1 /*
2 * Copyright (c) 1996, 2017, 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 jdk.internal.misc.Unsafe;
52 import jdk.internal.reflect.CallerSensitive;
53 import jdk.internal.reflect.Reflection;
54 import jdk.internal.reflect.ReflectionFactory;
55 import sun.reflect.misc.ReflectUtil;
56
57 import static java.io.ObjectStreamField.*;
58
59 /**
60 * Serialization's descriptor for classes. It contains the name and
61 * serialVersionUID of the class. The ObjectStreamClass for a specific class
62 * loaded in this Java VM can be found/created using the lookup method.
63 *
64 * <p>The algorithm to compute the SerialVersionUID is described in
65 * <a href="{@docRoot}/../specs/serialization/class.html#stream-unique-identifiers">
66 * Object Serialization Specification, Section 4.6, Stream Unique Identifiers</a>.
67 *
68 * @author Mike Warres
69 * @author Roger Riggs
70 * @see ObjectStreamField
71 * @see <a href="{@docRoot}/../specs/serialization/class.html">
72 * Object Serialization Specification, Section 4, Class Descriptors</a>
73 * @since 1.1
74 */
75 public class ObjectStreamClass implements Serializable {
76
77 /** serialPersistentFields value indicating no serializable fields */
78 public static final ObjectStreamField[] NO_FIELDS =
79 new ObjectStreamField[0];
80
81 private static final long serialVersionUID = -6120832682080437368L;
82 private static final ObjectStreamField[] serialPersistentFields =
83 NO_FIELDS;
84
85 /** reflection factory for obtaining serialization constructors */
86 private static final ReflectionFactory reflFactory =
87 AccessController.doPrivileged(
88 new ReflectionFactory.GetReflectionFactoryAction());
89
90 private static class Caches {
91 /** cache mapping local classes -> descriptors */
92 static final ConcurrentMap<WeakClassKey,Reference<?>> localDescs =
93 new ConcurrentHashMap<>();
94
95 /** cache mapping field group/local desc pairs -> field reflectors */
96 static final ConcurrentMap<FieldReflectorKey,Reference<?>> reflectors =
97 new ConcurrentHashMap<>();
98
99 /** queue for WeakReferences to local classes */
100 private static final ReferenceQueue<Class<?>> localDescsQueue =
101 new ReferenceQueue<>();
102 /** queue for WeakReferences to field reflectors keys */
103 private static final ReferenceQueue<Class<?>> reflectorsQueue =
104 new ReferenceQueue<>();
105 }
106
107 /** class associated with this descriptor (if any) */
108 private Class<?> cl;
109 /** name of class represented by this descriptor */
110 private String name;
111 /** serialVersionUID of represented class (null if not computed yet) */
112 private volatile Long suid;
113
114 /** true if represents dynamic proxy class */
115 private boolean isProxy;
116 /** true if represents enum type */
117 private boolean isEnum;
118 /** true if represented class implements Serializable */
119 private boolean serializable;
120 /** true if represented class implements Externalizable */
121 private boolean externalizable;
122 /** true if desc has data written by class-defined writeObject method */
123 private boolean hasWriteObjectData;
124 /**
125 * true if desc has externalizable data written in block data format; this
126 * must be true by default to accommodate ObjectInputStream subclasses which
127 * override readClassDescriptor() to return class descriptors obtained from
128 * ObjectStreamClass.lookup() (see 4461737)
129 */
130 private boolean hasBlockExternalData = true;
131
132 /**
133 * Contains information about InvalidClassException instances to be thrown
134 * when attempting operations on an invalid class. Note that instances of
135 * this class are immutable and are potentially shared among
136 * ObjectStreamClass instances.
137 */
138 private static class ExceptionInfo {
139 private final String className;
140 private final String message;
141
142 ExceptionInfo(String cn, String msg) {
143 className = cn;
144 message = msg;
145 }
146
147 /**
148 * Returns (does not throw) an InvalidClassException instance created
149 * from the information in this object, suitable for being thrown by
150 * the caller.
151 */
152 InvalidClassException newInvalidClassException() {
153 return new InvalidClassException(className, message);
154 }
155 }
156
157 /** exception (if any) thrown while attempting to resolve class */
158 private ClassNotFoundException resolveEx;
159 /** exception (if any) to throw if non-enum deserialization attempted */
160 private ExceptionInfo deserializeEx;
161 /** exception (if any) to throw if non-enum serialization attempted */
162 private ExceptionInfo serializeEx;
163 /** exception (if any) to throw if default serialization attempted */
164 private ExceptionInfo defaultSerializeEx;
165
166 /** serializable fields */
167 private ObjectStreamField[] fields;
168 /** aggregate marshalled size of primitive fields */
169 private int primDataSize;
170 /** number of non-primitive fields */
171 private int numObjFields;
172 /** reflector for setting/getting serializable field values */
173 private FieldReflector fieldRefl;
174 /** data layout of serialized objects described by this class desc */
175 private volatile ClassDataSlot[] dataLayout;
176
177 /** serialization-appropriate constructor, or null if none */
178 private Constructor<?> cons;
179 /** class-defined writeObject method, or null if none */
180 private Method writeObjectMethod;
181 /** class-defined readObject method, or null if none */
182 private Method readObjectMethod;
183 /** class-defined readObjectNoData method, or null if none */
184 private Method readObjectNoDataMethod;
185 /** class-defined writeReplace method, or null if none */
186 private Method writeReplaceMethod;
187 /** class-defined readResolve method, or null if none */
188 private Method readResolveMethod;
189
190 /** local class descriptor for represented class (may point to self) */
191 private ObjectStreamClass localDesc;
192 /** superclass descriptor appearing in stream */
193 private ObjectStreamClass superDesc;
194
195 /** true if, and only if, the object has been correctly initialized */
196 private boolean initialized;
197
198 /**
199 * Initializes native code.
200 */
201 private static native void initNative();
202 static {
203 initNative();
204 }
205
206 /**
207 * Find the descriptor for a class that can be serialized. Creates an
208 * ObjectStreamClass instance if one does not exist yet for class. Null is
209 * returned if the specified class does not implement java.io.Serializable
210 * or java.io.Externalizable.
211 *
212 * @param cl class for which to get the descriptor
213 * @return the class descriptor for the specified class
214 */
215 public static ObjectStreamClass lookup(Class<?> cl) {
216 return lookup(cl, false);
217 }
218
219 /**
220 * Returns the descriptor for any class, regardless of whether it
221 * implements {@link Serializable}.
222 *
223 * @param cl class for which to get the descriptor
224 * @return the class descriptor for the specified class
225 * @since 1.6
226 */
227 public static ObjectStreamClass lookupAny(Class<?> cl) {
228 return lookup(cl, true);
229 }
230
231 /**
232 * Returns the name of the class described by this descriptor.
233 * This method returns the name of the class in the format that
234 * is used by the {@link Class#getName} method.
235 *
236 * @return a string representing the name of the class
237 */
238 public String getName() {
239 return name;
240 }
241
242 /**
243 * Return the serialVersionUID for this class. The serialVersionUID
244 * defines a set of classes all with the same name that have evolved from a
245 * common root class and agree to be serialized and deserialized using a
246 * common format. NonSerializable classes have a serialVersionUID of 0L.
247 *
248 * @return the SUID of the class described by this descriptor
249 */
250 public long getSerialVersionUID() {
251 // REMIND: synchronize instead of relying on volatile?
252 if (suid == null) {
253 suid = AccessController.doPrivileged(
254 new PrivilegedAction<Long>() {
255 public Long run() {
256 return computeDefaultSUID(cl);
257 }
258 }
259 );
260 }
261 return suid.longValue();
262 }
263
264 /**
265 * Return the class in the local VM that this version is mapped to. Null
266 * is returned if there is no corresponding local class.
267 *
268 * @return the <code>Class</code> instance that this descriptor represents
269 */
270 @CallerSensitive
271 public Class<?> forClass() {
272 if (cl == null) {
273 return null;
274 }
275 requireInitialized();
276 if (System.getSecurityManager() != null) {
277 Class<?> caller = Reflection.getCallerClass();
278 if (ReflectUtil.needsPackageAccessCheck(caller.getClassLoader(), cl.getClassLoader())) {
279 ReflectUtil.checkPackageAccess(cl);
280 }
281 }
282 return cl;
283 }
284
285 /**
286 * Return an array of the fields of this serializable class.
287 *
288 * @return an array containing an element for each persistent field of
289 * this class. Returns an array of length zero if there are no
290 * fields.
291 * @since 1.2
292 */
293 public ObjectStreamField[] getFields() {
294 return getFields(true);
295 }
296
297 /**
298 * Get the field of this class by name.
299 *
300 * @param name the name of the data field to look for
301 * @return The ObjectStreamField object of the named field or null if
302 * there is no such named field.
303 */
304 public ObjectStreamField getField(String name) {
305 return getField(name, null);
306 }
307
308 /**
309 * Return a string describing this ObjectStreamClass.
310 */
311 public String toString() {
312 return name + ": static final long serialVersionUID = " +
313 getSerialVersionUID() + "L;";
314 }
315
316 /**
317 * Looks up and returns class descriptor for given class, or null if class
318 * is non-serializable and "all" is set to false.
319 *
320 * @param cl class to look up
321 * @param all if true, return descriptors for all classes; if false, only
322 * return descriptors for serializable classes
323 */
324 static ObjectStreamClass lookup(Class<?> cl, boolean all) {
325 if (!(all || Serializable.class.isAssignableFrom(cl))) {
326 return null;
327 }
328 processQueue(Caches.localDescsQueue, Caches.localDescs);
329 WeakClassKey key = new WeakClassKey(cl, Caches.localDescsQueue);
330 Reference<?> ref = Caches.localDescs.get(key);
331 Object entry = null;
332 if (ref != null) {
333 entry = ref.get();
334 }
335 EntryFuture future = null;
336 if (entry == null) {
337 EntryFuture newEntry = new EntryFuture();
338 Reference<?> newRef = new SoftReference<>(newEntry);
339 do {
340 if (ref != null) {
341 Caches.localDescs.remove(key, ref);
342 }
343 ref = Caches.localDescs.putIfAbsent(key, newRef);
344 if (ref != null) {
345 entry = ref.get();
346 }
347 } while (ref != null && entry == null);
348 if (entry == null) {
349 future = newEntry;
350 }
351 }
352
353 if (entry instanceof ObjectStreamClass) { // check common case first
354 return (ObjectStreamClass) entry;
355 }
356 if (entry instanceof EntryFuture) {
357 future = (EntryFuture) entry;
358 if (future.getOwner() == Thread.currentThread()) {
359 /*
360 * Handle nested call situation described by 4803747: waiting
361 * for future value to be set by a lookup() call further up the
362 * stack will result in deadlock, so calculate and set the
363 * future value here instead.
364 */
365 entry = null;
366 } else {
367 entry = future.get();
368 }
369 }
370 if (entry == null) {
371 try {
372 entry = new ObjectStreamClass(cl);
373 } catch (Throwable th) {
374 entry = th;
375 }
376 if (future.set(entry)) {
377 Caches.localDescs.put(key, new SoftReference<>(entry));
378 } else {
379 // nested lookup call already set future
380 entry = future.get();
381 }
382 }
383
384 if (entry instanceof ObjectStreamClass) {
385 return (ObjectStreamClass) entry;
386 } else if (entry instanceof RuntimeException) {
387 throw (RuntimeException) entry;
388 } else if (entry instanceof Error) {
389 throw (Error) entry;
390 } else {
391 throw new InternalError("unexpected entry: " + entry);
392 }
393 }
394
395 /**
396 * Placeholder used in class descriptor and field reflector lookup tables
397 * for an entry in the process of being initialized. (Internal) callers
398 * which receive an EntryFuture belonging to another thread as the result
399 * of a lookup should call the get() method of the EntryFuture; this will
400 * return the actual entry once it is ready for use and has been set(). To
401 * conserve objects, EntryFutures synchronize on themselves.
402 */
403 private static class EntryFuture {
404
405 private static final Object unset = new Object();
406 private final Thread owner = Thread.currentThread();
407 private Object entry = unset;
408
409 /**
410 * Attempts to set the value contained by this EntryFuture. If the
411 * EntryFuture's value has not been set already, then the value is
412 * saved, any callers blocked in the get() method are notified, and
413 * true is returned. If the value has already been set, then no saving
414 * or notification occurs, and false is returned.
415 */
416 synchronized boolean set(Object entry) {
417 if (this.entry != unset) {
418 return false;
419 }
420 this.entry = entry;
421 notifyAll();
422 return true;
423 }
424
425 /**
426 * Returns the value contained by this EntryFuture, blocking if
427 * necessary until a value is set.
428 */
429 synchronized Object get() {
430 boolean interrupted = false;
431 while (entry == unset) {
432 try {
433 wait();
434 } catch (InterruptedException ex) {
435 interrupted = true;
436 }
437 }
438 if (interrupted) {
439 AccessController.doPrivileged(
440 new PrivilegedAction<>() {
441 public Void run() {
442 Thread.currentThread().interrupt();
443 return null;
444 }
445 }
446 );
447 }
448 return entry;
449 }
450
451 /**
452 * Returns the thread that created this EntryFuture.
453 */
454 Thread getOwner() {
455 return owner;
456 }
457 }
458
459 /**
460 * Creates local class descriptor representing given class.
461 */
462 private ObjectStreamClass(final Class<?> cl) {
463 this.cl = cl;
464 name = cl.getName();
465 isProxy = Proxy.isProxyClass(cl);
466 isEnum = Enum.class.isAssignableFrom(cl);
467 serializable = Serializable.class.isAssignableFrom(cl);
468 externalizable = Externalizable.class.isAssignableFrom(cl);
469
470 Class<?> superCl = cl.getSuperclass();
471 superDesc = (superCl != null) ? lookup(superCl, false) : null;
472 localDesc = this;
473
474 if (serializable) {
475 AccessController.doPrivileged(new PrivilegedAction<>() {
476 public Void run() {
477 if (isEnum) {
478 suid = Long.valueOf(0);
479 fields = NO_FIELDS;
480 return null;
481 }
482 if (cl.isArray()) {
483 fields = NO_FIELDS;
484 return null;
485 }
486
487 suid = getDeclaredSUID(cl);
488 try {
489 fields = getSerialFields(cl);
490 computeFieldOffsets();
491 } catch (InvalidClassException e) {
492 serializeEx = deserializeEx =
493 new ExceptionInfo(e.classname, e.getMessage());
494 fields = NO_FIELDS;
495 }
496
497 if (externalizable) {
498 cons = getExternalizableConstructor(cl);
499 } else {
500 cons = getSerializableConstructor(cl);
501 writeObjectMethod = getPrivateMethod(cl, "writeObject",
502 new Class<?>[] { ObjectOutputStream.class },
503 Void.TYPE);
504 readObjectMethod = getPrivateMethod(cl, "readObject",
505 new Class<?>[] { ObjectInputStream.class },
506 Void.TYPE);
507 readObjectNoDataMethod = getPrivateMethod(
508 cl, "readObjectNoData", null, Void.TYPE);
509 hasWriteObjectData = (writeObjectMethod != null);
510 }
511 writeReplaceMethod = getInheritableMethod(
512 cl, "writeReplace", null, Object.class);
513 readResolveMethod = getInheritableMethod(
514 cl, "readResolve", null, Object.class);
515 return null;
516 }
517 });
518 } else {
519 suid = Long.valueOf(0);
520 fields = NO_FIELDS;
521 }
522
523 try {
524 fieldRefl = getReflector(fields, this);
525 } catch (InvalidClassException ex) {
526 // field mismatches impossible when matching local fields vs. self
527 throw new InternalError(ex);
528 }
529
530 if (deserializeEx == null) {
531 if (isEnum) {
532 deserializeEx = new ExceptionInfo(name, "enum type");
533 } else if (cons == null) {
534 deserializeEx = new ExceptionInfo(name, "no valid constructor");
535 }
536 }
537 for (int i = 0; i < fields.length; i++) {
538 if (fields[i].getField() == null) {
539 defaultSerializeEx = new ExceptionInfo(
540 name, "unmatched serializable field(s) declared");
541 }
542 }
543 initialized = true;
544 }
545
546 /**
547 * Creates blank class descriptor which should be initialized via a
548 * subsequent call to initProxy(), initNonProxy() or readNonProxy().
549 */
550 ObjectStreamClass() {
551 }
552
553 /**
554 * Initializes class descriptor representing a proxy class.
555 */
556 void initProxy(Class<?> cl,
557 ClassNotFoundException resolveEx,
558 ObjectStreamClass superDesc)
559 throws InvalidClassException
560 {
561 ObjectStreamClass osc = null;
562 if (cl != null) {
563 osc = lookup(cl, true);
564 if (!osc.isProxy) {
565 throw new InvalidClassException(
566 "cannot bind proxy descriptor to a non-proxy class");
567 }
568 }
569 this.cl = cl;
570 this.resolveEx = resolveEx;
571 this.superDesc = superDesc;
572 isProxy = true;
573 serializable = true;
574 suid = Long.valueOf(0);
575 fields = NO_FIELDS;
576 if (osc != null) {
577 localDesc = osc;
578 name = localDesc.name;
579 externalizable = localDesc.externalizable;
580 writeReplaceMethod = localDesc.writeReplaceMethod;
581 readResolveMethod = localDesc.readResolveMethod;
582 deserializeEx = localDesc.deserializeEx;
583 cons = localDesc.cons;
584 }
585 fieldRefl = getReflector(fields, localDesc);
586 initialized = true;
587 }
588
589 /**
590 * Initializes class descriptor representing a non-proxy class.
591 */
592 void initNonProxy(ObjectStreamClass model,
593 Class<?> cl,
594 ClassNotFoundException resolveEx,
595 ObjectStreamClass superDesc)
596 throws InvalidClassException
597 {
598 long suid = Long.valueOf(model.getSerialVersionUID());
599 ObjectStreamClass osc = null;
600 if (cl != null) {
601 osc = lookup(cl, true);
602 if (osc.isProxy) {
603 throw new InvalidClassException(
604 "cannot bind non-proxy descriptor to a proxy class");
605 }
606 if (model.isEnum != osc.isEnum) {
607 throw new InvalidClassException(model.isEnum ?
608 "cannot bind enum descriptor to a non-enum class" :
609 "cannot bind non-enum descriptor to an enum class");
610 }
611
612 if (model.serializable == osc.serializable &&
613 !cl.isArray() &&
614 suid != osc.getSerialVersionUID()) {
615 throw new InvalidClassException(osc.name,
616 "local class incompatible: " +
617 "stream classdesc serialVersionUID = " + suid +
618 ", local class serialVersionUID = " +
619 osc.getSerialVersionUID());
620 }
621
622 if (!classNamesEqual(model.name, osc.name)) {
623 throw new InvalidClassException(osc.name,
624 "local class name incompatible with stream class " +
625 "name \"" + model.name + "\"");
626 }
627
628 if (!model.isEnum) {
629 if ((model.serializable == osc.serializable) &&
630 (model.externalizable != osc.externalizable)) {
631 throw new InvalidClassException(osc.name,
632 "Serializable incompatible with Externalizable");
633 }
634
635 if ((model.serializable != osc.serializable) ||
636 (model.externalizable != osc.externalizable) ||
637 !(model.serializable || model.externalizable)) {
638 deserializeEx = new ExceptionInfo(
639 osc.name, "class invalid for deserialization");
640 }
641 }
642 }
643
644 this.cl = cl;
645 this.resolveEx = resolveEx;
646 this.superDesc = superDesc;
647 name = model.name;
648 this.suid = suid;
649 isProxy = false;
650 isEnum = model.isEnum;
651 serializable = model.serializable;
652 externalizable = model.externalizable;
653 hasBlockExternalData = model.hasBlockExternalData;
654 hasWriteObjectData = model.hasWriteObjectData;
655 fields = model.fields;
656 primDataSize = model.primDataSize;
657 numObjFields = model.numObjFields;
658
659 if (osc != null) {
660 localDesc = osc;
661 writeObjectMethod = localDesc.writeObjectMethod;
662 readObjectMethod = localDesc.readObjectMethod;
663 readObjectNoDataMethod = localDesc.readObjectNoDataMethod;
664 writeReplaceMethod = localDesc.writeReplaceMethod;
665 readResolveMethod = localDesc.readResolveMethod;
666 if (deserializeEx == null) {
667 deserializeEx = localDesc.deserializeEx;
668 }
669 cons = localDesc.cons;
670 }
671
672 fieldRefl = getReflector(fields, localDesc);
673 // reassign to matched fields so as to reflect local unshared settings
674 fields = fieldRefl.getFields();
675 initialized = true;
676 }
677
678 /**
679 * Reads non-proxy class descriptor information from given input stream.
680 * The resulting class descriptor is not fully functional; it can only be
681 * used as input to the ObjectInputStream.resolveClass() and
682 * ObjectStreamClass.initNonProxy() methods.
683 */
684 void readNonProxy(ObjectInputStream in)
685 throws IOException, ClassNotFoundException
686 {
687 name = in.readUTF();
688 suid = Long.valueOf(in.readLong());
689 isProxy = false;
690
691 byte flags = in.readByte();
692 hasWriteObjectData =
693 ((flags & ObjectStreamConstants.SC_WRITE_METHOD) != 0);
694 hasBlockExternalData =
695 ((flags & ObjectStreamConstants.SC_BLOCK_DATA) != 0);
696 externalizable =
697 ((flags & ObjectStreamConstants.SC_EXTERNALIZABLE) != 0);
698 boolean sflag =
699 ((flags & ObjectStreamConstants.SC_SERIALIZABLE) != 0);
700 if (externalizable && sflag) {
701 throw new InvalidClassException(
702 name, "serializable and externalizable flags conflict");
703 }
704 serializable = externalizable || sflag;
705 isEnum = ((flags & ObjectStreamConstants.SC_ENUM) != 0);
706 if (isEnum && suid.longValue() != 0L) {
707 throw new InvalidClassException(name,
708 "enum descriptor has non-zero serialVersionUID: " + suid);
709 }
710
711 int numFields = in.readShort();
712 if (isEnum && numFields != 0) {
713 throw new InvalidClassException(name,
714 "enum descriptor has non-zero field count: " + numFields);
715 }
716 fields = (numFields > 0) ?
717 new ObjectStreamField[numFields] : NO_FIELDS;
718 for (int i = 0; i < numFields; i++) {
719 char tcode = (char) in.readByte();
720 String fname = in.readUTF();
721 String signature = ((tcode == 'L') || (tcode == '[')) ?
722 in.readTypeString() : new String(new char[] { tcode });
723 try {
724 fields[i] = new ObjectStreamField(fname, signature, false);
725 } catch (RuntimeException e) {
726 throw (IOException) new InvalidClassException(name,
727 "invalid descriptor for field " + fname).initCause(e);
728 }
729 }
730 computeFieldOffsets();
731 }
732
733 /**
734 * Writes non-proxy class descriptor information to given output stream.
735 */
736 void writeNonProxy(ObjectOutputStream out) throws IOException {
737 out.writeUTF(name);
738 out.writeLong(getSerialVersionUID());
739
740 byte flags = 0;
741 if (externalizable) {
742 flags |= ObjectStreamConstants.SC_EXTERNALIZABLE;
743 int protocol = out.getProtocolVersion();
744 if (protocol != ObjectStreamConstants.PROTOCOL_VERSION_1) {
745 flags |= ObjectStreamConstants.SC_BLOCK_DATA;
746 }
747 } else if (serializable) {
748 flags |= ObjectStreamConstants.SC_SERIALIZABLE;
749 }
750 if (hasWriteObjectData) {
751 flags |= ObjectStreamConstants.SC_WRITE_METHOD;
752 }
753 if (isEnum) {
754 flags |= ObjectStreamConstants.SC_ENUM;
755 }
756 out.writeByte(flags);
757
758 out.writeShort(fields.length);
759 for (int i = 0; i < fields.length; i++) {
760 ObjectStreamField f = fields[i];
761 out.writeByte(f.getTypeCode());
762 out.writeUTF(f.getName());
763 if (!f.isPrimitive()) {
764 out.writeTypeString(f.getTypeString());
765 }
766 }
767 }
768
769 /**
770 * Returns ClassNotFoundException (if any) thrown while attempting to
771 * resolve local class corresponding to this class descriptor.
772 */
773 ClassNotFoundException getResolveException() {
774 return resolveEx;
775 }
776
777 /**
778 * Throws InternalError if not initialized.
779 */
780 private final void requireInitialized() {
781 if (!initialized)
782 throw new InternalError("Unexpected call when not initialized");
783 }
784
785 /**
786 * Throws an InvalidClassException if object instances referencing this
787 * class descriptor should not be allowed to deserialize. This method does
788 * not apply to deserialization of enum constants.
789 */
790 void checkDeserialize() throws InvalidClassException {
791 requireInitialized();
792 if (deserializeEx != null) {
793 throw deserializeEx.newInvalidClassException();
794 }
795 }
796
797 /**
798 * Throws an InvalidClassException if objects whose class is represented by
799 * this descriptor should not be allowed to serialize. This method does
800 * not apply to serialization of enum constants.
801 */
802 void checkSerialize() throws InvalidClassException {
803 requireInitialized();
804 if (serializeEx != null) {
805 throw serializeEx.newInvalidClassException();
806 }
807 }
808
809 /**
810 * Throws an InvalidClassException if objects whose class is represented by
811 * this descriptor should not be permitted to use default serialization
812 * (e.g., if the class declares serializable fields that do not correspond
813 * to actual fields, and hence must use the GetField API). This method
814 * does not apply to deserialization of enum constants.
815 */
816 void checkDefaultSerialize() throws InvalidClassException {
817 requireInitialized();
818 if (defaultSerializeEx != null) {
819 throw defaultSerializeEx.newInvalidClassException();
820 }
821 }
822
823 /**
824 * Returns superclass descriptor. Note that on the receiving side, the
825 * superclass descriptor may be bound to a class that is not a superclass
826 * of the subclass descriptor's bound class.
827 */
828 ObjectStreamClass getSuperDesc() {
829 requireInitialized();
830 return superDesc;
831 }
832
833 /**
834 * Returns the "local" class descriptor for the class associated with this
835 * class descriptor (i.e., the result of
836 * ObjectStreamClass.lookup(this.forClass())) or null if there is no class
837 * associated with this descriptor.
838 */
839 ObjectStreamClass getLocalDesc() {
840 requireInitialized();
841 return localDesc;
842 }
843
844 /**
845 * Returns arrays of ObjectStreamFields representing the serializable
846 * fields of the represented class. If copy is true, a clone of this class
847 * descriptor's field array is returned, otherwise the array itself is
848 * returned.
849 */
850 ObjectStreamField[] getFields(boolean copy) {
851 return copy ? fields.clone() : fields;
852 }
853
854 /**
855 * Looks up a serializable field of the represented class by name and type.
856 * A specified type of null matches all types, Object.class matches all
857 * non-primitive types, and any other non-null type matches assignable
858 * types only. Returns matching field, or null if no match found.
859 */
860 ObjectStreamField getField(String name, Class<?> type) {
861 for (int i = 0; i < fields.length; i++) {
862 ObjectStreamField f = fields[i];
863 if (f.getName().equals(name)) {
864 if (type == null ||
865 (type == Object.class && !f.isPrimitive()))
866 {
867 return f;
868 }
869 Class<?> ftype = f.getType();
870 if (ftype != null && type.isAssignableFrom(ftype)) {
871 return f;
872 }
873 }
874 }
875 return null;
876 }
877
878 /**
879 * Returns true if class descriptor represents a dynamic proxy class, false
880 * otherwise.
881 */
882 boolean isProxy() {
883 requireInitialized();
884 return isProxy;
885 }
886
887 /**
888 * Returns true if class descriptor represents an enum type, false
889 * otherwise.
890 */
891 boolean isEnum() {
892 requireInitialized();
893 return isEnum;
894 }
895
896 /**
897 * Returns true if represented class implements Externalizable, false
898 * otherwise.
899 */
900 boolean isExternalizable() {
901 requireInitialized();
902 return externalizable;
903 }
904
905 /**
906 * Returns true if represented class implements Serializable, false
907 * otherwise.
908 */
909 boolean isSerializable() {
910 requireInitialized();
911 return serializable;
912 }
913
914 /**
915 * Returns true if class descriptor represents externalizable class that
916 * has written its data in 1.2 (block data) format, false otherwise.
917 */
918 boolean hasBlockExternalData() {
919 requireInitialized();
920 return hasBlockExternalData;
921 }
922
923 /**
924 * Returns true if class descriptor represents serializable (but not
925 * externalizable) class which has written its data via a custom
926 * writeObject() method, false otherwise.
927 */
928 boolean hasWriteObjectData() {
929 requireInitialized();
930 return hasWriteObjectData;
931 }
932
933 /**
934 * Returns true if represented class is serializable/externalizable and can
935 * be instantiated by the serialization runtime--i.e., if it is
936 * externalizable and defines a public no-arg constructor, or if it is
937 * non-externalizable and its first non-serializable superclass defines an
938 * accessible no-arg constructor. Otherwise, returns false.
939 */
940 boolean isInstantiable() {
941 requireInitialized();
942 return (cons != null);
943 }
944
945 /**
946 * Returns true if represented class is serializable (but not
947 * externalizable) and defines a conformant writeObject method. Otherwise,
948 * returns false.
949 */
950 boolean hasWriteObjectMethod() {
951 requireInitialized();
952 return (writeObjectMethod != null);
953 }
954
955 /**
956 * Returns true if represented class is serializable (but not
957 * externalizable) and defines a conformant readObject method. Otherwise,
958 * returns false.
959 */
960 boolean hasReadObjectMethod() {
961 requireInitialized();
962 return (readObjectMethod != null);
963 }
964
965 /**
966 * Returns true if represented class is serializable (but not
967 * externalizable) and defines a conformant readObjectNoData method.
968 * Otherwise, returns false.
969 */
970 boolean hasReadObjectNoDataMethod() {
971 requireInitialized();
972 return (readObjectNoDataMethod != null);
973 }
974
975 /**
976 * Returns true if represented class is serializable or externalizable and
977 * defines a conformant writeReplace method. Otherwise, returns false.
978 */
979 boolean hasWriteReplaceMethod() {
980 requireInitialized();
981 return (writeReplaceMethod != null);
982 }
983
984 /**
985 * Returns true if represented class is serializable or externalizable and
986 * defines a conformant readResolve method. Otherwise, returns false.
987 */
988 boolean hasReadResolveMethod() {
989 requireInitialized();
990 return (readResolveMethod != null);
991 }
992
993 /**
994 * Creates a new instance of the represented class. If the class is
995 * externalizable, invokes its public no-arg constructor; otherwise, if the
996 * class is serializable, invokes the no-arg constructor of the first
997 * non-serializable superclass. Throws UnsupportedOperationException if
998 * this class descriptor is not associated with a class, if the associated
999 * class is non-serializable or if the appropriate no-arg constructor is
1000 * inaccessible/unavailable.
1001 */
1002 Object newInstance()
1003 throws InstantiationException, InvocationTargetException,
1004 UnsupportedOperationException
1005 {
1006 requireInitialized();
1007 if (cons != null) {
1008 try {
1009 return cons.newInstance();
1010 } catch (IllegalAccessException ex) {
1011 // should not occur, as access checks have been suppressed
1012 throw new InternalError(ex);
1013 }
1014 } else {
1015 throw new UnsupportedOperationException();
1016 }
1017 }
1018
1019 /**
1020 * Invokes the writeObject method of the represented serializable class.
1021 * Throws UnsupportedOperationException if this class descriptor is not
1022 * associated with a class, or if the class is externalizable,
1023 * non-serializable or does not define writeObject.
1024 */
1025 void invokeWriteObject(Object obj, ObjectOutputStream out)
1026 throws IOException, UnsupportedOperationException
1027 {
1028 requireInitialized();
1029 if (writeObjectMethod != null) {
1030 try {
1031 writeObjectMethod.invoke(obj, new Object[]{ out });
1032 } catch (InvocationTargetException ex) {
1033 Throwable th = ex.getTargetException();
1034 if (th instanceof IOException) {
1035 throw (IOException) th;
1036 } else {
1037 throwMiscException(th);
1038 }
1039 } catch (IllegalAccessException ex) {
1040 // should not occur, as access checks have been suppressed
1041 throw new InternalError(ex);
1042 }
1043 } else {
1044 throw new UnsupportedOperationException();
1045 }
1046 }
1047
1048 /**
1049 * Invokes the readObject method of the represented serializable class.
1050 * Throws UnsupportedOperationException if this class descriptor is not
1051 * associated with a class, or if the class is externalizable,
1052 * non-serializable or does not define readObject.
1053 */
1054 void invokeReadObject(Object obj, ObjectInputStream in)
1055 throws ClassNotFoundException, IOException,
1056 UnsupportedOperationException
1057 {
1058 requireInitialized();
1059 if (readObjectMethod != null) {
1060 try {
1061 readObjectMethod.invoke(obj, new Object[]{ in });
1062 } catch (InvocationTargetException ex) {
1063 Throwable th = ex.getTargetException();
1064 if (th instanceof ClassNotFoundException) {
1065 throw (ClassNotFoundException) th;
1066 } else if (th instanceof IOException) {
1067 throw (IOException) th;
1068 } else {
1069 throwMiscException(th);
1070 }
1071 } catch (IllegalAccessException ex) {
1072 // should not occur, as access checks have been suppressed
1073 throw new InternalError(ex);
1074 }
1075 } else {
1076 throw new UnsupportedOperationException();
1077 }
1078 }
1079
1080 /**
1081 * Invokes the readObjectNoData method of the represented serializable
1082 * class. Throws UnsupportedOperationException if this class descriptor is
1083 * not associated with a class, or if the class is externalizable,
1084 * non-serializable or does not define readObjectNoData.
1085 */
1086 void invokeReadObjectNoData(Object obj)
1087 throws IOException, UnsupportedOperationException
1088 {
1089 requireInitialized();
1090 if (readObjectNoDataMethod != null) {
1091 try {
1092 readObjectNoDataMethod.invoke(obj, (Object[]) null);
1093 } catch (InvocationTargetException ex) {
1094 Throwable th = ex.getTargetException();
1095 if (th instanceof ObjectStreamException) {
1096 throw (ObjectStreamException) th;
1097 } else {
1098 throwMiscException(th);
1099 }
1100 } catch (IllegalAccessException ex) {
1101 // should not occur, as access checks have been suppressed
1102 throw new InternalError(ex);
1103 }
1104 } else {
1105 throw new UnsupportedOperationException();
1106 }
1107 }
1108
1109 /**
1110 * Invokes the writeReplace method of the represented serializable class and
1111 * returns the result. Throws UnsupportedOperationException if this class
1112 * descriptor is not associated with a class, or if the class is
1113 * non-serializable or does not define writeReplace.
1114 */
1115 Object invokeWriteReplace(Object obj)
1116 throws IOException, UnsupportedOperationException
1117 {
1118 requireInitialized();
1119 if (writeReplaceMethod != null) {
1120 try {
1121 return writeReplaceMethod.invoke(obj, (Object[]) null);
1122 } catch (InvocationTargetException ex) {
1123 Throwable th = ex.getTargetException();
1124 if (th instanceof ObjectStreamException) {
1125 throw (ObjectStreamException) th;
1126 } else {
1127 throwMiscException(th);
1128 throw new InternalError(th); // never reached
1129 }
1130 } catch (IllegalAccessException ex) {
1131 // should not occur, as access checks have been suppressed
1132 throw new InternalError(ex);
1133 }
1134 } else {
1135 throw new UnsupportedOperationException();
1136 }
1137 }
1138
1139 /**
1140 * Invokes the readResolve method of the represented serializable class and
1141 * returns the result. Throws UnsupportedOperationException if this class
1142 * descriptor is not associated with a class, or if the class is
1143 * non-serializable or does not define readResolve.
1144 */
1145 Object invokeReadResolve(Object obj)
1146 throws IOException, UnsupportedOperationException
1147 {
1148 requireInitialized();
1149 if (readResolveMethod != null) {
1150 try {
1151 return readResolveMethod.invoke(obj, (Object[]) null);
1152 } catch (InvocationTargetException ex) {
1153 Throwable th = ex.getTargetException();
1154 if (th instanceof ObjectStreamException) {
1155 throw (ObjectStreamException) th;
1156 } else {
1157 throwMiscException(th);
1158 throw new InternalError(th); // never reached
1159 }
1160 } catch (IllegalAccessException ex) {
1161 // should not occur, as access checks have been suppressed
1162 throw new InternalError(ex);
1163 }
1164 } else {
1165 throw new UnsupportedOperationException();
1166 }
1167 }
1168
1169 /**
1170 * Class representing the portion of an object's serialized form allotted
1171 * to data described by a given class descriptor. If "hasData" is false,
1172 * the object's serialized form does not contain data associated with the
1173 * class descriptor.
1174 */
1175 static class ClassDataSlot {
1176
1177 /** class descriptor "occupying" this slot */
1178 final ObjectStreamClass desc;
1179 /** true if serialized form includes data for this slot's descriptor */
1180 final boolean hasData;
1181
1182 ClassDataSlot(ObjectStreamClass desc, boolean hasData) {
1183 this.desc = desc;
1184 this.hasData = hasData;
1185 }
1186 }
1187
1188 private static final Unsafe U = Unsafe.getUnsafe();
1189 private static final long CDS_OFFSET;
1190
1191 static {
1192 Field field = null;
1193 try {
1194 field = ObjectStreamClass.class.getDeclaredField("dataLayout");
1195 } catch(NoSuchFieldException | SecurityException e) {
1196 }
1197 if(field == null) {
1198 CDS_OFFSET = Unsafe.INVALID_FIELD_OFFSET;
1199 } else {
1200 CDS_OFFSET = U.objectFieldOffset(field);
1201 }
1202 }
1203
1204 /**
1205 * Returns array of ClassDataSlot instances representing the data layout
1206 * (including superclass data) for serialized objects described by this
1207 * class descriptor. ClassDataSlots are ordered by inheritance with those
1208 * containing "higher" superclasses appearing first. The final
1209 * ClassDataSlot contains a reference to this descriptor.
1210 */
1211 ClassDataSlot[] getClassDataLayout() throws InvalidClassException {
1212 // REMIND: synchronize instead of relying on volatile?
1213 ClassDataSlot[] slots = (ClassDataSlot[])U.getObjectAcquire(this, CDS_OFFSET);
1214 if (slots == null) {
1215 slots = getClassDataLayout0();
1216 U.putObjectRelease(this, CDS_OFFSET, slots);
1217 }
1218 return slots;
1219 }
1220
1221 private ClassDataSlot[] getClassDataLayout0()
1222 throws InvalidClassException
1223 {
1224 ArrayList<ClassDataSlot> slots = new ArrayList<>();
1225 Class<?> start = cl, end = cl;
1226
1227 // locate closest non-serializable superclass
1228 while (end != null && Serializable.class.isAssignableFrom(end)) {
1229 end = end.getSuperclass();
1230 }
1231
1232 HashSet<String> oscNames = new HashSet<>(3);
1233
1234 for (ObjectStreamClass d = this; d != null; d = d.superDesc) {
1235 if (oscNames.contains(d.name)) {
1236 throw new InvalidClassException("Circular reference.");
1237 } else {
1238 oscNames.add(d.name);
1239 }
1240
1241 // search up inheritance hierarchy for class with matching name
1242 String searchName = (d.cl != null) ? d.cl.getName() : d.name;
1243 Class<?> match = null;
1244 for (Class<?> c = start; c != end; c = c.getSuperclass()) {
1245 if (searchName.equals(c.getName())) {
1246 match = c;
1247 break;
1248 }
1249 }
1250
1251 // add "no data" slot for each unmatched class below match
1252 if (match != null) {
1253 for (Class<?> c = start; c != match; c = c.getSuperclass()) {
1254 slots.add(new ClassDataSlot(
1255 ObjectStreamClass.lookup(c, true), false));
1256 }
1257 start = match.getSuperclass();
1258 }
1259
1260 // record descriptor/class pairing
1261 slots.add(new ClassDataSlot(d.getVariantFor(match), true));
1262 }
1263
1264 // add "no data" slot for any leftover unmatched classes
1265 for (Class<?> c = start; c != end; c = c.getSuperclass()) {
1266 slots.add(new ClassDataSlot(
1267 ObjectStreamClass.lookup(c, true), false));
1268 }
1269
1270 // order slots from superclass -> subclass
1271 Collections.reverse(slots);
1272 return slots.toArray(new ClassDataSlot[slots.size()]);
1273 }
1274
1275 /**
1276 * Returns aggregate size (in bytes) of marshalled primitive field values
1277 * for represented class.
1278 */
1279 int getPrimDataSize() {
1280 return primDataSize;
1281 }
1282
1283 /**
1284 * Returns number of non-primitive serializable fields of represented
1285 * class.
1286 */
1287 int getNumObjFields() {
1288 return numObjFields;
1289 }
1290
1291 /**
1292 * Fetches the serializable primitive field values of object obj and
1293 * marshals them into byte array buf starting at offset 0. It is the
1294 * responsibility of the caller to ensure that obj is of the proper type if
1295 * non-null.
1296 */
1297 void getPrimFieldValues(Object obj, byte[] buf) {
1298 fieldRefl.getPrimFieldValues(obj, buf);
1299 }
1300
1301 /**
1302 * Sets the serializable primitive fields of object obj using values
1303 * unmarshalled from byte array buf starting at offset 0. It is the
1304 * responsibility of the caller to ensure that obj is of the proper type if
1305 * non-null.
1306 */
1307 void setPrimFieldValues(Object obj, byte[] buf) {
1308 fieldRefl.setPrimFieldValues(obj, buf);
1309 }
1310
1311 /**
1312 * Fetches the serializable object field values of object obj and stores
1313 * them in array vals starting at offset 0. It is the responsibility of
1314 * the caller to ensure that obj is of the proper type if non-null.
1315 */
1316 void getObjFieldValues(Object obj, Object[] vals) {
1317 fieldRefl.getObjFieldValues(obj, vals);
1318 }
1319
1320 /**
1321 * Checks that the given values, from array vals starting at offset 0,
1322 * are assignable to the given serializable object fields.
1323 * @throws ClassCastException if any value is not assignable
1324 */
1325 void checkObjFieldValueTypes(Object obj, Object[] vals) {
1326 fieldRefl.checkObjectFieldValueTypes(obj, vals);
1327 }
1328
1329 /**
1330 * Sets the serializable object fields of object obj using values from
1331 * array vals starting at offset 0. It is the responsibility of the caller
1332 * to ensure that obj is of the proper type if non-null.
1333 */
1334 void setObjFieldValues(Object obj, Object[] vals) {
1335 fieldRefl.setObjFieldValues(obj, vals);
1336 }
1337
1338 /**
1339 * Calculates and sets serializable field offsets, as well as primitive
1340 * data size and object field count totals. Throws InvalidClassException
1341 * if fields are illegally ordered.
1342 */
1343 private void computeFieldOffsets() throws InvalidClassException {
1344 primDataSize = 0;
1345 numObjFields = 0;
1346 int firstObjIndex = -1;
1347
1348 for (int i = 0; i < fields.length; i++) {
1349 ObjectStreamField f = fields[i];
1350 switch (f.getTypeCode()) {
1351 case 'Z':
1352 case 'B':
1353 f.setOffset(primDataSize++);
1354 break;
1355
1356 case 'C':
1357 case 'S':
1358 f.setOffset(primDataSize);
1359 primDataSize += 2;
1360 break;
1361
1362 case 'I':
1363 case 'F':
1364 f.setOffset(primDataSize);
1365 primDataSize += 4;
1366 break;
1367
1368 case 'J':
1369 case 'D':
1370 f.setOffset(primDataSize);
1371 primDataSize += 8;
1372 break;
1373
1374 case '[':
1375 case 'L':
1376 f.setOffset(numObjFields++);
1377 if (firstObjIndex == -1) {
1378 firstObjIndex = i;
1379 }
1380 break;
1381
1382 default:
1383 throw new InternalError();
1384 }
1385 }
1386 if (firstObjIndex != -1 &&
1387 firstObjIndex + numObjFields != fields.length)
1388 {
1389 throw new InvalidClassException(name, "illegal field order");
1390 }
1391 }
1392
1393 /**
1394 * If given class is the same as the class associated with this class
1395 * descriptor, returns reference to this class descriptor. Otherwise,
1396 * returns variant of this class descriptor bound to given class.
1397 */
1398 private ObjectStreamClass getVariantFor(Class<?> cl)
1399 throws InvalidClassException
1400 {
1401 if (this.cl == cl) {
1402 return this;
1403 }
1404 ObjectStreamClass desc = new ObjectStreamClass();
1405 if (isProxy) {
1406 desc.initProxy(cl, null, superDesc);
1407 } else {
1408 desc.initNonProxy(this, cl, null, superDesc);
1409 }
1410 return desc;
1411 }
1412
1413 /**
1414 * Returns public no-arg constructor of given class, or null if none found.
1415 * Access checks are disabled on the returned constructor (if any), since
1416 * the defining class may still be non-public.
1417 */
1418 private static Constructor<?> getExternalizableConstructor(Class<?> cl) {
1419 try {
1420 Constructor<?> cons = cl.getDeclaredConstructor((Class<?>[]) null);
1421 cons.setAccessible(true);
1422 return ((cons.getModifiers() & Modifier.PUBLIC) != 0) ?
1423 cons : null;
1424 } catch (NoSuchMethodException ex) {
1425 return null;
1426 }
1427 }
1428
1429 /**
1430 * Returns subclass-accessible no-arg constructor of first non-serializable
1431 * superclass, or null if none found. Access checks are disabled on the
1432 * returned constructor (if any).
1433 */
1434 private static Constructor<?> getSerializableConstructor(Class<?> cl) {
1435 return reflFactory.newConstructorForSerialization(cl);
1436 }
1437
1438 /**
1439 * Returns non-static, non-abstract method with given signature provided it
1440 * is defined by or accessible (via inheritance) by the given class, or
1441 * null if no match found. Access checks are disabled on the returned
1442 * method (if any).
1443 */
1444 private static Method getInheritableMethod(Class<?> cl, String name,
1445 Class<?>[] argTypes,
1446 Class<?> returnType)
1447 {
1448 Method meth = null;
1449 Class<?> defCl = cl;
1450 while (defCl != null) {
1451 try {
1452 meth = defCl.getDeclaredMethod(name, argTypes);
1453 break;
1454 } catch (NoSuchMethodException ex) {
1455 defCl = defCl.getSuperclass();
1456 }
1457 }
1458
1459 if ((meth == null) || (meth.getReturnType() != returnType)) {
1460 return null;
1461 }
1462 meth.setAccessible(true);
1463 int mods = meth.getModifiers();
1464 if ((mods & (Modifier.STATIC | Modifier.ABSTRACT)) != 0) {
1465 return null;
1466 } else if ((mods & (Modifier.PUBLIC | Modifier.PROTECTED)) != 0) {
1467 return meth;
1468 } else if ((mods & Modifier.PRIVATE) != 0) {
1469 return (cl == defCl) ? meth : null;
1470 } else {
1471 return packageEquals(cl, defCl) ? meth : null;
1472 }
1473 }
1474
1475 /**
1476 * Returns non-static private method with given signature defined by given
1477 * class, or null if none found. Access checks are disabled on the
1478 * returned method (if any).
1479 */
1480 private static Method getPrivateMethod(Class<?> cl, String name,
1481 Class<?>[] argTypes,
1482 Class<?> returnType)
1483 {
1484 try {
1485 Method meth = cl.getDeclaredMethod(name, argTypes);
1486 meth.setAccessible(true);
1487 int mods = meth.getModifiers();
1488 return ((meth.getReturnType() == returnType) &&
1489 ((mods & Modifier.STATIC) == 0) &&
1490 ((mods & Modifier.PRIVATE) != 0)) ? meth : null;
1491 } catch (NoSuchMethodException ex) {
1492 return null;
1493 }
1494 }
1495
1496 /**
1497 * Returns true if classes are defined in the same runtime package, false
1498 * otherwise.
1499 */
1500 private static boolean packageEquals(Class<?> cl1, Class<?> cl2) {
1501 return (cl1.getClassLoader() == cl2.getClassLoader() &&
1502 getPackageName(cl1).equals(getPackageName(cl2)));
1503 }
1504
1505 /**
1506 * Returns package name of given class.
1507 */
1508 private static String getPackageName(Class<?> cl) {
1509 String s = cl.getName();
1510 int i = s.lastIndexOf('[');
1511 i = (i < 0) ? 0 : i + 2;
1512 int j = s.lastIndexOf('.');
1513 return (i < j) ? s.substring(i, j) : "";
1514 }
1515
1516 /**
1517 * Compares class names for equality, ignoring package names. Returns true
1518 * if class names equal, false otherwise.
1519 */
1520 private static boolean classNamesEqual(String name1, String name2) {
1521 int idx1 = name1.lastIndexOf('.') + 1;
1522 int idx2 = name2.lastIndexOf('.') + 1;
1523 int len1 = name1.length() - idx1;
1524 int len2 = name2.length() - idx2;
1525 return len1 == len2 &&
1526 name1.regionMatches(idx1, name2, idx2, len1);
1527 }
1528
1529 /**
1530 * Returns JVM type signature for given list of parameters and return type.
1531 */
1532 private static String getMethodSignature(Class<?>[] paramTypes,
1533 Class<?> retType)
1534 {
1535 StringBuilder sb = new StringBuilder();
1536 sb.append('(');
1537 for (int i = 0; i < paramTypes.length; i++) {
1538 appendClassSignature(sb, paramTypes[i]);
1539 }
1540 sb.append(')');
1541 appendClassSignature(sb, retType);
1542 return sb.toString();
1543 }
1544
1545 /**
1546 * Convenience method for throwing an exception that is either a
1547 * RuntimeException, Error, or of some unexpected type (in which case it is
1548 * wrapped inside an IOException).
1549 */
1550 private static void throwMiscException(Throwable th) throws IOException {
1551 if (th instanceof RuntimeException) {
1552 throw (RuntimeException) th;
1553 } else if (th instanceof Error) {
1554 throw (Error) th;
1555 } else {
1556 IOException ex = new IOException("unexpected exception type");
1557 ex.initCause(th);
1558 throw ex;
1559 }
1560 }
1561
1562 /**
1563 * Returns ObjectStreamField array describing the serializable fields of
1564 * the given class. Serializable fields backed by an actual field of the
1565 * class are represented by ObjectStreamFields with corresponding non-null
1566 * Field objects. Throws InvalidClassException if the (explicitly
1567 * declared) serializable fields are invalid.
1568 */
1569 private static ObjectStreamField[] getSerialFields(Class<?> cl)
1570 throws InvalidClassException
1571 {
1572 ObjectStreamField[] fields;
1573 if (Serializable.class.isAssignableFrom(cl) &&
1574 !Externalizable.class.isAssignableFrom(cl) &&
1575 !Proxy.isProxyClass(cl) &&
1576 !cl.isInterface())
1577 {
1578 if ((fields = getDeclaredSerialFields(cl)) == null) {
1579 fields = getDefaultSerialFields(cl);
1580 }
1581 Arrays.sort(fields);
1582 } else {
1583 fields = NO_FIELDS;
1584 }
1585 return fields;
1586 }
1587
1588 /**
1589 * Returns serializable fields of given class as defined explicitly by a
1590 * "serialPersistentFields" field, or null if no appropriate
1591 * "serialPersistentFields" field is defined. Serializable fields backed
1592 * by an actual field of the class are represented by ObjectStreamFields
1593 * with corresponding non-null Field objects. For compatibility with past
1594 * releases, a "serialPersistentFields" field with a null value is
1595 * considered equivalent to not declaring "serialPersistentFields". Throws
1596 * InvalidClassException if the declared serializable fields are
1597 * invalid--e.g., if multiple fields share the same name.
1598 */
1599 private static ObjectStreamField[] getDeclaredSerialFields(Class<?> cl)
1600 throws InvalidClassException
1601 {
1602 ObjectStreamField[] serialPersistentFields = null;
1603 try {
1604 Field f = cl.getDeclaredField("serialPersistentFields");
1605 int mask = Modifier.PRIVATE | Modifier.STATIC | Modifier.FINAL;
1606 if ((f.getModifiers() & mask) == mask) {
1607 f.setAccessible(true);
1608 serialPersistentFields = (ObjectStreamField[]) f.get(null);
1609 }
1610 } catch (Exception ex) {
1611 }
1612 if (serialPersistentFields == null) {
1613 return null;
1614 } else if (serialPersistentFields.length == 0) {
1615 return NO_FIELDS;
1616 }
1617
1618 ObjectStreamField[] boundFields =
1619 new ObjectStreamField[serialPersistentFields.length];
1620 Set<String> fieldNames = new HashSet<>(serialPersistentFields.length);
1621
1622 for (int i = 0; i < serialPersistentFields.length; i++) {
1623 ObjectStreamField spf = serialPersistentFields[i];
1624
1625 String fname = spf.getName();
1626 if (fieldNames.contains(fname)) {
1627 throw new InvalidClassException(
1628 "multiple serializable fields named " + fname);
1629 }
1630 fieldNames.add(fname);
1631
1632 try {
1633 Field f = cl.getDeclaredField(fname);
1634 if ((f.getType() == spf.getType()) &&
1635 ((f.getModifiers() & Modifier.STATIC) == 0))
1636 {
1637 boundFields[i] =
1638 new ObjectStreamField(f, spf.isUnshared(), true);
1639 }
1640 } catch (NoSuchFieldException ex) {
1641 }
1642 if (boundFields[i] == null) {
1643 boundFields[i] = new ObjectStreamField(
1644 fname, spf.getType(), spf.isUnshared());
1645 }
1646 }
1647 return boundFields;
1648 }
1649
1650 /**
1651 * Returns array of ObjectStreamFields corresponding to all non-static
1652 * non-transient fields declared by given class. Each ObjectStreamField
1653 * contains a Field object for the field it represents. If no default
1654 * serializable fields exist, NO_FIELDS is returned.
1655 */
1656 private static ObjectStreamField[] getDefaultSerialFields(Class<?> cl) {
1657 Field[] clFields = cl.getDeclaredFields();
1658 ArrayList<ObjectStreamField> list = new ArrayList<>();
1659 int mask = Modifier.STATIC | Modifier.TRANSIENT;
1660
1661 for (int i = 0; i < clFields.length; i++) {
1662 if ((clFields[i].getModifiers() & mask) == 0) {
1663 list.add(new ObjectStreamField(clFields[i], false, true));
1664 }
1665 }
1666 int size = list.size();
1667 return (size == 0) ? NO_FIELDS :
1668 list.toArray(new ObjectStreamField[size]);
1669 }
1670
1671 /**
1672 * Returns explicit serial version UID value declared by given class, or
1673 * null if none.
1674 */
1675 private static Long getDeclaredSUID(Class<?> cl) {
1676 try {
1677 Field f = cl.getDeclaredField("serialVersionUID");
1678 int mask = Modifier.STATIC | Modifier.FINAL;
1679 if ((f.getModifiers() & mask) == mask) {
1680 f.setAccessible(true);
1681 return Long.valueOf(f.getLong(null));
1682 }
1683 } catch (Exception ex) {
1684 }
1685 return null;
1686 }
1687
1688 /**
1689 * Computes the default serial version UID value for the given class.
1690 */
1691 private static long computeDefaultSUID(Class<?> cl) {
1692 if (!Serializable.class.isAssignableFrom(cl) || Proxy.isProxyClass(cl))
1693 {
1694 return 0L;
1695 }
1696
1697 try {
1698 ByteArrayOutputStream bout = new ByteArrayOutputStream();
1699 DataOutputStream dout = new DataOutputStream(bout);
1700
1701 dout.writeUTF(cl.getName());
1702
1703 int classMods = cl.getModifiers() &
1704 (Modifier.PUBLIC | Modifier.FINAL |
1705 Modifier.INTERFACE | Modifier.ABSTRACT);
1706
1707 /*
1708 * compensate for javac bug in which ABSTRACT bit was set for an
1709 * interface only if the interface declared methods
1710 */
1711 Method[] methods = cl.getDeclaredMethods();
1712 if ((classMods & Modifier.INTERFACE) != 0) {
1713 classMods = (methods.length > 0) ?
1714 (classMods | Modifier.ABSTRACT) :
1715 (classMods & ~Modifier.ABSTRACT);
1716 }
1717 dout.writeInt(classMods);
1718
1719 if (!cl.isArray()) {
1720 /*
1721 * compensate for change in 1.2FCS in which
1722 * Class.getInterfaces() was modified to return Cloneable and
1723 * Serializable for array classes.
1724 */
1725 Class<?>[] interfaces = cl.getInterfaces();
1726 String[] ifaceNames = new String[interfaces.length];
1727 for (int i = 0; i < interfaces.length; i++) {
1728 ifaceNames[i] = interfaces[i].getName();
1729 }
1730 Arrays.sort(ifaceNames);
1731 for (int i = 0; i < ifaceNames.length; i++) {
1732 dout.writeUTF(ifaceNames[i]);
1733 }
1734 }
1735
1736 Field[] fields = cl.getDeclaredFields();
1737 MemberSignature[] fieldSigs = new MemberSignature[fields.length];
1738 for (int i = 0; i < fields.length; i++) {
1739 fieldSigs[i] = new MemberSignature(fields[i]);
1740 }
1741 Arrays.sort(fieldSigs, new Comparator<>() {
1742 public int compare(MemberSignature ms1, MemberSignature ms2) {
1743 return ms1.name.compareTo(ms2.name);
1744 }
1745 });
1746 for (int i = 0; i < fieldSigs.length; i++) {
1747 MemberSignature sig = fieldSigs[i];
1748 int mods = sig.member.getModifiers() &
1749 (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
1750 Modifier.STATIC | Modifier.FINAL | Modifier.VOLATILE |
1751 Modifier.TRANSIENT);
1752 if (((mods & Modifier.PRIVATE) == 0) ||
1753 ((mods & (Modifier.STATIC | Modifier.TRANSIENT)) == 0))
1754 {
1755 dout.writeUTF(sig.name);
1756 dout.writeInt(mods);
1757 dout.writeUTF(sig.signature);
1758 }
1759 }
1760
1761 if (hasStaticInitializer(cl)) {
1762 dout.writeUTF("<clinit>");
1763 dout.writeInt(Modifier.STATIC);
1764 dout.writeUTF("()V");
1765 }
1766
1767 Constructor<?>[] cons = cl.getDeclaredConstructors();
1768 MemberSignature[] consSigs = new MemberSignature[cons.length];
1769 for (int i = 0; i < cons.length; i++) {
1770 consSigs[i] = new MemberSignature(cons[i]);
1771 }
1772 Arrays.sort(consSigs, new Comparator<>() {
1773 public int compare(MemberSignature ms1, MemberSignature ms2) {
1774 return ms1.signature.compareTo(ms2.signature);
1775 }
1776 });
1777 for (int i = 0; i < consSigs.length; i++) {
1778 MemberSignature sig = consSigs[i];
1779 int mods = sig.member.getModifiers() &
1780 (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
1781 Modifier.STATIC | Modifier.FINAL |
1782 Modifier.SYNCHRONIZED | Modifier.NATIVE |
1783 Modifier.ABSTRACT | Modifier.STRICT);
1784 if ((mods & Modifier.PRIVATE) == 0) {
1785 dout.writeUTF("<init>");
1786 dout.writeInt(mods);
1787 dout.writeUTF(sig.signature.replace('/', '.'));
1788 }
1789 }
1790
1791 MemberSignature[] methSigs = new MemberSignature[methods.length];
1792 for (int i = 0; i < methods.length; i++) {
1793 methSigs[i] = new MemberSignature(methods[i]);
1794 }
1795 Arrays.sort(methSigs, new Comparator<>() {
1796 public int compare(MemberSignature ms1, MemberSignature ms2) {
1797 int comp = ms1.name.compareTo(ms2.name);
1798 if (comp == 0) {
1799 comp = ms1.signature.compareTo(ms2.signature);
1800 }
1801 return comp;
1802 }
1803 });
1804 for (int i = 0; i < methSigs.length; i++) {
1805 MemberSignature sig = methSigs[i];
1806 int mods = sig.member.getModifiers() &
1807 (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
1808 Modifier.STATIC | Modifier.FINAL |
1809 Modifier.SYNCHRONIZED | Modifier.NATIVE |
1810 Modifier.ABSTRACT | Modifier.STRICT);
1811 if ((mods & Modifier.PRIVATE) == 0) {
1812 dout.writeUTF(sig.name);
1813 dout.writeInt(mods);
1814 dout.writeUTF(sig.signature.replace('/', '.'));
1815 }
1816 }
1817
1818 dout.flush();
1819
1820 MessageDigest md = MessageDigest.getInstance("SHA");
1821 byte[] hashBytes = md.digest(bout.toByteArray());
1822 long hash = 0;
1823 for (int i = Math.min(hashBytes.length, 8) - 1; i >= 0; i--) {
1824 hash = (hash << 8) | (hashBytes[i] & 0xFF);
1825 }
1826 return hash;
1827 } catch (IOException ex) {
1828 throw new InternalError(ex);
1829 } catch (NoSuchAlgorithmException ex) {
1830 throw new SecurityException(ex.getMessage());
1831 }
1832 }
1833
1834 /**
1835 * Returns true if the given class defines a static initializer method,
1836 * false otherwise.
1837 */
1838 private static native boolean hasStaticInitializer(Class<?> cl);
1839
1840 /**
1841 * Class for computing and caching field/constructor/method signatures
1842 * during serialVersionUID calculation.
1843 */
1844 private static class MemberSignature {
1845
1846 public final Member member;
1847 public final String name;
1848 public final String signature;
1849
1850 public MemberSignature(Field field) {
1851 member = field;
1852 name = field.getName();
1853 signature = getClassSignature(field.getType());
1854 }
1855
1856 public MemberSignature(Constructor<?> cons) {
1857 member = cons;
1858 name = cons.getName();
1859 signature = getMethodSignature(
1860 cons.getParameterTypes(), Void.TYPE);
1861 }
1862
1863 public MemberSignature(Method meth) {
1864 member = meth;
1865 name = meth.getName();
1866 signature = getMethodSignature(
1867 meth.getParameterTypes(), meth.getReturnType());
1868 }
1869 }
1870
1871 /**
1872 * Class for setting and retrieving serializable field values in batch.
1873 */
1874 // REMIND: dynamically generate these?
1875 private static class FieldReflector {
1876
1877 /** handle for performing unsafe operations */
1878 private static final Unsafe unsafe = Unsafe.getUnsafe();
1879
1880 /** fields to operate on */
1881 private final ObjectStreamField[] fields;
1882 /** number of primitive fields */
1883 private final int numPrimFields;
1884 /** unsafe field keys for reading fields - may contain dupes */
1885 private final long[] readKeys;
1886 /** unsafe fields keys for writing fields - no dupes */
1887 private final long[] writeKeys;
1888 /** field data offsets */
1889 private final int[] offsets;
1890 /** field type codes */
1891 private final char[] typeCodes;
1892 /** field types */
1893 private final Class<?>[] types;
1894
1895 /**
1896 * Constructs FieldReflector capable of setting/getting values from the
1897 * subset of fields whose ObjectStreamFields contain non-null
1898 * reflective Field objects. ObjectStreamFields with null Fields are
1899 * treated as filler, for which get operations return default values
1900 * and set operations discard given values.
1901 */
1902 FieldReflector(ObjectStreamField[] fields) {
1903 this.fields = fields;
1904 int nfields = fields.length;
1905 readKeys = new long[nfields];
1906 writeKeys = new long[nfields];
1907 offsets = new int[nfields];
1908 typeCodes = new char[nfields];
1909 ArrayList<Class<?>> typeList = new ArrayList<>();
1910 Set<Long> usedKeys = new HashSet<>();
1911
1912
1913 for (int i = 0; i < nfields; i++) {
1914 ObjectStreamField f = fields[i];
1915 Field rf = f.getField();
1916 long key = (rf != null) ?
1917 unsafe.objectFieldOffset(rf) : Unsafe.INVALID_FIELD_OFFSET;
1918 readKeys[i] = key;
1919 writeKeys[i] = usedKeys.add(key) ?
1920 key : Unsafe.INVALID_FIELD_OFFSET;
1921 offsets[i] = f.getOffset();
1922 typeCodes[i] = f.getTypeCode();
1923 if (!f.isPrimitive()) {
1924 typeList.add((rf != null) ? rf.getType() : null);
1925 }
1926 }
1927
1928 types = typeList.toArray(new Class<?>[typeList.size()]);
1929 numPrimFields = nfields - types.length;
1930 }
1931
1932 /**
1933 * Returns list of ObjectStreamFields representing fields operated on
1934 * by this reflector. The shared/unshared values and Field objects
1935 * contained by ObjectStreamFields in the list reflect their bindings
1936 * to locally defined serializable fields.
1937 */
1938 ObjectStreamField[] getFields() {
1939 return fields;
1940 }
1941
1942 /**
1943 * Fetches the serializable primitive field values of object obj and
1944 * marshals them into byte array buf starting at offset 0. The caller
1945 * is responsible for ensuring that obj is of the proper type.
1946 */
1947 void getPrimFieldValues(Object obj, byte[] buf) {
1948 if (obj == null) {
1949 throw new NullPointerException();
1950 }
1951 /* assuming checkDefaultSerialize() has been called on the class
1952 * descriptor this FieldReflector was obtained from, no field keys
1953 * in array should be equal to Unsafe.INVALID_FIELD_OFFSET.
1954 */
1955 for (int i = 0; i < numPrimFields; i++) {
1956 long key = readKeys[i];
1957 int off = offsets[i];
1958 switch (typeCodes[i]) {
1959 case 'Z':
1960 Bits.putBoolean(buf, off, unsafe.getBoolean(obj, key));
1961 break;
1962
1963 case 'B':
1964 buf[off] = unsafe.getByte(obj, key);
1965 break;
1966
1967 case 'C':
1968 Bits.putChar(buf, off, unsafe.getChar(obj, key));
1969 break;
1970
1971 case 'S':
1972 Bits.putShort(buf, off, unsafe.getShort(obj, key));
1973 break;
1974
1975 case 'I':
1976 Bits.putInt(buf, off, unsafe.getInt(obj, key));
1977 break;
1978
1979 case 'F':
1980 Bits.putFloat(buf, off, unsafe.getFloat(obj, key));
1981 break;
1982
1983 case 'J':
1984 Bits.putLong(buf, off, unsafe.getLong(obj, key));
1985 break;
1986
1987 case 'D':
1988 Bits.putDouble(buf, off, unsafe.getDouble(obj, key));
1989 break;
1990
1991 default:
1992 throw new InternalError();
1993 }
1994 }
1995 }
1996
1997 /**
1998 * Sets the serializable primitive fields of object obj using values
1999 * unmarshalled from byte array buf starting at offset 0. The caller
2000 * is responsible for ensuring that obj is of the proper type.
2001 */
2002 void setPrimFieldValues(Object obj, byte[] buf) {
2003 if (obj == null) {
2004 throw new NullPointerException();
2005 }
2006 for (int i = 0; i < numPrimFields; i++) {
2007 long key = writeKeys[i];
2008 if (key == Unsafe.INVALID_FIELD_OFFSET) {
2009 continue; // discard value
2010 }
2011 int off = offsets[i];
2012 switch (typeCodes[i]) {
2013 case 'Z':
2014 unsafe.putBoolean(obj, key, Bits.getBoolean(buf, off));
2015 break;
2016
2017 case 'B':
2018 unsafe.putByte(obj, key, buf[off]);
2019 break;
2020
2021 case 'C':
2022 unsafe.putChar(obj, key, Bits.getChar(buf, off));
2023 break;
2024
2025 case 'S':
2026 unsafe.putShort(obj, key, Bits.getShort(buf, off));
2027 break;
2028
2029 case 'I':
2030 unsafe.putInt(obj, key, Bits.getInt(buf, off));
2031 break;
2032
2033 case 'F':
2034 unsafe.putFloat(obj, key, Bits.getFloat(buf, off));
2035 break;
2036
2037 case 'J':
2038 unsafe.putLong(obj, key, Bits.getLong(buf, off));
2039 break;
2040
2041 case 'D':
2042 unsafe.putDouble(obj, key, Bits.getDouble(buf, off));
2043 break;
2044
2045 default:
2046 throw new InternalError();
2047 }
2048 }
2049 }
2050
2051 /**
2052 * Fetches the serializable object field values of object obj and
2053 * stores them in array vals starting at offset 0. The caller is
2054 * responsible for ensuring that obj is of the proper type.
2055 */
2056 void getObjFieldValues(Object obj, Object[] vals) {
2057 if (obj == null) {
2058 throw new NullPointerException();
2059 }
2060 /* assuming checkDefaultSerialize() has been called on the class
2061 * descriptor this FieldReflector was obtained from, no field keys
2062 * in array should be equal to Unsafe.INVALID_FIELD_OFFSET.
2063 */
2064 for (int i = numPrimFields; i < fields.length; i++) {
2065 switch (typeCodes[i]) {
2066 case 'L':
2067 case '[':
2068 vals[offsets[i]] = unsafe.getObject(obj, readKeys[i]);
2069 break;
2070
2071 default:
2072 throw new InternalError();
2073 }
2074 }
2075 }
2076
2077 /**
2078 * Checks that the given values, from array vals starting at offset 0,
2079 * are assignable to the given serializable object fields.
2080 * @throws ClassCastException if any value is not assignable
2081 */
2082 void checkObjectFieldValueTypes(Object obj, Object[] vals) {
2083 setObjFieldValues(obj, vals, true);
2084 }
2085
2086 /**
2087 * Sets the serializable object fields of object obj using values from
2088 * array vals starting at offset 0. The caller is responsible for
2089 * ensuring that obj is of the proper type; however, attempts to set a
2090 * field with a value of the wrong type will trigger an appropriate
2091 * ClassCastException.
2092 */
2093 void setObjFieldValues(Object obj, Object[] vals) {
2094 setObjFieldValues(obj, vals, false);
2095 }
2096
2097 private void setObjFieldValues(Object obj, Object[] vals, boolean dryRun) {
2098 if (obj == null) {
2099 throw new NullPointerException();
2100 }
2101 for (int i = numPrimFields; i < fields.length; i++) {
2102 long key = writeKeys[i];
2103 if (key == Unsafe.INVALID_FIELD_OFFSET) {
2104 continue; // discard value
2105 }
2106 switch (typeCodes[i]) {
2107 case 'L':
2108 case '[':
2109 Object val = vals[offsets[i]];
2110 if (val != null &&
2111 !types[i - numPrimFields].isInstance(val))
2112 {
2113 Field f = fields[i].getField();
2114 throw new ClassCastException(
2115 "cannot assign instance of " +
2116 val.getClass().getName() + " to field " +
2117 f.getDeclaringClass().getName() + "." +
2118 f.getName() + " of type " +
2119 f.getType().getName() + " in instance of " +
2120 obj.getClass().getName());
2121 }
2122 if (!dryRun)
2123 unsafe.putObject(obj, key, val);
2124 break;
2125
2126 default:
2127 throw new InternalError();
2128 }
2129 }
2130 }
2131 }
2132
2133 /**
2134 * Matches given set of serializable fields with serializable fields
2135 * described by the given local class descriptor, and returns a
2136 * FieldReflector instance capable of setting/getting values from the
2137 * subset of fields that match (non-matching fields are treated as filler,
2138 * for which get operations return default values and set operations
2139 * discard given values). Throws InvalidClassException if unresolvable
2140 * type conflicts exist between the two sets of fields.
2141 */
2142 private static FieldReflector getReflector(ObjectStreamField[] fields,
2143 ObjectStreamClass localDesc)
2144 throws InvalidClassException
2145 {
2146 // class irrelevant if no fields
2147 Class<?> cl = (localDesc != null && fields.length > 0) ?
2148 localDesc.cl : null;
2149 processQueue(Caches.reflectorsQueue, Caches.reflectors);
2150 FieldReflectorKey key = new FieldReflectorKey(cl, fields,
2151 Caches.reflectorsQueue);
2152 Reference<?> ref = Caches.reflectors.get(key);
2153 Object entry = null;
2154 if (ref != null) {
2155 entry = ref.get();
2156 }
2157 EntryFuture future = null;
2158 if (entry == null) {
2159 EntryFuture newEntry = new EntryFuture();
2160 Reference<?> newRef = new SoftReference<>(newEntry);
2161 do {
2162 if (ref != null) {
2163 Caches.reflectors.remove(key, ref);
2164 }
2165 ref = Caches.reflectors.putIfAbsent(key, newRef);
2166 if (ref != null) {
2167 entry = ref.get();
2168 }
2169 } while (ref != null && entry == null);
2170 if (entry == null) {
2171 future = newEntry;
2172 }
2173 }
2174
2175 if (entry instanceof FieldReflector) { // check common case first
2176 return (FieldReflector) entry;
2177 } else if (entry instanceof EntryFuture) {
2178 entry = ((EntryFuture) entry).get();
2179 } else if (entry == null) {
2180 try {
2181 entry = new FieldReflector(matchFields(fields, localDesc));
2182 } catch (Throwable th) {
2183 entry = th;
2184 }
2185 future.set(entry);
2186 Caches.reflectors.put(key, new SoftReference<>(entry));
2187 }
2188
2189 if (entry instanceof FieldReflector) {
2190 return (FieldReflector) entry;
2191 } else if (entry instanceof InvalidClassException) {
2192 throw (InvalidClassException) entry;
2193 } else if (entry instanceof RuntimeException) {
2194 throw (RuntimeException) entry;
2195 } else if (entry instanceof Error) {
2196 throw (Error) entry;
2197 } else {
2198 throw new InternalError("unexpected entry: " + entry);
2199 }
2200 }
2201
2202 /**
2203 * FieldReflector cache lookup key. Keys are considered equal if they
2204 * refer to the same class and equivalent field formats.
2205 */
2206 private static class FieldReflectorKey extends WeakReference<Class<?>> {
2207
2208 private final String sigs;
2209 private final int hash;
2210 private final boolean nullClass;
2211
2212 FieldReflectorKey(Class<?> cl, ObjectStreamField[] fields,
2213 ReferenceQueue<Class<?>> queue)
2214 {
2215 super(cl, queue);
2216 nullClass = (cl == null);
2217 StringBuilder sbuf = new StringBuilder();
2218 for (int i = 0; i < fields.length; i++) {
2219 ObjectStreamField f = fields[i];
2220 sbuf.append(f.getName()).append(f.getSignature());
2221 }
2222 sigs = sbuf.toString();
2223 hash = System.identityHashCode(cl) + sigs.hashCode();
2224 }
2225
2226 public int hashCode() {
2227 return hash;
2228 }
2229
2230 public boolean equals(Object obj) {
2231 if (obj == this) {
2232 return true;
2233 }
2234
2235 if (obj instanceof FieldReflectorKey) {
2236 FieldReflectorKey other = (FieldReflectorKey) obj;
2237 Class<?> referent;
2238 return (nullClass ? other.nullClass
2239 : ((referent = get()) != null) &&
2240 (referent == other.get())) &&
2241 sigs.equals(other.sigs);
2242 } else {
2243 return false;
2244 }
2245 }
2246 }
2247
2248 /**
2249 * Matches given set of serializable fields with serializable fields
2250 * obtained from the given local class descriptor (which contain bindings
2251 * to reflective Field objects). Returns list of ObjectStreamFields in
2252 * which each ObjectStreamField whose signature matches that of a local
2253 * field contains a Field object for that field; unmatched
2254 * ObjectStreamFields contain null Field objects. Shared/unshared settings
2255 * of the returned ObjectStreamFields also reflect those of matched local
2256 * ObjectStreamFields. Throws InvalidClassException if unresolvable type
2257 * conflicts exist between the two sets of fields.
2258 */
2259 private static ObjectStreamField[] matchFields(ObjectStreamField[] fields,
2260 ObjectStreamClass localDesc)
2261 throws InvalidClassException
2262 {
2263 ObjectStreamField[] localFields = (localDesc != null) ?
2264 localDesc.fields : NO_FIELDS;
2265
2266 /*
2267 * Even if fields == localFields, we cannot simply return localFields
2268 * here. In previous implementations of serialization,
2269 * ObjectStreamField.getType() returned Object.class if the
2270 * ObjectStreamField represented a non-primitive field and belonged to
2271 * a non-local class descriptor. To preserve this (questionable)
2272 * behavior, the ObjectStreamField instances returned by matchFields
2273 * cannot report non-primitive types other than Object.class; hence
2274 * localFields cannot be returned directly.
2275 */
2276
2277 ObjectStreamField[] matches = new ObjectStreamField[fields.length];
2278 for (int i = 0; i < fields.length; i++) {
2279 ObjectStreamField f = fields[i], m = null;
2280 for (int j = 0; j < localFields.length; j++) {
2281 ObjectStreamField lf = localFields[j];
2282 if (f.getName().equals(lf.getName())) {
2283 if ((f.isPrimitive() || lf.isPrimitive()) &&
2284 f.getTypeCode() != lf.getTypeCode())
2285 {
2286 throw new InvalidClassException(localDesc.name,
2287 "incompatible types for field " + f.getName());
2288 }
2289 if (lf.getField() != null) {
2290 m = new ObjectStreamField(
2291 lf.getField(), lf.isUnshared(), false);
2292 } else {
2293 m = new ObjectStreamField(
2294 lf.getName(), lf.getSignature(), lf.isUnshared());
2295 }
2296 }
2297 }
2298 if (m == null) {
2299 m = new ObjectStreamField(
2300 f.getName(), f.getSignature(), false);
2301 }
2302 m.setOffset(f.getOffset());
2303 matches[i] = m;
2304 }
2305 return matches;
2306 }
2307
2308 /**
2309 * Removes from the specified map any keys that have been enqueued
2310 * on the specified reference queue.
2311 */
2312 static void processQueue(ReferenceQueue<Class<?>> queue,
2313 ConcurrentMap<? extends
2314 WeakReference<Class<?>>, ?> map)
2315 {
2316 Reference<? extends Class<?>> ref;
2317 while((ref = queue.poll()) != null) {
2318 map.remove(ref);
2319 }
2320 }
2321
2322 /**
2323 * Weak key for Class objects.
2324 *
2325 **/
2326 static class WeakClassKey extends WeakReference<Class<?>> {
2327 /**
2328 * saved value of the referent's identity hash code, to maintain
2329 * a consistent hash code after the referent has been cleared
2330 */
2331 private final int hash;
2332
2333 /**
2334 * Create a new WeakClassKey to the given object, registered
2335 * with a queue.
2336 */
2337 WeakClassKey(Class<?> cl, ReferenceQueue<Class<?>> refQueue) {
2338 super(cl, refQueue);
2339 hash = System.identityHashCode(cl);
2340 }
2341
2342 /**
2343 * Returns the identity hash code of the original referent.
2344 */
2345 public int hashCode() {
2346 return hash;
2347 }
2348
2349 /**
2350 * Returns true if the given object is this identical
2351 * WeakClassKey instance, or, if this object's referent has not
2352 * been cleared, if the given object is another WeakClassKey
2353 * instance with the identical non-null referent as this one.
2354 */
2355 public boolean equals(Object obj) {
2356 if (obj == this) {
2357 return true;
2358 }
2359
2360 if (obj instanceof WeakClassKey) {
2361 Object referent = get();
2362 return (referent != null) &&
2363 (referent == ((WeakClassKey) obj).get());
2364 } else {
2365 return false;
2366 }
2367 }
2368 }
2369 }