (requestModel.getRequest() != request)) {
	requestModel = new HttpRequestHashModel(request, response, wrapper);
	request.setAttribute(ATTR_REQUEST_MODEL, requestModel);
	}

	model.put(KEY_REQUEST_MODEL, requestModel);


	// Create hash model wrapper for request parameters
	HttpRequestParametersHashModel reqParametersModel = (HttpRequestParametersHashModel) request.getAttribute(ATTR_REQUEST_PARAMETERS_MODEL);
	if (reqParametersModel == null \|\| requestModel.getRequest() != request) {
	reqParametersModel = new HttpRequestParametersHashModel(request);
	request.setAttribute(ATTR_REQUEST_PARAMETERS_MODEL, reqParametersModel);
	}
	model.put(KEY_REQUEST_PARAMETER_MODEL, reqParametersModel);

	return model;
	}

	protected void populateContext(ScopesHashModel model, OgnlValueStack stack, Object action, HttpServletRequest request, HttpServletResponse response) {
	// put the same objects into the context that the velocity result uses
	Map standard = ContextUtil.getStandardContext(stack, request, response);
	model.putAll(standard);

	// support for JSP exception pages, exposing the servlet or JSP exception
	Throwable exception = (Throwable) request.getAttribute("javax.servlet.error.exception");

	if (exception == null) {
	exception = (Throwable) request.getAttribute("javax.servlet.error.JspException");
	}

	if (exception != null) {
	model.put(KEY_EXCEPTION, exception);
	}
	}

	protected BeansWrapper getObjectWrapper() {
	return new StrutsBeanWrapper();
	}

	/**
	* The default template loader is a MultiTemplateLoader which includes
	* a ClassTemplateLoader and a WebappTemplateLoader (and a FileTemplateLoader depending on
	* the init-parameter 'TemplatePath').
	* <p/>
	* The ClassTemplateLoader will resolve fully qualified template includes
	* that begin with a slash. for example /com/company/template/common.ftl
	* <p/>
	* The WebappTemplateLoader attempts to resolve templates relative to the web root folder
	*/
	protected TemplateLoader getTemplateLoader(ServletContext servletContext) {
	// construct a FileTemplateLoader for the init-param 'TemplatePath'
	FileTemplateLoader templatePathLoader = null;

	String templatePath = servletContext.getInitParameter("TemplatePath");
	if (templatePath == null) {
	templatePath = servletContext.getInitParameter("templatePath");
	}

	if (templatePath != null) {
	try {
	templatePathLoader = new FileTemplateLoader(new File(templatePath));
	} catch (IOException e) {
	log.error("Invalid template path specified: " + e.getMessage(), e);
	}
	}

	// presume that most apps will require the class and webapp template loader
	// if people wish to
	return templatePathLoader != null ?
	new MultiTemplateLoader(new TemplateLoader[]{
	templatePathLoader,
	new WebappTemplateLoader(servletContext),
	new StrutsClassTemplateLoader()
	})
	: new MultiTemplateLoader(new TemplateLoader[]{
	new WebappTemplateLoader(servletContext),
	new StrutsClassTemplateLoader()
	});
	}

	/**
	* Create the instance of the freemarker Configuration object.
	* <p/>
	* this implementation
	* <ul>
	* <li>obtains the default configuration from Configuration.getDefaultConfiguration()
	* <li>sets up template loading from a ClassTemplateLoader and a WebappTemplateLoader
	* <li>sets up the object wrapper to be the BeansWrapper
	* <li>loads settings from the classpath file /freemarker.properties
	* </ul>
	*
	* @param servletContext
	*/
	protected freemarker.template.Configuration createConfiguration(ServletContext servletContext) throws TemplateException {
	freemarker.template.Configuration configuration = new freemarker.template.Configuration();

	configuration.setTemplateLoader(getTemplateLoader(servletContext));

	configuration.setTemplateExceptionHandler(TemplateExceptionHandler.HTML_DEBUG_HANDLER);

	configuration.setObjectWrapper(getObjectWrapper());

	if (Settings.isSet(StrutsConstants.STRUTS_I18N_ENCODING)) {
	configuration.setDefaultEncoding(Settings.get(StrutsConstants.STRUTS_I18N_ENCODING));
	}

	loadSettings(servletContext, configuration);

	return configuration;
	}

	/**
	* Load the settings from the /freemarker.properties file on the classpath
	*
	* @see freemarker.template.Configuration#setSettings for the definition of valid settings
	*/
	protected void loadSettings(ServletContext servletContext, freemarker.template.Configuration configuration) {
	try {
	InputStream in = FileManager.loadFile("freemarker.properties", FreemarkerManager.class);

	if (in != null) {
	Properties p = new Properties();
	p.load(in);
	configuration.setSettings(p);
	}
	} catch (IOException e) {
	log.error("Error while loading freemarker settings from /freemarker.properties", e);
	} catch (TemplateException e) {
	log.error("Error while loading freemarker settings from /freemarker.properties", e);
	}
	}

	public SimpleHash buildTemplateModel(OgnlValueStack stack, Object action, ServletContext servletContext, HttpServletRequest request, HttpServletResponse response, ObjectWrapper wrapper) {
	ScopesHashModel model = buildScopesHashModel(servletContext, request, response, wrapper, stack);
	populateContext(model, stack, action, request, response);
	model.put("s", new StrutsModels(stack, request, response));
	return model;
	}
	}