1 /**
2 * This file Copyright (c) 2003-2018 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.virtualuri.mapping;
35
36 import java.net.URI;
37 import java.util.Optional;
38 import java.util.Random;
39
40 import org.apache.commons.lang3.StringUtils;
41 import org.slf4j.Logger;
42 import org.slf4j.LoggerFactory;
43
44 /**
45 * <p>
46 * An extension of {@link RegexpVirtualUriMapping} that allows a rotation between different destination urls. In order
47 * to rotate <code>toUri</code> must contain the <code>*</code> that will be replaced by a random number between
48 * <code>start</code> (default is <code>1</code>) and <code>end</code> (defaults is <code>3</code>).
49 * </p>
50 * <p>
51 * An additional property <code>padding</code> can specify the left 0 padding for numbers (defaults is <code>2</code>).
52 * So for example a destination url like <code>forward:/banner/image_*.jpg</code> will randomly forward the request to
53 * <code>/banner/image_01.jpg</code>, <code>/banner/image_02.jpg</code> or <code>/banner/image_03.jpg</code>
54 * </p>
55 */
56 public class RotatingVirtualUriMapping extends RegexpVirtualUriMapping {
57
58 private static final Logger log = LoggerFactory.getLogger(RotatingVirtualUriMapping.class);
59
60 /**
61 * Placeholder that will be replaced by a random number.
62 */
63 private static final String RANDOM_PLACEHOLDER = "*";
64
65 /**
66 * Lower bound for the generated random number.
67 */
68 private int start = 1;
69
70 /**
71 * Upper bound for the generated random number.
72 */
73 private int end = 3;
74
75 /**
76 * Left padding (using 0s).
77 */
78 private int padding = 2;
79
80 /**
81 * Sets the start.
82 *
83 * @param start the start to set
84 */
85 public void setStart(int start) {
86 this.start = start;
87 }
88
89 /**
90 * Sets the end.
91 *
92 * @param end the end to set
93 */
94 public void setEnd(int end) {
95 this.end = end;
96 }
97
98 /**
99 * Sets the padding.
100 *
101 * @param padding the padding to set
102 */
103 public void setPadding(int padding) {
104 this.padding = padding;
105 }
106
107 @Override
108 public Optional<Result> mapUri(URI uri) {
109 // delegate the initial processing to RegexpVirtualUriMapping
110 Optional<Result> defaultResult = super.mapUri(uri);
111
112 if (defaultResult.isPresent()) {
113 if (end > start) {
114 int randomNumber = new Random().nextInt(end - (start - 1)) + start;
115 String randomAsString = StringUtils.leftPad(Integer.toString(randomNumber), padding, '0');
116
117 Result result = defaultResult.get();
118 String randomizedUri = StringUtils.replace(result.getToUri(), RANDOM_PLACEHOLDER, randomAsString);
119
120 return Optional.of(new Result(randomizedUri, result.getWeight(), this));
121 } else {
122 log.warn("End value must be greater than start value.");
123 }
124 }
125
126 return defaultResult;
127 }
128 }