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