1 /*
2 * Copyright (c) 1998, 2008, 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
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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package sun.awt;
27
28 import java.awt.EventQueue;
29 import java.awt.Window;
30 import java.awt.SystemTray;
31 import java.awt.TrayIcon;
32 import java.awt.Toolkit;
33 import java.awt.GraphicsEnvironment;
34 import java.awt.event.InvocationEvent;
35 import java.security.AccessController;
36 import java.security.PrivilegedAction;
37 import java.util.Collections;
38 import java.util.HashMap;
39 import java.util.IdentityHashMap;
40 import java.util.Map;
41 import java.util.Set;
42 import java.util.HashSet;
43 import java.beans.PropertyChangeSupport;
44 import java.beans.PropertyChangeListener;
45 import sun.util.logging.PlatformLogger;
46 import java.util.concurrent.locks.Condition;
47 import java.util.concurrent.locks.Lock;
48 import java.util.concurrent.locks.ReentrantLock;
49 import java.util.concurrent.atomic.AtomicInteger;
50
51 /**
52 * The AppContext is a table referenced by ThreadGroup which stores
53 * application service instances. (If you are not writing an application
54 * service, or don't know what one is, please do not use this class.)
55 * The AppContext allows applet access to what would otherwise be
56 * potentially dangerous services, such as the ability to peek at
57 * EventQueues or change the look-and-feel of a Swing application.<p>
58 *
59 * Most application services use a singleton object to provide their
60 * services, either as a default (such as getSystemEventQueue or
61 * getDefaultToolkit) or as static methods with class data (System).
62 * The AppContext works with the former method by extending the concept
63 * of "default" to be ThreadGroup-specific. Application services
64 * lookup their singleton in the AppContext.<p>
65 *
66 * For example, here we have a Foo service, with its pre-AppContext
67 * code:<p>
68 * <code><pre>
69 * public class Foo {
70 * private static Foo defaultFoo = new Foo();
71 *
72 * public static Foo getDefaultFoo() {
73 * return defaultFoo;
74 * }
75 *
76 * ... Foo service methods
77 * }</pre></code><p>
78 *
79 * The problem with the above is that the Foo service is global in scope,
80 * so that applets and other untrusted code can execute methods on the
81 * single, shared Foo instance. The Foo service therefore either needs
82 * to block its use by untrusted code using a SecurityManager test, or
83 * restrict its capabilities so that it doesn't matter if untrusted code
84 * executes it.<p>
85 *
86 * Here's the Foo class written to use the AppContext:<p>
87 * <code><pre>
88 * public class Foo {
89 * public static Foo getDefaultFoo() {
90 * Foo foo = (Foo)AppContext.getAppContext().get(Foo.class);
91 * if (foo == null) {
92 * foo = new Foo();
93 * getAppContext().put(Foo.class, foo);
94 * }
95 * return foo;
96 * }
97 *
98 * ... Foo service methods
99 * }</pre></code><p>
100 *
101 * Since a separate AppContext can exist for each ThreadGroup, trusted
102 * and untrusted code have access to different Foo instances. This allows
103 * untrusted code access to "system-wide" services -- the service remains
104 * within the AppContext "sandbox". For example, say a malicious applet
105 * wants to peek all of the key events on the EventQueue to listen for
106 * passwords; if separate EventQueues are used for each ThreadGroup
107 * using AppContexts, the only key events that applet will be able to
108 * listen to are its own. A more reasonable applet request would be to
109 * change the Swing default look-and-feel; with that default stored in
110 * an AppContext, the applet's look-and-feel will change without
111 * disrupting other applets or potentially the browser itself.<p>
112 *
113 * Because the AppContext is a facility for safely extending application
114 * service support to applets, none of its methods may be blocked by a
115 * a SecurityManager check in a valid Java implementation. Applets may
116 * therefore safely invoke any of its methods without worry of being
117 * blocked.
118 *
119 * Note: If a SecurityManager is installed which derives from
120 * sun.awt.AWTSecurityManager, it may override the
121 * AWTSecurityManager.getAppContext() method to return the proper
122 * AppContext based on the execution context, in the case where
123 * the default ThreadGroup-based AppContext indexing would return
124 * the main "system" AppContext. For example, in an applet situation,
125 * if a system thread calls into an applet, rather than returning the
126 * main "system" AppContext (the one corresponding to the system thread),
127 * an installed AWTSecurityManager may return the applet's AppContext
128 * based on the execution context.
129 *
130 * @author Thomas Ball
131 * @author Fred Ecks
132 */
133 public final class AppContext {
134 private static final PlatformLogger log = PlatformLogger.getLogger("sun.awt.AppContext");
135
136 /* Since the contents of an AppContext are unique to each Java
137 * session, this class should never be serialized. */
138
139 /*
140 * The key to put()/get() the Java EventQueue into/from the AppContext.
141 */
142 public static final Object EVENT_QUEUE_KEY = new StringBuffer("EventQueue");
143
144 /*
145 * The keys to store EventQueue push/pop lock and condition.
146 */
147 public final static Object EVENT_QUEUE_LOCK_KEY = new StringBuilder("EventQueue.Lock");
148 public final static Object EVENT_QUEUE_COND_KEY = new StringBuilder("EventQueue.Condition");
149
150 /* A map of AppContexts, referenced by ThreadGroup.
151 */
152 private static final Map<ThreadGroup, AppContext> threadGroup2appContext =
153 Collections.synchronizedMap(new IdentityHashMap<ThreadGroup, AppContext>());
154
155 /**
156 * Returns a set containing all <code>AppContext</code>s.
157 */
158 public static Set<AppContext> getAppContexts() {
159 synchronized (threadGroup2appContext) {
160 return new HashSet<AppContext>(threadGroup2appContext.values());
161 }
162 }
163
164 /* The main "system" AppContext, used by everything not otherwise
165 contained in another AppContext. It is implicitly created for
166 standalone apps only (i.e. not applets)
167 */
168 private static volatile AppContext mainAppContext = null;
169
170 /*
171 * The hash map associated with this AppContext. A private delegate
172 * is used instead of subclassing HashMap so as to avoid all of
173 * HashMap's potentially risky methods, such as clear(), elements(),
174 * putAll(), etc.
175 */
176 private final Map<Object, Object> table = new HashMap<>();
177
178 private final ThreadGroup threadGroup;
179
180 /**
181 * If any <code>PropertyChangeListeners</code> have been registered,
182 * the <code>changeSupport</code> field describes them.
183 *
184 * @see #addPropertyChangeListener
185 * @see #removePropertyChangeListener
186 * @see #firePropertyChange
187 */
188 private PropertyChangeSupport changeSupport = null;
189
190 public static final String DISPOSED_PROPERTY_NAME = "disposed";
191 public static final String GUI_DISPOSED = "guidisposed";
192
193 private enum State {
194 VALID,
195 BEING_DISPOSED,
196 DISPOSED
197 };
198
199 private volatile State state = State.VALID;
200
201 public boolean isDisposed() {
202 return state == State.DISPOSED;
203 }
204
205 /*
206 * The total number of AppContexts, system-wide. This number is
207 * incremented at the beginning of the constructor, and decremented
208 * at the end of dispose(). getAppContext() checks to see if this
209 * number is 1. If so, it returns the sole AppContext without
210 * checking Thread.currentThread().
211 */
212 private static final AtomicInteger numAppContexts = new AtomicInteger(0);
213
214
215 /*
216 * The context ClassLoader that was used to create this AppContext.
217 */
218 private final ClassLoader contextClassLoader;
219
220 /**
221 * Constructor for AppContext. This method is <i>not</i> public,
222 * nor should it ever be used as such. The proper way to construct
223 * an AppContext is through the use of SunToolkit.createNewAppContext.
224 * A ThreadGroup is created for the new AppContext, a Thread is
225 * created within that ThreadGroup, and that Thread calls
226 * SunToolkit.createNewAppContext before calling anything else.
227 * That creates both the new AppContext and its EventQueue.
228 *
229 * @param threadGroup The ThreadGroup for the new AppContext
230 * @see sun.awt.SunToolkit
231 * @since 1.2
232 */
233 AppContext(ThreadGroup threadGroup) {
234 numAppContexts.incrementAndGet();
235
236 this.threadGroup = threadGroup;
237 threadGroup2appContext.put(threadGroup, this);
238
239 this.contextClassLoader =
240 AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() {
241 public ClassLoader run() {
242 return Thread.currentThread().getContextClassLoader();
243 }
244 });
245
246 // Initialize push/pop lock and its condition to be used by all the
247 // EventQueues within this AppContext
248 Lock eventQueuePushPopLock = new ReentrantLock();
249 put(EVENT_QUEUE_LOCK_KEY, eventQueuePushPopLock);
250 Condition eventQueuePushPopCond = eventQueuePushPopLock.newCondition();
251 put(EVENT_QUEUE_COND_KEY, eventQueuePushPopCond);
252 }
253
254 private static final ThreadLocal<AppContext> threadAppContext =
255 new ThreadLocal<AppContext>();
256
257 private final static void initMainAppContext() {
258 // On the main Thread, we get the ThreadGroup, make a corresponding
259 // AppContext, and instantiate the Java EventQueue. This way, legacy
260 // code is unaffected by the move to multiple AppContext ability.
261 AccessController.doPrivileged(new PrivilegedAction<Void>() {
262 public Void run() {
263 ThreadGroup currentThreadGroup =
264 Thread.currentThread().getThreadGroup();
265 ThreadGroup parentThreadGroup = currentThreadGroup.getParent();
266 while (parentThreadGroup != null) {
267 // Find the root ThreadGroup to construct our main AppContext
268 currentThreadGroup = parentThreadGroup;
269 parentThreadGroup = currentThreadGroup.getParent();
270 }
271
272 mainAppContext = SunToolkit.createNewAppContext(currentThreadGroup);
273 return null;
274 }
275 });
276 }
277
278 /**
279 * Returns the appropriate AppContext for the caller,
280 * as determined by its ThreadGroup. If the main "system" AppContext
281 * would be returned and there's an AWTSecurityManager installed, it
282 * is called to get the proper AppContext based on the execution
283 * context.
284 *
285 * @return the AppContext for the caller.
286 * @see java.lang.ThreadGroup
287 * @since 1.2
288 */
289 public final static AppContext getAppContext() {
290 // we are standalone app, return the main app context
291 if (numAppContexts.get() == 1 && mainAppContext != null) {
292 return mainAppContext;
293 }
294
295 AppContext appContext = threadAppContext.get();
296
297 if (null == appContext) {
298 appContext = AccessController.doPrivileged(new PrivilegedAction<AppContext>()
299 {
300 public AppContext run() {
301 // Get the current ThreadGroup, and look for it and its
302 // parents in the hash from ThreadGroup to AppContext --
303 // it should be found, because we use createNewContext()
304 // when new AppContext objects are created.
305 ThreadGroup currentThreadGroup = Thread.currentThread().getThreadGroup();
306 ThreadGroup threadGroup = currentThreadGroup;
307
308 // Special case: we implicitly create the main app context
309 // if no contexts have been created yet. This covers standalone apps
310 // and excludes applets because by the time applet starts
311 // a number of contexts have already been created by the plugin.
312 if (numAppContexts.get() == 0) {
313 if (System.getProperty("javaplugin.version") == null &&
314 System.getProperty("javawebstart.version") == null) {
315 initMainAppContext();
316 } else if (System.getProperty("javafx.version") != null &&
317 threadGroup.getParent() != null) {
318 // Swing inside JavaFX case
319 SunToolkit.createNewAppContext();
320 }
321 }
322
323 AppContext context = threadGroup2appContext.get(threadGroup);
324 while (context == null) {
325 threadGroup = threadGroup.getParent();
326 if (threadGroup == null) {
327 return null;
328 }
329 context = threadGroup2appContext.get(threadGroup);
330 }
331
332 // In case we did anything in the above while loop, we add
333 // all the intermediate ThreadGroups to threadGroup2appContext
334 // so we won't spin again.
335 for (ThreadGroup tg = currentThreadGroup; tg != threadGroup; tg = tg.getParent()) {
336 threadGroup2appContext.put(tg, context);
337 }
338
339 // Now we're done, so we cache the latest key/value pair.
340 threadAppContext.set(context);
341
342 return context;
343 }
344 });
345 }
346
347 return appContext;
348 }
349
350 /**
351 * Returns true if the specified AppContext is the main AppContext.
352 *
353 * @param ctx the context to compare with the main context
354 * @return true if the specified AppContext is the main AppContext.
355 * @since 1.8
356 */
357 public final static boolean isMainContext(AppContext ctx) {
358 return (ctx != null && ctx == mainAppContext);
359 }
360
361 private final static AppContext getExecutionAppContext() {
362 SecurityManager securityManager = System.getSecurityManager();
363 if ((securityManager != null) &&
364 (securityManager instanceof AWTSecurityManager))
365 {
366 AWTSecurityManager awtSecMgr = (AWTSecurityManager) securityManager;
367 AppContext secAppContext = awtSecMgr.getAppContext();
368 return secAppContext; // Return what we're told
369 }
370 return null;
371 }
372
373 private long DISPOSAL_TIMEOUT = 5000; // Default to 5-second timeout
374 // for disposal of all Frames
375 // (we wait for this time twice,
376 // once for dispose(), and once
377 // to clear the EventQueue).
378
379 private long THREAD_INTERRUPT_TIMEOUT = 1000;
380 // Default to 1-second timeout for all
381 // interrupted Threads to exit, and another
382 // 1 second for all stopped Threads to die.
383
384 /**
385 * Disposes of this AppContext, all of its top-level Frames, and
386 * all Threads and ThreadGroups contained within it.
387 *
388 * This method must be called from a Thread which is not contained
389 * within this AppContext.
390 *
391 * @exception IllegalThreadStateException if the current thread is
392 * contained within this AppContext
393 * @since 1.2
394 */
395 public void dispose() throws IllegalThreadStateException {
396 // Check to be sure that the current Thread isn't in this AppContext
397 if (this.threadGroup.parentOf(Thread.currentThread().getThreadGroup())) {
398 throw new IllegalThreadStateException(
399 "Current Thread is contained within AppContext to be disposed."
400 );
401 }
402
403 synchronized(this) {
404 if (this.state != State.VALID) {
405 return; // If already disposed or being disposed, bail.
406 }
407
408 this.state = State.BEING_DISPOSED;
409 }
410
411 final PropertyChangeSupport changeSupport = this.changeSupport;
412 if (changeSupport != null) {
413 changeSupport.firePropertyChange(DISPOSED_PROPERTY_NAME, false, true);
414 }
415
416 // First, we post an InvocationEvent to be run on the
417 // EventDispatchThread which disposes of all top-level Frames and TrayIcons
418
419 final Object notificationLock = new Object();
420
421 Runnable runnable = new Runnable() {
422 public void run() {
423 Window[] windowsToDispose = Window.getOwnerlessWindows();
424 for (Window w : windowsToDispose) {
425 try {
426 w.dispose();
427 } catch (Throwable t) {
428 log.finer("exception occured while disposing app context", t);
429 }
430 }
431 AccessController.doPrivileged(new PrivilegedAction<Void>() {
432 public Void run() {
433 if (!GraphicsEnvironment.isHeadless() && SystemTray.isSupported())
434 {
435 SystemTray systemTray = SystemTray.getSystemTray();
436 TrayIcon[] trayIconsToDispose = systemTray.getTrayIcons();
437 for (TrayIcon ti : trayIconsToDispose) {
438 systemTray.remove(ti);
439 }
440 }
441 return null;
442 }
443 });
444 // Alert PropertyChangeListeners that the GUI has been disposed.
445 if (changeSupport != null) {
446 changeSupport.firePropertyChange(GUI_DISPOSED, false, true);
447 }
448 synchronized(notificationLock) {
449 notificationLock.notifyAll(); // Notify caller that we're done
450 }
451 }
452 };
453 synchronized(notificationLock) {
454 SunToolkit.postEvent(this,
455 new InvocationEvent(Toolkit.getDefaultToolkit(), runnable));
456 try {
457 notificationLock.wait(DISPOSAL_TIMEOUT);
458 } catch (InterruptedException e) { }
459 }
460
461 // Next, we post another InvocationEvent to the end of the
462 // EventQueue. When it's executed, we know we've executed all
463 // events in the queue.
464
465 runnable = new Runnable() { public void run() {
466 synchronized(notificationLock) {
467 notificationLock.notifyAll(); // Notify caller that we're done
468 }
469 } };
470 synchronized(notificationLock) {
471 SunToolkit.postEvent(this,
472 new InvocationEvent(Toolkit.getDefaultToolkit(), runnable));
473 try {
474 notificationLock.wait(DISPOSAL_TIMEOUT);
475 } catch (InterruptedException e) { }
476 }
477
478 // We are done with posting events, so change the state to disposed
479 synchronized(this) {
480 this.state = State.DISPOSED;
481 }
482
483 // Next, we interrupt all Threads in the ThreadGroup
484 this.threadGroup.interrupt();
485 // Note, the EventDispatchThread we've interrupted may dump an
486 // InterruptedException to the console here. This needs to be
487 // fixed in the EventDispatchThread, not here.
488
489 // Next, we sleep 10ms at a time, waiting for all of the active
490 // Threads in the ThreadGroup to exit.
491
492 long startTime = System.currentTimeMillis();
493 long endTime = startTime + THREAD_INTERRUPT_TIMEOUT;
494 while ((this.threadGroup.activeCount() > 0) &&
495 (System.currentTimeMillis() < endTime)) {
496 try {
497 Thread.sleep(10);
498 } catch (InterruptedException e) { }
499 }
500
501 // Then, we stop any remaining Threads
502 this.threadGroup.stop();
503
504 // Next, we sleep 10ms at a time, waiting for all of the active
505 // Threads in the ThreadGroup to die.
506
507 startTime = System.currentTimeMillis();
508 endTime = startTime + THREAD_INTERRUPT_TIMEOUT;
509 while ((this.threadGroup.activeCount() > 0) &&
510 (System.currentTimeMillis() < endTime)) {
511 try {
512 Thread.sleep(10);
513 } catch (InterruptedException e) { }
514 }
515
516 // Next, we remove this and all subThreadGroups from threadGroup2appContext
517 int numSubGroups = this.threadGroup.activeGroupCount();
518 if (numSubGroups > 0) {
519 ThreadGroup [] subGroups = new ThreadGroup[numSubGroups];
520 numSubGroups = this.threadGroup.enumerate(subGroups);
521 for (int subGroup = 0; subGroup < numSubGroups; subGroup++) {
522 threadGroup2appContext.remove(subGroups[subGroup]);
523 }
524 }
525 threadGroup2appContext.remove(this.threadGroup);
526
527 threadAppContext.set(null);
528
529 // Finally, we destroy the ThreadGroup entirely.
530 try {
531 this.threadGroup.destroy();
532 } catch (IllegalThreadStateException e) {
533 // Fired if not all the Threads died, ignore it and proceed
534 }
535
536 synchronized (table) {
537 this.table.clear(); // Clear out the Hashtable to ease garbage collection
538 }
539
540 numAppContexts.decrementAndGet();
541
542 mostRecentKeyValue = null;
543 }
544
545 static final class PostShutdownEventRunnable implements Runnable {
546 private final AppContext appContext;
547
548 public PostShutdownEventRunnable(AppContext ac) {
549 appContext = ac;
550 }
551
552 public void run() {
553 final EventQueue eq = (EventQueue)appContext.get(EVENT_QUEUE_KEY);
554 if (eq != null) {
555 eq.postEvent(AWTAutoShutdown.getShutdownEvent());
556 }
557 }
558 }
559
560 static final class CreateThreadAction implements PrivilegedAction<Thread> {
561 private final AppContext appContext;
562 private final Runnable runnable;
563
564 public CreateThreadAction(AppContext ac, Runnable r) {
565 appContext = ac;
566 runnable = r;
567 }
568
569 public Thread run() {
570 Thread t = new Thread(appContext.getThreadGroup(), runnable);
571 t.setContextClassLoader(appContext.getContextClassLoader());
572 t.setPriority(Thread.NORM_PRIORITY + 1);
573 t.setDaemon(true);
574 return t;
575 }
576 }
577
578 static void stopEventDispatchThreads() {
579 for (AppContext appContext: getAppContexts()) {
580 if (appContext.isDisposed()) {
581 continue;
582 }
583 Runnable r = new PostShutdownEventRunnable(appContext);
584 // For security reasons EventQueue.postEvent should only be called
585 // on a thread that belongs to the corresponding thread group.
586 if (appContext != AppContext.getAppContext()) {
587 // Create a thread that belongs to the thread group associated
588 // with the AppContext and invokes EventQueue.postEvent.
589 PrivilegedAction<Thread> action = new CreateThreadAction(appContext, r);
590 Thread thread = AccessController.doPrivileged(action);
591 thread.start();
592 } else {
593 r.run();
594 }
595 }
596 }
597
598 private MostRecentKeyValue mostRecentKeyValue = null;
599 private MostRecentKeyValue shadowMostRecentKeyValue = null;
600
601 /**
602 * Returns the value to which the specified key is mapped in this context.
603 *
604 * @param key a key in the AppContext.
605 * @return the value to which the key is mapped in this AppContext;
606 * <code>null</code> if the key is not mapped to any value.
607 * @see #put(Object, Object)
608 * @since 1.2
609 */
610 public Object get(Object key) {
611 /*
612 * The most recent reference should be updated inside a synchronized
613 * block to avoid a race when put() and get() are executed in
614 * parallel on different threads.
615 */
616 synchronized (table) {
617 // Note: this most recent key/value caching is thread-hot.
618 // A simple test using SwingSet found that 72% of lookups
619 // were matched using the most recent key/value. By instantiating
620 // a simple MostRecentKeyValue object on cache misses, the
621 // cache hits can be processed without synchronization.
622
623 MostRecentKeyValue recent = mostRecentKeyValue;
624 if ((recent != null) && (recent.key == key)) {
625 return recent.value;
626 }
627
628 Object value = table.get(key);
629 if(mostRecentKeyValue == null) {
630 mostRecentKeyValue = new MostRecentKeyValue(key, value);
631 shadowMostRecentKeyValue = new MostRecentKeyValue(key, value);
632 } else {
633 MostRecentKeyValue auxKeyValue = mostRecentKeyValue;
634 shadowMostRecentKeyValue.setPair(key, value);
635 mostRecentKeyValue = shadowMostRecentKeyValue;
636 shadowMostRecentKeyValue = auxKeyValue;
637 }
638 return value;
639 }
640 }
641
642 /**
643 * Maps the specified <code>key</code> to the specified
644 * <code>value</code> in this AppContext. Neither the key nor the
645 * value can be <code>null</code>.
646 * <p>
647 * The value can be retrieved by calling the <code>get</code> method
648 * with a key that is equal to the original key.
649 *
650 * @param key the AppContext key.
651 * @param value the value.
652 * @return the previous value of the specified key in this
653 * AppContext, or <code>null</code> if it did not have one.
654 * @exception NullPointerException if the key or value is
655 * <code>null</code>.
656 * @see #get(Object)
657 * @since 1.2
658 */
659 public Object put(Object key, Object value) {
660 synchronized (table) {
661 MostRecentKeyValue recent = mostRecentKeyValue;
662 if ((recent != null) && (recent.key == key))
663 recent.value = value;
664 return table.put(key, value);
665 }
666 }
667
668 /**
669 * Removes the key (and its corresponding value) from this
670 * AppContext. This method does nothing if the key is not in the
671 * AppContext.
672 *
673 * @param key the key that needs to be removed.
674 * @return the value to which the key had been mapped in this AppContext,
675 * or <code>null</code> if the key did not have a mapping.
676 * @since 1.2
677 */
678 public Object remove(Object key) {
679 synchronized (table) {
680 MostRecentKeyValue recent = mostRecentKeyValue;
681 if ((recent != null) && (recent.key == key))
682 recent.value = null;
683 return table.remove(key);
684 }
685 }
686
687 /**
688 * Returns the root ThreadGroup for all Threads contained within
689 * this AppContext.
690 * @since 1.2
691 */
692 public ThreadGroup getThreadGroup() {
693 return threadGroup;
694 }
695
696 /**
697 * Returns the context ClassLoader that was used to create this
698 * AppContext.
699 *
700 * @see java.lang.Thread#getContextClassLoader
701 */
702 public ClassLoader getContextClassLoader() {
703 return contextClassLoader;
704 }
705
706 /**
707 * Returns a string representation of this AppContext.
708 * @since 1.2
709 */
710 @Override
711 public String toString() {
712 return getClass().getName() + "[threadGroup=" + threadGroup.getName() + "]";
713 }
714
715 /**
716 * Returns an array of all the property change listeners
717 * registered on this component.
718 *
719 * @return all of this component's <code>PropertyChangeListener</code>s
720 * or an empty array if no property change
721 * listeners are currently registered
722 *
723 * @see #addPropertyChangeListener
724 * @see #removePropertyChangeListener
725 * @see #getPropertyChangeListeners(java.lang.String)
726 * @see java.beans.PropertyChangeSupport#getPropertyChangeListeners
727 * @since 1.4
728 */
729 public synchronized PropertyChangeListener[] getPropertyChangeListeners() {
730 if (changeSupport == null) {
731 return new PropertyChangeListener[0];
732 }
733 return changeSupport.getPropertyChangeListeners();
734 }
735
736 /**
737 * Adds a PropertyChangeListener to the listener list for a specific
738 * property. The specified property may be one of the following:
739 * <ul>
740 * <li>if this AppContext is disposed ("disposed")</li>
741 * </ul>
742 * <ul>
743 * <li>if this AppContext's unowned Windows have been disposed
744 * ("guidisposed"). Code to cleanup after the GUI is disposed
745 * (such as LookAndFeel.uninitialize()) should execute in response to
746 * this property being fired. Notifications for the "guidisposed"
747 * property are sent on the event dispatch thread.</li>
748 * </ul>
749 * <p>
750 * If listener is null, no exception is thrown and no action is performed.
751 *
752 * @param propertyName one of the property names listed above
753 * @param listener the PropertyChangeListener to be added
754 *
755 * @see #removePropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
756 * @see #getPropertyChangeListeners(java.lang.String)
757 * @see #addPropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
758 */
759 public synchronized void addPropertyChangeListener(
760 String propertyName,
761 PropertyChangeListener listener) {
762 if (listener == null) {
763 return;
764 }
765 if (changeSupport == null) {
766 changeSupport = new PropertyChangeSupport(this);
767 }
768 changeSupport.addPropertyChangeListener(propertyName, listener);
769 }
770
771 /**
772 * Removes a PropertyChangeListener from the listener list for a specific
773 * property. This method should be used to remove PropertyChangeListeners
774 * that were registered for a specific bound property.
775 * <p>
776 * If listener is null, no exception is thrown and no action is performed.
777 *
778 * @param propertyName a valid property name
779 * @param listener the PropertyChangeListener to be removed
780 *
781 * @see #addPropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
782 * @see #getPropertyChangeListeners(java.lang.String)
783 * @see #removePropertyChangeListener(java.beans.PropertyChangeListener)
784 */
785 public synchronized void removePropertyChangeListener(
786 String propertyName,
787 PropertyChangeListener listener) {
788 if (listener == null || changeSupport == null) {
789 return;
790 }
791 changeSupport.removePropertyChangeListener(propertyName, listener);
792 }
793
794 /**
795 * Returns an array of all the listeners which have been associated
796 * with the named property.
797 *
798 * @return all of the <code>PropertyChangeListeners</code> associated with
799 * the named property or an empty array if no listeners have
800 * been added
801 *
802 * @see #addPropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
803 * @see #removePropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
804 * @see #getPropertyChangeListeners
805 * @since 1.4
806 */
807 public synchronized PropertyChangeListener[] getPropertyChangeListeners(
808 String propertyName) {
809 if (changeSupport == null) {
810 return new PropertyChangeListener[0];
811 }
812 return changeSupport.getPropertyChangeListeners(propertyName);
813 }
814
815 // Set up JavaAWTAccess in SharedSecrets
816 static {
817 sun.misc.SharedSecrets.setJavaAWTAccess(new sun.misc.JavaAWTAccess() {
818 public Object get(Object key) {
819 AppContext ac = getAppContext();
820 return (ac == null) ? null : ac.get(key);
821 }
822 public void put(Object key, Object value) {
823 AppContext ac = getAppContext();
824 if (ac != null) {
825 ac.put(key, value);
826 }
827 }
828 public void remove(Object key) {
829 AppContext ac = getAppContext();
830 if (ac != null) {
831 ac.remove(key);
832 }
833 }
834 public boolean isDisposed() {
835 AppContext ac = getAppContext();
836 return (ac == null) ? true : ac.isDisposed();
837 }
838 public boolean isMainAppContext() {
839 return (numAppContexts.get() == 1 && mainAppContext != null);
840 }
841
842 /**
843 * Returns the AppContext used for applet logging isolation, or null if
844 * the default global context can be used.
845 * If there's no applet, or if the caller is a stand alone application,
846 * or running in the main app context, returns null.
847 * Otherwise, returns the AppContext of the calling applet.
848 * @return null if the global default context can be used,
849 * an AppContext otherwise.
850 **/
851 public Object getAppletContext() {
852 // There's no AppContext: return null.
853 // No need to call getAppContext() if numAppContext == 0:
854 // it means that no AppContext has been created yet, and
855 // we don't want to trigger the creation of a main app
856 // context since we don't need it.
857 if (numAppContexts.get() == 0) return null;
858
859 // Get the context from the security manager
860 AppContext ecx = getExecutionAppContext();
861
862 // Not sure we really need to re-check numAppContexts here.
863 // If all applets have gone away then we could have a
864 // numAppContexts coming back to 0. So we recheck
865 // it here because we don't want to trigger the
866 // creation of a main AppContext in that case.
867 // This is probably not 100% MT-safe but should reduce
868 // the window of opportunity in which that issue could
869 // happen.
870 if (numAppContexts.get() > 0) {
871 // Defaults to thread group caching.
872 // This is probably not required as we only really need
873 // isolation in a deployed applet environment, in which
874 // case ecx will not be null when we reach here
875 // However it helps emulate the deployed environment,
876 // in tests for instance.
877 ecx = ecx != null ? ecx : getAppContext();
878 }
879
880 // getAppletContext() may be called when initializing the main
881 // app context - in which case mainAppContext will still be
882 // null. To work around this issue we simply use
883 // AppContext.threadGroup.getParent() == null instead, since
884 // mainAppContext is the only AppContext which should have
885 // the root TG as its thread group.
886 // See: JDK-8023258
887 final boolean isMainAppContext = ecx == null
888 || mainAppContext == ecx
889 || mainAppContext == null && ecx.threadGroup.getParent() == null;
890
891 return isMainAppContext ? null : ecx;
892 }
893
894 });
895 }
896 }
897
898 final class MostRecentKeyValue {
899 Object key;
900 Object value;
901 MostRecentKeyValue(Object k, Object v) {
902 key = k;
903 value = v;
904 }
905 void setPair(Object k, Object v) {
906 key = k;
907 value = v;
908 }
909 }