1 /*
2 * Copyright (c) 1999, 2009, Oracle and/or its affiliates. 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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
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20 *
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24 */
25
26 package javax.naming;
27
28 import java.util.Hashtable;
29 import javax.naming.spi.NamingManager;
30 import com.sun.naming.internal.ResourceManager;
31
32 /**
33 * This class is the starting context for performing naming operations.
34 *<p>
35 * All naming operations are relative to a context.
36 * The initial context implements the Context interface and
37 * provides the starting point for resolution of names.
38 *<p>
39 * <a name=ENVIRONMENT></a>
40 * When the initial context is constructed, its environment
41 * is initialized with properties defined in the environment parameter
42 * passed to the constructor, and in any
43 * <a href=Context.html#RESOURCEFILES>application resource files</a>.
44 * In addition, a small number of standard JNDI properties may
45 * be specified as system properties or as applet parameters
46 * (through the use of {@link Context#APPLET}).
47 * These special properties are listed in the field detail sections of the
48 * <a href=Context.html#field_detail><tt>Context</tt></a> and
49 * <a href=ldap/LdapContext.html#field_detail><tt>LdapContext</tt></a>
50 * interface documentation.
51 *<p>
52 * JNDI determines each property's value by merging
53 * the values from the following two sources, in order:
54 * <ol>
55 * <li>
56 * The first occurrence of the property from the constructor's
57 * environment parameter and (for appropriate properties) the applet
58 * parameters and system properties.
59 * <li>
60 * The application resource files (<tt>jndi.properties</tt>).
61 * </ol>
62 * For each property found in both of these two sources, or in
63 * more than one application resource file, the property's value
64 * is determined as follows. If the property is
65 * one of the standard JNDI properties that specify a list of JNDI
66 * factories (see <a href=Context.html#LISTPROPS><tt>Context</tt></a>),
67 * all of the values are
68 * concatenated into a single colon-separated list. For other
69 * properties, only the first value found is used.
70 *
71 *<p>
72 * The initial context implementation is determined at runtime.
73 * The default policy uses the environment property
74 * "{@link Context#INITIAL_CONTEXT_FACTORY java.naming.factory.initial}",
75 * which contains the class name of the initial context factory.
76 * An exception to this policy is made when resolving URL strings, as described
77 * below.
78 *<p>
79 * When a URL string (a <tt>String</tt> of the form
80 * <em>scheme_id:rest_of_name</em>) is passed as a name parameter to
81 * any method, a URL context factory for handling that scheme is
82 * located and used to resolve the URL. If no such factory is found,
83 * the initial context specified by
84 * <tt>"java.naming.factory.initial"</tt> is used. Similarly, when a
85 * <tt>CompositeName</tt> object whose first component is a URL string is
86 * passed as a name parameter to any method, a URL context factory is
87 * located and used to resolve the first name component.
88 * See {@link NamingManager#getURLContext
89 * <tt>NamingManager.getURLContext()</tt>} for a description of how URL
90 * context factories are located.
91 *<p>
92 * This default policy of locating the initial context and URL context
93 * factories may be overridden
94 * by calling
95 * <tt>NamingManager.setInitialContextFactoryBuilder()</tt>.
96 *<p>
97 * NoInitialContextException is thrown when an initial context cannot
98 * be instantiated. This exception can be thrown during any interaction
99 * with the InitialContext, not only when the InitialContext is constructed.
100 * For example, the implementation of the initial context might lazily
101 * retrieve the context only when actual methods are invoked on it.
102 * The application should not have any dependency on when the existence
103 * of an initial context is determined.
104 *<p>
105 * When the environment property "java.naming.factory.initial" is
106 * non-null, the InitialContext constructor will attempt to create the
107 * initial context specified therein. At that time, the initial context factory
108 * involved might throw an exception if a problem is encountered. However,
109 * it is provider implementation-dependent when it verifies and indicates
110 * to the users of the initial context any environment property- or
111 * connection- related problems. It can do so lazily--delaying until
112 * an operation is performed on the context, or eagerly, at the time
113 * the context is constructed.
114 *<p>
115 * An InitialContext instance is not synchronized against concurrent
116 * access by multiple threads. Multiple threads each manipulating a
117 * different InitialContext instance need not synchronize.
118 * Threads that need to access a single InitialContext instance
119 * concurrently should synchronize amongst themselves and provide the
120 * necessary locking.
121 *
122 * @author Rosanna Lee
123 * @author Scott Seligman
124 *
125 * @see Context
126 * @see NamingManager#setInitialContextFactoryBuilder
127 * NamingManager.setInitialContextFactoryBuilder
128 * @since JNDI 1.1 / Java 2 Platform, Standard Edition, v 1.3
129 */
130
131 public class InitialContext implements Context {
132
133 /**
134 * The environment associated with this InitialContext.
135 * It is initialized to null and is updated by the constructor
136 * that accepts an environment or by the <tt>init()</tt> method.
137 * @see #addToEnvironment
138 * @see #removeFromEnvironment
139 * @see #getEnvironment
140 */
141 protected Hashtable<Object,Object> myProps = null;
142
143 /**
144 * Field holding the result of calling NamingManager.getInitialContext().
145 * It is set by getDefaultInitCtx() the first time getDefaultInitCtx()
146 * is called. Subsequent invocations of getDefaultInitCtx() return
147 * the value of defaultInitCtx.
148 * @see #getDefaultInitCtx
149 */
150 protected Context defaultInitCtx = null;
151
152 /**
153 * Field indicating whether the initial context has been obtained
154 * by calling NamingManager.getInitialContext().
155 * If true, its result is in <code>defaultInitCtx</code>.
156 */
157 protected boolean gotDefault = false;
158
159 /**
160 * Constructs an initial context with the option of not
161 * initializing it. This may be used by a constructor in
162 * a subclass when the value of the environment parameter
163 * is not yet known at the time the <tt>InitialContext</tt>
164 * constructor is called. The subclass's constructor will
165 * call this constructor, compute the value of the environment,
166 * and then call <tt>init()</tt> before returning.
167 *
168 * @param lazy
169 * true means do not initialize the initial context; false
170 * is equivalent to calling <tt>new InitialContext()</tt>
171 * @throws NamingException if a naming exception is encountered
172 *
173 * @see #init(Hashtable)
174 * @since 1.3
175 */
176 protected InitialContext(boolean lazy) throws NamingException {
177 if (!lazy) {
178 init(null);
179 }
180 }
181
182 /**
183 * Constructs an initial context.
184 * No environment properties are supplied.
185 * Equivalent to <tt>new InitialContext(null)</tt>.
186 *
187 * @throws NamingException if a naming exception is encountered
188 *
189 * @see #InitialContext(Hashtable)
190 */
191 public InitialContext() throws NamingException {
192 init(null);
193 }
194
195 /**
196 * Constructs an initial context using the supplied environment.
197 * Environment properties are discussed in the class description.
198 *
199 * <p> This constructor will not modify <tt>environment</tt>
200 * or save a reference to it, but may save a clone.
201 * Caller should not modify mutable keys and values in
202 * <tt>environment</tt> after it has been passed to the constructor.
203 *
204 * @param environment
205 * environment used to create the initial context.
206 * Null indicates an empty environment.
207 *
208 * @throws NamingException if a naming exception is encountered
209 */
210 public InitialContext(Hashtable<?,?> environment)
211 throws NamingException
212 {
213 if (environment != null) {
214 environment = (Hashtable)environment.clone();
215 }
216 init(environment);
217 }
218
219 /**
220 * Initializes the initial context using the supplied environment.
221 * Environment properties are discussed in the class description.
222 *
223 * <p> This method will modify <tt>environment</tt> and save
224 * a reference to it. The caller may no longer modify it.
225 *
226 * @param environment
227 * environment used to create the initial context.
228 * Null indicates an empty environment.
229 *
230 * @throws NamingException if a naming exception is encountered
231 *
232 * @see #InitialContext(boolean)
233 * @since 1.3
234 */
235 protected void init(Hashtable<?,?> environment)
236 throws NamingException
237 {
238 myProps = ResourceManager.getInitialEnvironment(environment);
239
240 if (myProps.get(Context.INITIAL_CONTEXT_FACTORY) != null) {
241 // user has specified initial context factory; try to get it
242 getDefaultInitCtx();
243 }
244 }
245
246 /**
247 * A static method to retrieve the named object.
248 * This is a shortcut method equivalent to invoking:
249 * <p>
250 * <code>
251 * InitialContext ic = new InitialContext();
252 * Object obj = ic.lookup();
253 * </code>
254 * <p> If <tt>name</tt> is empty, returns a new instance of this context
255 * (which represents the same naming context as this context, but its
256 * environment may be modified independently and it may be accessed
257 * concurrently).
258 *
259 * @param name
260 * the name of the object to look up
261 * @return the object bound to <tt>name</tt>
262 * @throws NamingException if a naming exception is encountered
263 *
264 * @see #doLookup(String)
265 * @see #lookup(Name)
266 * @since 1.6
267 */
268 public static <T> T doLookup(Name name)
269 throws NamingException {
270 return (T) (new InitialContext()).lookup(name);
271 }
272
273 /**
274 * A static method to retrieve the named object.
275 * See {@link #doLookup(Name)} for details.
276 * @param name
277 * the name of the object to look up
278 * @return the object bound to <tt>name</tt>
279 * @throws NamingException if a naming exception is encountered
280 * @since 1.6
281 */
282 public static <T> T doLookup(String name)
283 throws NamingException {
284 return (T) (new InitialContext()).lookup(name);
285 }
286
287 private static String getURLScheme(String str) {
288 int colon_posn = str.indexOf(':');
289 int slash_posn = str.indexOf('/');
290
291 if (colon_posn > 0 && (slash_posn == -1 || colon_posn < slash_posn))
292 return str.substring(0, colon_posn);
293 return null;
294 }
295
296 /**
297 * Retrieves the initial context by calling
298 * <code>NamingManager.getInitialContext()</code>
299 * and cache it in defaultInitCtx.
300 * Set <code>gotDefault</code> so that we know we've tried this before.
301 * @return The non-null cached initial context.
302 * @exception NoInitialContextException If cannot find an initial context.
303 * @exception NamingException If a naming exception was encountered.
304 */
305 protected Context getDefaultInitCtx() throws NamingException{
306 if (!gotDefault) {
307 defaultInitCtx = NamingManager.getInitialContext(myProps);
308 gotDefault = true;
309 }
310 if (defaultInitCtx == null)
311 throw new NoInitialContextException();
312
313 return defaultInitCtx;
314 }
315
316 /**
317 * Retrieves a context for resolving the string name <code>name</code>.
318 * If <code>name</code> name is a URL string, then attempt
319 * to find a URL context for it. If none is found, or if
320 * <code>name</code> is not a URL string, then return
321 * <code>getDefaultInitCtx()</code>.
322 *<p>
323 * See getURLOrDefaultInitCtx(Name) for description
324 * of how a subclass should use this method.
325 * @param name The non-null name for which to get the context.
326 * @return A URL context for <code>name</code> or the cached
327 * initial context. The result cannot be null.
328 * @exception NoInitialContextException If cannot find an initial context.
329 * @exception NamingException In a naming exception is encountered.
330 * @see javax.naming.spi.NamingManager#getURLContext
331 */
332 protected Context getURLOrDefaultInitCtx(String name)
333 throws NamingException {
334 if (NamingManager.hasInitialContextFactoryBuilder()) {
335 return getDefaultInitCtx();
336 }
337 String scheme = getURLScheme(name);
338 if (scheme != null) {
339 Context ctx = NamingManager.getURLContext(scheme, myProps);
340 if (ctx != null) {
341 return ctx;
342 }
343 }
344 return getDefaultInitCtx();
345 }
346
347 /**
348 * Retrieves a context for resolving <code>name</code>.
349 * If the first component of <code>name</code> name is a URL string,
350 * then attempt to find a URL context for it. If none is found, or if
351 * the first component of <code>name</code> is not a URL string,
352 * then return <code>getDefaultInitCtx()</code>.
353 *<p>
354 * When creating a subclass of InitialContext, use this method as
355 * follows.
356 * Define a new method that uses this method to get an initial
357 * context of the desired subclass.
358 * <p><blockquote><pre>
359 * protected XXXContext getURLOrDefaultInitXXXCtx(Name name)
360 * throws NamingException {
361 * Context answer = getURLOrDefaultInitCtx(name);
362 * if (!(answer instanceof XXXContext)) {
363 * if (answer == null) {
364 * throw new NoInitialContextException();
365 * } else {
366 * throw new NotContextException("Not an XXXContext");
367 * }
368 * }
369 * return (XXXContext)answer;
370 * }
371 * </pre></blockquote>
372 * When providing implementations for the new methods in the subclass,
373 * use this newly defined method to get the initial context.
374 * <p><blockquote><pre>
375 * public Object XXXMethod1(Name name, ...) {
376 * throws NamingException {
377 * return getURLOrDefaultInitXXXCtx(name).XXXMethod1(name, ...);
378 * }
379 * </pre></blockquote>
380 *
381 * @param name The non-null name for which to get the context.
382 * @return A URL context for <code>name</code> or the cached
383 * initial context. The result cannot be null.
384 * @exception NoInitialContextException If cannot find an initial context.
385 * @exception NamingException In a naming exception is encountered.
386 *
387 * @see javax.naming.spi.NamingManager#getURLContext
388 */
389 protected Context getURLOrDefaultInitCtx(Name name)
390 throws NamingException {
391 if (NamingManager.hasInitialContextFactoryBuilder()) {
392 return getDefaultInitCtx();
393 }
394 if (name.size() > 0) {
395 String first = name.get(0);
396 String scheme = getURLScheme(first);
397 if (scheme != null) {
398 Context ctx = NamingManager.getURLContext(scheme, myProps);
399 if (ctx != null) {
400 return ctx;
401 }
402 }
403 }
404 return getDefaultInitCtx();
405 }
406
407 // Context methods
408 // Most Javadoc is deferred to the Context interface.
409
410 public Object lookup(String name) throws NamingException {
411 return getURLOrDefaultInitCtx(name).lookup(name);
412 }
413
414 public Object lookup(Name name) throws NamingException {
415 return getURLOrDefaultInitCtx(name).lookup(name);
416 }
417
418 public void bind(String name, Object obj) throws NamingException {
419 getURLOrDefaultInitCtx(name).bind(name, obj);
420 }
421
422 public void bind(Name name, Object obj) throws NamingException {
423 getURLOrDefaultInitCtx(name).bind(name, obj);
424 }
425
426 public void rebind(String name, Object obj) throws NamingException {
427 getURLOrDefaultInitCtx(name).rebind(name, obj);
428 }
429
430 public void rebind(Name name, Object obj) throws NamingException {
431 getURLOrDefaultInitCtx(name).rebind(name, obj);
432 }
433
434 public void unbind(String name) throws NamingException {
435 getURLOrDefaultInitCtx(name).unbind(name);
436 }
437
438 public void unbind(Name name) throws NamingException {
439 getURLOrDefaultInitCtx(name).unbind(name);
440 }
441
442 public void rename(String oldName, String newName) throws NamingException {
443 getURLOrDefaultInitCtx(oldName).rename(oldName, newName);
444 }
445
446 public void rename(Name oldName, Name newName)
447 throws NamingException
448 {
449 getURLOrDefaultInitCtx(oldName).rename(oldName, newName);
450 }
451
452 public NamingEnumeration<NameClassPair> list(String name)
453 throws NamingException
454 {
455 return (getURLOrDefaultInitCtx(name).list(name));
456 }
457
458 public NamingEnumeration<NameClassPair> list(Name name)
459 throws NamingException
460 {
461 return (getURLOrDefaultInitCtx(name).list(name));
462 }
463
464 public NamingEnumeration<Binding> listBindings(String name)
465 throws NamingException {
466 return getURLOrDefaultInitCtx(name).listBindings(name);
467 }
468
469 public NamingEnumeration<Binding> listBindings(Name name)
470 throws NamingException {
471 return getURLOrDefaultInitCtx(name).listBindings(name);
472 }
473
474 public void destroySubcontext(String name) throws NamingException {
475 getURLOrDefaultInitCtx(name).destroySubcontext(name);
476 }
477
478 public void destroySubcontext(Name name) throws NamingException {
479 getURLOrDefaultInitCtx(name).destroySubcontext(name);
480 }
481
482 public Context createSubcontext(String name) throws NamingException {
483 return getURLOrDefaultInitCtx(name).createSubcontext(name);
484 }
485
486 public Context createSubcontext(Name name) throws NamingException {
487 return getURLOrDefaultInitCtx(name).createSubcontext(name);
488 }
489
490 public Object lookupLink(String name) throws NamingException {
491 return getURLOrDefaultInitCtx(name).lookupLink(name);
492 }
493
494 public Object lookupLink(Name name) throws NamingException {
495 return getURLOrDefaultInitCtx(name).lookupLink(name);
496 }
497
498 public NameParser getNameParser(String name) throws NamingException {
499 return getURLOrDefaultInitCtx(name).getNameParser(name);
500 }
501
502 public NameParser getNameParser(Name name) throws NamingException {
503 return getURLOrDefaultInitCtx(name).getNameParser(name);
504 }
505
506 /**
507 * Composes the name of this context with a name relative to
508 * this context.
509 * Since an initial context may never be named relative
510 * to any context other than itself, the value of the
511 * <tt>prefix</tt> parameter must be an empty name (<tt>""</tt>).
512 */
513 public String composeName(String name, String prefix)
514 throws NamingException {
515 return name;
516 }
517
518 /**
519 * Composes the name of this context with a name relative to
520 * this context.
521 * Since an initial context may never be named relative
522 * to any context other than itself, the value of the
523 * <tt>prefix</tt> parameter must be an empty name.
524 */
525 public Name composeName(Name name, Name prefix)
526 throws NamingException
527 {
528 return (Name)name.clone();
529 }
530
531 public Object addToEnvironment(String propName, Object propVal)
532 throws NamingException {
533 myProps.put(propName, propVal);
534 return getDefaultInitCtx().addToEnvironment(propName, propVal);
535 }
536
537 public Object removeFromEnvironment(String propName)
538 throws NamingException {
539 myProps.remove(propName);
540 return getDefaultInitCtx().removeFromEnvironment(propName);
541 }
542
543 public Hashtable<?,?> getEnvironment() throws NamingException {
544 return getDefaultInitCtx().getEnvironment();
545 }
546
547 public void close() throws NamingException {
548 myProps = null;
549 if (defaultInitCtx != null) {
550 defaultInitCtx.close();
551 defaultInitCtx = null;
552 }
553 gotDefault = false;
554 }
555
556 public String getNameInNamespace() throws NamingException {
557 return getDefaultInitCtx().getNameInNamespace();
558 }
559 };