1 /*
2 * Copyright (c) 1996, 2010, 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 java.io;
27
28 import java.lang.ref.Reference;
29 import java.lang.ref.ReferenceQueue;
30 import java.lang.ref.SoftReference;
31 import java.lang.ref.WeakReference;
32 import java.lang.reflect.Constructor;
33 import java.lang.reflect.Field;
34 import java.lang.reflect.InvocationTargetException;
35 import java.lang.reflect.Member;
36 import java.lang.reflect.Method;
37 import java.lang.reflect.Modifier;
38 import java.lang.reflect.Proxy;
39 import java.security.AccessController;
40 import java.security.MessageDigest;
41 import java.security.NoSuchAlgorithmException;
42 import java.security.PrivilegedAction;
43 import java.util.ArrayList;
44 import java.util.Arrays;
45 import java.util.Collections;
46 import java.util.Comparator;
47 import java.util.HashSet;
48 import java.util.Set;
49 import java.util.concurrent.ConcurrentHashMap;
50 import java.util.concurrent.ConcurrentMap;
51 import sun.misc.Unsafe;
52 import sun.reflect.ReflectionFactory;
53
54 /**
55 * Serialization's descriptor for classes. It contains the name and
56 * serialVersionUID of the class. The ObjectStreamClass for a specific class
57 * loaded in this Java VM can be found/created using the lookup method.
58 *
59 * <p>The algorithm to compute the SerialVersionUID is described in
60 * <a href="../../../platform/serialization/spec/class.html#4100">Object
61 * Serialization Specification, Section 4.6, Stream Unique Identifiers</a>.
62 *
63 * @author Mike Warres
64 * @author Roger Riggs
65 * @see ObjectStreamField
66 * @see <a href="../../../platform/serialization/spec/class.html">Object Serialization Specification, Section 4, Class Descriptors</a>
67 * @since JDK1.1
68 */
69 public class ObjectStreamClass implements Serializable {
70
71 /** serialPersistentFields value indicating no serializable fields */
72 public static final ObjectStreamField[] NO_FIELDS =
73 new ObjectStreamField[0];
74
75 private static final long serialVersionUID = -6120832682080437368L;
76 private static final ObjectStreamField[] serialPersistentFields =
77 NO_FIELDS;
78
79 /** reflection factory for obtaining serialization constructors */
80 private static final ReflectionFactory reflFactory =
81 AccessController.doPrivileged(
82 new ReflectionFactory.GetReflectionFactoryAction());
83
84 private static class Caches {
85 /** cache mapping local classes -> descriptors */
86 static final ConcurrentMap<WeakClassKey,Reference<?>> localDescs =
87 new ConcurrentHashMap<WeakClassKey,Reference<?>>();
88
89 /** cache mapping field group/local desc pairs -> field reflectors */
90 static final ConcurrentMap<FieldReflectorKey,Reference<?>> reflectors =
91 new ConcurrentHashMap<FieldReflectorKey,Reference<?>>();
92
93 /** queue for WeakReferences to local classes */
94 private static final ReferenceQueue<Class<?>> localDescsQueue =
95 new ReferenceQueue<Class<?>>();
96 /** queue for WeakReferences to field reflectors keys */
97 private static final ReferenceQueue<Class<?>> reflectorsQueue =
98 new ReferenceQueue<Class<?>>();
99 }
100
101 /** class associated with this descriptor (if any) */
102 private Class<?> cl;
103 /** name of class represented by this descriptor */
104 private String name;
105 /** serialVersionUID of represented class (null if not computed yet) */
106 private volatile Long suid;
107
108 /** true if represents dynamic proxy class */
109 private boolean isProxy;
110 /** true if represents enum type */
111 private boolean isEnum;
112 /** true if represented class implements Serializable */
113 private boolean serializable;
114 /** true if represented class implements Externalizable */
115 private boolean externalizable;
116 /** true if desc has data written by class-defined writeObject method */
117 private boolean hasWriteObjectData;
118 /**
119 * true if desc has externalizable data written in block data format; this
120 * must be true by default to accommodate ObjectInputStream subclasses which
121 * override readClassDescriptor() to return class descriptors obtained from
122 * ObjectStreamClass.lookup() (see 4461737)
123 */
124 private boolean hasBlockExternalData = true;
125
126 /** exception (if any) thrown while attempting to resolve class */
127 private ClassNotFoundException resolveEx;
128 /** exception (if any) to throw if non-enum deserialization attempted */
129 private InvalidClassException deserializeEx;
130 /** exception (if any) to throw if non-enum serialization attempted */
131 private InvalidClassException serializeEx;
132 /** exception (if any) to throw if default serialization attempted */
133 private InvalidClassException defaultSerializeEx;
134
135 /** serializable fields */
136 private ObjectStreamField[] fields;
137 /** aggregate marshalled size of primitive fields */
138 private int primDataSize;
139 /** number of non-primitive fields */
140 private int numObjFields;
141 /** reflector for setting/getting serializable field values */
142 private FieldReflector fieldRefl;
143 /** data layout of serialized objects described by this class desc */
144 private volatile ClassDataSlot[] dataLayout;
145
146 /** serialization-appropriate constructor, or null if none */
147 private Constructor cons;
148 /** class-defined writeObject method, or null if none */
149 private Method writeObjectMethod;
150 /** class-defined readObject method, or null if none */
151 private Method readObjectMethod;
152 /** class-defined readObjectNoData method, or null if none */
153 private Method readObjectNoDataMethod;
154 /** class-defined writeReplace method, or null if none */
155 private Method writeReplaceMethod;
156 /** class-defined readResolve method, or null if none */
157 private Method readResolveMethod;
158
159 /** local class descriptor for represented class (may point to self) */
160 private ObjectStreamClass localDesc;
161 /** superclass descriptor appearing in stream */
162 private ObjectStreamClass superDesc;
163
164 /**
165 * Initializes native code.
166 */
167 private static native void initNative();
168 static {
169 initNative();
170 }
171
172 /**
173 * Find the descriptor for a class that can be serialized. Creates an
174 * ObjectStreamClass instance if one does not exist yet for class. Null is
175 * returned if the specified class does not implement java.io.Serializable
176 * or java.io.Externalizable.
177 *
178 * @param cl class for which to get the descriptor
179 * @return the class descriptor for the specified class
180 */
181 public static ObjectStreamClass lookup(Class<?> cl) {
182 return lookup(cl, false);
183 }
184
185 /**
186 * Returns the descriptor for any class, regardless of whether it
187 * implements {@link Serializable}.
188 *
189 * @param cl class for which to get the descriptor
190 * @return the class descriptor for the specified class
191 * @since 1.6
192 */
193 public static ObjectStreamClass lookupAny(Class<?> cl) {
194 return lookup(cl, true);
195 }
196
197 /**
198 * Returns the name of the class described by this descriptor.
199 * This method returns the name of the class in the format that
200 * is used by the {@link Class#getName} method.
201 *
202 * @return a string representing the name of the class
203 */
204 public String getName() {
205 return name;
206 }
207
208 /**
209 * Return the serialVersionUID for this class. The serialVersionUID
210 * defines a set of classes all with the same name that have evolved from a
211 * common root class and agree to be serialized and deserialized using a
212 * common format. NonSerializable classes have a serialVersionUID of 0L.
213 *
214 * @return the SUID of the class described by this descriptor
215 */
216 public long getSerialVersionUID() {
217 // REMIND: synchronize instead of relying on volatile?
218 if (suid == null) {
219 suid = AccessController.doPrivileged(
220 new PrivilegedAction<Long>() {
221 public Long run() {
222 return computeDefaultSUID(cl);
223 }
224 }
225 );
226 }
227 return suid.longValue();
228 }
229
230 /**
231 * Return the class in the local VM that this version is mapped to. Null
232 * is returned if there is no corresponding local class.
233 *
234 * @return the <code>Class</code> instance that this descriptor represents
235 */
236 public Class<?> forClass() {
237 return cl;
238 }
239
240 /**
241 * Return an array of the fields of this serializable class.
242 *
243 * @return an array containing an element for each persistent field of
244 * this class. Returns an array of length zero if there are no
245 * fields.
246 * @since 1.2
247 */
248 public ObjectStreamField[] getFields() {
249 return getFields(true);
250 }
251
252 /**
253 * Get the field of this class by name.
254 *
255 * @param name the name of the data field to look for
256 * @return The ObjectStreamField object of the named field or null if
257 * there is no such named field.
258 */
259 public ObjectStreamField getField(String name) {
260 return getField(name, null);
261 }
262
263 /**
264 * Return a string describing this ObjectStreamClass.
265 */
266 public String toString() {
267 return name + ": static final long serialVersionUID = " +
268 getSerialVersionUID() + "L;";
269 }
270
271 /**
272 * Looks up and returns class descriptor for given class, or null if class
273 * is non-serializable and "all" is set to false.
274 *
275 * @param cl class to look up
276 * @param all if true, return descriptors for all classes; if false, only
277 * return descriptors for serializable classes
278 */
279 static ObjectStreamClass lookup(Class<?> cl, boolean all) {
280 if (!(all || Serializable.class.isAssignableFrom(cl))) {
281 return null;
282 }
283 processQueue(Caches.localDescsQueue, Caches.localDescs);
284 WeakClassKey key = new WeakClassKey(cl, Caches.localDescsQueue);
285 Reference<?> ref = Caches.localDescs.get(key);
286 Object entry = null;
287 if (ref != null) {
288 entry = ref.get();
289 }
290 EntryFuture future = null;
291 if (entry == null) {
292 EntryFuture newEntry = new EntryFuture();
293 Reference<?> newRef = new SoftReference<EntryFuture>(newEntry);
294 do {
295 if (ref != null) {
296 Caches.localDescs.remove(key, ref);
297 }
298 ref = Caches.localDescs.putIfAbsent(key, newRef);
299 if (ref != null) {
300 entry = ref.get();
301 }
302 } while (ref != null && entry == null);
303 if (entry == null) {
304 future = newEntry;
305 }
306 }
307
308 if (entry instanceof ObjectStreamClass) { // check common case first
309 return (ObjectStreamClass) entry;
310 }
311 if (entry instanceof EntryFuture) {
312 future = (EntryFuture) entry;
313 if (future.getOwner() == Thread.currentThread()) {
314 /*
315 * Handle nested call situation described by 4803747: waiting
316 * for future value to be set by a lookup() call further up the
317 * stack will result in deadlock, so calculate and set the
318 * future value here instead.
319 */
320 entry = null;
321 } else {
322 entry = future.get();
323 }
324 }
325 if (entry == null) {
326 try {
327 entry = new ObjectStreamClass(cl);
328 } catch (Throwable th) {
329 entry = th;
330 }
331 if (future.set(entry)) {
332 Caches.localDescs.put(key, new SoftReference<Object>(entry));
333 } else {
334 // nested lookup call already set future
335 entry = future.get();
336 }
337 }
338
339 if (entry instanceof ObjectStreamClass) {
340 return (ObjectStreamClass) entry;
341 } else if (entry instanceof RuntimeException) {
342 throw (RuntimeException) entry;
343 } else if (entry instanceof Error) {
344 throw (Error) entry;
345 } else {
346 throw new InternalError("unexpected entry: " + entry);
347 }
348 }
349
350 /**
351 * Placeholder used in class descriptor and field reflector lookup tables
352 * for an entry in the process of being initialized. (Internal) callers
353 * which receive an EntryFuture belonging to another thread as the result
354 * of a lookup should call the get() method of the EntryFuture; this will
355 * return the actual entry once it is ready for use and has been set(). To
356 * conserve objects, EntryFutures synchronize on themselves.
357 */
358 private static class EntryFuture {
359
360 private static final Object unset = new Object();
361 private final Thread owner = Thread.currentThread();
362 private Object entry = unset;
363
364 /**
365 * Attempts to set the value contained by this EntryFuture. If the
366 * EntryFuture's value has not been set already, then the value is
367 * saved, any callers blocked in the get() method are notified, and
368 * true is returned. If the value has already been set, then no saving
369 * or notification occurs, and false is returned.
370 */
371 synchronized boolean set(Object entry) {
372 if (this.entry != unset) {
373 return false;
374 }
375 this.entry = entry;
376 notifyAll();
377 return true;
378 }
379
380 /**
381 * Returns the value contained by this EntryFuture, blocking if
382 * necessary until a value is set.
383 */
384 synchronized Object get() {
385 boolean interrupted = false;
386 while (entry == unset) {
387 try {
388 wait();
389 } catch (InterruptedException ex) {
390 interrupted = true;
391 }
392 }
393 if (interrupted) {
394 AccessController.doPrivileged(
395 new PrivilegedAction<Void>() {
396 public Void run() {
397 Thread.currentThread().interrupt();
398 return null;
399 }
400 }
401 );
402 }
403 return entry;
404 }
405
406 /**
407 * Returns the thread that created this EntryFuture.
408 */
409 Thread getOwner() {
410 return owner;
411 }
412 }
413
414 /**
415 * Creates local class descriptor representing given class.
416 */
417 private ObjectStreamClass(final Class<?> cl) {
418 this.cl = cl;
419 name = cl.getName();
420 isProxy = Proxy.isProxyClass(cl);
421 isEnum = Enum.class.isAssignableFrom(cl);
422 serializable = Serializable.class.isAssignableFrom(cl);
423 externalizable = Externalizable.class.isAssignableFrom(cl);
424
425 Class<?> superCl = cl.getSuperclass();
426 superDesc = (superCl != null) ? lookup(superCl, false) : null;
427 localDesc = this;
428
429 if (serializable) {
430 AccessController.doPrivileged(new PrivilegedAction<Void>() {
431 public Void run() {
432 if (isEnum) {
433 suid = Long.valueOf(0);
434 fields = NO_FIELDS;
435 return null;
436 }
437 if (cl.isArray()) {
438 fields = NO_FIELDS;
439 return null;
440 }
441
442 suid = getDeclaredSUID(cl);
443 try {
444 fields = getSerialFields(cl);
445 computeFieldOffsets();
446 } catch (InvalidClassException e) {
447 serializeEx = deserializeEx = e;
448 fields = NO_FIELDS;
449 }
450
451 if (externalizable) {
452 cons = getExternalizableConstructor(cl);
453 } else {
454 cons = getSerializableConstructor(cl);
455 writeObjectMethod = getPrivateMethod(cl, "writeObject",
456 new Class<?>[] { ObjectOutputStream.class },
457 Void.TYPE);
458 readObjectMethod = getPrivateMethod(cl, "readObject",
459 new Class<?>[] { ObjectInputStream.class },
460 Void.TYPE);
461 readObjectNoDataMethod = getPrivateMethod(
462 cl, "readObjectNoData", null, Void.TYPE);
463 hasWriteObjectData = (writeObjectMethod != null);
464 }
465 writeReplaceMethod = getInheritableMethod(
466 cl, "writeReplace", null, Object.class);
467 readResolveMethod = getInheritableMethod(
468 cl, "readResolve", null, Object.class);
469 return null;
470 }
471 });
472 } else {
473 suid = Long.valueOf(0);
474 fields = NO_FIELDS;
475 }
476
477 try {
478 fieldRefl = getReflector(fields, this);
479 } catch (InvalidClassException ex) {
480 // field mismatches impossible when matching local fields vs. self
481 throw new InternalError();
482 }
483
484 if (deserializeEx == null) {
485 if (isEnum) {
486 deserializeEx = new InvalidClassException(name, "enum type");
487 } else if (cons == null) {
488 deserializeEx = new InvalidClassException(
489 name, "no valid constructor");
490 }
491 }
492 for (int i = 0; i < fields.length; i++) {
493 if (fields[i].getField() == null) {
494 defaultSerializeEx = new InvalidClassException(
495 name, "unmatched serializable field(s) declared");
496 }
497 }
498 }
499
500 /**
501 * Creates blank class descriptor which should be initialized via a
502 * subsequent call to initProxy(), initNonProxy() or readNonProxy().
503 */
504 ObjectStreamClass() {
505 }
506
507 /**
508 * Initializes class descriptor representing a proxy class.
509 */
510 void initProxy(Class<?> cl,
511 ClassNotFoundException resolveEx,
512 ObjectStreamClass superDesc)
513 throws InvalidClassException
514 {
515 this.cl = cl;
516 this.resolveEx = resolveEx;
517 this.superDesc = superDesc;
518 isProxy = true;
519 serializable = true;
520 suid = Long.valueOf(0);
521 fields = NO_FIELDS;
522
523 if (cl != null) {
524 localDesc = lookup(cl, true);
525 if (!localDesc.isProxy) {
526 throw new InvalidClassException(
527 "cannot bind proxy descriptor to a non-proxy class");
528 }
529 name = localDesc.name;
530 externalizable = localDesc.externalizable;
531 cons = localDesc.cons;
532 writeReplaceMethod = localDesc.writeReplaceMethod;
533 readResolveMethod = localDesc.readResolveMethod;
534 deserializeEx = localDesc.deserializeEx;
535 }
536 fieldRefl = getReflector(fields, localDesc);
537 }
538
539 /**
540 * Initializes class descriptor representing a non-proxy class.
541 */
542 void initNonProxy(ObjectStreamClass model,
543 Class<?> cl,
544 ClassNotFoundException resolveEx,
545 ObjectStreamClass superDesc)
546 throws InvalidClassException
547 {
548 this.cl = cl;
549 this.resolveEx = resolveEx;
550 this.superDesc = superDesc;
551 name = model.name;
552 suid = Long.valueOf(model.getSerialVersionUID());
553 isProxy = false;
554 isEnum = model.isEnum;
555 serializable = model.serializable;
556 externalizable = model.externalizable;
557 hasBlockExternalData = model.hasBlockExternalData;
558 hasWriteObjectData = model.hasWriteObjectData;
559 fields = model.fields;
560 primDataSize = model.primDataSize;
561 numObjFields = model.numObjFields;
562
563 if (cl != null) {
564 localDesc = lookup(cl, true);
565 if (localDesc.isProxy) {
566 throw new InvalidClassException(
567 "cannot bind non-proxy descriptor to a proxy class");
568 }
569 if (isEnum != localDesc.isEnum) {
570 throw new InvalidClassException(isEnum ?
571 "cannot bind enum descriptor to a non-enum class" :
572 "cannot bind non-enum descriptor to an enum class");
573 }
574
575 if (serializable == localDesc.serializable &&
576 !cl.isArray() &&
577 suid.longValue() != localDesc.getSerialVersionUID())
578 {
579 throw new InvalidClassException(localDesc.name,
580 "local class incompatible: " +
581 "stream classdesc serialVersionUID = " + suid +
582 ", local class serialVersionUID = " +
583 localDesc.getSerialVersionUID());
584 }
585
586 if (!classNamesEqual(name, localDesc.name)) {
587 throw new InvalidClassException(localDesc.name,
588 "local class name incompatible with stream class " +
589 "name \"" + name + "\"");
590 }
591
592 if (!isEnum) {
593 if ((serializable == localDesc.serializable) &&
594 (externalizable != localDesc.externalizable))
595 {
596 throw new InvalidClassException(localDesc.name,
597 "Serializable incompatible with Externalizable");
598 }
599
600 if ((serializable != localDesc.serializable) ||
601 (externalizable != localDesc.externalizable) ||
602 !(serializable || externalizable))
603 {
604 deserializeEx = new InvalidClassException(localDesc.name,
605 "class invalid for deserialization");
606 }
607 }
608
609 cons = localDesc.cons;
610 writeObjectMethod = localDesc.writeObjectMethod;
611 readObjectMethod = localDesc.readObjectMethod;
612 readObjectNoDataMethod = localDesc.readObjectNoDataMethod;
613 writeReplaceMethod = localDesc.writeReplaceMethod;
614 readResolveMethod = localDesc.readResolveMethod;
615 if (deserializeEx == null) {
616 deserializeEx = localDesc.deserializeEx;
617 }
618 }
619 fieldRefl = getReflector(fields, localDesc);
620 // reassign to matched fields so as to reflect local unshared settings
621 fields = fieldRefl.getFields();
622 }
623
624 /**
625 * Reads non-proxy class descriptor information from given input stream.
626 * The resulting class descriptor is not fully functional; it can only be
627 * used as input to the ObjectInputStream.resolveClass() and
628 * ObjectStreamClass.initNonProxy() methods.
629 */
630 void readNonProxy(ObjectInputStream in)
631 throws IOException, ClassNotFoundException
632 {
633 name = in.readUTF();
634 suid = Long.valueOf(in.readLong());
635 isProxy = false;
636
637 byte flags = in.readByte();
638 hasWriteObjectData =
639 ((flags & ObjectStreamConstants.SC_WRITE_METHOD) != 0);
640 hasBlockExternalData =
641 ((flags & ObjectStreamConstants.SC_BLOCK_DATA) != 0);
642 externalizable =
643 ((flags & ObjectStreamConstants.SC_EXTERNALIZABLE) != 0);
644 boolean sflag =
645 ((flags & ObjectStreamConstants.SC_SERIALIZABLE) != 0);
646 if (externalizable && sflag) {
647 throw new InvalidClassException(
648 name, "serializable and externalizable flags conflict");
649 }
650 serializable = externalizable || sflag;
651 isEnum = ((flags & ObjectStreamConstants.SC_ENUM) != 0);
652 if (isEnum && suid.longValue() != 0L) {
653 throw new InvalidClassException(name,
654 "enum descriptor has non-zero serialVersionUID: " + suid);
655 }
656
657 int numFields = in.readShort();
658 if (isEnum && numFields != 0) {
659 throw new InvalidClassException(name,
660 "enum descriptor has non-zero field count: " + numFields);
661 }
662 fields = (numFields > 0) ?
663 new ObjectStreamField[numFields] : NO_FIELDS;
664 for (int i = 0; i < numFields; i++) {
665 char tcode = (char) in.readByte();
666 String fname = in.readUTF();
667 String signature = ((tcode == 'L') || (tcode == '[')) ?
668 in.readTypeString() : new String(new char[] { tcode });
669 try {
670 fields[i] = new ObjectStreamField(fname, signature, false);
671 } catch (RuntimeException e) {
672 throw (IOException) new InvalidClassException(name,
673 "invalid descriptor for field " + fname).initCause(e);
674 }
675 }
676 computeFieldOffsets();
677 }
678
679 /**
680 * Writes non-proxy class descriptor information to given output stream.
681 */
682 void writeNonProxy(ObjectOutputStream out) throws IOException {
683 out.writeUTF(name);
684 out.writeLong(getSerialVersionUID());
685
686 byte flags = 0;
687 if (externalizable) {
688 flags |= ObjectStreamConstants.SC_EXTERNALIZABLE;
689 int protocol = out.getProtocolVersion();
690 if (protocol != ObjectStreamConstants.PROTOCOL_VERSION_1) {
691 flags |= ObjectStreamConstants.SC_BLOCK_DATA;
692 }
693 } else if (serializable) {
694 flags |= ObjectStreamConstants.SC_SERIALIZABLE;
695 }
696 if (hasWriteObjectData) {
697 flags |= ObjectStreamConstants.SC_WRITE_METHOD;
698 }
699 if (isEnum) {
700 flags |= ObjectStreamConstants.SC_ENUM;
701 }
702 out.writeByte(flags);
703
704 out.writeShort(fields.length);
705 for (int i = 0; i < fields.length; i++) {
706 ObjectStreamField f = fields[i];
707 out.writeByte(f.getTypeCode());
708 out.writeUTF(f.getName());
709 if (!f.isPrimitive()) {
710 out.writeTypeString(f.getTypeString());
711 }
712 }
713 }
714
715 /**
716 * Returns ClassNotFoundException (if any) thrown while attempting to
717 * resolve local class corresponding to this class descriptor.
718 */
719 ClassNotFoundException getResolveException() {
720 return resolveEx;
721 }
722
723 /**
724 * Throws an InvalidClassException if object instances referencing this
725 * class descriptor should not be allowed to deserialize. This method does
726 * not apply to deserialization of enum constants.
727 */
728 void checkDeserialize() throws InvalidClassException {
729 if (deserializeEx != null) {
730 InvalidClassException ice =
731 new InvalidClassException(deserializeEx.classname,
732 deserializeEx.getMessage());
733 ice.initCause(deserializeEx);
734 throw ice;
735 }
736 }
737
738 /**
739 * Throws an InvalidClassException if objects whose class is represented by
740 * this descriptor should not be allowed to serialize. This method does
741 * not apply to serialization of enum constants.
742 */
743 void checkSerialize() throws InvalidClassException {
744 if (serializeEx != null) {
745 InvalidClassException ice =
746 new InvalidClassException(serializeEx.classname,
747 serializeEx.getMessage());
748 ice.initCause(serializeEx);
749 throw ice;
750 }
751 }
752
753 /**
754 * Throws an InvalidClassException if objects whose class is represented by
755 * this descriptor should not be permitted to use default serialization
756 * (e.g., if the class declares serializable fields that do not correspond
757 * to actual fields, and hence must use the GetField API). This method
758 * does not apply to deserialization of enum constants.
759 */
760 void checkDefaultSerialize() throws InvalidClassException {
761 if (defaultSerializeEx != null) {
762 InvalidClassException ice =
763 new InvalidClassException(defaultSerializeEx.classname,
764 defaultSerializeEx.getMessage());
765 ice.initCause(defaultSerializeEx);
766 throw ice;
767 }
768 }
769
770 /**
771 * Returns superclass descriptor. Note that on the receiving side, the
772 * superclass descriptor may be bound to a class that is not a superclass
773 * of the subclass descriptor's bound class.
774 */
775 ObjectStreamClass getSuperDesc() {
776 return superDesc;
777 }
778
779 /**
780 * Returns the "local" class descriptor for the class associated with this
781 * class descriptor (i.e., the result of
782 * ObjectStreamClass.lookup(this.forClass())) or null if there is no class
783 * associated with this descriptor.
784 */
785 ObjectStreamClass getLocalDesc() {
786 return localDesc;
787 }
788
789 /**
790 * Returns arrays of ObjectStreamFields representing the serializable
791 * fields of the represented class. If copy is true, a clone of this class
792 * descriptor's field array is returned, otherwise the array itself is
793 * returned.
794 */
795 ObjectStreamField[] getFields(boolean copy) {
796 return copy ? fields.clone() : fields;
797 }
798
799 /**
800 * Looks up a serializable field of the represented class by name and type.
801 * A specified type of null matches all types, Object.class matches all
802 * non-primitive types, and any other non-null type matches assignable
803 * types only. Returns matching field, or null if no match found.
804 */
805 ObjectStreamField getField(String name, Class<?> type) {
806 for (int i = 0; i < fields.length; i++) {
807 ObjectStreamField f = fields[i];
808 if (f.getName().equals(name)) {
809 if (type == null ||
810 (type == Object.class && !f.isPrimitive()))
811 {
812 return f;
813 }
814 Class<?> ftype = f.getType();
815 if (ftype != null && type.isAssignableFrom(ftype)) {
816 return f;
817 }
818 }
819 }
820 return null;
821 }
822
823 /**
824 * Returns true if class descriptor represents a dynamic proxy class, false
825 * otherwise.
826 */
827 boolean isProxy() {
828 return isProxy;
829 }
830
831 /**
832 * Returns true if class descriptor represents an enum type, false
833 * otherwise.
834 */
835 boolean isEnum() {
836 return isEnum;
837 }
838
839 /**
840 * Returns true if represented class implements Externalizable, false
841 * otherwise.
842 */
843 boolean isExternalizable() {
844 return externalizable;
845 }
846
847 /**
848 * Returns true if represented class implements Serializable, false
849 * otherwise.
850 */
851 boolean isSerializable() {
852 return serializable;
853 }
854
855 /**
856 * Returns true if class descriptor represents externalizable class that
857 * has written its data in 1.2 (block data) format, false otherwise.
858 */
859 boolean hasBlockExternalData() {
860 return hasBlockExternalData;
861 }
862
863 /**
864 * Returns true if class descriptor represents serializable (but not
865 * externalizable) class which has written its data via a custom
866 * writeObject() method, false otherwise.
867 */
868 boolean hasWriteObjectData() {
869 return hasWriteObjectData;
870 }
871
872 /**
873 * Returns true if represented class is serializable/externalizable and can
874 * be instantiated by the serialization runtime--i.e., if it is
875 * externalizable and defines a public no-arg constructor, or if it is
876 * non-externalizable and its first non-serializable superclass defines an
877 * accessible no-arg constructor. Otherwise, returns false.
878 */
879 boolean isInstantiable() {
880 return (cons != null);
881 }
882
883 /**
884 * Returns true if represented class is serializable (but not
885 * externalizable) and defines a conformant writeObject method. Otherwise,
886 * returns false.
887 */
888 boolean hasWriteObjectMethod() {
889 return (writeObjectMethod != null);
890 }
891
892 /**
893 * Returns true if represented class is serializable (but not
894 * externalizable) and defines a conformant readObject method. Otherwise,
895 * returns false.
896 */
897 boolean hasReadObjectMethod() {
898 return (readObjectMethod != null);
899 }
900
901 /**
902 * Returns true if represented class is serializable (but not
903 * externalizable) and defines a conformant readObjectNoData method.
904 * Otherwise, returns false.
905 */
906 boolean hasReadObjectNoDataMethod() {
907 return (readObjectNoDataMethod != null);
908 }
909
910 /**
911 * Returns true if represented class is serializable or externalizable and
912 * defines a conformant writeReplace method. Otherwise, returns false.
913 */
914 boolean hasWriteReplaceMethod() {
915 return (writeReplaceMethod != null);
916 }
917
918 /**
919 * Returns true if represented class is serializable or externalizable and
920 * defines a conformant readResolve method. Otherwise, returns false.
921 */
922 boolean hasReadResolveMethod() {
923 return (readResolveMethod != null);
924 }
925
926 /**
927 * Creates a new instance of the represented class. If the class is
928 * externalizable, invokes its public no-arg constructor; otherwise, if the
929 * class is serializable, invokes the no-arg constructor of the first
930 * non-serializable superclass. Throws UnsupportedOperationException if
931 * this class descriptor is not associated with a class, if the associated
932 * class is non-serializable or if the appropriate no-arg constructor is
933 * inaccessible/unavailable.
934 */
935 Object newInstance()
936 throws InstantiationException, InvocationTargetException,
937 UnsupportedOperationException
938 {
939 if (cons != null) {
940 try {
941 return cons.newInstance();
942 } catch (IllegalAccessException ex) {
943 // should not occur, as access checks have been suppressed
944 throw new InternalError();
945 }
946 } else {
947 throw new UnsupportedOperationException();
948 }
949 }
950
951 /**
952 * Invokes the writeObject method of the represented serializable class.
953 * Throws UnsupportedOperationException if this class descriptor is not
954 * associated with a class, or if the class is externalizable,
955 * non-serializable or does not define writeObject.
956 */
957 void invokeWriteObject(Object obj, ObjectOutputStream out)
958 throws IOException, UnsupportedOperationException
959 {
960 if (writeObjectMethod != null) {
961 try {
962 writeObjectMethod.invoke(obj, new Object[]{ out });
963 } catch (InvocationTargetException ex) {
964 Throwable th = ex.getTargetException();
965 if (th instanceof IOException) {
966 throw (IOException) th;
967 } else {
968 throwMiscException(th);
969 }
970 } catch (IllegalAccessException ex) {
971 // should not occur, as access checks have been suppressed
972 throw new InternalError();
973 }
974 } else {
975 throw new UnsupportedOperationException();
976 }
977 }
978
979 /**
980 * Invokes the readObject method of the represented serializable class.
981 * Throws UnsupportedOperationException if this class descriptor is not
982 * associated with a class, or if the class is externalizable,
983 * non-serializable or does not define readObject.
984 */
985 void invokeReadObject(Object obj, ObjectInputStream in)
986 throws ClassNotFoundException, IOException,
987 UnsupportedOperationException
988 {
989 if (readObjectMethod != null) {
990 try {
991 readObjectMethod.invoke(obj, new Object[]{ in });
992 } catch (InvocationTargetException ex) {
993 Throwable th = ex.getTargetException();
994 if (th instanceof ClassNotFoundException) {
995 throw (ClassNotFoundException) th;
996 } else if (th instanceof IOException) {
997 throw (IOException) th;
998 } else {
999 throwMiscException(th);
1000 }
1001 } catch (IllegalAccessException ex) {
1002 // should not occur, as access checks have been suppressed
1003 throw new InternalError();
1004 }
1005 } else {
1006 throw new UnsupportedOperationException();
1007 }
1008 }
1009
1010 /**
1011 * Invokes the readObjectNoData method of the represented serializable
1012 * class. Throws UnsupportedOperationException if this class descriptor is
1013 * not associated with a class, or if the class is externalizable,
1014 * non-serializable or does not define readObjectNoData.
1015 */
1016 void invokeReadObjectNoData(Object obj)
1017 throws IOException, UnsupportedOperationException
1018 {
1019 if (readObjectNoDataMethod != null) {
1020 try {
1021 readObjectNoDataMethod.invoke(obj, (Object[]) null);
1022 } catch (InvocationTargetException ex) {
1023 Throwable th = ex.getTargetException();
1024 if (th instanceof ObjectStreamException) {
1025 throw (ObjectStreamException) th;
1026 } else {
1027 throwMiscException(th);
1028 }
1029 } catch (IllegalAccessException ex) {
1030 // should not occur, as access checks have been suppressed
1031 throw new InternalError();
1032 }
1033 } else {
1034 throw new UnsupportedOperationException();
1035 }
1036 }
1037
1038 /**
1039 * Invokes the writeReplace method of the represented serializable class and
1040 * returns the result. Throws UnsupportedOperationException if this class
1041 * descriptor is not associated with a class, or if the class is
1042 * non-serializable or does not define writeReplace.
1043 */
1044 Object invokeWriteReplace(Object obj)
1045 throws IOException, UnsupportedOperationException
1046 {
1047 if (writeReplaceMethod != null) {
1048 try {
1049 return writeReplaceMethod.invoke(obj, (Object[]) null);
1050 } catch (InvocationTargetException ex) {
1051 Throwable th = ex.getTargetException();
1052 if (th instanceof ObjectStreamException) {
1053 throw (ObjectStreamException) th;
1054 } else {
1055 throwMiscException(th);
1056 throw new InternalError(); // never reached
1057 }
1058 } catch (IllegalAccessException ex) {
1059 // should not occur, as access checks have been suppressed
1060 throw new InternalError();
1061 }
1062 } else {
1063 throw new UnsupportedOperationException();
1064 }
1065 }
1066
1067 /**
1068 * Invokes the readResolve method of the represented serializable class and
1069 * returns the result. Throws UnsupportedOperationException if this class
1070 * descriptor is not associated with a class, or if the class is
1071 * non-serializable or does not define readResolve.
1072 */
1073 Object invokeReadResolve(Object obj)
1074 throws IOException, UnsupportedOperationException
1075 {
1076 if (readResolveMethod != null) {
1077 try {
1078 return readResolveMethod.invoke(obj, (Object[]) null);
1079 } catch (InvocationTargetException ex) {
1080 Throwable th = ex.getTargetException();
1081 if (th instanceof ObjectStreamException) {
1082 throw (ObjectStreamException) th;
1083 } else {
1084 throwMiscException(th);
1085 throw new InternalError(); // never reached
1086 }
1087 } catch (IllegalAccessException ex) {
1088 // should not occur, as access checks have been suppressed
1089 throw new InternalError();
1090 }
1091 } else {
1092 throw new UnsupportedOperationException();
1093 }
1094 }
1095
1096 /**
1097 * Class representing the portion of an object's serialized form allotted
1098 * to data described by a given class descriptor. If "hasData" is false,
1099 * the object's serialized form does not contain data associated with the
1100 * class descriptor.
1101 */
1102 static class ClassDataSlot {
1103
1104 /** class descriptor "occupying" this slot */
1105 final ObjectStreamClass desc;
1106 /** true if serialized form includes data for this slot's descriptor */
1107 final boolean hasData;
1108
1109 ClassDataSlot(ObjectStreamClass desc, boolean hasData) {
1110 this.desc = desc;
1111 this.hasData = hasData;
1112 }
1113 }
1114
1115 /**
1116 * Returns array of ClassDataSlot instances representing the data layout
1117 * (including superclass data) for serialized objects described by this
1118 * class descriptor. ClassDataSlots are ordered by inheritance with those
1119 * containing "higher" superclasses appearing first. The final
1120 * ClassDataSlot contains a reference to this descriptor.
1121 */
1122 ClassDataSlot[] getClassDataLayout() throws InvalidClassException {
1123 // REMIND: synchronize instead of relying on volatile?
1124 if (dataLayout == null) {
1125 dataLayout = getClassDataLayout0();
1126 }
1127 return dataLayout;
1128 }
1129
1130 private ClassDataSlot[] getClassDataLayout0()
1131 throws InvalidClassException
1132 {
1133 ArrayList<ClassDataSlot> slots = new ArrayList<ClassDataSlot>();
1134 Class<?> start = cl, end = cl;
1135
1136 // locate closest non-serializable superclass
1137 while (end != null && Serializable.class.isAssignableFrom(end)) {
1138 end = end.getSuperclass();
1139 }
1140
1141 for (ObjectStreamClass d = this; d != null; d = d.superDesc) {
1142
1143 // search up inheritance hierarchy for class with matching name
1144 String searchName = (d.cl != null) ? d.cl.getName() : d.name;
1145 Class<?> match = null;
1146 for (Class<?> c = start; c != end; c = c.getSuperclass()) {
1147 if (searchName.equals(c.getName())) {
1148 match = c;
1149 break;
1150 }
1151 }
1152
1153 // add "no data" slot for each unmatched class below match
1154 if (match != null) {
1155 for (Class<?> c = start; c != match; c = c.getSuperclass()) {
1156 slots.add(new ClassDataSlot(
1157 ObjectStreamClass.lookup(c, true), false));
1158 }
1159 start = match.getSuperclass();
1160 }
1161
1162 // record descriptor/class pairing
1163 slots.add(new ClassDataSlot(d.getVariantFor(match), true));
1164 }
1165
1166 // add "no data" slot for any leftover unmatched classes
1167 for (Class<?> c = start; c != end; c = c.getSuperclass()) {
1168 slots.add(new ClassDataSlot(
1169 ObjectStreamClass.lookup(c, true), false));
1170 }
1171
1172 // order slots from superclass -> subclass
1173 Collections.reverse(slots);
1174 return slots.toArray(new ClassDataSlot[slots.size()]);
1175 }
1176
1177 /**
1178 * Returns aggregate size (in bytes) of marshalled primitive field values
1179 * for represented class.
1180 */
1181 int getPrimDataSize() {
1182 return primDataSize;
1183 }
1184
1185 /**
1186 * Returns number of non-primitive serializable fields of represented
1187 * class.
1188 */
1189 int getNumObjFields() {
1190 return numObjFields;
1191 }
1192
1193 /**
1194 * Fetches the serializable primitive field values of object obj and
1195 * marshals them into byte array buf starting at offset 0. It is the
1196 * responsibility of the caller to ensure that obj is of the proper type if
1197 * non-null.
1198 */
1199 void getPrimFieldValues(Object obj, byte[] buf) {
1200 fieldRefl.getPrimFieldValues(obj, buf);
1201 }
1202
1203 /**
1204 * Sets the serializable primitive fields of object obj using values
1205 * unmarshalled from byte array buf starting at offset 0. It is the
1206 * responsibility of the caller to ensure that obj is of the proper type if
1207 * non-null.
1208 */
1209 void setPrimFieldValues(Object obj, byte[] buf) {
1210 fieldRefl.setPrimFieldValues(obj, buf);
1211 }
1212
1213 /**
1214 * Fetches the serializable object field values of object obj and stores
1215 * them in array vals starting at offset 0. It is the responsibility of
1216 * the caller to ensure that obj is of the proper type if non-null.
1217 */
1218 void getObjFieldValues(Object obj, Object[] vals) {
1219 fieldRefl.getObjFieldValues(obj, vals);
1220 }
1221
1222 /**
1223 * Sets the serializable object fields of object obj using values from
1224 * array vals starting at offset 0. It is the responsibility of the caller
1225 * to ensure that obj is of the proper type if non-null.
1226 */
1227 void setObjFieldValues(Object obj, Object[] vals) {
1228 fieldRefl.setObjFieldValues(obj, vals);
1229 }
1230
1231 /**
1232 * Calculates and sets serializable field offsets, as well as primitive
1233 * data size and object field count totals. Throws InvalidClassException
1234 * if fields are illegally ordered.
1235 */
1236 private void computeFieldOffsets() throws InvalidClassException {
1237 primDataSize = 0;
1238 numObjFields = 0;
1239 int firstObjIndex = -1;
1240
1241 for (int i = 0; i < fields.length; i++) {
1242 ObjectStreamField f = fields[i];
1243 switch (f.getTypeCode()) {
1244 case 'Z':
1245 case 'B':
1246 f.setOffset(primDataSize++);
1247 break;
1248
1249 case 'C':
1250 case 'S':
1251 f.setOffset(primDataSize);
1252 primDataSize += 2;
1253 break;
1254
1255 case 'I':
1256 case 'F':
1257 f.setOffset(primDataSize);
1258 primDataSize += 4;
1259 break;
1260
1261 case 'J':
1262 case 'D':
1263 f.setOffset(primDataSize);
1264 primDataSize += 8;
1265 break;
1266
1267 case '[':
1268 case 'L':
1269 f.setOffset(numObjFields++);
1270 if (firstObjIndex == -1) {
1271 firstObjIndex = i;
1272 }
1273 break;
1274
1275 default:
1276 throw new InternalError();
1277 }
1278 }
1279 if (firstObjIndex != -1 &&
1280 firstObjIndex + numObjFields != fields.length)
1281 {
1282 throw new InvalidClassException(name, "illegal field order");
1283 }
1284 }
1285
1286 /**
1287 * If given class is the same as the class associated with this class
1288 * descriptor, returns reference to this class descriptor. Otherwise,
1289 * returns variant of this class descriptor bound to given class.
1290 */
1291 private ObjectStreamClass getVariantFor(Class<?> cl)
1292 throws InvalidClassException
1293 {
1294 if (this.cl == cl) {
1295 return this;
1296 }
1297 ObjectStreamClass desc = new ObjectStreamClass();
1298 if (isProxy) {
1299 desc.initProxy(cl, null, superDesc);
1300 } else {
1301 desc.initNonProxy(this, cl, null, superDesc);
1302 }
1303 return desc;
1304 }
1305
1306 /**
1307 * Returns public no-arg constructor of given class, or null if none found.
1308 * Access checks are disabled on the returned constructor (if any), since
1309 * the defining class may still be non-public.
1310 */
1311 private static Constructor getExternalizableConstructor(Class<?> cl) {
1312 try {
1313 Constructor cons = cl.getDeclaredConstructor((Class<?>[]) null);
1314 cons.setAccessible(true);
1315 return ((cons.getModifiers() & Modifier.PUBLIC) != 0) ?
1316 cons : null;
1317 } catch (NoSuchMethodException ex) {
1318 return null;
1319 }
1320 }
1321
1322 /**
1323 * Returns subclass-accessible no-arg constructor of first non-serializable
1324 * superclass, or null if none found. Access checks are disabled on the
1325 * returned constructor (if any).
1326 */
1327 private static Constructor getSerializableConstructor(Class<?> cl) {
1328 Class<?> initCl = cl;
1329 while (Serializable.class.isAssignableFrom(initCl)) {
1330 if ((initCl = initCl.getSuperclass()) == null) {
1331 return null;
1332 }
1333 }
1334 try {
1335 Constructor cons = initCl.getDeclaredConstructor((Class<?>[]) null);
1336 int mods = cons.getModifiers();
1337 if ((mods & Modifier.PRIVATE) != 0 ||
1338 ((mods & (Modifier.PUBLIC | Modifier.PROTECTED)) == 0 &&
1339 !packageEquals(cl, initCl)))
1340 {
1341 return null;
1342 }
1343 cons = reflFactory.newConstructorForSerialization(cl, cons);
1344 cons.setAccessible(true);
1345 return cons;
1346 } catch (NoSuchMethodException ex) {
1347 return null;
1348 }
1349 }
1350
1351 /**
1352 * Returns non-static, non-abstract method with given signature provided it
1353 * is defined by or accessible (via inheritance) by the given class, or
1354 * null if no match found. Access checks are disabled on the returned
1355 * method (if any).
1356 */
1357 private static Method getInheritableMethod(Class<?> cl, String name,
1358 Class<?>[] argTypes,
1359 Class<?> returnType)
1360 {
1361 Method meth = null;
1362 Class<?> defCl = cl;
1363 while (defCl != null) {
1364 try {
1365 meth = defCl.getDeclaredMethod(name, argTypes);
1366 break;
1367 } catch (NoSuchMethodException ex) {
1368 defCl = defCl.getSuperclass();
1369 }
1370 }
1371
1372 if ((meth == null) || (meth.getReturnType() != returnType)) {
1373 return null;
1374 }
1375 meth.setAccessible(true);
1376 int mods = meth.getModifiers();
1377 if ((mods & (Modifier.STATIC | Modifier.ABSTRACT)) != 0) {
1378 return null;
1379 } else if ((mods & (Modifier.PUBLIC | Modifier.PROTECTED)) != 0) {
1380 return meth;
1381 } else if ((mods & Modifier.PRIVATE) != 0) {
1382 return (cl == defCl) ? meth : null;
1383 } else {
1384 return packageEquals(cl, defCl) ? meth : null;
1385 }
1386 }
1387
1388 /**
1389 * Returns non-static private method with given signature defined by given
1390 * class, or null if none found. Access checks are disabled on the
1391 * returned method (if any).
1392 */
1393 private static Method getPrivateMethod(Class<?> cl, String name,
1394 Class<?>[] argTypes,
1395 Class<?> returnType)
1396 {
1397 try {
1398 Method meth = cl.getDeclaredMethod(name, argTypes);
1399 meth.setAccessible(true);
1400 int mods = meth.getModifiers();
1401 return ((meth.getReturnType() == returnType) &&
1402 ((mods & Modifier.STATIC) == 0) &&
1403 ((mods & Modifier.PRIVATE) != 0)) ? meth : null;
1404 } catch (NoSuchMethodException ex) {
1405 return null;
1406 }
1407 }
1408
1409 /**
1410 * Returns true if classes are defined in the same runtime package, false
1411 * otherwise.
1412 */
1413 private static boolean packageEquals(Class<?> cl1, Class<?> cl2) {
1414 return (cl1.getClassLoader() == cl2.getClassLoader() &&
1415 getPackageName(cl1).equals(getPackageName(cl2)));
1416 }
1417
1418 /**
1419 * Returns package name of given class.
1420 */
1421 private static String getPackageName(Class<?> cl) {
1422 String s = cl.getName();
1423 int i = s.lastIndexOf('[');
1424 if (i >= 0) {
1425 s = s.substring(i + 2);
1426 }
1427 i = s.lastIndexOf('.');
1428 return (i >= 0) ? s.substring(0, i) : "";
1429 }
1430
1431 /**
1432 * Compares class names for equality, ignoring package names. Returns true
1433 * if class names equal, false otherwise.
1434 */
1435 private static boolean classNamesEqual(String name1, String name2) {
1436 name1 = name1.substring(name1.lastIndexOf('.') + 1);
1437 name2 = name2.substring(name2.lastIndexOf('.') + 1);
1438 return name1.equals(name2);
1439 }
1440
1441 /**
1442 * Returns JVM type signature for given class.
1443 */
1444 private static String getClassSignature(Class<?> cl) {
1445 StringBuilder sbuf = new StringBuilder();
1446 while (cl.isArray()) {
1447 sbuf.append('[');
1448 cl = cl.getComponentType();
1449 }
1450 if (cl.isPrimitive()) {
1451 if (cl == Integer.TYPE) {
1452 sbuf.append('I');
1453 } else if (cl == Byte.TYPE) {
1454 sbuf.append('B');
1455 } else if (cl == Long.TYPE) {
1456 sbuf.append('J');
1457 } else if (cl == Float.TYPE) {
1458 sbuf.append('F');
1459 } else if (cl == Double.TYPE) {
1460 sbuf.append('D');
1461 } else if (cl == Short.TYPE) {
1462 sbuf.append('S');
1463 } else if (cl == Character.TYPE) {
1464 sbuf.append('C');
1465 } else if (cl == Boolean.TYPE) {
1466 sbuf.append('Z');
1467 } else if (cl == Void.TYPE) {
1468 sbuf.append('V');
1469 } else {
1470 throw new InternalError();
1471 }
1472 } else {
1473 sbuf.append('L' + cl.getName().replace('.', '/') + ';');
1474 }
1475 return sbuf.toString();
1476 }
1477
1478 /**
1479 * Returns JVM type signature for given list of parameters and return type.
1480 */
1481 private static String getMethodSignature(Class<?>[] paramTypes,
1482 Class<?> retType)
1483 {
1484 StringBuilder sbuf = new StringBuilder();
1485 sbuf.append('(');
1486 for (int i = 0; i < paramTypes.length; i++) {
1487 sbuf.append(getClassSignature(paramTypes[i]));
1488 }
1489 sbuf.append(')');
1490 sbuf.append(getClassSignature(retType));
1491 return sbuf.toString();
1492 }
1493
1494 /**
1495 * Convenience method for throwing an exception that is either a
1496 * RuntimeException, Error, or of some unexpected type (in which case it is
1497 * wrapped inside an IOException).
1498 */
1499 private static void throwMiscException(Throwable th) throws IOException {
1500 if (th instanceof RuntimeException) {
1501 throw (RuntimeException) th;
1502 } else if (th instanceof Error) {
1503 throw (Error) th;
1504 } else {
1505 IOException ex = new IOException("unexpected exception type");
1506 ex.initCause(th);
1507 throw ex;
1508 }
1509 }
1510
1511 /**
1512 * Returns ObjectStreamField array describing the serializable fields of
1513 * the given class. Serializable fields backed by an actual field of the
1514 * class are represented by ObjectStreamFields with corresponding non-null
1515 * Field objects. Throws InvalidClassException if the (explicitly
1516 * declared) serializable fields are invalid.
1517 */
1518 private static ObjectStreamField[] getSerialFields(Class<?> cl)
1519 throws InvalidClassException
1520 {
1521 ObjectStreamField[] fields;
1522 if (Serializable.class.isAssignableFrom(cl) &&
1523 !Externalizable.class.isAssignableFrom(cl) &&
1524 !Proxy.isProxyClass(cl) &&
1525 !cl.isInterface())
1526 {
1527 if ((fields = getDeclaredSerialFields(cl)) == null) {
1528 fields = getDefaultSerialFields(cl);
1529 }
1530 Arrays.sort(fields);
1531 } else {
1532 fields = NO_FIELDS;
1533 }
1534 return fields;
1535 }
1536
1537 /**
1538 * Returns serializable fields of given class as defined explicitly by a
1539 * "serialPersistentFields" field, or null if no appropriate
1540 * "serialPersistentFields" field is defined. Serializable fields backed
1541 * by an actual field of the class are represented by ObjectStreamFields
1542 * with corresponding non-null Field objects. For compatibility with past
1543 * releases, a "serialPersistentFields" field with a null value is
1544 * considered equivalent to not declaring "serialPersistentFields". Throws
1545 * InvalidClassException if the declared serializable fields are
1546 * invalid--e.g., if multiple fields share the same name.
1547 */
1548 private static ObjectStreamField[] getDeclaredSerialFields(Class<?> cl)
1549 throws InvalidClassException
1550 {
1551 ObjectStreamField[] serialPersistentFields = null;
1552 try {
1553 Field f = cl.getDeclaredField("serialPersistentFields");
1554 int mask = Modifier.PRIVATE | Modifier.STATIC | Modifier.FINAL;
1555 if ((f.getModifiers() & mask) == mask) {
1556 f.setAccessible(true);
1557 serialPersistentFields = (ObjectStreamField[]) f.get(null);
1558 }
1559 } catch (Exception ex) {
1560 }
1561 if (serialPersistentFields == null) {
1562 return null;
1563 } else if (serialPersistentFields.length == 0) {
1564 return NO_FIELDS;
1565 }
1566
1567 ObjectStreamField[] boundFields =
1568 new ObjectStreamField[serialPersistentFields.length];
1569 Set<String> fieldNames = new HashSet<String>(serialPersistentFields.length);
1570
1571 for (int i = 0; i < serialPersistentFields.length; i++) {
1572 ObjectStreamField spf = serialPersistentFields[i];
1573
1574 String fname = spf.getName();
1575 if (fieldNames.contains(fname)) {
1576 throw new InvalidClassException(
1577 "multiple serializable fields named " + fname);
1578 }
1579 fieldNames.add(fname);
1580
1581 try {
1582 Field f = cl.getDeclaredField(fname);
1583 if ((f.getType() == spf.getType()) &&
1584 ((f.getModifiers() & Modifier.STATIC) == 0))
1585 {
1586 boundFields[i] =
1587 new ObjectStreamField(f, spf.isUnshared(), true);
1588 }
1589 } catch (NoSuchFieldException ex) {
1590 }
1591 if (boundFields[i] == null) {
1592 boundFields[i] = new ObjectStreamField(
1593 fname, spf.getType(), spf.isUnshared());
1594 }
1595 }
1596 return boundFields;
1597 }
1598
1599 /**
1600 * Returns array of ObjectStreamFields corresponding to all non-static
1601 * non-transient fields declared by given class. Each ObjectStreamField
1602 * contains a Field object for the field it represents. If no default
1603 * serializable fields exist, NO_FIELDS is returned.
1604 */
1605 private static ObjectStreamField[] getDefaultSerialFields(Class<?> cl) {
1606 Field[] clFields = cl.getDeclaredFields();
1607 ArrayList<ObjectStreamField> list = new ArrayList<ObjectStreamField>();
1608 int mask = Modifier.STATIC | Modifier.TRANSIENT;
1609
1610 for (int i = 0; i < clFields.length; i++) {
1611 if ((clFields[i].getModifiers() & mask) == 0) {
1612 list.add(new ObjectStreamField(clFields[i], false, true));
1613 }
1614 }
1615 int size = list.size();
1616 return (size == 0) ? NO_FIELDS :
1617 list.toArray(new ObjectStreamField[size]);
1618 }
1619
1620 /**
1621 * Returns explicit serial version UID value declared by given class, or
1622 * null if none.
1623 */
1624 private static Long getDeclaredSUID(Class<?> cl) {
1625 try {
1626 Field f = cl.getDeclaredField("serialVersionUID");
1627 int mask = Modifier.STATIC | Modifier.FINAL;
1628 if ((f.getModifiers() & mask) == mask) {
1629 f.setAccessible(true);
1630 return Long.valueOf(f.getLong(null));
1631 }
1632 } catch (Exception ex) {
1633 }
1634 return null;
1635 }
1636
1637 /**
1638 * Computes the default serial version UID value for the given class.
1639 */
1640 private static long computeDefaultSUID(Class<?> cl) {
1641 if (!Serializable.class.isAssignableFrom(cl) || Proxy.isProxyClass(cl))
1642 {
1643 return 0L;
1644 }
1645
1646 try {
1647 ByteArrayOutputStream bout = new ByteArrayOutputStream();
1648 DataOutputStream dout = new DataOutputStream(bout);
1649
1650 dout.writeUTF(cl.getName());
1651
1652 int classMods = cl.getModifiers() &
1653 (Modifier.PUBLIC | Modifier.FINAL |
1654 Modifier.INTERFACE | Modifier.ABSTRACT);
1655
1656 /*
1657 * compensate for javac bug in which ABSTRACT bit was set for an
1658 * interface only if the interface declared methods
1659 */
1660 Method[] methods = cl.getDeclaredMethods();
1661 if ((classMods & Modifier.INTERFACE) != 0) {
1662 classMods = (methods.length > 0) ?
1663 (classMods | Modifier.ABSTRACT) :
1664 (classMods & ~Modifier.ABSTRACT);
1665 }
1666 dout.writeInt(classMods);
1667
1668 if (!cl.isArray()) {
1669 /*
1670 * compensate for change in 1.2FCS in which
1671 * Class.getInterfaces() was modified to return Cloneable and
1672 * Serializable for array classes.
1673 */
1674 Class<?>[] interfaces = cl.getInterfaces();
1675 String[] ifaceNames = new String[interfaces.length];
1676 for (int i = 0; i < interfaces.length; i++) {
1677 ifaceNames[i] = interfaces[i].getName();
1678 }
1679 Arrays.sort(ifaceNames);
1680 for (int i = 0; i < ifaceNames.length; i++) {
1681 dout.writeUTF(ifaceNames[i]);
1682 }
1683 }
1684
1685 Field[] fields = cl.getDeclaredFields();
1686 MemberSignature[] fieldSigs = new MemberSignature[fields.length];
1687 for (int i = 0; i < fields.length; i++) {
1688 fieldSigs[i] = new MemberSignature(fields[i]);
1689 }
1690 Arrays.sort(fieldSigs, new Comparator<MemberSignature>() {
1691 public int compare(MemberSignature ms1, MemberSignature ms2) {
1692 return ms1.name.compareTo(ms2.name);
1693 }
1694 });
1695 for (int i = 0; i < fieldSigs.length; i++) {
1696 MemberSignature sig = fieldSigs[i];
1697 int mods = sig.member.getModifiers() &
1698 (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
1699 Modifier.STATIC | Modifier.FINAL | Modifier.VOLATILE |
1700 Modifier.TRANSIENT);
1701 if (((mods & Modifier.PRIVATE) == 0) ||
1702 ((mods & (Modifier.STATIC | Modifier.TRANSIENT)) == 0))
1703 {
1704 dout.writeUTF(sig.name);
1705 dout.writeInt(mods);
1706 dout.writeUTF(sig.signature);
1707 }
1708 }
1709
1710 if (hasStaticInitializer(cl)) {
1711 dout.writeUTF("<clinit>");
1712 dout.writeInt(Modifier.STATIC);
1713 dout.writeUTF("()V");
1714 }
1715
1716 Constructor[] cons = cl.getDeclaredConstructors();
1717 MemberSignature[] consSigs = new MemberSignature[cons.length];
1718 for (int i = 0; i < cons.length; i++) {
1719 consSigs[i] = new MemberSignature(cons[i]);
1720 }
1721 Arrays.sort(consSigs, new Comparator<MemberSignature>() {
1722 public int compare(MemberSignature ms1, MemberSignature ms2) {
1723 return ms1.signature.compareTo(ms2.signature);
1724 }
1725 });
1726 for (int i = 0; i < consSigs.length; i++) {
1727 MemberSignature sig = consSigs[i];
1728 int mods = sig.member.getModifiers() &
1729 (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
1730 Modifier.STATIC | Modifier.FINAL |
1731 Modifier.SYNCHRONIZED | Modifier.NATIVE |
1732 Modifier.ABSTRACT | Modifier.STRICT);
1733 if ((mods & Modifier.PRIVATE) == 0) {
1734 dout.writeUTF("<init>");
1735 dout.writeInt(mods);
1736 dout.writeUTF(sig.signature.replace('/', '.'));
1737 }
1738 }
1739
1740 MemberSignature[] methSigs = new MemberSignature[methods.length];
1741 for (int i = 0; i < methods.length; i++) {
1742 methSigs[i] = new MemberSignature(methods[i]);
1743 }
1744 Arrays.sort(methSigs, new Comparator<MemberSignature>() {
1745 public int compare(MemberSignature ms1, MemberSignature ms2) {
1746 int comp = ms1.name.compareTo(ms2.name);
1747 if (comp == 0) {
1748 comp = ms1.signature.compareTo(ms2.signature);
1749 }
1750 return comp;
1751 }
1752 });
1753 for (int i = 0; i < methSigs.length; i++) {
1754 MemberSignature sig = methSigs[i];
1755 int mods = sig.member.getModifiers() &
1756 (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
1757 Modifier.STATIC | Modifier.FINAL |
1758 Modifier.SYNCHRONIZED | Modifier.NATIVE |
1759 Modifier.ABSTRACT | Modifier.STRICT);
1760 if ((mods & Modifier.PRIVATE) == 0) {
1761 dout.writeUTF(sig.name);
1762 dout.writeInt(mods);
1763 dout.writeUTF(sig.signature.replace('/', '.'));
1764 }
1765 }
1766
1767 dout.flush();
1768
1769 MessageDigest md = MessageDigest.getInstance("SHA");
1770 byte[] hashBytes = md.digest(bout.toByteArray());
1771 long hash = 0;
1772 for (int i = Math.min(hashBytes.length, 8) - 1; i >= 0; i--) {
1773 hash = (hash << 8) | (hashBytes[i] & 0xFF);
1774 }
1775 return hash;
1776 } catch (IOException ex) {
1777 throw new InternalError();
1778 } catch (NoSuchAlgorithmException ex) {
1779 throw new SecurityException(ex.getMessage());
1780 }
1781 }
1782
1783 /**
1784 * Returns true if the given class defines a static initializer method,
1785 * false otherwise.
1786 */
1787 private native static boolean hasStaticInitializer(Class<?> cl);
1788
1789 /**
1790 * Class for computing and caching field/constructor/method signatures
1791 * during serialVersionUID calculation.
1792 */
1793 private static class MemberSignature {
1794
1795 public final Member member;
1796 public final String name;
1797 public final String signature;
1798
1799 public MemberSignature(Field field) {
1800 member = field;
1801 name = field.getName();
1802 signature = getClassSignature(field.getType());
1803 }
1804
1805 public MemberSignature(Constructor cons) {
1806 member = cons;
1807 name = cons.getName();
1808 signature = getMethodSignature(
1809 cons.getParameterTypes(), Void.TYPE);
1810 }
1811
1812 public MemberSignature(Method meth) {
1813 member = meth;
1814 name = meth.getName();
1815 signature = getMethodSignature(
1816 meth.getParameterTypes(), meth.getReturnType());
1817 }
1818 }
1819
1820 /**
1821 * Class for setting and retrieving serializable field values in batch.
1822 */
1823 // REMIND: dynamically generate these?
1824 private static class FieldReflector {
1825
1826 /** handle for performing unsafe operations */
1827 private static final Unsafe unsafe = Unsafe.getUnsafe();
1828
1829 /** fields to operate on */
1830 private final ObjectStreamField[] fields;
1831 /** number of primitive fields */
1832 private final int numPrimFields;
1833 /** unsafe field keys for reading fields - may contain dupes */
1834 private final long[] readKeys;
1835 /** unsafe fields keys for writing fields - no dupes */
1836 private final long[] writeKeys;
1837 /** field data offsets */
1838 private final int[] offsets;
1839 /** field type codes */
1840 private final char[] typeCodes;
1841 /** field types */
1842 private final Class<?>[] types;
1843
1844 /**
1845 * Constructs FieldReflector capable of setting/getting values from the
1846 * subset of fields whose ObjectStreamFields contain non-null
1847 * reflective Field objects. ObjectStreamFields with null Fields are
1848 * treated as filler, for which get operations return default values
1849 * and set operations discard given values.
1850 */
1851 FieldReflector(ObjectStreamField[] fields) {
1852 this.fields = fields;
1853 int nfields = fields.length;
1854 readKeys = new long[nfields];
1855 writeKeys = new long[nfields];
1856 offsets = new int[nfields];
1857 typeCodes = new char[nfields];
1858 ArrayList<Class<?>> typeList = new ArrayList<Class<?>>();
1859 Set<Long> usedKeys = new HashSet<Long>();
1860
1861
1862 for (int i = 0; i < nfields; i++) {
1863 ObjectStreamField f = fields[i];
1864 Field rf = f.getField();
1865 long key = (rf != null) ?
1866 unsafe.objectFieldOffset(rf) : Unsafe.INVALID_FIELD_OFFSET;
1867 readKeys[i] = key;
1868 writeKeys[i] = usedKeys.add(key) ?
1869 key : Unsafe.INVALID_FIELD_OFFSET;
1870 offsets[i] = f.getOffset();
1871 typeCodes[i] = f.getTypeCode();
1872 if (!f.isPrimitive()) {
1873 typeList.add((rf != null) ? rf.getType() : null);
1874 }
1875 }
1876
1877 types = typeList.toArray(new Class<?>[typeList.size()]);
1878 numPrimFields = nfields - types.length;
1879 }
1880
1881 /**
1882 * Returns list of ObjectStreamFields representing fields operated on
1883 * by this reflector. The shared/unshared values and Field objects
1884 * contained by ObjectStreamFields in the list reflect their bindings
1885 * to locally defined serializable fields.
1886 */
1887 ObjectStreamField[] getFields() {
1888 return fields;
1889 }
1890
1891 /**
1892 * Fetches the serializable primitive field values of object obj and
1893 * marshals them into byte array buf starting at offset 0. The caller
1894 * is responsible for ensuring that obj is of the proper type.
1895 */
1896 void getPrimFieldValues(Object obj, byte[] buf) {
1897 if (obj == null) {
1898 throw new NullPointerException();
1899 }
1900 /* assuming checkDefaultSerialize() has been called on the class
1901 * descriptor this FieldReflector was obtained from, no field keys
1902 * in array should be equal to Unsafe.INVALID_FIELD_OFFSET.
1903 */
1904 for (int i = 0; i < numPrimFields; i++) {
1905 long key = readKeys[i];
1906 int off = offsets[i];
1907 switch (typeCodes[i]) {
1908 case 'Z':
1909 Bits.putBoolean(buf, off, unsafe.getBoolean(obj, key));
1910 break;
1911
1912 case 'B':
1913 buf[off] = unsafe.getByte(obj, key);
1914 break;
1915
1916 case 'C':
1917 Bits.putChar(buf, off, unsafe.getChar(obj, key));
1918 break;
1919
1920 case 'S':
1921 Bits.putShort(buf, off, unsafe.getShort(obj, key));
1922 break;
1923
1924 case 'I':
1925 Bits.putInt(buf, off, unsafe.getInt(obj, key));
1926 break;
1927
1928 case 'F':
1929 Bits.putFloat(buf, off, unsafe.getFloat(obj, key));
1930 break;
1931
1932 case 'J':
1933 Bits.putLong(buf, off, unsafe.getLong(obj, key));
1934 break;
1935
1936 case 'D':
1937 Bits.putDouble(buf, off, unsafe.getDouble(obj, key));
1938 break;
1939
1940 default:
1941 throw new InternalError();
1942 }
1943 }
1944 }
1945
1946 /**
1947 * Sets the serializable primitive fields of object obj using values
1948 * unmarshalled from byte array buf starting at offset 0. The caller
1949 * is responsible for ensuring that obj is of the proper type.
1950 */
1951 void setPrimFieldValues(Object obj, byte[] buf) {
1952 if (obj == null) {
1953 throw new NullPointerException();
1954 }
1955 for (int i = 0; i < numPrimFields; i++) {
1956 long key = writeKeys[i];
1957 if (key == Unsafe.INVALID_FIELD_OFFSET) {
1958 continue; // discard value
1959 }
1960 int off = offsets[i];
1961 switch (typeCodes[i]) {
1962 case 'Z':
1963 unsafe.putBoolean(obj, key, Bits.getBoolean(buf, off));
1964 break;
1965
1966 case 'B':
1967 unsafe.putByte(obj, key, buf[off]);
1968 break;
1969
1970 case 'C':
1971 unsafe.putChar(obj, key, Bits.getChar(buf, off));
1972 break;
1973
1974 case 'S':
1975 unsafe.putShort(obj, key, Bits.getShort(buf, off));
1976 break;
1977
1978 case 'I':
1979 unsafe.putInt(obj, key, Bits.getInt(buf, off));
1980 break;
1981
1982 case 'F':
1983 unsafe.putFloat(obj, key, Bits.getFloat(buf, off));
1984 break;
1985
1986 case 'J':
1987 unsafe.putLong(obj, key, Bits.getLong(buf, off));
1988 break;
1989
1990 case 'D':
1991 unsafe.putDouble(obj, key, Bits.getDouble(buf, off));
1992 break;
1993
1994 default:
1995 throw new InternalError();
1996 }
1997 }
1998 }
1999
2000 /**
2001 * Fetches the serializable object field values of object obj and
2002 * stores them in array vals starting at offset 0. The caller is
2003 * responsible for ensuring that obj is of the proper type.
2004 */
2005 void getObjFieldValues(Object obj, Object[] vals) {
2006 if (obj == null) {
2007 throw new NullPointerException();
2008 }
2009 /* assuming checkDefaultSerialize() has been called on the class
2010 * descriptor this FieldReflector was obtained from, no field keys
2011 * in array should be equal to Unsafe.INVALID_FIELD_OFFSET.
2012 */
2013 for (int i = numPrimFields; i < fields.length; i++) {
2014 switch (typeCodes[i]) {
2015 case 'L':
2016 case '[':
2017 vals[offsets[i]] = unsafe.getObject(obj, readKeys[i]);
2018 break;
2019
2020 default:
2021 throw new InternalError();
2022 }
2023 }
2024 }
2025
2026 /**
2027 * Sets the serializable object fields of object obj using values from
2028 * array vals starting at offset 0. The caller is responsible for
2029 * ensuring that obj is of the proper type; however, attempts to set a
2030 * field with a value of the wrong type will trigger an appropriate
2031 * ClassCastException.
2032 */
2033 void setObjFieldValues(Object obj, Object[] vals) {
2034 if (obj == null) {
2035 throw new NullPointerException();
2036 }
2037 for (int i = numPrimFields; i < fields.length; i++) {
2038 long key = writeKeys[i];
2039 if (key == Unsafe.INVALID_FIELD_OFFSET) {
2040 continue; // discard value
2041 }
2042 switch (typeCodes[i]) {
2043 case 'L':
2044 case '[':
2045 Object val = vals[offsets[i]];
2046 if (val != null &&
2047 !types[i - numPrimFields].isInstance(val))
2048 {
2049 Field f = fields[i].getField();
2050 throw new ClassCastException(
2051 "cannot assign instance of " +
2052 val.getClass().getName() + " to field " +
2053 f.getDeclaringClass().getName() + "." +
2054 f.getName() + " of type " +
2055 f.getType().getName() + " in instance of " +
2056 obj.getClass().getName());
2057 }
2058 unsafe.putObject(obj, key, val);
2059 break;
2060
2061 default:
2062 throw new InternalError();
2063 }
2064 }
2065 }
2066 }
2067
2068 /**
2069 * Matches given set of serializable fields with serializable fields
2070 * described by the given local class descriptor, and returns a
2071 * FieldReflector instance capable of setting/getting values from the
2072 * subset of fields that match (non-matching fields are treated as filler,
2073 * for which get operations return default values and set operations
2074 * discard given values). Throws InvalidClassException if unresolvable
2075 * type conflicts exist between the two sets of fields.
2076 */
2077 private static FieldReflector getReflector(ObjectStreamField[] fields,
2078 ObjectStreamClass localDesc)
2079 throws InvalidClassException
2080 {
2081 // class irrelevant if no fields
2082 Class<?> cl = (localDesc != null && fields.length > 0) ?
2083 localDesc.cl : null;
2084 processQueue(Caches.reflectorsQueue, Caches.reflectors);
2085 FieldReflectorKey key = new FieldReflectorKey(cl, fields,
2086 Caches.reflectorsQueue);
2087 Reference<?> ref = Caches.reflectors.get(key);
2088 Object entry = null;
2089 if (ref != null) {
2090 entry = ref.get();
2091 }
2092 EntryFuture future = null;
2093 if (entry == null) {
2094 EntryFuture newEntry = new EntryFuture();
2095 Reference<?> newRef = new SoftReference<EntryFuture>(newEntry);
2096 do {
2097 if (ref != null) {
2098 Caches.reflectors.remove(key, ref);
2099 }
2100 ref = Caches.reflectors.putIfAbsent(key, newRef);
2101 if (ref != null) {
2102 entry = ref.get();
2103 }
2104 } while (ref != null && entry == null);
2105 if (entry == null) {
2106 future = newEntry;
2107 }
2108 }
2109
2110 if (entry instanceof FieldReflector) { // check common case first
2111 return (FieldReflector) entry;
2112 } else if (entry instanceof EntryFuture) {
2113 entry = ((EntryFuture) entry).get();
2114 } else if (entry == null) {
2115 try {
2116 entry = new FieldReflector(matchFields(fields, localDesc));
2117 } catch (Throwable th) {
2118 entry = th;
2119 }
2120 future.set(entry);
2121 Caches.reflectors.put(key, new SoftReference<Object>(entry));
2122 }
2123
2124 if (entry instanceof FieldReflector) {
2125 return (FieldReflector) entry;
2126 } else if (entry instanceof InvalidClassException) {
2127 throw (InvalidClassException) entry;
2128 } else if (entry instanceof RuntimeException) {
2129 throw (RuntimeException) entry;
2130 } else if (entry instanceof Error) {
2131 throw (Error) entry;
2132 } else {
2133 throw new InternalError("unexpected entry: " + entry);
2134 }
2135 }
2136
2137 /**
2138 * FieldReflector cache lookup key. Keys are considered equal if they
2139 * refer to the same class and equivalent field formats.
2140 */
2141 private static class FieldReflectorKey extends WeakReference<Class<?>> {
2142
2143 private final String sigs;
2144 private final int hash;
2145 private final boolean nullClass;
2146
2147 FieldReflectorKey(Class<?> cl, ObjectStreamField[] fields,
2148 ReferenceQueue<Class<?>> queue)
2149 {
2150 super(cl, queue);
2151 nullClass = (cl == null);
2152 StringBuilder sbuf = new StringBuilder();
2153 for (int i = 0; i < fields.length; i++) {
2154 ObjectStreamField f = fields[i];
2155 sbuf.append(f.getName()).append(f.getSignature());
2156 }
2157 sigs = sbuf.toString();
2158 hash = System.identityHashCode(cl) + sigs.hashCode();
2159 }
2160
2161 public int hashCode() {
2162 return hash;
2163 }
2164
2165 public boolean equals(Object obj) {
2166 if (obj == this) {
2167 return true;
2168 }
2169
2170 if (obj instanceof FieldReflectorKey) {
2171 FieldReflectorKey other = (FieldReflectorKey) obj;
2172 Class<?> referent;
2173 return (nullClass ? other.nullClass
2174 : ((referent = get()) != null) &&
2175 (referent == other.get())) &&
2176 sigs.equals(other.sigs);
2177 } else {
2178 return false;
2179 }
2180 }
2181 }
2182
2183 /**
2184 * Matches given set of serializable fields with serializable fields
2185 * obtained from the given local class descriptor (which contain bindings
2186 * to reflective Field objects). Returns list of ObjectStreamFields in
2187 * which each ObjectStreamField whose signature matches that of a local
2188 * field contains a Field object for that field; unmatched
2189 * ObjectStreamFields contain null Field objects. Shared/unshared settings
2190 * of the returned ObjectStreamFields also reflect those of matched local
2191 * ObjectStreamFields. Throws InvalidClassException if unresolvable type
2192 * conflicts exist between the two sets of fields.
2193 */
2194 private static ObjectStreamField[] matchFields(ObjectStreamField[] fields,
2195 ObjectStreamClass localDesc)
2196 throws InvalidClassException
2197 {
2198 ObjectStreamField[] localFields = (localDesc != null) ?
2199 localDesc.fields : NO_FIELDS;
2200
2201 /*
2202 * Even if fields == localFields, we cannot simply return localFields
2203 * here. In previous implementations of serialization,
2204 * ObjectStreamField.getType() returned Object.class if the
2205 * ObjectStreamField represented a non-primitive field and belonged to
2206 * a non-local class descriptor. To preserve this (questionable)
2207 * behavior, the ObjectStreamField instances returned by matchFields
2208 * cannot report non-primitive types other than Object.class; hence
2209 * localFields cannot be returned directly.
2210 */
2211
2212 ObjectStreamField[] matches = new ObjectStreamField[fields.length];
2213 for (int i = 0; i < fields.length; i++) {
2214 ObjectStreamField f = fields[i], m = null;
2215 for (int j = 0; j < localFields.length; j++) {
2216 ObjectStreamField lf = localFields[j];
2217 if (f.getName().equals(lf.getName())) {
2218 if ((f.isPrimitive() || lf.isPrimitive()) &&
2219 f.getTypeCode() != lf.getTypeCode())
2220 {
2221 throw new InvalidClassException(localDesc.name,
2222 "incompatible types for field " + f.getName());
2223 }
2224 if (lf.getField() != null) {
2225 m = new ObjectStreamField(
2226 lf.getField(), lf.isUnshared(), false);
2227 } else {
2228 m = new ObjectStreamField(
2229 lf.getName(), lf.getSignature(), lf.isUnshared());
2230 }
2231 }
2232 }
2233 if (m == null) {
2234 m = new ObjectStreamField(
2235 f.getName(), f.getSignature(), false);
2236 }
2237 m.setOffset(f.getOffset());
2238 matches[i] = m;
2239 }
2240 return matches;
2241 }
2242
2243 /**
2244 * Removes from the specified map any keys that have been enqueued
2245 * on the specified reference queue.
2246 */
2247 static void processQueue(ReferenceQueue<Class<?>> queue,
2248 ConcurrentMap<? extends
2249 WeakReference<Class<?>>, ?> map)
2250 {
2251 Reference<? extends Class<?>> ref;
2252 while((ref = queue.poll()) != null) {
2253 map.remove(ref);
2254 }
2255 }
2256
2257 /**
2258 * Weak key for Class objects.
2259 *
2260 **/
2261 static class WeakClassKey extends WeakReference<Class<?>> {
2262 /**
2263 * saved value of the referent's identity hash code, to maintain
2264 * a consistent hash code after the referent has been cleared
2265 */
2266 private final int hash;
2267
2268 /**
2269 * Create a new WeakClassKey to the given object, registered
2270 * with a queue.
2271 */
2272 WeakClassKey(Class<?> cl, ReferenceQueue<Class<?>> refQueue) {
2273 super(cl, refQueue);
2274 hash = System.identityHashCode(cl);
2275 }
2276
2277 /**
2278 * Returns the identity hash code of the original referent.
2279 */
2280 public int hashCode() {
2281 return hash;
2282 }
2283
2284 /**
2285 * Returns true if the given object is this identical
2286 * WeakClassKey instance, or, if this object's referent has not
2287 * been cleared, if the given object is another WeakClassKey
2288 * instance with the identical non-null referent as this one.
2289 */
2290 public boolean equals(Object obj) {
2291 if (obj == this) {
2292 return true;
2293 }
2294
2295 if (obj instanceof WeakClassKey) {
2296 Object referent = get();
2297 return (referent != null) &&
2298 (referent == ((WeakClassKey) obj).get());
2299 } else {
2300 return false;
2301 }
2302 }
2303 }
2304 }