net.alpha.velocity.spring.support.VelocityEngineUtils.java Source code

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Here is the source code for net.alpha.velocity.spring.support.VelocityEngineUtils.java

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/*
 * Copyright 2002-2013 the original author or authors.
 *
 * 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 net.alpha.velocity.spring.support;

import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.exception.VelocityException;

import java.io.StringWriter;
import java.io.Writer;
import java.util.Map;

/**
 * Utility class for working with a VelocityEngine.
 * Provides convenience methods to merge a Velocity template with a model.
 *
 * @author Juergen Hoeller
 * @since 22.01.2004
 */
public abstract class VelocityEngineUtils {

    /**
     * Merge the specified Velocity template with the given model and write
     * the result to the given Writer.
     *
     * @param velocityEngine   VelocityEngine to work with
     * @param templateLocation the location of template, relative to Velocity's resource loader path
     * @param model            the Map that contains model names as keys and model objects as values
     * @param writer           the Writer to write the result to
     * @throws VelocityException if the template wasn't found or rendering failed
     * @deprecated Use {@link #mergeTemplate(VelocityEngine, String, String, Map, Writer)}
     * instead, following Velocity 1.6's corresponding deprecation in its own API.
     */
    @Deprecated
    public static void mergeTemplate(VelocityEngine velocityEngine, String templateLocation,
            Map<String, Object> model, Writer writer) throws VelocityException {

        VelocityContext velocityContext = new VelocityContext(model);
        velocityEngine.mergeTemplate(templateLocation, velocityContext, writer);
    }

    /**
     * Merge the specified Velocity template with the given model and write the result
     * to the given Writer.
     *
     * @param velocityEngine   VelocityEngine to work with
     * @param templateLocation the location of template, relative to Velocity's resource loader path
     * @param encoding         the encoding of the template file
     * @param model            the Map that contains model names as keys and model objects as values
     * @param writer           the Writer to write the result to
     * @throws VelocityException if the template wasn't found or rendering failed
     */
    public static void mergeTemplate(VelocityEngine velocityEngine, String templateLocation, String encoding,
            Map<String, Object> model, Writer writer) throws VelocityException {

        VelocityContext velocityContext = new VelocityContext(model);
        velocityEngine.mergeTemplate(templateLocation, encoding, velocityContext, writer);
    }

    /**
     * Merge the specified Velocity template with the given model into a String.
     * <p>When using this method to prepare a text for a mail to be sent with Spring's
     * mail support, consider wrapping VelocityException in MailPreparationException.
     *
     * @param velocityEngine   VelocityEngine to work with
     * @param templateLocation the location of template, relative to Velocity's resource loader path
     * @param model            the Map that contains model names as keys and model objects as values
     * @return the result as String
     * @throws VelocityException if the template wasn't found or rendering failed
     * @see org.springframework.mail.MailPreparationException
     * @deprecated Use {@link #mergeTemplateIntoString(VelocityEngine, String, String, Map)}
     * instead, following Velocity 1.6's corresponding deprecation in its own API.
     */
    @Deprecated
    public static String mergeTemplateIntoString(VelocityEngine velocityEngine, String templateLocation,
            Map<String, Object> model) throws VelocityException {

        StringWriter result = new StringWriter();
        mergeTemplate(velocityEngine, templateLocation, model, result);
        return result.toString();
    }

    /**
     * Merge the specified Velocity template with the given model into a String.
     * <p>When using this method to prepare a text for a mail to be sent with Spring's
     * mail support, consider wrapping VelocityException in MailPreparationException.
     *
     * @param velocityEngine   VelocityEngine to work with
     * @param templateLocation the location of template, relative to Velocity's resource loader path
     * @param encoding         the encoding of the template file
     * @param model            the Map that contains model names as keys and model objects as values
     * @return the result as String
     * @throws VelocityException if the template wasn't found or rendering failed
     * @see org.springframework.mail.MailPreparationException
     */
    public static String mergeTemplateIntoString(VelocityEngine velocityEngine, String templateLocation,
            String encoding, Map<String, Object> model) throws VelocityException {

        StringWriter result = new StringWriter();
        mergeTemplate(velocityEngine, templateLocation, encoding, model, result);
        return result.toString();
    }

}