001/* NamingManager.java -- Creates contexts and objects 002 Copyright (C) 2000, 2001, 2002, 2003, 2004, 003 2006 Free Software Foundation, Inc. 004 005This file is part of GNU Classpath. 006 007GNU Classpath is free software; you can redistribute it and/or modify 008it under the terms of the GNU General Public License as published by 009the Free Software Foundation; either version 2, or (at your option) 010any later version. 011 012GNU Classpath is distributed in the hope that it will be useful, but 013WITHOUT ANY WARRANTY; without even the implied warranty of 014MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 015General Public License for more details. 016 017You should have received a copy of the GNU General Public License 018along with GNU Classpath; see the file COPYING. If not, write to the 019Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02002110-1301 USA. 021 022Linking this library statically or dynamically with other modules is 023making a combined work based on this library. Thus, the terms and 024conditions of the GNU General Public License cover the whole 025combination. 026 027As a special exception, the copyright holders of this library give you 028permission to link this library with independent modules to produce an 029executable, regardless of the license terms of these independent 030modules, and to copy and distribute the resulting executable under 031terms of your choice, provided that you also meet, for each linked 032independent module, the terms and conditions of the license of that 033module. An independent module is a module which is not derived from 034or based on this library. If you modify this library, you may extend 035this exception to your version of the library, but you are not 036obligated to do so. If you do not wish to do so, delete this 037exception statement from your version. */ 038 039 040package javax.naming.spi; 041 042import gnu.classpath.VMStackWalker; 043 044import gnu.java.lang.CPStringBuilder; 045 046import java.util.Enumeration; 047import java.util.Hashtable; 048import java.util.StringTokenizer; 049 050import javax.naming.CannotProceedException; 051import javax.naming.Context; 052import javax.naming.Name; 053import javax.naming.NamingException; 054import javax.naming.NoInitialContextException; 055import javax.naming.RefAddr; 056import javax.naming.Reference; 057import javax.naming.Referenceable; 058import javax.naming.StringRefAddr; 059 060/** 061 * Contains methods for creating contexts and objects referred to by 062 * location information. The location is specified in the scope of the 063 * certain naming or directory service. This class only contais static 064 * methods and cannot be instantiated. 065 */ 066public class NamingManager 067{ 068 /** 069 * The environment property into which getContinuationContext() stores the 070 * value of the CannotProceedException parameter. The value of this field 071 * is <i>java.naming.spi.CannotProceedException<i>. 072 */ 073 public static final String CPE = "java.naming.spi.CannotProceedException"; 074 075 private static InitialContextFactoryBuilder icfb; 076 077 // Package private so DirectoryManager can access it. 078 static ObjectFactoryBuilder ofb; 079 080 // This class cannot be instantiated. 081 NamingManager () 082 { 083 } 084 085 /** 086 * Checks if the initial context factory builder has been set. 087 * 088 * @return true if the builder has been set 089 * 090 * @see #setInitialContextFactoryBuilder(InitialContextFactoryBuilder) 091 */ 092 public static boolean hasInitialContextFactoryBuilder () 093 { 094 return icfb != null; 095 } 096 097 /** 098 * Creates the initial context. If the initial object factory builder has 099 * been set with {@link #setObjectFactoryBuilder(ObjectFactoryBuilder)}, 100 * the work is delegated to this builder. Otherwise, the method searches 101 * for the property Context.INITIAL_CONTEXT_FACTORY first in the passed 102 * table and then in the system properties. The value of this property is 103 * uses as a class name to install the context factory. The corresponding 104 * class must exist, be public and have the public parameterless constructor. 105 * 106 * @param environment the properties, used to create the context. 107 * 108 * @return the created context 109 * 110 * @throws NoInitialContextException if the initial builder is not set, 111 * the property Context.INITIAL_CONTEXT_FACTORY is missing of the 112 * class, named by this property, cannot be instantiated. 113 * @throws NamingException if throws by the context factory 114 */ 115 public static Context getInitialContext (Hashtable<?, ?> environment) 116 throws NamingException 117 { 118 InitialContextFactory icf = null; 119 120 if (icfb != null) 121 icf = icfb.createInitialContextFactory(environment); 122 else 123 { 124 String java_naming_factory_initial = null; 125 if (environment != null) 126 java_naming_factory_initial 127 = (String) environment.get (Context.INITIAL_CONTEXT_FACTORY); 128 if (java_naming_factory_initial == null) 129 java_naming_factory_initial = 130 System.getProperty (Context.INITIAL_CONTEXT_FACTORY); 131 if (java_naming_factory_initial == null) 132 throw new 133 NoInitialContextException ("Can't find property: " 134 + Context.INITIAL_CONTEXT_FACTORY); 135 136 try 137 { 138 icf = (InitialContextFactory)Class.forName 139 (java_naming_factory_initial, true, 140 Thread.currentThread().getContextClassLoader()) 141 .newInstance (); 142 } 143 catch (Exception exception) 144 { 145 NoInitialContextException e 146 = new NoInitialContextException 147 ("Can't load InitialContextFactory class: " 148 + java_naming_factory_initial); 149 e.setRootCause(exception); 150 throw e; 151 } 152 } 153 154 return icf.getInitialContext (environment); 155 } 156 157 /** 158 * <p> 159 * Creates the URL context for the given URL scheme id. 160 * </p> 161 * <p> 162 * The class name of the factory that creates the context has the naming 163 * pattern scheme-idURLContextFactory. For instance, the factory for the "ftp" 164 * sheme should be named "ftpURLContextFactory". 165 * </p> 166 * <p> 167 * The Context.URL_PKG_PREFIXES environment property contains the 168 * colon-separated list of the possible package prefixes. The package name is 169 * constructed concatenating the package prefix with the scheme id. This 170 * property is searched in the passed <i>environment</i> parameter and later 171 * in the system properties. 172 * </p> 173 * <p> 174 * If the factory class cannot be found in the specified packages, system will 175 * try to use the default internal factory for the given scheme. 176 * </p> 177 * <p> 178 * After the factory is instantiated, its method 179 * {@link ObjectFactory#getObjectInstance(Object, Name, Context, Hashtable)} 180 * is called to create and return the object instance. 181 * 182 * @param refInfo passed to the factory 183 * @param name passed to the factory 184 * @param nameCtx passed to the factory 185 * @param scheme the url scheme that must be supported by the given context 186 * @param environment the properties for creating the factory and context (may 187 * be null) 188 * @return the created context 189 * @throws NamingException if thrown by the factory when creating the context. 190 */ 191 static Context getURLContext(Object refInfo, Name name, Context nameCtx, 192 String scheme, Hashtable<?,?> environment) 193 throws NamingException 194 { 195 // Doc specifies com.sun.jndi.url as the final destination, but we cannot 196 // put our classes into such namespace. 197 String defaultPrefix = "gnu.javax.naming.jndi.url"; 198 199 // The final default location, as specified in the documentation. 200 String finalPrefix = "com.sun.jndi.url"; 201 202 CPStringBuilder allPrefixes = new CPStringBuilder(); 203 204 String prefixes; 205 if (environment != null) 206 { 207 prefixes = (String) environment.get(Context.URL_PKG_PREFIXES); 208 if (prefixes != null) 209 allPrefixes.append(prefixes); 210 } 211 212 prefixes = System.getProperty(Context.URL_PKG_PREFIXES); 213 if (prefixes != null) 214 { 215 if (allPrefixes.length() > 0) 216 allPrefixes.append(':'); 217 allPrefixes.append(prefixes); 218 } 219 220 if (allPrefixes.length() > 0) 221 allPrefixes.append(':'); 222 allPrefixes.append(defaultPrefix); 223 allPrefixes.append(':'); 224 allPrefixes.append(finalPrefix); 225 226 scheme = scheme + "." + scheme + "URLContextFactory"; 227 228 StringTokenizer tokens = new StringTokenizer(allPrefixes.toString(), ":"); 229 while (tokens.hasMoreTokens()) 230 { 231 String aTry = tokens.nextToken(); 232 try 233 { 234 String tryClass = aTry + "." + scheme; 235 Class factoryClass = forName(tryClass); 236 if (factoryClass != null) 237 { 238 Object obj; 239 try 240 { 241 ObjectFactory factory = (ObjectFactory) factoryClass.newInstance(); 242 obj = factory.getObjectInstance(refInfo, name, nameCtx, 243 environment); 244 Context ctx = (Context) obj; 245 if (ctx != null) 246 return ctx; 247 } 248 catch (RuntimeException e) 249 { 250 // TODO Auto-generated catch block 251 e.printStackTrace(); 252 } 253 } 254 } 255 catch (ClassNotFoundException _1) 256 { 257 // Ignore it. 258 } 259 catch (ClassCastException _2) 260 { 261 // This means that the class we found was not an 262 // ObjectFactory or that the factory returned something 263 // which was not a Context. 264 } 265 catch (InstantiationException _3) 266 { 267 // If we couldn't instantiate the factory we might get 268 // this. 269 } 270 catch (IllegalAccessException _4) 271 { 272 // Another possibility when instantiating. 273 } 274 catch (NamingException _5) 275 { 276 throw _5; 277 } 278 catch (Exception _6) 279 { 280 // Anything from getObjectInstance. 281 } 282 } 283 284 return null; 285 } 286 287 /** 288 * Load the class with the given name. This method tries to use the context 289 * class loader first. If this fails, it searches for the suitable class 290 * loader in the caller stack trace. This method is a central point where all 291 * requests to find a class by name are delegated. 292 */ 293 static Class forName(String className) 294 { 295 try 296 { 297 return Class.forName(className, true, 298 Thread.currentThread().getContextClassLoader()); 299 } 300 catch (ClassNotFoundException nex) 301 { 302 /** 303 * Returns the first user defined class loader on the call stack, or 304 * null when no non-null class loader was found. 305 */ 306 Class[] ctx = VMStackWalker.getClassContext(); 307 for (int i = 0; i < ctx.length; i++) 308 { 309 // Since we live in a class loaded by the bootstrap 310 // class loader, getClassLoader is safe to call without 311 // needing to be wrapped in a privileged action. 312 ClassLoader cl = ctx[i].getClassLoader(); 313 try 314 { 315 if (cl != null) 316 return Class.forName(className, true, cl); 317 } 318 catch (ClassNotFoundException nex2) 319 { 320 // Try next. 321 } 322 } 323 } 324 return null; 325 } 326 327 328 /** 329 * <p> 330 * Creates the URL context for the given URL scheme id. 331 * </p> 332 * <p> 333 * The class name of the factory that creates the context has the naming 334 * pattern scheme-idURLContextFactory. For instance, the factory for the 335 * "ftp" scheme should be named "ftpURLContextFactory". 336 * The Context.URL_PKG_PREFIXES environment property contains the 337 * colon-separated list of the possible package prefixes. The package name 338 * is constructed by concatenating the package prefix with the scheme id. 339 * </p> 340 * <p> 341 * If the factory class cannot be found in the specified packages, the 342 * system will try to use the default internal factory for the given scheme. 343 * </p> 344 * <p> 345 * After the factory is instantiated, its method 346 * {@link ObjectFactory#getObjectInstance(Object, Name, Context, Hashtable)} 347 * is called to create and return the object instance. 348 * 349 * @param scheme the url scheme that must be supported by the given context 350 * @param environment the properties for creating the factory and context 351 * (may be null) 352 * @return the created context 353 * @throws NamingException if thrown by the factory when creating the 354 * context. 355 */ 356 public static Context getURLContext (String scheme, 357 Hashtable<?, ?> environment) 358 throws NamingException 359 { 360 return getURLContext (null, null, null, scheme, environment); 361 } 362 363 /** 364 * Sets the initial object factory builder. 365 * 366 * @param builder the builder to set 367 * 368 * @throws SecurityException if the builder cannot be installed due 369 * security restrictions. 370 * @throws NamingException if the builder cannot be installed due other 371 * reasons 372 * @throws IllegalStateException if setting the builder repeatedly 373 */ 374 public static void setObjectFactoryBuilder (ObjectFactoryBuilder builder) 375 throws NamingException 376 { 377 SecurityManager sm = System.getSecurityManager (); 378 if (sm != null) 379 sm.checkSetFactory (); 380 // Once the builder is installed it cannot be replaced. 381 if (ofb != null) 382 throw new IllegalStateException ("object factory builder already installed"); 383 if (builder != null) 384 ofb = builder; 385 } 386 387 static StringTokenizer getPlusPath (String property, Hashtable env, 388 Context nameCtx) 389 throws NamingException 390 { 391 String path = (String) env.get (property); 392 if (nameCtx == null) 393 nameCtx = getInitialContext (env); 394 String path2 = (String) nameCtx.getEnvironment ().get (property); 395 if (path == null) 396 path = path2; 397 else if (path2 != null) 398 path += ":" + path2; 399 return new StringTokenizer (path != null ? path : "", ":"); 400 } 401 402 /** 403 * <p>Creates an object for the specified name context, environment and 404 * referencing context object.</p> 405 * <p> 406 * If the builder factory is set by 407 * {@link #setObjectFactoryBuilder(ObjectFactoryBuilder)}, the call is 408 * delegated to that factory. Otherwise, the object is created using the 409 * following rules: 410 * <ul> 411 * <li>If the referencing object (refInfo) contains the factory class name, 412 * the object is created by this factory. If the creation fails, 413 * the parameter refInfo is returned as the method return value.</li> 414 * <li>If the referencing object has no factory class name, and the addresses 415 * are StringRefAddrs having the address type "URL", the object is 416 * created by the URL context factory. The used factory corresponds the 417 * the naming schema of the each URL. If the attempt to create 418 * the object this way is not successful, the subsequent rule is 419 * tried.</li> 420 * <li> If the refInfo is not an instance of Reference or Referencable 421 * (for example, null), the object is created by the factories, 422 * specified in the Context.OBJECT_FACTORIES property of the 423 * environment and the provider resource file, associated with the 424 * nameCtx. The value of this property is the colon separated list 425 * of the possible factories. If none of the factories can be 426 * loaded, the refInfo is returned. 427 * </ul> 428 * </p> 429 * <p>The object factory must be public and have the public parameterless 430 * constructor.</p> 431 * 432 * @param refInfo the referencing object, for which the new object must be 433 * created (can be null). If not null, it is usually an instance of 434 * the {@link Reference} or {@link Referenceable}. 435 * @param name the name of the object. The name is relative to 436 * the nameCtx naming context. The value of this parameter can be 437 * null if the name is not specified. 438 * @param nameCtx the naming context, in which scope the name of the new 439 * object is specified. If this parameter is null, the name is 440 * specified in the scope of the initial context. 441 * @param environment contains additional information for creating the object. 442 * This paramter can be null if there is no need to provide any 443 * additional information. 444 * 445 * @return the created object. If the creation fails, in some cases 446 * the parameter refInfo may be returned. 447 * 448 * @throws NamingException if the attempt to name the new object has failed 449 * @throws Exception if the object factory throws it. The object factory 450 * only throws an exception if it does not want other factories 451 * to be used to create the object. 452 */ 453 public static Object getObjectInstance (Object refInfo, 454 Name name, 455 Context nameCtx, 456 Hashtable<?, ?> environment) 457 throws Exception 458 { 459 ObjectFactory factory = null; 460 461 if (ofb != null) 462 factory = ofb.createObjectFactory (refInfo, environment); 463 else 464 { 465 // First see if we have a Reference or a Referenceable. If so 466 // we do some special processing. 467 Object ref2 = refInfo; 468 if (refInfo instanceof Referenceable) 469 ref2 = ((Referenceable) refInfo).getReference (); 470 if (ref2 instanceof Reference) 471 { 472 Reference ref = (Reference) ref2; 473 474 // If we have a factory class name then we use that. 475 String fClass = ref.getFactoryClassName (); 476 if (fClass != null) 477 { 478 // Exceptions here are passed to the caller. 479 Class k = Class.forName (fClass, 480 true, 481 Thread.currentThread().getContextClassLoader()); 482 factory = (ObjectFactory) k.newInstance (); 483 } 484 else 485 { 486 // There's no factory class name. If the address is a 487 // StringRefAddr with address type `URL', then we try 488 // the URL's context factory. 489 Enumeration e = ref.getAll (); 490 while (e.hasMoreElements ()) 491 { 492 RefAddr ra = (RefAddr) e.nextElement (); 493 if (ra instanceof StringRefAddr 494 && "URL".equals (ra.getType ())) 495 { 496 factory 497 = (ObjectFactory) getURLContext (refInfo, 498 name, 499 nameCtx, 500 (String) ra.getContent (), 501 environment); 502 Object obj = factory.getObjectInstance (refInfo, 503 name, 504 nameCtx, 505 environment); 506 if (obj != null) 507 return obj; 508 } 509 } 510 511 // Have to try the next step. 512 factory = null; 513 } 514 } 515 516 // Now look at OBJECT_FACTORIES to find the factory. 517 if (factory == null) 518 { 519 StringTokenizer tokens = getPlusPath (Context.OBJECT_FACTORIES, 520 environment, nameCtx); 521 522 while (tokens.hasMoreTokens ()) 523 { 524 String klassName = tokens.nextToken (); 525 Class k = Class.forName (klassName, 526 true, 527 Thread.currentThread().getContextClassLoader()); 528 factory = (ObjectFactory) k.newInstance (); 529 Object obj = factory.getObjectInstance (refInfo, name, 530 nameCtx, environment); 531 if (obj != null) 532 return obj; 533 } 534 535 // Failure. 536 return refInfo; 537 } 538 } 539 540 if (factory == null) 541 return refInfo; 542 Object obj = factory.getObjectInstance (refInfo, name, 543 nameCtx, environment); 544 return obj == null ? refInfo : obj; 545 } 546 547 /** 548 * Sets the initial context factory builder. 549 * 550 * @param builder the builder to set 551 * 552 * @throws SecurityException if the builder cannot be installed due 553 * security restrictions. 554 * @throws NamingException if the builder cannot be installed due other 555 * reasons 556 * @throws IllegalStateException if setting the builder repeatedly 557 * 558 * @see #hasInitialContextFactoryBuilder() 559 */ 560 public static void setInitialContextFactoryBuilder 561 (InitialContextFactoryBuilder builder) 562 throws NamingException 563 { 564 SecurityManager sm = System.getSecurityManager (); 565 if (sm != null) 566 sm.checkSetFactory (); 567 // Once the builder is installed it cannot be replaced. 568 if (icfb != null) 569 throw new IllegalStateException ("ctx factory builder already installed"); 570 if (builder != null) 571 icfb = builder; 572 } 573 574 /** 575 * Creates a context in which the context operation must be continued. 576 * This method is used by operations on names that span multiple namespaces. 577 * 578 * @param cpe the exception that triggered this continuation. This method 579 * obtains the environment ({@link CannotProceedException#getEnvironment()} 580 * and sets the environment property {@link #CPE} = cpe. 581 * 582 * @return a non null context for continuing the operation 583 * 584 * @throws NamingException if the naming problems have occured 585 */ 586 public static Context getContinuationContext (CannotProceedException cpe) 587 throws NamingException 588 { 589 Hashtable env = cpe.getEnvironment (); 590 if (env != null) 591 env.put (CPE, cpe); 592 593 // TODO: Check if this implementation matches the API specification 594 try 595 { 596 Object obj = getObjectInstance (cpe.getResolvedObj(), 597 cpe.getAltName (), 598 cpe.getAltNameCtx (), 599 env); 600 if (obj != null) 601 return (Context) obj; 602 } 603 catch (Exception _) 604 { 605 } 606 607 // fix stack trace for re-thrown exception (message confusing otherwise) 608 cpe.fillInStackTrace(); 609 610 throw cpe; 611 } 612 613 /** 614 * Get the object state for binding. 615 * 616 * @param obj the object, for that the binding state must be retrieved. Cannot 617 * be null. 618 * @param name the name of this object, related to the nameCtx. Can be null if 619 * not specified. 620 * @param nameCtx the naming context, to that the object name is related. Can 621 * be null if the name is related to the initial default context. 622 * @param environment the properties for creating the object state. Can be 623 * null if no properties are provided. 624 * @return the object state for binding, may be null if no changes are 625 * returned by the factory 626 * @throws NamingException 627 */ 628 public static Object getStateToBind (Object obj, Name name, 629 Context nameCtx, Hashtable<?, ?> environment) 630 throws NamingException 631 { 632 StringTokenizer tokens = getPlusPath (Context.STATE_FACTORIES, 633 environment, nameCtx); 634 while (tokens.hasMoreTokens ()) 635 { 636 String klassName = tokens.nextToken (); 637 try 638 { 639 Class k = Class.forName (klassName, 640 true, 641 Thread.currentThread().getContextClassLoader()); 642 StateFactory factory = (StateFactory) k.newInstance (); 643 Object o = factory.getStateToBind (obj, name, nameCtx, 644 environment); 645 if (o != null) 646 return o; 647 } 648 catch (ClassNotFoundException _1) 649 { 650 // Ignore it. 651 } 652 catch (ClassCastException _2) 653 { 654 // This means that the class we found was not an 655 // ObjectFactory or that the factory returned something 656 // which was not a Context. 657 } 658 catch (InstantiationException _3) 659 { 660 // If we couldn't instantiate the factory we might get 661 // this. 662 } 663 catch (IllegalAccessException _4) 664 { 665 // Another possibility when instantiating. 666 } 667 } 668 669 return obj; 670 } 671}