examples/app_example1/Example.java

/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000-2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Velocity", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */


import org.apache.velocity.app.Velocity;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.Template;

import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;

import java.io.*;
import java.util.ArrayList;

/**
 * This class is a simple demonstration of how the Velocity Template Engine
 * can be used in a standalone application.
 *
 * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
 * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
 * @version $Id: Example.java,v 1.4 2001/10/22 03:53:22 jon Exp $
 */

public class Example
{
    public Example(String templateFile)
    {
        try
        {
            /*
             * setup
             */

            Velocity.init("velocity.properties");
            
            /*
             *  Make a context object and populate with the data.  This 
             *  is where the Velocity engine gets the data to resolve the
             *  references (ex. $list) in the template
             */

            VelocityContext context = new VelocityContext();
            context.put("list", getNames());
            
            /*
             *  get the Template object.  This is the parsed version of your 
             *  template input file.  Note that getTemplate() can throw
             *   ResourceNotFoundException : if it doesn't find the template
             *   ParseErrorException : if there is something wrong with the VTL
             *   Exception : if something else goes wrong (this is generally
             *        indicative of as serious problem...)
             */

            Template template =  null;

            try 
            {
                template = Velocity.getTemplate(templateFile);
            }
            catch( ResourceNotFoundException rnfe )
            {
                System.out.println("Example : error : cannot find template " + templateFile );
            }
            catch( ParseErrorException pee )
            {
                System.out.println("Example : Syntax error in template " + templateFile + ":" + pee );
            }

            /*
             *  Now have the template engine process your template using the
             *  data placed into the context.  Think of it as a  'merge' 
             *  of the template and the data to produce the output stream.
             */

            BufferedWriter writer = writer = new BufferedWriter(
                new OutputStreamWriter(System.out));

            if ( template != null)
                template.merge(context, writer);

            /*
             *  flush and cleanup
             */

            writer.flush();
            writer.close();
        }
        catch( Exception e )
        {
            System.out.println(e);
        }
    }

    public ArrayList getNames()
    {
        ArrayList list = new ArrayList();

        list.add("ArrayList element 1");
        list.add("ArrayList element 2");
        list.add("ArrayList element 3");
        list.add("ArrayList element 4");

        return list;
    }

    public static void main(String[] args)
    {
        Example t = new Example(args[0]);
    }
}