de.hybris.platform.commons.renderer.impl.VelocityTemplateRenderer.java Source code

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Here is the source code for de.hybris.platform.commons.renderer.impl.VelocityTemplateRenderer.java

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/*
 * [y] hybris Platform
 *
 * Copyright (c) 2000-2013 hybris AG
 * All rights reserved.
 *
 * This software is the confidential and proprietary information of hybris
 * ("Confidential Information"). You shall not disclose such Confidential
 * Information and shall use it only in accordance with the terms of the
 * license agreement you entered into with hybris.
 * 
 *  
 */
package de.hybris.platform.commons.renderer.impl;

import de.hybris.platform.commons.model.renderer.RendererTemplateModel;
import de.hybris.platform.commons.renderer.Renderer;
import de.hybris.platform.commons.renderer.exceptions.RendererException;
import de.hybris.platform.core.model.media.MediaModel;
import de.hybris.platform.servicelayer.media.MediaService;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.Writer;

import org.apache.commons.io.IOUtils;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.Velocity;
import org.springframework.beans.factory.annotation.Required;

/**
 * Renders velocity template. Rendered content is output to Writer specified as 3rd parameter passed to render method.
 * 
 * Context object is registered as 'contextName' property in Spring XML file. Context object stores properties as
 * key-value map. So if you set 'contextName' as 'ctx' and in context you place key1=value1 you refer to it as
 * $ctx.key1.
 */
public class VelocityTemplateRenderer implements Renderer {
    private MediaService mediaService;
    private String contextName;

    @Override
    public void render(final RendererTemplateModel template, final Object context, final Writer output) {
        Class clazz = null;

        try {
            clazz = Class.forName(template.getContextClass());
        } catch (final ClassNotFoundException e) {
            throw new RendererException("Cannot find class: " + template.getContextClass(), e);
        }

        InputStream inputStream = null;
        try {
            if ((context != null) && (!clazz.isAssignableFrom(context.getClass()))) {
                throw new RendererException(
                        "The context class [" + context.getClass().getName() + "] is not correctly defined.");
            }
            final MediaModel content = template.getContent();
            if (content == null) {
                throw new RendererException("No content found for template " + template.getCode());
            }

            inputStream = mediaService.getStreamFromMedia(content);

            writeToOutput(output, inputStream, context);
        } catch (final IOException e) {
            throw new RendererException("Problem during rendering", e);
        } finally {
            IOUtils.closeQuietly(inputStream);
        }
    }

    private void writeToOutput(final Writer result, final InputStream inputStream, final Object context)
            throws IOException {
        final VelocityContext ctx = new VelocityContext();
        ctx.put(contextName, context);

        final Reader reader = new InputStreamReader(inputStream, "UTF-8");

        try {
            evaluate(result, ctx, reader);
            result.flush();
        } catch (final Exception e) {
            throw new RendererException("Problem with get velocity stream", e);
        } finally {
            IOUtils.closeQuietly(reader);
        }
    }

    protected void evaluate(final Writer result, final VelocityContext ctx, final Reader reader)
            throws IOException {
        Velocity.evaluate(ctx, result, getClass().getName(), reader);
    }

    /**
     * @param mediaService
     *           the mediaService to set
     */
    @Required
    public void setMediaService(final MediaService mediaService) {
        this.mediaService = mediaService;
    }

    /**
     * @param contextName
     *           the contextName to set
     */
    @Required
    public void setContextName(final String contextName) {
        this.contextName = contextName;
    }

}