J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2003-2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.sql.rowset.spi; |
| 27 | |
| 28 | import java.util.Map; |
| 29 | import java.util.Hashtable; |
| 30 | import java.util.Enumeration; |
| 31 | import java.util.Vector; |
| 32 | import java.util.Properties; |
| 33 | import java.util.Collection; |
| 34 | import java.util.StringTokenizer; |
| 35 | import java.util.logging.*; |
| 36 | import java.util.*; |
| 37 | |
| 38 | import java.sql.*; |
| 39 | import javax.sql.*; |
| 40 | |
| 41 | import java.io.FileInputStream; |
| 42 | import java.io.IOException; |
| 43 | import java.io.FileNotFoundException; |
| 44 | |
| 45 | import javax.naming.*; |
| 46 | |
| 47 | /** |
| 48 | * The Service Provider Interface (SPI) mechanism that generates <code>SyncProvider</code> |
| 49 | * instances to be used by disconnected <code>RowSet</code> objects. |
| 50 | * The <code>SyncProvider</code> instances in turn provide the |
| 51 | * <code>javax.sql.RowSetReader</code> object the <code>RowSet</code> object |
| 52 | * needs to populate itself with data and the |
| 53 | * <code>javax.sql.RowSetWriter</code> object it needs to |
| 54 | * propagate changes to its |
| 55 | * data back to the underlying data source. |
| 56 | * <P> |
| 57 | * Because the methods in the <code>SyncFactory</code> class are all static, |
| 58 | * there is only one <code>SyncFactory</code> object |
| 59 | * per Java VM at any one time. This ensures that there is a single source from which a |
| 60 | * <code>RowSet</code> implementation can obtain its <code>SyncProvider</code> |
| 61 | * implementation. |
| 62 | * <p> |
| 63 | * <h3>1.0 Overview</h3> |
| 64 | * The <code>SyncFactory</code> class provides an internal registry of available |
| 65 | * synchronization provider implementations (<code>SyncProvider</code> objects). |
| 66 | * This registry may be queried to determine which |
| 67 | * synchronization providers are available. |
| 68 | * The following line of code gets an enumeration of the providers currently registered. |
| 69 | * <PRE> |
| 70 | * java.util.Enumeration e = SyncFactory.getRegisteredProviders(); |
| 71 | * </PRE> |
| 72 | * All standard <code>RowSet</code> implementations must provide at least two providers: |
| 73 | * <UL> |
| 74 | * <LI>an optimistic provider for use with a <code>CachedRowSet</code> implementation |
| 75 | * or an implementation derived from it |
| 76 | * <LI>an XML provider, which is used for reading and writing XML, such as with |
| 77 | * <code>WebRowSet</code> objects |
| 78 | * </UL> |
| 79 | * Note that the JDBC RowSet Implementations include the <code>SyncProvider</code> |
| 80 | * implemtations <code>RIOptimisticProvider</code> and <code>RIXmlProvider</code>, |
| 81 | * which satisfy this requirement. |
| 82 | * <P> |
| 83 | * The <code>SyncFactory</code> class provides accessor methods to assist |
| 84 | * applications in determining which synchronization providers are currently |
| 85 | * registered with the <code>SyncFactory</code>. |
| 86 | * <p> |
| 87 | * Other methods let <code>RowSet</code> persistence providers be |
| 88 | * registered or de-registered with the factory mechanism. This |
| 89 | * allows additional synchronization provider implementations to be made |
| 90 | * available to <code>RowSet</code> objects at run time. |
| 91 | * <p> |
| 92 | * Applications can apply a degree of filtering to determine the level of |
| 93 | * synchronization that a <code>SyncProvider</code> implementation offers. |
| 94 | * The following criteria determine whether a provider is |
| 95 | * made available to a <code>RowSet</code> object: |
| 96 | * <ol> |
| 97 | * <li>If a particular provider is specified by a <code>RowSet</code> object, and |
| 98 | * the <code>SyncFactory</code> does not contain a reference to this provider, |
| 99 | * a <code>SyncFactoryException</code> is thrown stating that the synchronization |
| 100 | * provider could not be found. |
| 101 | * <p> |
| 102 | * <li>If a <code>RowSet</code> implementation is instantiated with a specified |
| 103 | * provider and the specified provider has been properly registered, the |
| 104 | * requested provider is supplied. Otherwise a <code>SyncFactoryException</code> |
| 105 | * is thrown. |
| 106 | * <p> |
| 107 | * <li>If a <code>RowSet</code> object does not specify a |
| 108 | * <code>SyncProvider</code> implementation and no additional |
| 109 | * <code>SyncProvider</code> implementations are available, the reference |
| 110 | * implementation providers are supplied. |
| 111 | * </ol> |
| 112 | * <h3>2.0 Registering <code>SyncProvider</code> Implementations</h3> |
| 113 | * <p> |
| 114 | * Both vendors and developers can register <code>SyncProvider</code> |
| 115 | * implementations using one of the following mechanisms. |
| 116 | * <ul> |
| 117 | * <LI><B>Using the command line</B><BR> |
| 118 | * The name of the provider is supplied on the command line, which will add |
| 119 | * the provider to the system properties. |
| 120 | * For example: |
| 121 | * <PRE> |
| 122 | * -Drowset.provider.classname=com.fred.providers.HighAvailabilityProvider |
| 123 | * </PRE> |
| 124 | * <li><b>Using the Standard Properties File</b><BR> |
| 125 | * The reference implementation is targeted |
| 126 | * to ship with J2SE 1.5, which will include an additional resource file |
| 127 | * that may be edited by hand. Here is an example of the properties file |
| 128 | * included in the reference implementation: |
| 129 | * <PRE> |
| 130 | * #Default JDBC RowSet sync providers listing |
| 131 | * # |
| 132 | * |
| 133 | * # Optimistic synchronization provider |
| 134 | * rowset.provider.classname.0=com.sun.rowset.providers.RIOptimisticProvider |
| 135 | * rowset.provider.vendor.0=Sun Microsystems Inc |
| 136 | * rowset.provider.version.0=1.0 |
| 137 | * |
| 138 | * # XML Provider using standard XML schema |
| 139 | * rowset.provider.classname.1=com.sun.rowset.providers.RIXMLProvider |
| 140 | * rowset.provider.vendor.1=Sun Microsystems Inc. |
| 141 | * rowset.provider.version.1=1.0 |
| 142 | * </PRE> |
| 143 | * The <code>SyncFactory</code> checks this file and registers the |
| 144 | * <code>SyncProvider</code> implementations that it contains. A |
| 145 | * developer or vendor can add other implementations to this file. |
| 146 | * For example, here is a possible addition: |
| 147 | * <PRE> |
| 148 | * rowset.provider.classname.2=com.fred.providers.HighAvailabilityProvider |
| 149 | * rowset.provider.vendor.2=Fred, Inc. |
| 150 | * rowset.provider.version.2=1.0 |
| 151 | * </PRE> |
| 152 | * <p> |
| 153 | * <li><b>Using a JNDI Context</b><BR> |
| 154 | * Available providers can be registered on a JNDI |
| 155 | * context, and the <code>SyncFactory</code> will attempt to load |
| 156 | * <code>SyncProvider</code> implementations from that JNDI context. |
| 157 | * For example, the following code fragment registers a provider implementation |
| 158 | * on a JNDI context. This is something a deployer would normally do. In this |
| 159 | * example, <code>MyProvider</code> is being registered on a CosNaming |
| 160 | * namespace, which is the namespace used by J2EE resources. |
| 161 | * <PRE> |
| 162 | * import javax.naming.*; |
| 163 | * |
| 164 | * Hashtable svrEnv = new Hashtable(); |
| 165 | * srvEnv.put(Context.INITIAL_CONTEXT_FACTORY, "CosNaming"); |
| 166 | * |
| 167 | * Context ctx = new InitialContext(svrEnv); |
| 168 | * com.fred.providers.MyProvider = new MyProvider(); |
| 169 | * ctx.rebind("providers/MyProvider", syncProvider); |
| 170 | * </PRE> |
| 171 | * </ul> |
| 172 | * Next, an application will register the JNDI context with the |
| 173 | * <code>SyncFactory</code> instance. This allows the <code>SyncFactory</code> |
| 174 | * to browse within the JNDI context looking for <code>SyncProvider</code> |
| 175 | * implementations. |
| 176 | * <PRE> |
| 177 | * Hashtable appEnv = new Hashtable(); |
| 178 | * appEnv.put(Context.INITIAL_CONTEXT_FACTORY, "CosNaming"); |
| 179 | * appEnv.put(Context.PROVIDER_URL, "iiop://hostname/providers"); |
| 180 | * Context ctx = new InitialContext(appEnv); |
| 181 | * |
| 182 | * SyncFactory.registerJNDIContext(ctx); |
| 183 | * </PRE> |
| 184 | * If a <code>RowSet</code> object attempts to obtain a <code>MyProvider</code> |
| 185 | * object, the <code>SyncFactory</code> will try to locate it. First it searches |
| 186 | * for it in the system properties, then it looks in the resource files, and |
| 187 | * finally it checks the JNDI context that has been set. The <code>SyncFactory</code> |
| 188 | * instance verifies that the requested provider is a valid extension of the |
| 189 | * <code>SyncProvider</code> abstract class and then gives it to the |
| 190 | * <code>RowSet</code> object. In the following code fragment, a new |
| 191 | * <code>CachedRowSet</code> object is created and initialized with |
| 192 | * <i>env</i>, which contains the binding to <code>MyProvider</code>. |
| 193 | * <PRE> |
| 194 | * Hashtable env = new Hashtable(); |
| 195 | * env.put(SyncFactory.ROWSET_SYNC_PROVIDER, "com.fred.providers.MyProvider"); |
| 196 | * CachedRowSet crs = new com.sun.rowset.CachedRowSetImpl(env); |
| 197 | * </PRE> |
| 198 | * Further details on these mechanisms are available in the |
| 199 | * <code>javax.sql.rowset.spi</code> package specification. |
| 200 | * |
| 201 | * @author Jonathan Bruce |
| 202 | * @see javax.sql.rowset.spi.SyncProvider |
| 203 | * @see javax.sql.rowset.spi.SyncFactoryException |
| 204 | */ |
| 205 | public class SyncFactory { |
| 206 | |
| 207 | /* |
| 208 | * The variable that represents the singleton instance |
| 209 | * of the <code>SyncFactory</code> class. |
| 210 | */ |
| 211 | private static SyncFactory syncFactory = null; |
| 212 | |
| 213 | /** |
| 214 | * Creates a new <code>SyncFactory</code> object, which is the singleton |
| 215 | * instance. |
| 216 | * Having a private constructor guarantees that no more than |
| 217 | * one <code>SyncProvider</code> object can exist at a time. |
| 218 | */ |
| 219 | private SyncFactory() {}; |
| 220 | |
| 221 | /** |
| 222 | * The standard property-id for a synchronization provider implementation |
| 223 | * name. |
| 224 | */ |
| 225 | public static String ROWSET_SYNC_PROVIDER = |
| 226 | "rowset.provider.classname"; |
| 227 | |
| 228 | /** |
| 229 | * The standard property-id for a synchronization provider implementation |
| 230 | * vendor name. |
| 231 | */ |
| 232 | public static String ROWSET_SYNC_VENDOR = |
| 233 | "rowset.provider.vendor"; |
| 234 | |
| 235 | /** |
| 236 | * The standard property-id for a synchronization provider implementation |
| 237 | * version tag. |
| 238 | */ |
| 239 | public static String ROWSET_SYNC_PROVIDER_VERSION = |
| 240 | "rowset.provider.version"; |
| 241 | |
| 242 | /** |
| 243 | * The standard resource file name. |
| 244 | */ |
| 245 | private static String ROWSET_PROPERTIES = "rowset.properties"; |
| 246 | |
| 247 | /** |
| 248 | * The RI Optimistic Provider. |
| 249 | */ |
| 250 | private static String default_provider = |
| 251 | "com.sun.rowset.providers.RIOptimisticProvider"; |
| 252 | |
| 253 | /** |
| 254 | * The initial JNDI context where <code>SyncProvider</code> implementations can |
| 255 | * be stored and from which they can be invoked. |
| 256 | */ |
| 257 | private static Context ic; |
| 258 | |
| 259 | /** |
| 260 | * The <code>Logger</code> object to be used by the <code>SyncFactory</code>. |
| 261 | */ |
| 262 | private static Logger rsLogger; |
| 263 | |
| 264 | /** |
| 265 | * |
| 266 | */ |
| 267 | private static Level rsLevel; |
| 268 | |
| 269 | /** |
| 270 | * The registry of available <code>SyncProvider</code> implementations. |
| 271 | * See section 2.0 of the class comment for <code>SyncFactory</code> for an |
| 272 | * explanation of how a provider can be added to this registry. |
| 273 | */ |
| 274 | private static Hashtable implementations; |
| 275 | |
| 276 | /** |
| 277 | * Internal sync object used to maintain the SPI as a singleton |
| 278 | */ |
| 279 | private static Object logSync = new Object(); |
| 280 | |
| 281 | /** |
| 282 | * Internal PrintWriter field for logging facility |
| 283 | */ |
| 284 | private static java.io.PrintWriter logWriter = null; |
| 285 | |
| 286 | /** |
| 287 | * Adds the the given synchronization provider to the factory register. Guidelines |
| 288 | * are provided in the <code>SyncProvider</code> specification for the |
| 289 | * required naming conventions for <code>SyncProvider</code> |
| 290 | * implementations. |
| 291 | * <p> |
| 292 | * Synchronization providers bound to a JNDI context can be |
| 293 | * registered by binding a SyncProvider instance to a JNDI namespace. |
| 294 | * <ul> |
| 295 | * <pre> |
| 296 | * SyncProvider p = new MySyncProvider(); |
| 297 | * InitialContext ic = new InitialContext(); |
| 298 | * ic.bind ("jdbc/rowset/MySyncProvider", p); |
| 299 | * </pre> |
| 300 | * </ul> |
| 301 | * Furthermore, an initial JNDI context should be set with the |
| 302 | * <code>SyncFactory</code> using the <code>setJNDIContext</code> method. |
| 303 | * The <code>SyncFactory</code> leverages this context to search for |
| 304 | * available <code>SyncProvider</code> objects bound to the JNDI |
| 305 | * context and its child nodes. |
| 306 | * |
| 307 | * @param providerID A <code>String</code> object with the unique ID of the |
| 308 | * synchronization provider being registered |
| 309 | * @throws SyncFactoryException if an attempt is made to supply an empty |
| 310 | * or null provider name |
| 311 | * @see #setJNDIContext |
| 312 | */ |
| 313 | public static synchronized void registerProvider(String providerID) |
| 314 | throws SyncFactoryException { |
| 315 | |
| 316 | ProviderImpl impl = new ProviderImpl(); |
| 317 | impl.setClassname(providerID); |
| 318 | initMapIfNecessary(); |
| 319 | implementations.put(providerID, impl); |
| 320 | |
| 321 | } |
| 322 | |
| 323 | /** |
| 324 | * Returns the <code>SyncFactory</code> singleton. |
| 325 | * |
| 326 | * @return the <code>SyncFactory</code> instance |
| 327 | */ |
| 328 | public static SyncFactory getSyncFactory(){ |
| 329 | |
| 330 | // This method uses the Singleton Design Pattern |
| 331 | // with Double-Checked Locking Pattern for |
| 332 | // 1. Creating single instance of the SyncFactory |
| 333 | // 2. Make the class thread safe, so that at one time |
| 334 | // only one thread enters the synchronized block |
| 335 | // to instantiate. |
| 336 | |
| 337 | // if syncFactory object is already there |
| 338 | // don't go into synchronized block and return |
| 339 | // that object. |
| 340 | // else go into synchronized block |
| 341 | |
| 342 | if(syncFactory == null){ |
| 343 | synchronized(SyncFactory.class) { |
| 344 | if(syncFactory == null){ |
| 345 | syncFactory = new SyncFactory(); |
| 346 | } //end if |
| 347 | } //end synchronized block |
| 348 | } //end if |
| 349 | return syncFactory; |
| 350 | } |
| 351 | |
| 352 | /** |
| 353 | * Removes the designated currently registered synchronization provider from the |
| 354 | * Factory SPI register. |
| 355 | * |
| 356 | * @param providerID The unique-id of the synchronization provider |
| 357 | * @throws SyncFactoryException If an attempt is made to |
| 358 | * unregister a SyncProvider implementation that was not registered. |
| 359 | */ |
| 360 | public static synchronized void unregisterProvider(String providerID) |
| 361 | throws SyncFactoryException { |
| 362 | initMapIfNecessary(); |
| 363 | if (implementations.containsKey(providerID)) { |
| 364 | implementations.remove(providerID); |
| 365 | } |
| 366 | } |
| 367 | |
| 368 | private static String colon = ":"; |
| 369 | private static String strFileSep = "/"; |
| 370 | |
| 371 | private static synchronized void initMapIfNecessary() throws SyncFactoryException { |
| 372 | |
| 373 | // Local implementation class names and keys from Properties |
| 374 | // file, translate names into Class objects using Class.forName |
| 375 | // and store mappings |
| 376 | Properties properties = new Properties(); |
| 377 | |
| 378 | if (implementations == null) { |
| 379 | implementations = new Hashtable(); |
| 380 | |
| 381 | try { |
| 382 | |
| 383 | // check if user is supplying his Synchronisation Provider |
| 384 | // Implementation if not use Sun's implementation. |
| 385 | // properties.load(new FileInputStream(ROWSET_PROPERTIES)); |
| 386 | |
| 387 | // The rowset.properties needs to be in jdk/jre/lib when |
| 388 | // integrated with jdk. |
| 389 | // else it should be picked from -D option from command line. |
| 390 | |
| 391 | // -Drowset.properties will add to standard properties. Similar |
| 392 | // keys will over-write |
| 393 | |
| 394 | /* |
| 395 | * Dependent on application |
| 396 | */ |
| 397 | String strRowsetProperties = System.getProperty("rowset.properties"); |
| 398 | if ( strRowsetProperties != null) { |
| 399 | // Load user's implementation of SyncProvider |
| 400 | // here. -Drowset.properties=/abc/def/pqr.txt |
| 401 | ROWSET_PROPERTIES = strRowsetProperties; |
| 402 | properties.load(new FileInputStream(ROWSET_PROPERTIES)); |
| 403 | parseProperties(properties); |
| 404 | } |
| 405 | |
| 406 | /* |
| 407 | * Always available |
| 408 | */ |
| 409 | ROWSET_PROPERTIES = "javax" + strFileSep + "sql" + |
| 410 | strFileSep + "rowset" + strFileSep + |
| 411 | "rowset.properties"; |
| 412 | // properties.load( |
| 413 | // ClassLoader.getSystemResourceAsStream(ROWSET_PROPERTIES)); |
| 414 | |
| 415 | ClassLoader cl = Thread.currentThread().getContextClassLoader(); |
| 416 | |
| 417 | properties.load(cl.getResourceAsStream(ROWSET_PROPERTIES)); |
| 418 | parseProperties(properties); |
| 419 | |
| 420 | // removed else, has properties should sum together |
| 421 | |
| 422 | } catch (FileNotFoundException e) { |
| 423 | throw new SyncFactoryException("Cannot locate properties file: " + e); |
| 424 | } catch (IOException e) { |
| 425 | throw new SyncFactoryException("IOException: " + e); |
| 426 | } |
| 427 | |
| 428 | /* |
| 429 | * Now deal with -Drowset.provider.classname |
| 430 | * load additional properties from -D command line |
| 431 | */ |
| 432 | properties.clear(); |
| 433 | String providerImpls = System.getProperty(ROWSET_SYNC_PROVIDER); |
| 434 | |
| 435 | if (providerImpls != null) { |
| 436 | int i = 0; |
| 437 | if (providerImpls.indexOf(colon) > 0) { |
| 438 | StringTokenizer tokenizer = new StringTokenizer(providerImpls, colon); |
| 439 | while (tokenizer.hasMoreElements()) { |
| 440 | properties.put(ROWSET_SYNC_PROVIDER + "." + i, tokenizer.nextToken()); |
| 441 | i++; |
| 442 | } |
| 443 | } else { |
| 444 | properties.put(ROWSET_SYNC_PROVIDER, providerImpls); |
| 445 | } |
| 446 | parseProperties(properties); |
| 447 | } |
| 448 | } |
| 449 | } |
| 450 | |
| 451 | /** |
| 452 | * The internal boolean switch that indicates whether a JNDI |
| 453 | * context has been established or not. |
| 454 | */ |
| 455 | private static boolean jndiCtxEstablished = false; |
| 456 | |
| 457 | /** |
| 458 | * The internal debug switch. |
| 459 | */ |
| 460 | private static boolean debug = false; |
| 461 | |
| 462 | /** |
| 463 | * Internal registry count for the number of providers contained in the |
| 464 | * registry. |
| 465 | */ |
| 466 | private static int providerImplIndex = 0; |
| 467 | |
| 468 | /** |
| 469 | * Internal handler for all standard property parsing. Parses standard |
| 470 | * ROWSET properties and stores lazy references into the the internal registry. |
| 471 | */ |
| 472 | private static void parseProperties(Properties p) { |
| 473 | |
| 474 | ProviderImpl impl = null; |
| 475 | String key = null; |
| 476 | String[] propertyNames = null; |
| 477 | |
| 478 | for (Enumeration e = p.propertyNames(); e.hasMoreElements() ;) { |
| 479 | |
| 480 | String str = (String)e.nextElement(); |
| 481 | |
| 482 | int w = str.length(); |
| 483 | |
| 484 | if (str.startsWith(SyncFactory.ROWSET_SYNC_PROVIDER)) { |
| 485 | |
| 486 | impl = new ProviderImpl(); |
| 487 | impl.setIndex(providerImplIndex++); |
| 488 | |
| 489 | if (w == (SyncFactory.ROWSET_SYNC_PROVIDER).length()) { |
| 490 | // no property index has been set. |
| 491 | propertyNames = getPropertyNames(false); |
| 492 | } else { |
| 493 | // property index has been set. |
| 494 | propertyNames = getPropertyNames(true, str.substring(w-1)); |
| 495 | } |
| 496 | |
| 497 | key = p.getProperty(propertyNames[0]); |
| 498 | impl.setClassname(key); |
| 499 | impl.setVendor(p.getProperty(propertyNames[1])); |
| 500 | impl.setVersion(p.getProperty(propertyNames[2])); |
| 501 | implementations.put(key, impl); |
| 502 | } |
| 503 | } |
| 504 | } |
| 505 | |
| 506 | /** |
| 507 | * Used by the parseProperties methods to disassemble each property tuple. |
| 508 | */ |
| 509 | private static String[] getPropertyNames(boolean append) { |
| 510 | return getPropertyNames(append, null); |
| 511 | } |
| 512 | |
| 513 | /** |
| 514 | * Disassembles each property and its associated value. Also handles |
| 515 | * overloaded property names that contain indexes. |
| 516 | */ |
| 517 | private static String[] getPropertyNames(boolean append, |
| 518 | String propertyIndex) { |
| 519 | String dot = "."; |
| 520 | String[] propertyNames = |
| 521 | new String[] {SyncFactory.ROWSET_SYNC_PROVIDER, |
| 522 | SyncFactory.ROWSET_SYNC_VENDOR, |
| 523 | SyncFactory.ROWSET_SYNC_PROVIDER_VERSION}; |
| 524 | if (append) { |
| 525 | for (int i = 0; i < propertyNames.length; i++) { |
| 526 | propertyNames[i] = propertyNames[i] + |
| 527 | dot + |
| 528 | propertyIndex; |
| 529 | } |
| 530 | return propertyNames; |
| 531 | } else { |
| 532 | return propertyNames; |
| 533 | } |
| 534 | } |
| 535 | |
| 536 | /** |
| 537 | * Internal debug method that outputs the registry contents. |
| 538 | */ |
| 539 | private static void showImpl(ProviderImpl impl) { |
| 540 | System.out.println("Provider implementation:"); |
| 541 | System.out.println("Classname: " + impl.getClassname()); |
| 542 | System.out.println("Vendor: " + impl.getVendor()); |
| 543 | System.out.println("Version: " + impl.getVersion()); |
| 544 | System.out.println("Impl index: " + impl.getIndex()); |
| 545 | } |
| 546 | |
| 547 | /** |
| 548 | * Returns the <code>SyncProvider</code> instance identified by <i>providerID</i>. |
| 549 | * |
| 550 | * @param providerID the unique identifier of the provider |
| 551 | * @return a <code>SyncProvider</code> implementation |
| 552 | * @throws SyncFactoryException If the SyncProvider cannot be found or |
| 553 | * some error was encountered when trying to invoke this provider. |
| 554 | */ |
| 555 | public static SyncProvider getInstance(String providerID) |
| 556 | throws SyncFactoryException { |
| 557 | initMapIfNecessary(); // populate HashTable |
| 558 | initJNDIContext(); // check JNDI context for any additional bindings |
| 559 | |
| 560 | ProviderImpl impl = (ProviderImpl)implementations.get(providerID); |
| 561 | |
| 562 | if (impl == null) { |
| 563 | // Requested SyncProvider is unavailable. Return default provider. |
| 564 | return new com.sun.rowset.providers.RIOptimisticProvider(); |
| 565 | } |
| 566 | |
| 567 | // Attempt to invoke classname from registered SyncProvider list |
| 568 | Class c = null; |
| 569 | try { |
| 570 | ClassLoader cl = Thread.currentThread().getContextClassLoader(); |
| 571 | |
| 572 | /** |
| 573 | * The SyncProvider implementation of the user will be in |
| 574 | * the classpath. We need to find the ClassLoader which loads |
| 575 | * this SyncFactory and try to laod the SyncProvider class from |
| 576 | * there. |
| 577 | **/ |
| 578 | |
| 579 | c = Class.forName(providerID, true, cl); |
| 580 | |
| 581 | if (c != null) { |
| 582 | return (SyncProvider)c.newInstance(); |
| 583 | } else { |
| 584 | return new com.sun.rowset.providers.RIOptimisticProvider(); |
| 585 | } |
| 586 | |
| 587 | } catch (IllegalAccessException e) { |
| 588 | throw new SyncFactoryException("IllegalAccessException: " + e.getMessage()); |
| 589 | } catch (InstantiationException e) { |
| 590 | throw new SyncFactoryException("InstantiationException: " + e.getMessage()); |
| 591 | } catch (ClassNotFoundException e) { |
| 592 | throw new SyncFactoryException("ClassNotFoundException: " + e.getMessage()); |
| 593 | } |
| 594 | } |
| 595 | /** |
| 596 | * Returns an Enumeration of currently registered synchronization |
| 597 | * providers. A <code>RowSet</code> implementation may use any provider in |
| 598 | * the enumeration as its <code>SyncProvider</code> object. |
| 599 | * <p> |
| 600 | * At a minimum, the reference synchronization provider allowing |
| 601 | * RowSet content data to be stored using a JDBC driver should be |
| 602 | * possible. |
| 603 | * |
| 604 | * @return Enumeration A enumeration of available synchronization |
| 605 | * providers that are registered with this Factory |
| 606 | */ |
| 607 | public static Enumeration<SyncProvider> getRegisteredProviders() |
| 608 | throws SyncFactoryException { |
| 609 | initMapIfNecessary(); |
| 610 | // return a collection of classnames |
| 611 | // of type SyncProvider |
| 612 | return implementations.elements(); |
| 613 | } |
| 614 | |
| 615 | /** |
| 616 | * Sets the logging object to be used by the <code>SyncProvider</code> |
| 617 | * implementation provided by the <code>SyncFactory</code>. All |
| 618 | * <code>SyncProvider</code> implementations can log their events to |
| 619 | * this object and the application can retrieve a handle to this |
| 620 | * object using the <code>getLogger</code> method. |
| 621 | * |
| 622 | * @param logger A Logger object instance |
| 623 | */ |
| 624 | public static void setLogger(Logger logger) { |
| 625 | rsLogger = logger; |
| 626 | } |
| 627 | |
| 628 | /** |
| 629 | * Sets the logging object that is used by <code>SyncProvider</code> |
| 630 | * implementations provided by the <code>SyncFactory</code> SPI. All |
| 631 | * <code>SyncProvider</code> implementations can log their events |
| 632 | * to this object and the application can retrieve a handle to this |
| 633 | * object using the <code>getLogger</code> method. |
| 634 | * |
| 635 | * @param logger a Logger object instance |
| 636 | * @param level a Level object instance indicating the degree of logging |
| 637 | * required |
| 638 | */ |
| 639 | public static void setLogger(Logger logger, Level level) { |
| 640 | // singleton |
| 641 | |
| 642 | rsLogger = logger; |
| 643 | rsLogger.setLevel(level); |
| 644 | } |
| 645 | |
| 646 | /** |
| 647 | * Returns the logging object for applications to retrieve |
| 648 | * synchronization events posted by SyncProvider implementations. |
| 649 | * |
| 650 | * @throws SyncFactoryException if no logging object has been set. |
| 651 | */ |
| 652 | public static Logger getLogger() throws SyncFactoryException { |
| 653 | // only one logger per session |
| 654 | if(rsLogger == null){ |
| 655 | throw new SyncFactoryException("(SyncFactory) : No logger has been set"); |
| 656 | } |
| 657 | return rsLogger; |
| 658 | } |
| 659 | |
| 660 | /** |
| 661 | * Sets the initial JNDI context from which SyncProvider implementations |
| 662 | * can be retrieved from a JNDI namespace |
| 663 | * |
| 664 | * @param ctx a valid JNDI context |
| 665 | * @throws SyncFactoryException if the supplied JNDI context is null |
| 666 | */ |
| 667 | public static void setJNDIContext(javax.naming.Context ctx) |
| 668 | throws SyncFactoryException { |
| 669 | if (ctx == null) { |
| 670 | throw new SyncFactoryException("Invalid JNDI context supplied"); |
| 671 | } |
| 672 | ic = ctx; |
| 673 | jndiCtxEstablished = true; |
| 674 | } |
| 675 | |
| 676 | /** |
| 677 | * Controls JNDI context intialization. |
| 678 | * |
| 679 | * @throws SyncFactoryException if an error occurs parsing the JNDI context |
| 680 | */ |
| 681 | private static void initJNDIContext() throws SyncFactoryException { |
| 682 | |
| 683 | if (jndiCtxEstablished && (ic != null) && (lazyJNDICtxRefresh == false)) { |
| 684 | try { |
| 685 | parseProperties(parseJNDIContext()); |
| 686 | lazyJNDICtxRefresh = true; // touch JNDI namespace once. |
| 687 | } catch (NamingException e) { |
| 688 | e.printStackTrace(); |
| 689 | throw new SyncFactoryException("SPI: NamingException: " + e.getExplanation()); |
| 690 | } catch (Exception e) { |
| 691 | e.printStackTrace(); |
| 692 | throw new SyncFactoryException("SPI: Exception: " + e.getMessage()); |
| 693 | } |
| 694 | } |
| 695 | } |
| 696 | /** |
| 697 | * Internal switch indicating whether the JNDI namespace should be re-read. |
| 698 | */ |
| 699 | private static boolean lazyJNDICtxRefresh = false; |
| 700 | |
| 701 | /** |
| 702 | * Parses the set JNDI Context and passes bindings to the enumerateBindings |
| 703 | * method when complete. |
| 704 | */ |
| 705 | private static Properties parseJNDIContext() throws NamingException { |
| 706 | |
| 707 | NamingEnumeration bindings = ic.listBindings(""); |
| 708 | Properties properties = new Properties(); |
| 709 | |
| 710 | // Hunt one level below context for available SyncProvider objects |
| 711 | enumerateBindings(bindings, properties); |
| 712 | |
| 713 | return properties; |
| 714 | } |
| 715 | |
| 716 | /** |
| 717 | * Scans each binding on JNDI context and determines if any binding is an |
| 718 | * instance of SyncProvider, if so, add this to the registry and continue to |
| 719 | * scan the current context using a re-entrant call to this method until all |
| 720 | * bindings have been enumerated. |
| 721 | */ |
| 722 | private static void enumerateBindings(NamingEnumeration bindings, |
| 723 | Properties properties) throws NamingException { |
| 724 | |
| 725 | boolean syncProviderObj = false; // move to parameters ? |
| 726 | |
| 727 | try { |
| 728 | Binding bd = null; |
| 729 | Object elementObj = null; |
| 730 | String element = null; |
| 731 | while (bindings.hasMore()) { |
| 732 | bd = (Binding)bindings.next(); |
| 733 | element = bd.getName(); |
| 734 | elementObj = bd.getObject(); |
| 735 | |
| 736 | if (!(ic.lookup(element) instanceof Context)) { |
| 737 | // skip directories/sub-contexts |
| 738 | if (ic.lookup(element) instanceof SyncProvider) { |
| 739 | syncProviderObj = true; |
| 740 | } |
| 741 | } |
| 742 | |
| 743 | if (syncProviderObj) { |
| 744 | SyncProvider sync = (SyncProvider)elementObj; |
| 745 | properties.put(SyncFactory.ROWSET_SYNC_PROVIDER, |
| 746 | sync.getProviderID()); |
| 747 | syncProviderObj = false; // reset |
| 748 | } |
| 749 | |
| 750 | } |
| 751 | } catch (javax.naming.NotContextException e) { |
| 752 | bindings.next(); |
| 753 | // Re-entrant call into method |
| 754 | enumerateBindings(bindings, properties); |
| 755 | } |
| 756 | } |
| 757 | } |
| 758 | |
| 759 | /** |
| 760 | * Internal class that defines the lazy reference construct for each registered |
| 761 | * SyncProvider implementation. |
| 762 | */ |
| 763 | class ProviderImpl extends SyncProvider { |
| 764 | private String className = null; |
| 765 | private String vendorName = null; |
| 766 | private String ver = null; |
| 767 | private int index; |
| 768 | |
| 769 | public void setClassname(String classname) { |
| 770 | className = classname; |
| 771 | } |
| 772 | |
| 773 | public String getClassname() { |
| 774 | return className; |
| 775 | } |
| 776 | |
| 777 | public void setVendor(String vendor) { |
| 778 | vendorName = vendor; |
| 779 | } |
| 780 | |
| 781 | public String getVendor() { |
| 782 | return vendorName; |
| 783 | } |
| 784 | |
| 785 | public void setVersion(String providerVer) { |
| 786 | ver = providerVer; |
| 787 | } |
| 788 | |
| 789 | public String getVersion() { |
| 790 | return ver; |
| 791 | } |
| 792 | |
| 793 | public void setIndex(int i) { |
| 794 | index = i; |
| 795 | } |
| 796 | |
| 797 | public int getIndex() { |
| 798 | return index; |
| 799 | } |
| 800 | |
| 801 | public int getDataSourceLock() throws SyncProviderException { |
| 802 | |
| 803 | int dsLock = 0; |
| 804 | try |
| 805 | { |
| 806 | dsLock = SyncFactory.getInstance(className).getDataSourceLock(); |
| 807 | } catch(SyncFactoryException sfEx) { |
| 808 | |
| 809 | throw new SyncProviderException(sfEx.getMessage()); |
| 810 | } |
| 811 | |
| 812 | return dsLock; |
| 813 | } |
| 814 | |
| 815 | public int getProviderGrade() { |
| 816 | |
| 817 | int grade = 0; |
| 818 | |
| 819 | try |
| 820 | { |
| 821 | grade = SyncFactory.getInstance(className).getProviderGrade(); |
| 822 | } catch(SyncFactoryException sfEx) { |
| 823 | // |
| 824 | } |
| 825 | |
| 826 | return grade; |
| 827 | } |
| 828 | |
| 829 | public String getProviderID() { |
| 830 | return className; |
| 831 | } |
| 832 | |
| 833 | /* |
| 834 | public javax.sql.RowSetInternal getRowSetInternal() { |
| 835 | try |
| 836 | { |
| 837 | return SyncFactory.getInstance(className).getRowSetInternal(); |
| 838 | } catch(SyncFactoryException sfEx) { |
| 839 | // |
| 840 | } |
| 841 | } |
| 842 | */ |
| 843 | |
| 844 | public javax.sql.RowSetReader getRowSetReader() { |
| 845 | |
| 846 | RowSetReader rsReader = null;; |
| 847 | |
| 848 | try |
| 849 | { |
| 850 | rsReader = SyncFactory.getInstance(className).getRowSetReader(); |
| 851 | } catch(SyncFactoryException sfEx) { |
| 852 | // |
| 853 | } |
| 854 | |
| 855 | return rsReader; |
| 856 | |
| 857 | } |
| 858 | |
| 859 | public javax.sql.RowSetWriter getRowSetWriter() { |
| 860 | |
| 861 | RowSetWriter rsWriter = null; |
| 862 | try |
| 863 | { |
| 864 | rsWriter = SyncFactory.getInstance(className).getRowSetWriter(); |
| 865 | } catch(SyncFactoryException sfEx) { |
| 866 | // |
| 867 | } |
| 868 | |
| 869 | return rsWriter; |
| 870 | } |
| 871 | public void setDataSourceLock(int param) |
| 872 | throws SyncProviderException { |
| 873 | |
| 874 | try |
| 875 | { |
| 876 | SyncFactory.getInstance(className).setDataSourceLock(param); |
| 877 | } catch(SyncFactoryException sfEx) { |
| 878 | |
| 879 | throw new SyncProviderException(sfEx.getMessage()); |
| 880 | } |
| 881 | } |
| 882 | |
| 883 | public int supportsUpdatableView() { |
| 884 | |
| 885 | int view = 0; |
| 886 | |
| 887 | try |
| 888 | { |
| 889 | view = SyncFactory.getInstance(className).supportsUpdatableView(); |
| 890 | } catch(SyncFactoryException sfEx) { |
| 891 | // |
| 892 | } |
| 893 | |
| 894 | return view; |
| 895 | } |
| 896 | |
| 897 | } |