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1 package org.apache.turbine.om; 2 3 /* ==================================================================== 4 * The Apache Software License, Version 1.1 5 * 6 * Copyright (c) 2001 The Apache Software Foundation. All rights 7 * reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. The end-user documentation included with the redistribution, 22 * if any, must include the following acknowledgment: 23 * "This product includes software developed by the 24 * Apache Software Foundation (http://www.apache.org/)." 25 * Alternately, this acknowledgment may appear in the software itself, 26 * if and wherever such third-party acknowledgments normally appear. 27 * 28 * 4. The names "Apache" and "Apache Software Foundation" and 29 * "Apache Turbine" must not be used to endorse or promote products 30 * derived from this software without prior written permission. For 31 * written permission, please contact apache@apache.org. 32 * 33 * 5. Products derived from this software may not be called "Apache", 34 * "Apache Turbine", nor may "Apache" appear in their name, without 35 * prior written permission of the Apache Software Foundation. 36 * 37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 40 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 43 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 44 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 45 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 46 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 47 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 48 * SUCH DAMAGE. 49 * ==================================================================== 50 * 51 * This software consists of voluntary contributions made by many 52 * individuals on behalf of the Apache Software Foundation. For more 53 * information on the Apache Software Foundation, please see 54 * <http://www.apache.org/>;. 55 */ 56 57 import java.util.HashMap; 58 import java.util.Map; 59 import org.apache.turbine.services.pull.ApplicationTool; 60 import org.apache.turbine.services.resources.TurbineResources; 61 import org.apache.turbine.util.pool.Recyclable; 62 63 /*** 64 * A Pull tool to make om objects available to a template 65 * 66 * @author <a href="mailto:jmcnally@collab.net">John D. McNally</a> 67 * @version $Id: OMTool.java,v 1.2 2002/07/11 14:28:45 mpoeschl Exp $ 68 */ 69 public class OMTool implements ApplicationTool, Recyclable 70 { 71 // private RunData data; 72 private HashMap omMap; 73 74 // note the following could be a static attribute to reduce memory 75 // footprint. Might require a service to front load the 76 // PullHelpers to avoid MT issues. A multiple write is not so bad 77 // though 78 79 /*** The cache of PullHelpers. **/ 80 private static Map pullMap = new HashMap(); 81 82 /*** 83 * The Factory responsible for retrieving the 84 * objects from storage 85 */ 86 private RetrieverFactory omFactory; 87 88 public OMTool()throws Exception 89 { 90 omMap = new HashMap(); 91 String className = TurbineResources.getString("tool.om.factory"); 92 // RetrieverFactory omFactory = 93 // (RetrieverFactory)Class.forName(className).newInstance(); 94 } 95 96 /*** 97 * Prepares tool for a single request 98 */ 99 public void init(Object runData) 100 { 101 // data = (RunData)runData; 102 } 103 104 /*** 105 * Implementation of ApplicationTool interface is not needed for this 106 * method as the tool is request scoped 107 */ 108 public void refresh() 109 { 110 // empty 111 } 112 113 /*** 114 * Inner class to present a nice interface to the template designer 115 */ 116 private class PullHelper 117 { 118 String omName; 119 120 private PullHelper(String omName) 121 { 122 this.omName = omName; 123 } 124 125 public Object setKey(String key) 126 throws Exception 127 { 128 Object om = null; 129 130 String inputKey = omName + key; 131 if (omMap.containsKey(inputKey)) 132 { 133 om = omMap.get(inputKey); 134 } 135 else 136 { 137 om = omFactory.getInstance(omName).retrieve(key); 138 omMap.put(inputKey, om); 139 } 140 141 return om; 142 } 143 } 144 145 public Object get(String omName) throws Exception 146 { 147 if (!pullMap.containsKey(omName)) 148 { 149 // MT could overwrite a PullHelper, but that is not a problem 150 // should still synchronize to avoid two threads adding at 151 // same time 152 synchronized (this.getClass()) 153 { 154 pullMap.put(omName, new OMTool.PullHelper(omName)); 155 } 156 } 157 158 return pullMap.get(omName); 159 } 160 161 public Object get(String omName, String key) throws Exception 162 { 163 return ((OMTool.PullHelper) get(omName)).setKey(key); 164 } 165 166 167 public String getName() 168 { 169 return "om"; 170 } 171 172 173 // ****************** Recyclable implementation ************************ 174 175 private boolean disposed; 176 177 /*** 178 * Recycles the object for a new client. Recycle methods with 179 * parameters must be added to implementing object and they will be 180 * automatically called by pool implementations when the object is 181 * taken from the pool for a new client. The parameters must 182 * correspond to the parameters of the constructors of the object. 183 * For new objects, constructors can call their corresponding recycle 184 * methods whenever applicable. 185 * The recycle methods must call their super. 186 */ 187 public void recycle() 188 { 189 disposed = false; 190 } 191 192 /*** 193 * Disposes the object after use. The method is called 194 * when the object is returned to its pool. 195 * The dispose method must call its super. 196 */ 197 public void dispose() 198 { 199 omMap.clear(); 200 // data = null; 201 disposed = true; 202 } 203 204 /*** 205 * Checks whether the recyclable has been disposed. 206 * @return true, if the recyclable is disposed. 207 */ 208 public boolean isDisposed() 209 { 210 return disposed; 211 } 212 } 213 214 215 216 217 218 219 220

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