| 1 | /* |
| 2 | * @(#) $Id: SlugConfig.java,v 1.1.1.1 2006/03/19 06:09:42 rossen Exp $ |
| 3 | * |
| 4 | * Copyright (c) 2006, WebHydra.com |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions are met: |
| 9 | * |
| 10 | * * Redistributions of source code must retain the above copyright notice, |
| 11 | * this list of conditions and the following disclaimer. |
| 12 | * * Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * * Neither the name of the WebHydra.com nor the names of its contributors |
| 16 | * may be used to endorse or promote products derived from this software |
| 17 | * without specific prior written permission. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| 20 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| 23 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 29 | * POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | package com.webhydra.slug; |
| 33 | |
| 34 | import com.webhydra.slug.process.IProcessStatusTranslator; |
| 35 | import com.webhydra.slug.process.ISlugService; |
| 36 | import com.webhydra.slug.SlugInitializationException; |
| 37 | import com.webhydra.slug.process.ISlugRunner; |
| 38 | import com.webhydra.slug.process.SluggishProcess; |
| 39 | import java.io.IOException; |
| 40 | import java.io.InputStream; |
| 41 | import java.io.Serializable; |
| 42 | import java.lang.reflect.Method; |
| 43 | import java.util.ArrayList; |
| 44 | import java.util.Enumeration; |
| 45 | import java.util.HashMap; |
| 46 | import java.util.Iterator; |
| 47 | import java.util.LinkedList; |
| 48 | import java.util.List; |
| 49 | import java.util.Map; |
| 50 | import java.util.Properties; |
| 51 | import java.util.Set; |
| 52 | import java.util.StringTokenizer; |
| 53 | import javax.servlet.ServletContext; |
| 54 | |
| 55 | /** |
| 56 | * Slug configuration file. |
| 57 | * Holds all <code>ISlugRunner</code>s and <code>IProcessStatusTranslator</code>s |
| 58 | * and provide access to them. |
| 59 | * |
| 60 | * @author rossen |
| 61 | */ |
| 62 | class SlugConfig implements Serializable |
| 63 | { |
| 64 | |
| 65 | private static final long serialVersionUID = 1L; |
| 66 | |
| 67 | /** Singleton nistnace of SlugConfig */ |
| 68 | private static SlugConfig inst = new SlugConfig(); |
| 69 | |
| 70 | /** Holds all translators */ |
| 71 | private Map translators; |
| 72 | |
| 73 | /** |
| 74 | * Holds all ISlugRunner runners |
| 75 | */ |
| 76 | private Map runners; |
| 77 | |
| 78 | /** Holds the name of the first runner added as a default one */ |
| 79 | private Map defaultInstances; |
| 80 | |
| 81 | /** Key for the default runner implementation */ |
| 82 | private static final String RUNNER = "runner"; |
| 83 | |
| 84 | /** Key for the default translator implementation */ |
| 85 | private static final String TRANSLATOR = "translator"; |
| 86 | |
| 87 | /** Creates a new instance of SlugConfig |
| 88 | */ |
| 89 | private SlugConfig() { |
| 90 | defaultInstances = new HashMap(); |
| 91 | runners = new HashMap(); |
| 92 | translators = new HashMap(); |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * Initialize SlugConfig's singleton instance. |
| 97 | * This method should be called only once during the <code>Slug</code> servlet initialization. |
| 98 | * @param impl ISlugConfigParser implementation class name |
| 99 | * @param is Slug's configuration properties input stream. |
| 100 | * @exception SlugInitializationException if provided configurataion file is not |
| 101 | * accessible or is invald, or if provided implementation cannot be instantiated. |
| 102 | * @exception IllegalArgumentException in case of null parameter or if provided |
| 103 | * implementation does not implement ISlugConfigParser. |
| 104 | */ |
| 105 | static SlugConfig init(String impl, InputStream is) throws SlugInitializationException, IllegalArgumentException |
| 106 | { |
| 107 | if (is == null) |
| 108 | { |
| 109 | throw new IllegalArgumentException("Null input stream supplied!"); |
| 110 | } |
| 111 | if ((impl == null) || (impl.trim().length() == 0)) |
| 112 | { |
| 113 | throw new IllegalArgumentException("ISlugConfigParser implementation null or empty!"); |
| 114 | } |
| 115 | try |
| 116 | { |
| 117 | // instantiate the ISlugConfigParser implementation |
| 118 | Class implCls = Class.forName(impl); |
| 119 | ISlugConfigParser cfgParser = (ISlugConfigParser) implCls.newInstance(); |
| 120 | cfgParser.load(is); |
| 121 | |
| 122 | // load all runners and translators |
| 123 | inst.putRunnersInService(cfgParser.getRunnerDefs()); |
| 124 | inst.putTranslatorsInService(cfgParser.getTranslatorDefs()); |
| 125 | return inst; |
| 126 | } |
| 127 | catch (ClassCastException cce) |
| 128 | { |
| 129 | throw new IllegalArgumentException( |
| 130 | "Invalid ISlugConfigParser implementation!"); |
| 131 | } |
| 132 | catch (Throwable t) |
| 133 | { |
| 134 | throw new SlugInitializationException( |
| 135 | "ISlugConfigParser implementation istantiation failed!", t); |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | /** Obtain current instance |
| 140 | * @return SlugConfig instance. |
| 141 | */ |
| 142 | static SlugConfig getInstance() |
| 143 | { |
| 144 | return inst; |
| 145 | } |
| 146 | |
| 147 | /** |
| 148 | * Initialize and put in service provided <code>ISlugRuner</code> definitions. |
| 149 | * This is a simple wrapper arround putInService(String, Map, InstanceDef[]) |
| 150 | * @param defs instance definitiosns to be installed. |
| 151 | * @exception SlugInitializationException in case of instantiation problem. |
| 152 | * @see #putInService(String, Map, InstanceDef[]) |
| 153 | */ |
| 154 | private void putRunnersInService(InstanceDef[] defs) throws SlugInitializationException |
| 155 | { |
| 156 | putInService(RUNNER, runners, defs); |
| 157 | } |
| 158 | |
| 159 | /** |
| 160 | * Initialize and put in service provided <code>IProcessStatusTranslator</code> definitions. |
| 161 | * This is a simple wrapper arround putInService(String, Map, InstanceDef[]) |
| 162 | * @param defs instance definitiosns to be installed. |
| 163 | * @exception SlugInitializationException in case of instantiation problem. |
| 164 | * @see #putInService(String, Map, InstanceDef[]) |
| 165 | */ |
| 166 | private void putTranslatorsInService(InstanceDef[] defs) throws SlugInitializationException |
| 167 | { |
| 168 | putInService(TRANSLATOR, translators, defs); |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Initialize and put in service provided <code>ISlugService</code> definitions. |
| 173 | * @param type name of the ISlugService implementations. |
| 174 | * @param m container for instantiated instances. |
| 175 | * @param defs instance definitiosns to be installed. |
| 176 | * @exception SlugInitializationException in case of instantiation problem. |
| 177 | */ |
| 178 | private void putInService(String type, Map m, InstanceDef[] defs) throws SlugInitializationException |
| 179 | { |
| 180 | if ((defs == null) || (defs.length == 0)) |
| 181 | { |
| 182 | throw new SlugInitializationException("Missing " + type + " definitions!"); |
| 183 | } |
| 184 | for (int i = 0; i < defs.length; i++) |
| 185 | { |
| 186 | try |
| 187 | { |
| 188 | ISlugService svc = (ISlugService) Class.forName(defs[i].className).newInstance(); |
| 189 | svc.init(defs[i].params); |
| 190 | svc.prepare(); |
| 191 | m.put(defs[i].name, svc); |
| 192 | if (!defaultInstances.containsKey(type)) |
| 193 | { |
| 194 | defaultInstances.put(type, defs[i].name); |
| 195 | } |
| 196 | } |
| 197 | catch (SlugInitializationException sie) |
| 198 | { |
| 199 | throw sie; |
| 200 | } |
| 201 | catch (Throwable t) |
| 202 | { |
| 203 | throw new SlugInitializationException("Error instantiationg " + |
| 204 | type + " \"" + defs[i].name + "\": ", t); |
| 205 | } |
| 206 | } |
| 207 | } |
| 208 | |
| 209 | /** |
| 210 | * Retrieve named <code>ISlugRunner</code> |
| 211 | * |
| 212 | * @param rName name of a runner. |
| 213 | * @return <code>ISlugRunner</code> for provided name if instantiated, othewise null. |
| 214 | */ |
| 215 | ISlugRunner getRunner(String rName) |
| 216 | { |
| 217 | return (ISlugRunner) runners.get(rName); |
| 218 | } |
| 219 | |
| 220 | /** |
| 221 | * Retrieve named <code>IProcessStatusTranslator</code> |
| 222 | * |
| 223 | * @param tName name of a translator. |
| 224 | * @return <code>IProcessStatusTranslator</code> for provided name if |
| 225 | * instantiated, othewise null. |
| 226 | */ |
| 227 | IProcessStatusTranslator getTranslator(String tName) |
| 228 | { |
| 229 | return (IProcessStatusTranslator) translators.get(tName); |
| 230 | } |
| 231 | |
| 232 | /** |
| 233 | * Obtain default instance name for specified type. |
| 234 | * @return the name of the default instance for specified type. |
| 235 | */ |
| 236 | private String getDefaultName(String type) throws SlugInitializationException |
| 237 | { |
| 238 | String name = (String) defaultInstances.get(type); |
| 239 | if (name == null) |
| 240 | throw new SlugInitializationException("There are not any " + type + |
| 241 | "s in service yet!"); |
| 242 | return name; |
| 243 | } |
| 244 | |
| 245 | /** |
| 246 | * Getter for the defaultRunnerName property. |
| 247 | * |
| 248 | * @return the defaultRunnerName property value. |
| 249 | * @exception SlugInitializationException if no <code>ISlugRunner/code>s |
| 250 | * are put in service yet. |
| 251 | */ |
| 252 | String getDefaultRunnerName() throws SlugInitializationException |
| 253 | { |
| 254 | return getDefaultName(RUNNER); |
| 255 | } |
| 256 | |
| 257 | /** |
| 258 | * Getter for the defaultRunnerName property. |
| 259 | * |
| 260 | * @return the defaultTranslatorName property value. |
| 261 | * @exception SlugInitializationException if no <code>IProcessStatusTranslator/code>s |
| 262 | * are put in service yet. |
| 263 | */ |
| 264 | String getDefaultTranslatorName() throws SlugInitializationException |
| 265 | { |
| 266 | return getDefaultName(TRANSLATOR); |
| 267 | } |
| 268 | |
| 269 | /** Returns an array of all keys for the map. |
| 270 | * @param map source Map. |
| 271 | * @return String array of map's keys. If provided map is null or empty |
| 272 | * array with length 0 is returned. |
| 273 | */ |
| 274 | private String[] getMapKeys(Map m) |
| 275 | { |
| 276 | String [] result = new String[0]; |
| 277 | if ((m != null) && !m.isEmpty()) |
| 278 | { |
| 279 | Set keyNames = m.keySet(); |
| 280 | if ((keyNames != null) && !keyNames.isEmpty()) |
| 281 | { |
| 282 | result = (String []) keyNames.toArray(new String[keyNames.size()]); |
| 283 | } |
| 284 | } |
| 285 | return result; |
| 286 | } |
| 287 | |
| 288 | /** |
| 289 | * Retrieve a list of runner names. |
| 290 | * |
| 291 | * @return a list with the names of all instantiated <code>ISlugRunner</code>s. |
| 292 | */ |
| 293 | String [] getRunnerNames() |
| 294 | { |
| 295 | return getMapKeys(runners); |
| 296 | } |
| 297 | |
| 298 | /** |
| 299 | * Retrieve a list of translator aleiases. |
| 300 | * |
| 301 | * @return a list with the aliases of all instantiated <code>IProcessStatusTranslator</code>s. |
| 302 | */ |
| 303 | String [] getTranslatorNames() |
| 304 | { |
| 305 | return getMapKeys(translators); |
| 306 | } |
| 307 | |
| 308 | /** Clear all instantiated runners |
| 309 | */ |
| 310 | synchronized void clear() |
| 311 | { |
| 312 | // clear runners |
| 313 | String [] runnerNames = getRunnerNames(); |
| 314 | for (int i = 0; i < runnerNames.length; i++) |
| 315 | { |
| 316 | ISlugRunner r = getRunner(runnerNames[i]); |
| 317 | r.clear(); |
| 318 | runners.remove(runnerNames[i]); |
| 319 | } |
| 320 | // clear translators |
| 321 | translators = new HashMap(); |
| 322 | // clear the default instances |
| 323 | defaultInstances = new HashMap(); |
| 324 | } |
| 325 | |
| 326 | } |