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Java > Open Source Codes > org > blojsom > plugin > common > CollectionUtilitiesPlugin


1 /**
2  * Copyright (c) 2003-2006, David A. Czarnecki
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  * Redistributions of source code must retain the above copyright notice, this list of conditions and the
9  * following disclaimer.
10  * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
11  * following disclaimer in the documentation and/or other materials provided with the distribution.
12  * Neither the name of "David A. Czarnecki" and "blojsom" nor the names of its contributors may be used to
13  * endorse or promote products derived from this software without specific prior written permission.
14  * Products derived from this software may not be called "blojsom", nor may "blojsom" appear in their name,
15  * without prior written permission of David A. Czarnecki.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
18  * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
19  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
21  * EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
24  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
27  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */

31 package org.blojsom.plugin.common;
32
33 import org.blojsom.blog.Blog;
34 import org.blojsom.blog.Entry;
35 import org.blojsom.plugin.Plugin;
36 import org.blojsom.plugin.PluginException;
37
38 import javax.servlet.http.HttpServletRequest JavaDoc;
39 import javax.servlet.http.HttpServletResponse JavaDoc;
40 import java.util.Collections JavaDoc;
41 import java.util.List JavaDoc;
42 import java.util.Map JavaDoc;
43
44 /**
45  * CollectionUtilities plugin
46  *
47  * @author David Czarnecki
48  * @since blojsom 3.0
49  * @version $Id: CollectionUtilitiesPlugin.java,v 1.1 2006/03/20 21:30:54 czarneckid Exp $
50  */

51 public class CollectionUtilitiesPlugin implements Plugin {
52
53     private static final String JavaDoc BLOJSOM_PLUGIN_COLLECTION_UTILITIES = "BLOJSOM_PLUGIN_COLLECTION_UTILITIES";
54
55     /**
56      * Construct a new instance of the Collection Utilities plugin
57      */

58     public CollectionUtilitiesPlugin() {
59     }
60
61     /**
62      * Initialize this plugin. This method only called when the plugin is instantiated.
63      *
64      * @throws org.blojsom.plugin.PluginException
65      * If there is an error initializing the plugin
66      */

67     public void init() throws PluginException {
68     }
69
70     /**
71      * Process the blog entries
72      *
73      * @param httpServletRequest Request
74      * @param httpServletResponse Response
75      * @param blog {@link Blog} instance
76      * @param context Context
77      * @param entries Blog entries retrieved for the particular request
78      * @return Modified set of blog entries
79      * @throws PluginException If there is an error processing the blog entries
80      */

81     public Entry[] process(HttpServletRequest JavaDoc httpServletRequest, HttpServletResponse JavaDoc httpServletResponse, Blog blog, Map JavaDoc context, Entry[] entries) throws PluginException {
82         context.put(BLOJSOM_PLUGIN_COLLECTION_UTILITIES, new CollectionUtilities());
83
84         return entries;
85     }
86
87     /**
88      * Perform any cleanup for the plugin. Called after {@link #process}.
89      *
90      * @throws org.blojsom.plugin.PluginException
91      * If there is an error performing cleanup for this plugin
92      */

93     public void cleanup() throws PluginException {
94     }
95
96     /**
97      * Called when BlojsomServlet is taken out of service
98      *
99      * @throws org.blojsom.plugin.PluginException
100      * If there is an error in finalizing this plugin
101      */

102     public void destroy() throws PluginException {
103     }
104
105     /**
106      * Utility class for collection utility functions to make available to templates
107      */

108     public class CollectionUtilities {
109
110         /**
111          * Construct a new instance of CollectionUtilities
112          */

113         public CollectionUtilities() {
114         }
115
116         /**
117          * Reverse a list
118          *
119          * @param input List to be reversed
120          * @return List in reverse order
121          */

122         public List JavaDoc reverse(List JavaDoc input) {
123             if (input == null || input.size() == 0) {
124                 return input;
125             }
126
127             Collections.reverse(input);
128
129             return input;
130         }
131     }
132 }
133
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