org.sakaiproject.metaobj.utils.mvc.impl.LocalVelocityConfigurer.java Source code

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Here is the source code for org.sakaiproject.metaobj.utils.mvc.impl.LocalVelocityConfigurer.java

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/**********************************************************************************
 * $URL: https://source.sakaiproject.org/svn/metaobj/trunk/metaobj-util/tool-lib/src/java/org/sakaiproject/metaobj/utils/mvc/impl/LocalVelocityConfigurer.java $
 * $Id: LocalVelocityConfigurer.java 105079 2012-02-24 23:08:11Z ottenhoff@longsight.com $
 ***********************************************************************************
 *
 * Copyright (c) 2004, 2005, 2006, 2008 The Sakai Foundation
 *
 * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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.sakaiproject.metaobj.utils.mvc.impl;

import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.exception.VelocityException;
import org.apache.velocity.runtime.RuntimeConstants;
import org.apache.velocity.runtime.resource.loader.FileResourceLoader;
import org.sakaiproject.metaobj.utils.mvc.intf.VelocityEngineFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.web.context.WebApplicationContext;

/**
 * Created by IntelliJ IDEA.
 * User: John Ellis
 * Date: Jul 5, 2005
 * Time: 4:21:23 PM
 * To change this template use File | Settings | File Templates.
 */
public class LocalVelocityConfigurer implements InitializingBean, ApplicationContextAware, VelocityEngineFactory {

    protected final transient Log logger = LogFactory.getLog(getClass());

    private String resourceLoaderPath;

    private boolean preferFileSystemAccess = true;

    private Map velocityProperties;

    private VelocityEngine velocityEngine;

    private WebApplicationContext webApplicationContext;

    /**
     * Prepare the VelocityEngine instance and return it.
     *
     * @return the VelocityEngine instance
     * @throws java.io.IOException if the config file wasn't found
     * @throws org.apache.velocity.exception.VelocityException
     *                             on Velocity initialization failure
     */
    public VelocityEngine createVelocityEngine() throws IOException, VelocityException {
        VelocityEngine velocityEngine = new VelocityEngine();
        Properties props = new Properties();

        // Merge local properties if set.
        if (!this.velocityProperties.isEmpty()) {
            props.putAll(this.velocityProperties);
        }

        // Apply properties to VelocityEngine.
        for (Iterator it = props.entrySet().iterator(); it.hasNext();) {
            Map.Entry entry = (Map.Entry) it.next();
            if (!(entry.getKey() instanceof String)) {
                throw new IllegalArgumentException(
                        "Illegal property key [" + entry.getKey() + "]: only Strings allowed");
            }
            velocityEngine.setProperty((String) entry.getKey(), entry.getValue());
        }

        initResourceLoader(velocityEngine);

        try {
            // Perform actual initialization.
            velocityEngine.init();
        } catch (IOException ex) {
            throw ex;
        } catch (VelocityException ex) {
            throw ex;
        } catch (RuntimeException ex) {
            throw ex;
        } catch (Exception ex) {
            logger.error("Why does VelocityEngine throw a generic checked exception, after all?", ex);
            throw new VelocityException(ex.getMessage());
        }

        return velocityEngine;
    }

    public String getRealPath(String path) {
        return webApplicationContext.getServletContext().getRealPath(path);
    }

    /**
     * Initialize a SpringResourceLoader for the given VelocityEngine.
     *
     * @param velocityEngine the VelocityEngine to configure
     * @see org.springframework.ui.velocity.SpringResourceLoader
     */
    protected void initResourceLoader(VelocityEngine velocityEngine) {
        velocityEngine.setProperty(RuntimeConstants.RESOURCE_LOADER, "file");
        velocityEngine.setProperty("file.resource.loader.description", "Velocity File Resource Loader");
        velocityEngine.setProperty("file.resource.loader.class", FileResourceLoader.class.getName());
        velocityEngine.setProperty("file.resource.loader.path", getRealPath(getResourceLoaderPath()));
        velocityEngine.setProperty("file.resource.loader.cache", "true");
        velocityEngine.setProperty("file.resource.loader.modificationCheckInterval", "0");
    }

    /**
     * Initialize VelocityEngineFactory's VelocityEngine
     * if not overridden by a preconfigured VelocityEngine.
     *
     * @see #createVelocityEngine
     */
    public void afterPropertiesSet() throws IOException, VelocityException {
        if (this.velocityEngine == null) {
            this.velocityEngine = createVelocityEngine();
        }
    }

    public VelocityEngine getVelocityEngine() {
        return this.velocityEngine;
    }

    public String getResourceLoaderPath() {
        return resourceLoaderPath;
    }

    public void setResourceLoaderPath(String resourceLoaderPath) {
        this.resourceLoaderPath = resourceLoaderPath;
    }

    public boolean isPreferFileSystemAccess() {
        return preferFileSystemAccess;
    }

    public void setPreferFileSystemAccess(boolean preferFileSystemAccess) {
        this.preferFileSystemAccess = preferFileSystemAccess;
    }

    public Map getVelocityProperties() {
        return velocityProperties;
    }

    public void setVelocityProperties(Map velocityProperties) {
        this.velocityProperties = velocityProperties;
    }

    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.webApplicationContext = (WebApplicationContext) applicationContext;
    }
}