Struts example source code file (PortletFreemarkerResult.java)

This example Struts source code file (PortletFreemarkerResult.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Struts tags/keywords

actioninvocation, actioninvocation, http, httpservletrequest, io, ioexception, ioexception, objectwrapper, portletexception, portletfreemarkerresult, request, response, servlet, string, string, templateexception, templatemodel, templatemodel, templatemodelexception, util

The Struts PortletFreemarkerResult.java source code

/*
 * $Id: PortletFreemarkerResult.java 768802 2009-04-26 21:34:14Z nilsga $
 *
 * 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.
 */

package org.apache.struts2.views.freemarker;

import java.io.IOException;
import java.io.Writer;
import java.util.Locale;

import javax.portlet.ActionResponse;
import javax.portlet.PortletException;
import javax.portlet.PortletRequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.ServletActionContext;
import org.apache.struts2.dispatcher.StrutsResultSupport;
import org.apache.struts2.portlet.PortletActionConstants;
import org.apache.struts2.portlet.context.PortletActionContext;
import org.apache.struts2.views.util.ResourceUtil;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.util.ValueStack;

import freemarker.template.Configuration;
import freemarker.template.ObjectWrapper;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;

/**
 */
public class PortletFreemarkerResult extends StrutsResultSupport implements PortletActionConstants{

    private static final long serialVersionUID = -5570612389289887543L;

    protected ActionInvocation invocation;

    protected Configuration configuration;

    protected ObjectWrapper wrapper;
    protected FreemarkerManager freemarkerManager;

    /*
     * Struts results are constructed for each result execeution
     *
     * the current context is availible to subclasses via these protected fields
     */
    protected String location;

    private String pContentType = "text/html";

    public PortletFreemarkerResult() {
        super();
    }

    public PortletFreemarkerResult(String location) {
        super(location);
    }
    
    @Inject
    public void setFreemarkerManager(FreemarkerManager mgr) {
        this.freemarkerManager = mgr;
    }

    public void setContentType(String aContentType) {
        pContentType = aContentType;
    }

    /**
     * allow parameterization of the contentType the default being text/html
     */
    public String getContentType() {
        return pContentType;
    }

    /**
     * Execute this result, using the specified template location. <p/>The
     * template location has already been interoplated for any variable
     * substitutions <p/>this method obtains the freemarker configuration and
     * the object wrapper from the provided hooks. It them implements the
     * template processing workflow by calling the hooks for preTemplateProcess
     * and postTemplateProcess
     */
    public void doExecute(String location, ActionInvocation invocation)
            throws IOException, TemplateException, PortletException {
        if (PortletActionContext.isEvent()) {
            executeActionResult(location, invocation);
        } else if (PortletActionContext.isRender()) {
            executeRenderResult(location, invocation);
        }
    }

    /**
     * @param location
     * @param invocation
     */
    private void executeActionResult(String location,
                                     ActionInvocation invocation) {
        ActionResponse res = PortletActionContext.getActionResponse();
        // View is rendered outside an action...uh oh...
		invocation.getInvocationContext().getSession().put(RENDER_DIRECT_LOCATION, location);
        res.setRenderParameter(PortletActionConstants.ACTION_PARAM, "freemarkerDirect");
        res.setRenderParameter(PortletActionConstants.MODE_PARAM, PortletActionContext
                .getRequest().getPortletMode().toString());

    }

    /**
     * @param location
     * @param invocation
     * @throws TemplateException
     * @throws IOException
     * @throws TemplateModelException
     */
    private void executeRenderResult(String location,
                                     ActionInvocation invocation) throws TemplateException, IOException,
            TemplateModelException, PortletException {
        this.location = location;
        this.invocation = invocation;
        this.configuration = getConfiguration();
        this.wrapper = getObjectWrapper();

        HttpServletRequest req = ServletActionContext.getRequest();

        if (!location.startsWith("/")) {
            String base = ResourceUtil.getResourceBase(req);
            location = base + "/" + location;
        }

        Template template = configuration.getTemplate(location, deduceLocale());
        TemplateModel model = createModel();
        // Give subclasses a chance to hook into preprocessing
        if (preTemplateProcess(template, model)) {
            try {
                // Process the template
                PortletActionContext.getRenderResponse().setContentType(pContentType);
                template.process(model, getWriter());
            } finally {
                // Give subclasses a chance to hook into postprocessing
                postTemplateProcess(template, model);
            }
        }
    }

    /**
     * This method is called from {@link #doExecute(String, ActionInvocation)}
     * to obtain the FreeMarker configuration object that this result will use
     * for template loading. This is a hook that allows you to custom-configure
     * the configuration object in a subclass, or to fetch it from an IoC
     * container. <p/>The default implementation obtains the configuration
     * from the ConfigurationManager instance. </b>
     */
    protected Configuration getConfiguration() throws TemplateException {
        return freemarkerManager.getConfiguration(
                ServletActionContext.getServletContext());
    }

    /**
     * This method is called from {@link #doExecute(String, ActionInvocation)}
     * to obtain the FreeMarker object wrapper object that this result will use
     * for adapting objects into template models. This is a hook that allows you
     * to custom-configure the wrapper object in a subclass. <p/>The default
     * implementation returns {@link Configuration#getObjectWrapper()}</b>
     */
    protected ObjectWrapper getObjectWrapper() {
        return configuration.getObjectWrapper();
    }

    /**
     * The default writer writes directly to the response writer.
     */
    protected Writer getWriter() throws IOException {
        return PortletActionContext.getRenderResponse().getWriter();
    }

    /**
     * Build the instance of the ScopesHashModel, including JspTagLib support
     * <p/>Objects added to the model are 

     * <ul>
     * <li>Application - servlet context attributes hash model
     * <li>JspTaglibs - jsp tag lib factory model
     * <li>Request - request attributes hash model
     * <li>Session - session attributes hash model
     * <li>request - the HttpServletRequst object for direct access
     * <li>response - the HttpServletResponse object for direct access
     * <li>stack - the OgnLValueStack instance for direct access
     * <li>ognl - the instance of the OgnlTool
     * <li>action - the action itself
     * <li>exception - optional : the JSP or Servlet exception as per the
     * servlet spec (for JSP Exception pages)
     * <li>struts - instance of the StrutsUtil class
     * </ul>
     */
    protected TemplateModel createModel() throws TemplateModelException {
        ServletContext servletContext = ServletActionContext
                .getServletContext();
        HttpServletRequest request = ServletActionContext.getRequest();
        HttpServletResponse response = ServletActionContext.getResponse();
        ValueStack stack = ServletActionContext.getContext()
                .getValueStack();
        return freemarkerManager.buildTemplateModel(stack,
                invocation.getAction(), servletContext, request, response,
                wrapper);
    }

    /**
     * Returns the locale used for the
     * {@link Configuration#getTemplate(String, Locale)}call. The base
     * implementation simply returns the locale setting of the configuration.
     * Override this method to provide different behaviour,
     */
    protected Locale deduceLocale() {
        return configuration.getLocale();
    }

    /**
     * the default implementation of postTemplateProcess applies the contentType
     * parameter
     */
    protected void postTemplateProcess(Template template, TemplateModel data)
            throws IOException {
    }

    /**
     * Called before the execution is passed to template.process(). This is a
     * generic hook you might use in subclasses to perform a specific action
     * before the template is processed. By default does nothing. A typical
     * action to perform here is to inject application-specific objects into the
     * model root
     *
     * @return true to process the template, false to suppress template
     *         processing.
     */
    protected boolean preTemplateProcess(Template template, TemplateModel model)
            throws IOException {
        Object attrContentType = template.getCustomAttribute("content_type");

        if (attrContentType != null) {
            ServletActionContext.getResponse().setContentType(
                    attrContentType.toString());
        } else {
            String contentType = getContentType();

            if (contentType == null) {
                contentType = "text/html";
            }

            String encoding = template.getEncoding();

            if (encoding != null) {
                contentType = contentType + "; charset=" + encoding;
            }

            ServletActionContext.getResponse().setContentType(contentType);
        }

        return true;
    }
}