1 /*
2 * Copyright (c) 2005 The Visigoth Software Society. All rights
3 * reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
16 *
17 * 3. The end-user documentation included with the redistribution, if
18 * any, must include the following acknowledgement:
19 * "This product includes software developed by the
20 * Visigoth Software Society (http://www.visigoths.org/)."
21 * Alternately, this acknowledgement may appear in the software itself,
22 * if and wherever such third-party acknowledgements normally appear.
23 *
24 * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
25 * project contributors may be used to endorse or promote products derived
26 * from this software without prior written permission. For written
27 * permission, please contact visigoths@visigoths.org.
28 *
29 * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
30 * nor may "FreeMarker" or "Visigoth" appear in their names
31 * without prior written permission of the Visigoth Software Society.
32 *
33 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
34 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
35 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
36 * DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
37 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
38 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
39 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
40 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
41 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
42 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
43 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44 * SUCH DAMAGE.
45 * ====================================================================
46 *
47 * This software consists of voluntary contributions made by many
48 * individuals on behalf of the Visigoth Software Society. For more
49 * information on the Visigoth Software Society, please see
50 * http://www.visigoths.org/
51 */
52
53 package freemarker.cache;
54
55 import java.io.Reader;
56 import java.io.StringReader;
57 import java.util.HashMap;
58 import java.util.Map;
59
60 /**
61 * A {@link TemplateLoader} that uses a Map with Strings as its source of
62 * templates.
63 *
64 * In most case the regular way of loading templates from files will be fine.
65 * However, there can be situations where you don't want to or can't load a
66 * template from a file, e.g. if you have to deploy a single jar for
67 * JavaWebStart or if they are contained within a database.
68 * A single template can be created manually
69 * e.g.
70 * <pre>
71 * String templateStr="Hello ${user}";
72 * Template t = new Template("name", new StringReader(templateStr),
73 * new Configuration());
74 * </pre>
75 * If, however, you want to create templates from strings which import other
76 * templates this method doesn't work.
77 *
78 * In that case you can create a StringTemplateLoader and add each template to
79 * it:
80 * <pre>
81 * StringTemplateLoader stringLoader = new StringTemplateLoader();
82 * stringLoader.putTemplate("greetTemplate", "<#macro greet>Hello</#macro>");
83 * stringLoader.putTemplate("myTemplate", "<#include \"greetTemplate\"><@greet/> World!");
84 * </pre>
85 * Then you tell your Configuration object to use it:
86 * <pre>
87 * cfg.setTemplateLoader(stringLoader);
88 * </pre>
89 * After that you should be able to use the templates as usual. Often you will
90 * want to combine a <tt>StringTemplateLoader</tt> with another loader. You can
91 * do so using a {@link freemarker.cache.MultiTemplateLoader}.
92 *
93 * @version $Id: v 1.0 2005/04/01
94 * @author Meikel Bisping
95 * @author Attila Szegedi
96 * @version $Id: StringTemplateLoader.java,v 1.1 2005/04/08 11:47:53 szegedia Exp $
97 */
98 public class StringTemplateLoader implements TemplateLoader {
99 private final Map templates = new HashMap();
100
101 /**
102 * Puts a template into the loader. A call to this method is identical to
103 * the call to the three-arg {@link #putTemplate(String, String, long)}
104 * passing <tt>System.currentTimeMillis()</tt> as the third argument.
105 * @param name the name of the template.
106 * @param templateSource the source code of the template.
107 */
108 public void putTemplate(String name, String templateSource) {
109 putTemplate(name, templateSource, System.currentTimeMillis());
110 }
111
112 /**
113 * Puts a template into the loader. The name can contain slashes to denote
114 * logical directory structure, but must not start with a slash. If the
115 * method is called multiple times for the same name and with different
116 * last modified time, the configuration's template cache will reload the
117 * template according to its own refresh settings (note that if the refresh
118 * is disabled in the template cache, the template will not be reloaded).
119 * Also, since the cache uses lastModified to trigger reloads, calling the
120 * method with different source and identical timestamp won't trigger
121 * reloading.
122 * @param name the name of the template.
123 * @param templateSource the source code of the template.
124 * @param lastModified the time of last modification of the template in
125 * terms of <tt>System.currentTimeMillis()</tt>
126 */
127 public void putTemplate(String name, String templateSource, long lastModified) {
128 templates.put(name, new StringTemplateSource(name, templateSource, lastModified));
129 }
130
131 public void closeTemplateSource(Object templateSource) {
132 }
133
134 public Object findTemplateSource(String name) {
135 return templates.get(name);
136 }
137
138 public long getLastModified(Object templateSource) {
139 return ((StringTemplateSource)templateSource).lastModified;
140 }
141
142 public Reader getReader(Object templateSource, String encoding) {
143 return new StringReader(((StringTemplateSource)templateSource).source);
144 }
145
146 private static class StringTemplateSource {
147 private final String name;
148 private final String source;
149 private final long lastModified;
150
151 StringTemplateSource(String name, String source, long lastModified) {
152 if(name == null) {
153 throw new IllegalArgumentException("name == null");
154 }
155 if(source == null) {
156 throw new IllegalArgumentException("source == null");
157 }
158 if(lastModified < -1L) {
159 throw new IllegalArgumentException("lastModified < -1L");
160 }
161 this.name = name;
162 this.source = source;
163 this.lastModified = lastModified;
164 }
165
166 public boolean equals(Object obj) {
167 if(obj instanceof StringTemplateSource) {
168 return name.equals(((StringTemplateSource)obj).name);
169 }
170 return false;
171 }
172
173 public int hashCode() {
174 return name.hashCode();
175 }
176 }
177 }