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1   /*
2    * $Source$
3    * $Revision$
4    *
5    * Copyright (C) 2007 Tim Pizey
6    *
7    * Part of Melati (http://melati.org), a framework for the rapid
8    * development of clean, maintainable web applications.
9    *
10   * Melati is free software; Permission is granted to copy, distribute
11   * and/or modify this software under the terms either:
12   *
13   * a) the GNU General Public License as published by the Free Software
14   *    Foundation; either version 2 of the License, or (at your option)
15   *    any later version,
16   *
17   *    or
18   *
19   * b) any version of the Melati Software License, as published
20   *    at http://melati.org
21   *
22   * You should have received a copy of the GNU General Public License and
23   * the Melati Software License along with this program;
24   * if not, write to the Free Software Foundation, Inc.,
25   * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
26   * GNU General Public License and visit http://melati.org to obtain the
27   * Melati Software License.
28   *
29   * Feel free to contact the Developers of Melati (http://melati.org),
30   * if you would like to work out a different arrangement than the options
31   * outlined here.  It is our intention to allow Melati to be used by as
32   * wide an audience as possible.
33   *
34   * This program is distributed in the hope that it will be useful,
35   * but WITHOUT ANY WARRANTY; without even the implied warranty of
36   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
37   * GNU General Public License for more details.
38   *
39   * Contact details for copyright holder:
40   *
41   *     Tim Pizey <timp At paneris.org>
42   */
43  package org.melati.template.velocity;
44  
45  import java.io.IOException;
46  
47  import javax.servlet.http.HttpServlet;
48  import javax.servlet.http.HttpServletResponse;
49  
50  import org.apache.velocity.VelocityContext;
51  import org.melati.Melati;
52  import org.melati.MelatiConfig;
53  import org.melati.template.ServletTemplateContext;
54  import org.melati.template.ServletTemplateEngine;
55  import org.melati.template.TemplateEngineException;
56  import org.melati.template.TemplateIOException;
57  import org.melati.util.DelegatedHttpServletRequest;
58  import org.melati.util.MelatiWriter;
59  
60  /**
61   * @author timp
62   * @since 22 Aug 2007
63   *
64   */
65  public class VelocityServletTemplateEngine extends VelocityTemplateEngine
66          implements ServletTemplateEngine {
67  
68    /**
69     * Constructor.
70     */
71    public VelocityServletTemplateEngine() {
72      super();
73    }
74  
75    /**
76     * Construct a new Engine for use in a servlet environment. For Velocity this
77     * is no different to initialisation outside of a servlets environment.
78     * 
79     * @param melatiConfig
80     *          a {@link MelatiConfig}
81     * @param servlet
82     *          the servlet we are within
83     * @throws TemplateEngineException
84     *           if any problem occurs with the engine
85     * @see org.melati.template.ServletTemplateEngine#init(org.melati.MelatiConfig, javax.servlet.http.HttpServlet)
86     */
87    @Override
88    public void init(MelatiConfig melatiConfig, HttpServlet servlet)
89            throws TemplateEngineException {
90      init(melatiConfig);
91      
92    }
93  
94    /**
95     * @param response
96     *          the <code>HttpServletResponse</code> that this writer will be
97     *          part of
98     * @param buffered
99     *          whether the writer should be buffered
100    * @return a {@link MelatiWriter} appropriate for this engine.
101    * @see org.melati.template.ServletTemplateEngine#getServletWriter(javax.servlet.http.HttpServletResponse, boolean)
102    */
103   @Override
104   public MelatiWriter getServletWriter(HttpServletResponse response, 
105           boolean buffered) {
106     if (buffered) {
107       try {
108         return new MelatiBufferedVelocityWriter(response);
109       } catch (IOException e) {
110         throw new TemplateIOException(e);
111       }
112     } else {
113       try {
114         return new MelatiVelocityWriter(response);
115       } catch (IOException e) {
116         throw new TemplateIOException(e);
117       }
118     }
119   }
120 
121   /**
122    * Get the template context for Velocity, with servlet specific objects added.
123    * 
124    * @param melati
125    *        the {@link Melati}
126    * @return a {@link ServletTemplateContext}
127    * @see org.melati.template.ServletTemplateEngine#getServletTemplateContext(org.melati.Melati)
128    */
129   @Override
130   public ServletTemplateContext getServletTemplateContext(Melati melati) throws TemplateEngineException {
131     VelocityContext context = new VelocityContext();
132     context.put(VelocityServletTemplateContext.REQUEST, new DelegatedHttpServletRequest(melati.getRequest()));
133     context.put(VelocityServletTemplateContext.RESPONSE, melati.getResponse());
134     return new VelocityServletTemplateContext(context);
135   }
136 
137   
138 }