1 /**
2 * This file Copyright (c) 2003-2015 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.cms.beans.config;
35
36 import java.util.Random;
37
38 import org.apache.commons.lang3.StringUtils;
39 import org.slf4j.Logger;
40 import org.slf4j.LoggerFactory;
41
42
43 /**
44 * <p>
45 * An extension of {@link RegexpVirtualURIMapping} that allows a rotation between different destination urls. In order
46 * to rotate <code>toURI</code> must contain the <code>*</code> that will be replaced by a random number between
47 * <code>start</code> (default is <code>1</code>) and <code>end</code> (defaults is <code>3</code>).
48 * </p>
49 * <p>
50 * An additional property <code>padding</code> can specify the left 0 padding for numbers (defaults is <code>2</code>).
51 * So for example a destination url like <code>forward:/banner/image_*.jpg</code> will randomly forward the request to
52 * <code>/banner/image_01.jpg</code>, <code>/banner/image_02.jpg</code> or <code>/banner/image_03.jpg</code>
53 * </p>
54 */
55 public class RotatingVirtualURIMapping extends RegexpVirtualURIMapping {
56
57 private static final Logger log = LoggerFactory.getLogger(RotatingVirtualURIMapping.class);
58
59 /**
60 * Placeholder that will be replaced by a random number.
61 */
62 private static final String RANDOM_PLACEHOLDER = "*";
63
64 /**
65 * Lower bound for the generated random number.
66 */
67 private int start = 1;
68
69 /**
70 * Upper bound for the generated random number.
71 */
72 private int end = 3;
73
74 /**
75 * Left padding (using 0s).
76 */
77 private int padding = 2;
78
79 /**
80 * Sets the start.
81 *
82 * @param start the start to set
83 */
84 public void setStart(int start) {
85 this.start = start;
86 }
87
88 /**
89 * Sets the end.
90 *
91 * @param end the end to set
92 */
93 public void setEnd(int end) {
94 this.end = end;
95 }
96
97 /**
98 * Sets the padding.
99 *
100 * @param padding the padding to set
101 */
102 public void setPadding(int padding) {
103 this.padding = padding;
104 }
105
106 /**
107 * {@inheritDoc}
108 */
109 @Override
110 public MappingResult mapURI(String uri) {
111 // delegate the initial processing to RegexpVirtualURIMapping
112 MappingResult mr = super.mapURI(uri);
113
114 if (mr != null) {
115 if (end > start) {
116 int randomNumber = new Random().nextInt(end - (start - 1)) + start;
117 String randomAsString = StringUtils.leftPad(Integer.toString(randomNumber), padding, '0');
118
119 mr.setToURI(StringUtils.replace(mr.getToURI(), RANDOM_PLACEHOLDER, randomAsString));
120 } else {
121 log.warn("End value must be greater than start value.");
122 }
123 }
124 return mr;
125 }
126 }