1 /*
2 * Copyright (c) 1996, 2024, 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.invoke.MethodHandle;
29 import java.lang.invoke.MethodHandles;
30 import java.lang.invoke.MethodType;
31 import java.lang.reflect.Constructor;
32 import java.lang.reflect.Field;
33 import java.lang.reflect.InvocationTargetException;
34 import java.lang.reflect.RecordComponent;
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.MessageDigest;
40 import java.security.NoSuchAlgorithmException;
41 import java.util.ArrayList;
42 import java.util.Arrays;
43 import java.util.Collections;
44 import java.util.Comparator;
45 import java.util.HashSet;
46 import java.util.Map;
47 import java.util.Set;
48 import java.util.concurrent.ConcurrentHashMap;
49
50 import jdk.internal.event.SerializationMisdeclarationEvent;
51 import jdk.internal.misc.Unsafe;
52 import jdk.internal.reflect.ReflectionFactory;
53 import jdk.internal.util.ByteArray;
54
55 /**
56 * Serialization's descriptor for classes. It contains the name and
57 * serialVersionUID of the class. The ObjectStreamClass for a specific class
58 * loaded in this Java VM can be found/created using the lookup method.
59 *
60 * <p>The algorithm to compute the SerialVersionUID is described in
61 * <a href="{@docRoot}/../specs/serialization/class.html#stream-unique-identifiers">
62 * <cite>Java Object Serialization Specification,</cite> Section 4.6, "Stream Unique Identifiers"</a>.
63 *
64 * @spec serialization/index.html Java Object Serialization Specification
65 * @author Mike Warres
66 * @author Roger Riggs
67 * @see ObjectStreamField
68 * @see <a href="{@docRoot}/../specs/serialization/class.html">
69 * <cite>Java Object Serialization Specification,</cite> Section 4, "Class Descriptors"</a>
70 * @since 1.1
71 */
72 public final class ObjectStreamClass implements Serializable {
73
74 /** serialPersistentFields value indicating no serializable fields */
75 public static final ObjectStreamField[] NO_FIELDS =
76 new ObjectStreamField[0];
77
78 @java.io.Serial
79 private static final long serialVersionUID = -6120832682080437368L;
80 /**
81 * {@code ObjectStreamClass} has no fields for default serialization.
82 */
83 @java.io.Serial
84 private static final ObjectStreamField[] serialPersistentFields =
85 NO_FIELDS;
86
87 private static class Caches {
88 /** cache mapping local classes -> descriptors */
89 static final ClassCache<ObjectStreamClass> localDescs =
90 new ClassCache<>() {
91 @Override
92 protected ObjectStreamClass computeValue(Class<?> type) {
93 return new ObjectStreamClass(type);
94 }
95 };
96
97 /** cache mapping field group/local desc pairs -> field reflectors */
98 static final ClassCache<Map<FieldReflectorKey, FieldReflector>> reflectors =
99 new ClassCache<>() {
100 @Override
101 protected Map<FieldReflectorKey, FieldReflector> computeValue(Class<?> type) {
102 return new ConcurrentHashMap<>();
103 }
104 };
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 represents record type */
119 private boolean isRecord;
120 /** true if represented class implements Serializable */
121 private boolean serializable;
122 /** true if represented class implements Externalizable */
123 private boolean externalizable;
124 /** true if desc has data written by class-defined writeObject method */
125 private boolean hasWriteObjectData;
126 /**
127 * true if desc has externalizable data written in block data format; this
128 * must be true by default to accommodate ObjectInputStream subclasses which
129 * override readClassDescriptor() to return class descriptors obtained from
130 * ObjectStreamClass.lookup() (see 4461737)
131 */
132 private boolean hasBlockExternalData = true;
133
134 /**
135 * Contains information about InvalidClassException instances to be thrown
136 * when attempting operations on an invalid class. Note that instances of
137 * this class are immutable and are potentially shared among
138 * ObjectStreamClass instances.
139 */
140 private static class ExceptionInfo {
141 private final String className;
142 private final String message;
143
144 ExceptionInfo(String cn, String msg) {
145 className = cn;
146 message = msg;
147 }
148
149 /**
150 * Returns (does not throw) an InvalidClassException instance created
151 * from the information in this object, suitable for being thrown by
152 * the caller.
153 */
154 InvalidClassException newInvalidClassException() {
155 return new InvalidClassException(className, message);
156 }
157 }
158
159 /** exception (if any) thrown while attempting to resolve class */
160 private ClassNotFoundException resolveEx;
161 /** exception (if any) to throw if non-enum deserialization attempted */
162 private ExceptionInfo deserializeEx;
163 /** exception (if any) to throw if non-enum serialization attempted */
164 private ExceptionInfo serializeEx;
165 /** exception (if any) to throw if default serialization attempted */
166 private ExceptionInfo defaultSerializeEx;
167
168 /** serializable fields */
169 private ObjectStreamField[] fields;
170 /** aggregate marshalled size of primitive fields */
171 private int primDataSize;
172 /** number of non-primitive fields */
173 private int numObjFields;
174 /** reflector for setting/getting serializable field values */
175 private FieldReflector fieldRefl;
176 /** data layout of serialized objects described by this class desc */
177 private volatile ClassDataSlot[] dataLayout;
178
179 /** serialization-appropriate constructor, or null if none */
180 private Constructor<?> cons;
181 /** record canonical constructor (shared among OSCs for same class), or null */
182 private MethodHandle canonicalCtr;
183 /** cache of record deserialization constructors per unique set of stream fields
184 * (shared among OSCs for same class), or null */
185 private DeserializationConstructorsCache deserializationCtrs;
186 /** session-cache of record deserialization constructor
187 * (in de-serialized OSC only), or null */
188 private MethodHandle deserializationCtr;
189
190 /** class-defined writeObject method, or null if none */
191 private Method writeObjectMethod;
192 /** class-defined readObject method, or null if none */
193 private Method readObjectMethod;
194 /** class-defined readObjectNoData method, or null if none */
195 private Method readObjectNoDataMethod;
196 /** class-defined writeReplace method, or null if none */
197 private Method writeReplaceMethod;
198 /** class-defined readResolve method, or null if none */
199 private Method readResolveMethod;
200
201 /** local class descriptor for represented class (may point to self) */
202 private ObjectStreamClass localDesc;
203 /** superclass descriptor appearing in stream */
204 private ObjectStreamClass superDesc;
205
206 /** true if, and only if, the object has been correctly initialized */
207 private boolean initialized;
208
209 /**
210 * Initializes native code.
211 */
212 private static native void initNative();
213 static {
214 initNative();
215 }
216
217 /**
218 * Find the descriptor for a class that can be serialized. Creates an
219 * ObjectStreamClass instance if one does not exist yet for class. Null is
220 * returned if the specified class does not implement java.io.Serializable
221 * or java.io.Externalizable.
222 *
223 * @param cl class for which to get the descriptor
224 * @return the class descriptor for the specified class
225 */
226 public static ObjectStreamClass lookup(Class<?> cl) {
227 return lookup(cl, false);
228 }
229
230 /**
231 * Returns the descriptor for any class, regardless of whether it
232 * implements {@link Serializable}.
233 *
234 * @param cl class for which to get the descriptor
235 * @return the class descriptor for the specified class
236 * @since 1.6
237 */
238 public static ObjectStreamClass lookupAny(Class<?> cl) {
239 return lookup(cl, true);
240 }
241
242 /**
243 * Returns the name of the class described by this descriptor.
244 * This method returns the name of the class in the format that
245 * is used by the {@link Class#getName} method.
246 *
247 * @return a string representing the name of the class
248 */
249 public String getName() {
250 return name;
251 }
252
253 /**
254 * Return the serialVersionUID for this class. The serialVersionUID
255 * defines a set of classes all with the same name that have evolved from a
256 * common root class and agree to be serialized and deserialized using a
257 * common format. NonSerializable classes have a serialVersionUID of 0L.
258 *
259 * @return the SUID of the class described by this descriptor
260 */
261 public long getSerialVersionUID() {
262 // REMIND: synchronize instead of relying on volatile?
263 if (suid == null) {
264 if (isRecord)
265 return 0L;
266
267 suid = computeDefaultSUID(cl);
268 }
269 return suid.longValue();
270 }
271
272 /**
273 * Return the class in the local VM that this version is mapped to. Null
274 * is returned if there is no corresponding local class.
275 *
276 * @return the {@code Class} instance that this descriptor represents
277 */
278 public Class<?> forClass() {
279 if (cl == null) {
280 return null;
281 }
282 requireInitialized();
283 return cl;
284 }
285
286 /**
287 * Return an array of the fields of this serializable class.
288 *
289 * @return an array containing an element for each persistent field of
290 * this class. Returns an array of length zero if there are no
291 * fields.
292 * @since 1.2
293 */
294 public ObjectStreamField[] getFields() {
295 return getFields(true);
296 }
297
298 /**
299 * Get the field of this class by name.
300 *
301 * @param name the name of the data field to look for
302 * @return The ObjectStreamField object of the named field or null if
303 * there is no such named field.
304 */
305 public ObjectStreamField getField(String name) {
306 return getField(name, null);
307 }
308
309 /**
310 * Return a string describing this ObjectStreamClass.
311 */
312 public String toString() {
313 return name + ": static final long serialVersionUID = " +
314 getSerialVersionUID() + "L;";
315 }
316
317 /**
318 * Looks up and returns class descriptor for given class, or null if class
319 * is non-serializable and "all" is set to false.
320 *
321 * @param cl class to look up
322 * @param all if true, return descriptors for all classes; if false, only
323 * return descriptors for serializable classes
324 */
325 static ObjectStreamClass lookup(Class<?> cl, boolean all) {
326 if (!(all || Serializable.class.isAssignableFrom(cl))) {
327 return null;
328 }
329 return Caches.localDescs.get(cl);
330 }
331
332 /**
333 * Creates local class descriptor representing given class.
334 */
335 private ObjectStreamClass(final Class<?> cl) {
336 this.cl = cl;
337 name = cl.getName();
338 isProxy = Proxy.isProxyClass(cl);
339 isEnum = Enum.class.isAssignableFrom(cl);
340 isRecord = cl.isRecord();
341 serializable = Serializable.class.isAssignableFrom(cl);
342 externalizable = Externalizable.class.isAssignableFrom(cl);
343
344 Class<?> superCl = cl.getSuperclass();
345 superDesc = (superCl != null) ? lookup(superCl, false) : null;
346 localDesc = this;
347
348 if (serializable) {
349 if (isEnum) {
350 suid = 0L;
351 fields = NO_FIELDS;
352 } else if (cl.isArray()) {
353 fields = NO_FIELDS;
354 } else {
355 suid = getDeclaredSUID(cl);
356 try {
357 fields = getSerialFields(cl);
358 computeFieldOffsets();
359 } catch (InvalidClassException e) {
360 serializeEx = deserializeEx =
361 new ExceptionInfo(e.classname, e.getMessage());
362 fields = NO_FIELDS;
363 }
364
365 if (isRecord) {
366 canonicalCtr = canonicalRecordCtr(cl);
367 deserializationCtrs = new DeserializationConstructorsCache();
368 } else if (externalizable) {
369 cons = getExternalizableConstructor(cl);
370 } else {
371 cons = getSerializableConstructor(cl);
372 writeObjectMethod = getPrivateMethod(cl, "writeObject",
373 new Class<?>[]{ObjectOutputStream.class},
374 Void.TYPE);
375 readObjectMethod = getPrivateMethod(cl, "readObject",
376 new Class<?>[]{ObjectInputStream.class},
377 Void.TYPE);
378 readObjectNoDataMethod = getPrivateMethod(
379 cl, "readObjectNoData", null, Void.TYPE);
380 hasWriteObjectData = (writeObjectMethod != null);
381 }
382 writeReplaceMethod = getInheritableMethod(
383 cl, "writeReplace", null, Object.class);
384 readResolveMethod = getInheritableMethod(
385 cl, "readResolve", null, Object.class);
386 }
387 } else {
388 suid = 0L;
389 fields = NO_FIELDS;
390 }
391
392 try {
393 fieldRefl = getReflector(fields, this);
394 } catch (InvalidClassException ex) {
395 // field mismatches impossible when matching local fields vs. self
396 throw new InternalError(ex);
397 }
398
399 if (deserializeEx == null) {
400 if (isEnum) {
401 deserializeEx = new ExceptionInfo(name, "enum type");
402 } else if (cons == null && !isRecord) {
403 deserializeEx = new ExceptionInfo(name, "no valid constructor");
404 }
405 }
406 if (isRecord && canonicalCtr == null) {
407 deserializeEx = new ExceptionInfo(name, "record canonical constructor not found");
408 } else {
409 for (int i = 0; i < fields.length; i++) {
410 if (fields[i].getField() == null) {
411 defaultSerializeEx = new ExceptionInfo(
412 name, "unmatched serializable field(s) declared");
413 }
414 }
415 }
416 initialized = true;
417
418 if (SerializationMisdeclarationEvent.enabled() && serializable) {
419 SerializationMisdeclarationChecker.checkMisdeclarations(cl);
420 }
421 }
422
423 /**
424 * Creates blank class descriptor which should be initialized via a
425 * subsequent call to initProxy(), initNonProxy() or readNonProxy().
426 */
427 ObjectStreamClass() {
428 }
429
430 /**
431 * Initializes class descriptor representing a proxy class.
432 */
433 void initProxy(Class<?> cl,
434 ClassNotFoundException resolveEx,
435 ObjectStreamClass superDesc)
436 throws InvalidClassException
437 {
438 ObjectStreamClass osc = null;
439 if (cl != null) {
440 osc = lookup(cl, true);
441 if (!osc.isProxy) {
442 throw new InvalidClassException(
443 "cannot bind proxy descriptor to a non-proxy class");
444 }
445 }
446 this.cl = cl;
447 this.resolveEx = resolveEx;
448 this.superDesc = superDesc;
449 isProxy = true;
450 serializable = true;
451 suid = 0L;
452 fields = NO_FIELDS;
453 if (osc != null) {
454 localDesc = osc;
455 name = localDesc.name;
456 externalizable = localDesc.externalizable;
457 writeReplaceMethod = localDesc.writeReplaceMethod;
458 readResolveMethod = localDesc.readResolveMethod;
459 deserializeEx = localDesc.deserializeEx;
460 cons = localDesc.cons;
461 }
462 fieldRefl = getReflector(fields, localDesc);
463 initialized = true;
464 }
465
466 /**
467 * Initializes class descriptor representing a non-proxy class.
468 */
469 void initNonProxy(ObjectStreamClass model,
470 Class<?> cl,
471 ClassNotFoundException resolveEx,
472 ObjectStreamClass superDesc)
473 throws InvalidClassException
474 {
475 long suid = model.getSerialVersionUID();
476 ObjectStreamClass osc = null;
477 if (cl != null) {
478 osc = lookup(cl, true);
479 if (osc.isProxy) {
480 throw new InvalidClassException(
481 "cannot bind non-proxy descriptor to a proxy class");
482 }
483 if (model.isEnum != osc.isEnum) {
484 throw new InvalidClassException(model.isEnum ?
485 "cannot bind enum descriptor to a non-enum class" :
486 "cannot bind non-enum descriptor to an enum class");
487 }
488
489 if (model.serializable == osc.serializable &&
490 !cl.isArray() && !cl.isRecord() &&
491 suid != osc.getSerialVersionUID()) {
492 throw new InvalidClassException(osc.name,
493 "local class incompatible: " +
494 "stream classdesc serialVersionUID = " + suid +
495 ", local class serialVersionUID = " +
496 osc.getSerialVersionUID());
497 }
498
499 if (!classNamesEqual(model.name, osc.name)) {
500 throw new InvalidClassException(osc.name,
501 "local class name incompatible with stream class " +
502 "name \"" + model.name + "\"");
503 }
504
505 if (!model.isEnum) {
506 if ((model.serializable == osc.serializable) &&
507 (model.externalizable != osc.externalizable)) {
508 throw new InvalidClassException(osc.name,
509 "Serializable incompatible with Externalizable");
510 }
511
512 if ((model.serializable != osc.serializable) ||
513 (model.externalizable != osc.externalizable) ||
514 !(model.serializable || model.externalizable)) {
515 deserializeEx = new ExceptionInfo(
516 osc.name, "class invalid for deserialization");
517 }
518 }
519 }
520
521 this.cl = cl;
522 this.resolveEx = resolveEx;
523 this.superDesc = superDesc;
524 name = model.name;
525 this.suid = suid;
526 isProxy = false;
527 isEnum = model.isEnum;
528 serializable = model.serializable;
529 externalizable = model.externalizable;
530 hasBlockExternalData = model.hasBlockExternalData;
531 hasWriteObjectData = model.hasWriteObjectData;
532 fields = model.fields;
533 primDataSize = model.primDataSize;
534 numObjFields = model.numObjFields;
535
536 if (osc != null) {
537 localDesc = osc;
538 isRecord = localDesc.isRecord;
539 // canonical record constructor is shared
540 canonicalCtr = localDesc.canonicalCtr;
541 // cache of deserialization constructors is shared
542 deserializationCtrs = localDesc.deserializationCtrs;
543 writeObjectMethod = localDesc.writeObjectMethod;
544 readObjectMethod = localDesc.readObjectMethod;
545 readObjectNoDataMethod = localDesc.readObjectNoDataMethod;
546 writeReplaceMethod = localDesc.writeReplaceMethod;
547 readResolveMethod = localDesc.readResolveMethod;
548 if (deserializeEx == null) {
549 deserializeEx = localDesc.deserializeEx;
550 }
551 assert cl.isRecord() ? localDesc.cons == null : true;
552 cons = localDesc.cons;
553 }
554
555 fieldRefl = getReflector(fields, localDesc);
556 // reassign to matched fields so as to reflect local unshared settings
557 fields = fieldRefl.getFields();
558
559 initialized = true;
560 }
561
562 /**
563 * Reads non-proxy class descriptor information from given input stream.
564 * The resulting class descriptor is not fully functional; it can only be
565 * used as input to the ObjectInputStream.resolveClass() and
566 * ObjectStreamClass.initNonProxy() methods.
567 */
568 void readNonProxy(ObjectInputStream in)
569 throws IOException, ClassNotFoundException
570 {
571 name = in.readUTF();
572 suid = in.readLong();
573 isProxy = false;
574
575 byte flags = in.readByte();
576 hasWriteObjectData =
577 ((flags & ObjectStreamConstants.SC_WRITE_METHOD) != 0);
578 hasBlockExternalData =
579 ((flags & ObjectStreamConstants.SC_BLOCK_DATA) != 0);
580 externalizable =
581 ((flags & ObjectStreamConstants.SC_EXTERNALIZABLE) != 0);
582 boolean sflag =
583 ((flags & ObjectStreamConstants.SC_SERIALIZABLE) != 0);
584 if (externalizable && sflag) {
585 throw new InvalidClassException(
586 name, "serializable and externalizable flags conflict");
587 }
588 serializable = externalizable || sflag;
589 isEnum = ((flags & ObjectStreamConstants.SC_ENUM) != 0);
590 if (isEnum && suid.longValue() != 0L) {
591 throw new InvalidClassException(name,
592 "enum descriptor has non-zero serialVersionUID: " + suid);
593 }
594
595 int numFields = in.readShort();
596 if (isEnum && numFields != 0) {
597 throw new InvalidClassException(name,
598 "enum descriptor has non-zero field count: " + numFields);
599 }
600 fields = (numFields > 0) ?
601 new ObjectStreamField[numFields] : NO_FIELDS;
602 for (int i = 0; i < numFields; i++) {
603 char tcode = (char) in.readByte();
604 String fname = in.readUTF();
605 String signature = ((tcode == 'L') || (tcode == '[')) ?
606 in.readTypeString() : String.valueOf(tcode);
607 try {
608 fields[i] = new ObjectStreamField(fname, signature, false);
609 } catch (RuntimeException e) {
610 throw new InvalidClassException(name,
611 "invalid descriptor for field " +
612 fname, e);
613 }
614 }
615 computeFieldOffsets();
616 }
617
618 /**
619 * Writes non-proxy class descriptor information to given output stream.
620 */
621 void writeNonProxy(ObjectOutputStream out) throws IOException {
622 out.writeUTF(name);
623 out.writeLong(getSerialVersionUID());
624
625 byte flags = 0;
626 if (externalizable) {
627 flags |= ObjectStreamConstants.SC_EXTERNALIZABLE;
628 int protocol = out.getProtocolVersion();
629 if (protocol != ObjectStreamConstants.PROTOCOL_VERSION_1) {
630 flags |= ObjectStreamConstants.SC_BLOCK_DATA;
631 }
632 } else if (serializable) {
633 flags |= ObjectStreamConstants.SC_SERIALIZABLE;
634 }
635 if (hasWriteObjectData) {
636 flags |= ObjectStreamConstants.SC_WRITE_METHOD;
637 }
638 if (isEnum) {
639 flags |= ObjectStreamConstants.SC_ENUM;
640 }
641 out.writeByte(flags);
642
643 out.writeShort(fields.length);
644 for (int i = 0; i < fields.length; i++) {
645 ObjectStreamField f = fields[i];
646 out.writeByte(f.getTypeCode());
647 out.writeUTF(f.getName());
648 if (!f.isPrimitive()) {
649 out.writeTypeString(f.getTypeString());
650 }
651 }
652 }
653
654 /**
655 * Returns ClassNotFoundException (if any) thrown while attempting to
656 * resolve local class corresponding to this class descriptor.
657 */
658 ClassNotFoundException getResolveException() {
659 return resolveEx;
660 }
661
662 /**
663 * Throws InternalError if not initialized.
664 */
665 private final void requireInitialized() {
666 if (!initialized)
667 throw new InternalError("Unexpected call when not initialized");
668 }
669
670 /**
671 * Throws InvalidClassException if not initialized.
672 * To be called in cases where an uninitialized class descriptor indicates
673 * a problem in the serialization stream.
674 */
675 final void checkInitialized() throws InvalidClassException {
676 if (!initialized) {
677 throw new InvalidClassException("Class descriptor should be initialized");
678 }
679 }
680
681 /**
682 * Throws an InvalidClassException if object instances referencing this
683 * class descriptor should not be allowed to deserialize. This method does
684 * not apply to deserialization of enum constants.
685 */
686 void checkDeserialize() throws InvalidClassException {
687 requireInitialized();
688 if (deserializeEx != null) {
689 throw deserializeEx.newInvalidClassException();
690 }
691 }
692
693 /**
694 * Throws an InvalidClassException if objects whose class is represented by
695 * this descriptor should not be allowed to serialize. This method does
696 * not apply to serialization of enum constants.
697 */
698 void checkSerialize() throws InvalidClassException {
699 requireInitialized();
700 if (serializeEx != null) {
701 throw serializeEx.newInvalidClassException();
702 }
703 }
704
705 /**
706 * Throws an InvalidClassException if objects whose class is represented by
707 * this descriptor should not be permitted to use default serialization
708 * (e.g., if the class declares serializable fields that do not correspond
709 * to actual fields, and hence must use the GetField API). This method
710 * does not apply to deserialization of enum constants.
711 */
712 void checkDefaultSerialize() throws InvalidClassException {
713 requireInitialized();
714 if (defaultSerializeEx != null) {
715 throw defaultSerializeEx.newInvalidClassException();
716 }
717 }
718
719 /**
720 * Returns superclass descriptor. Note that on the receiving side, the
721 * superclass descriptor may be bound to a class that is not a superclass
722 * of the subclass descriptor's bound class.
723 */
724 ObjectStreamClass getSuperDesc() {
725 requireInitialized();
726 return superDesc;
727 }
728
729 /**
730 * Returns the "local" class descriptor for the class associated with this
731 * class descriptor (i.e., the result of
732 * ObjectStreamClass.lookup(this.forClass())) or null if there is no class
733 * associated with this descriptor.
734 */
735 ObjectStreamClass getLocalDesc() {
736 requireInitialized();
737 return localDesc;
738 }
739
740 /**
741 * Returns arrays of ObjectStreamFields representing the serializable
742 * fields of the represented class. If copy is true, a clone of this class
743 * descriptor's field array is returned, otherwise the array itself is
744 * returned.
745 */
746 ObjectStreamField[] getFields(boolean copy) {
747 return copy ? fields.clone() : fields;
748 }
749
750 /**
751 * Looks up a serializable field of the represented class by name and type.
752 * A specified type of null matches all types, Object.class matches all
753 * non-primitive types, and any other non-null type matches assignable
754 * types only. Returns matching field, or null if no match found.
755 */
756 ObjectStreamField getField(String name, Class<?> type) {
757 for (int i = 0; i < fields.length; i++) {
758 ObjectStreamField f = fields[i];
759 if (f.getName().equals(name)) {
760 if (type == null ||
761 (type == Object.class && !f.isPrimitive()))
762 {
763 return f;
764 }
765 Class<?> ftype = f.getType();
766 if (ftype != null && type.isAssignableFrom(ftype)) {
767 return f;
768 }
769 }
770 }
771 return null;
772 }
773
774 /**
775 * Returns true if class descriptor represents a dynamic proxy class, false
776 * otherwise.
777 */
778 boolean isProxy() {
779 requireInitialized();
780 return isProxy;
781 }
782
783 /**
784 * Returns true if class descriptor represents an enum type, false
785 * otherwise.
786 */
787 boolean isEnum() {
788 requireInitialized();
789 return isEnum;
790 }
791
792 /**
793 * Returns true if class descriptor represents a record type, false
794 * otherwise.
795 */
796 boolean isRecord() {
797 requireInitialized();
798 return isRecord;
799 }
800
801 /**
802 * Returns true if represented class implements Externalizable, false
803 * otherwise.
804 */
805 boolean isExternalizable() {
806 requireInitialized();
807 return externalizable;
808 }
809
810 /**
811 * Returns true if represented class implements Serializable, false
812 * otherwise.
813 */
814 boolean isSerializable() {
815 requireInitialized();
816 return serializable;
817 }
818
819 /**
820 * Returns true if class descriptor represents externalizable class that
821 * has written its data in 1.2 (block data) format, false otherwise.
822 */
823 boolean hasBlockExternalData() {
824 requireInitialized();
825 return hasBlockExternalData;
826 }
827
828 /**
829 * Returns true if class descriptor represents serializable (but not
830 * externalizable) class which has written its data via a custom
831 * writeObject() method, false otherwise.
832 */
833 boolean hasWriteObjectData() {
834 requireInitialized();
835 return hasWriteObjectData;
836 }
837
838 /**
839 * Returns true if represented class is serializable/externalizable and can
840 * be instantiated by the serialization runtime--i.e., if it is
841 * externalizable and defines a public no-arg constructor, or if it is
842 * non-externalizable and its first non-serializable superclass defines an
843 * accessible no-arg constructor. Otherwise, returns false.
844 */
845 boolean isInstantiable() {
846 requireInitialized();
847 return (cons != null);
848 }
849
850 /**
851 * Returns true if represented class is serializable (but not
852 * externalizable) and defines a conformant writeObject method. Otherwise,
853 * returns false.
854 */
855 boolean hasWriteObjectMethod() {
856 requireInitialized();
857 return (writeObjectMethod != null);
858 }
859
860 /**
861 * Returns true if represented class is serializable (but not
862 * externalizable) and defines a conformant readObject method. Otherwise,
863 * returns false.
864 */
865 boolean hasReadObjectMethod() {
866 requireInitialized();
867 return (readObjectMethod != null);
868 }
869
870 /**
871 * Returns true if represented class is serializable (but not
872 * externalizable) and defines a conformant readObjectNoData method.
873 * Otherwise, returns false.
874 */
875 boolean hasReadObjectNoDataMethod() {
876 requireInitialized();
877 return (readObjectNoDataMethod != null);
878 }
879
880 /**
881 * Returns true if represented class is serializable or externalizable and
882 * defines a conformant writeReplace method. Otherwise, returns false.
883 */
884 boolean hasWriteReplaceMethod() {
885 requireInitialized();
886 return (writeReplaceMethod != null);
887 }
888
889 /**
890 * Returns true if represented class is serializable or externalizable and
891 * defines a conformant readResolve method. Otherwise, returns false.
892 */
893 boolean hasReadResolveMethod() {
894 requireInitialized();
895 return (readResolveMethod != null);
896 }
897
898 /**
899 * Creates a new instance of the represented class. If the class is
900 * externalizable, invokes its public no-arg constructor; otherwise, if the
901 * class is serializable, invokes the no-arg constructor of the first
902 * non-serializable superclass. Throws UnsupportedOperationException if
903 * this class descriptor is not associated with a class, if the associated
904 * class is non-serializable or if the appropriate no-arg constructor is
905 * inaccessible/unavailable.
906 */
907 Object newInstance()
908 throws InstantiationException, InvocationTargetException,
909 UnsupportedOperationException
910 {
911 requireInitialized();
912 if (cons != null) {
913 try {
914 return cons.newInstance();
915 } catch (IllegalAccessException ex) {
916 // should not occur, as access checks have been suppressed
917 throw new InternalError(ex);
918 } catch (InvocationTargetException ex) {
919 Throwable cause = ex.getCause();
920 if (cause instanceof Error err)
921 throw err;
922 else
923 throw ex;
924 } catch (InstantiationError err) {
925 var ex = new InstantiationException();
926 ex.initCause(err);
927 throw ex;
928 }
929 } else {
930 throw new UnsupportedOperationException();
931 }
932 }
933
934 /**
935 * Invokes the writeObject method of the represented serializable class.
936 * Throws UnsupportedOperationException if this class descriptor is not
937 * associated with a class, or if the class is externalizable,
938 * non-serializable or does not define writeObject.
939 */
940 void invokeWriteObject(Object obj, ObjectOutputStream out)
941 throws IOException, UnsupportedOperationException
942 {
943 requireInitialized();
944 if (writeObjectMethod != null) {
945 try {
946 writeObjectMethod.invoke(obj, new Object[]{ out });
947 } catch (InvocationTargetException ex) {
948 Throwable th = ex.getCause();
949 if (th instanceof IOException) {
950 throw (IOException) th;
951 } else {
952 throwMiscException(th);
953 }
954 } catch (IllegalAccessException ex) {
955 // should not occur, as access checks have been suppressed
956 throw new InternalError(ex);
957 }
958 } else {
959 throw new UnsupportedOperationException();
960 }
961 }
962
963 /**
964 * Invokes the readObject method of the represented serializable class.
965 * Throws UnsupportedOperationException if this class descriptor is not
966 * associated with a class, or if the class is externalizable,
967 * non-serializable or does not define readObject.
968 */
969 void invokeReadObject(Object obj, ObjectInputStream in)
970 throws ClassNotFoundException, IOException,
971 UnsupportedOperationException
972 {
973 requireInitialized();
974 if (readObjectMethod != null) {
975 try {
976 readObjectMethod.invoke(obj, new Object[]{ in });
977 } catch (InvocationTargetException ex) {
978 Throwable th = ex.getCause();
979 if (th instanceof ClassNotFoundException) {
980 throw (ClassNotFoundException) th;
981 } else if (th instanceof IOException) {
982 throw (IOException) th;
983 } else {
984 throwMiscException(th);
985 }
986 } catch (IllegalAccessException ex) {
987 // should not occur, as access checks have been suppressed
988 throw new InternalError(ex);
989 }
990 } else {
991 throw new UnsupportedOperationException();
992 }
993 }
994
995 /**
996 * Invokes the readObjectNoData method of the represented serializable
997 * class. Throws UnsupportedOperationException if this class descriptor is
998 * not associated with a class, or if the class is externalizable,
999 * non-serializable or does not define readObjectNoData.
1000 */
1001 void invokeReadObjectNoData(Object obj)
1002 throws IOException, UnsupportedOperationException
1003 {
1004 requireInitialized();
1005 if (readObjectNoDataMethod != null) {
1006 try {
1007 readObjectNoDataMethod.invoke(obj, (Object[]) null);
1008 } catch (InvocationTargetException ex) {
1009 Throwable th = ex.getCause();
1010 if (th instanceof ObjectStreamException) {
1011 throw (ObjectStreamException) th;
1012 } else {
1013 throwMiscException(th);
1014 }
1015 } catch (IllegalAccessException ex) {
1016 // should not occur, as access checks have been suppressed
1017 throw new InternalError(ex);
1018 }
1019 } else {
1020 throw new UnsupportedOperationException();
1021 }
1022 }
1023
1024 /**
1025 * Invokes the writeReplace method of the represented serializable class and
1026 * returns the result. Throws UnsupportedOperationException if this class
1027 * descriptor is not associated with a class, or if the class is
1028 * non-serializable or does not define writeReplace.
1029 */
1030 Object invokeWriteReplace(Object obj)
1031 throws IOException, UnsupportedOperationException
1032 {
1033 requireInitialized();
1034 if (writeReplaceMethod != null) {
1035 try {
1036 return writeReplaceMethod.invoke(obj, (Object[]) null);
1037 } catch (InvocationTargetException ex) {
1038 Throwable th = ex.getCause();
1039 if (th instanceof ObjectStreamException) {
1040 throw (ObjectStreamException) th;
1041 } else {
1042 throwMiscException(th);
1043 throw new InternalError(th); // never reached
1044 }
1045 } catch (IllegalAccessException ex) {
1046 // should not occur, as access checks have been suppressed
1047 throw new InternalError(ex);
1048 }
1049 } else {
1050 throw new UnsupportedOperationException();
1051 }
1052 }
1053
1054 /**
1055 * Invokes the readResolve method of the represented serializable class and
1056 * returns the result. Throws UnsupportedOperationException if this class
1057 * descriptor is not associated with a class, or if the class is
1058 * non-serializable or does not define readResolve.
1059 */
1060 Object invokeReadResolve(Object obj)
1061 throws IOException, UnsupportedOperationException
1062 {
1063 requireInitialized();
1064 if (readResolveMethod != null) {
1065 try {
1066 return readResolveMethod.invoke(obj, (Object[]) null);
1067 } catch (InvocationTargetException ex) {
1068 Throwable th = ex.getCause();
1069 if (th instanceof ObjectStreamException) {
1070 throw (ObjectStreamException) th;
1071 } else {
1072 throwMiscException(th);
1073 throw new InternalError(th); // never reached
1074 }
1075 } catch (IllegalAccessException ex) {
1076 // should not occur, as access checks have been suppressed
1077 throw new InternalError(ex);
1078 }
1079 } else {
1080 throw new UnsupportedOperationException();
1081 }
1082 }
1083
1084 /**
1085 * Class representing the portion of an object's serialized form allotted
1086 * to data described by a given class descriptor. If "hasData" is false,
1087 * the object's serialized form does not contain data associated with the
1088 * class descriptor.
1089 */
1090 static class ClassDataSlot {
1091
1092 /** class descriptor "occupying" this slot */
1093 final ObjectStreamClass desc;
1094 /** true if serialized form includes data for this slot's descriptor */
1095 final boolean hasData;
1096
1097 ClassDataSlot(ObjectStreamClass desc, boolean hasData) {
1098 this.desc = desc;
1099 this.hasData = hasData;
1100 }
1101 }
1102
1103 /**
1104 * Returns array of ClassDataSlot instances representing the data layout
1105 * (including superclass data) for serialized objects described by this
1106 * class descriptor. ClassDataSlots are ordered by inheritance with those
1107 * containing "higher" superclasses appearing first. The final
1108 * ClassDataSlot contains a reference to this descriptor.
1109 */
1110 ClassDataSlot[] getClassDataLayout() throws InvalidClassException {
1111 // REMIND: synchronize instead of relying on volatile?
1112 if (dataLayout == null) {
1113 dataLayout = getClassDataLayout0();
1114 }
1115 return dataLayout;
1116 }
1117
1118 private ClassDataSlot[] getClassDataLayout0()
1119 throws InvalidClassException
1120 {
1121 ArrayList<ClassDataSlot> slots = new ArrayList<>();
1122 Class<?> start = cl, end = cl;
1123
1124 // locate closest non-serializable superclass
1125 while (end != null && Serializable.class.isAssignableFrom(end)) {
1126 end = end.getSuperclass();
1127 }
1128
1129 HashSet<String> oscNames = new HashSet<>(3);
1130
1131 for (ObjectStreamClass d = this; d != null; d = d.superDesc) {
1132 if (oscNames.contains(d.name)) {
1133 throw new InvalidClassException("Circular reference.");
1134 } else {
1135 oscNames.add(d.name);
1136 }
1137
1138 // search up inheritance hierarchy for class with matching name
1139 String searchName = (d.cl != null) ? d.cl.getName() : d.name;
1140 Class<?> match = null;
1141 for (Class<?> c = start; c != end; c = c.getSuperclass()) {
1142 if (searchName.equals(c.getName())) {
1143 match = c;
1144 break;
1145 }
1146 }
1147
1148 // add "no data" slot for each unmatched class below match
1149 if (match != null) {
1150 for (Class<?> c = start; c != match; c = c.getSuperclass()) {
1151 slots.add(new ClassDataSlot(
1152 ObjectStreamClass.lookup(c, true), false));
1153 }
1154 start = match.getSuperclass();
1155 }
1156
1157 // record descriptor/class pairing
1158 slots.add(new ClassDataSlot(d.getVariantFor(match), true));
1159 }
1160
1161 // add "no data" slot for any leftover unmatched classes
1162 for (Class<?> c = start; c != end; c = c.getSuperclass()) {
1163 slots.add(new ClassDataSlot(
1164 ObjectStreamClass.lookup(c, true), false));
1165 }
1166
1167 // order slots from superclass -> subclass
1168 Collections.reverse(slots);
1169 return slots.toArray(new ClassDataSlot[slots.size()]);
1170 }
1171
1172 /**
1173 * Returns aggregate size (in bytes) of marshalled primitive field values
1174 * for represented class.
1175 */
1176 int getPrimDataSize() {
1177 return primDataSize;
1178 }
1179
1180 /**
1181 * Returns number of non-primitive serializable fields of represented
1182 * class.
1183 */
1184 int getNumObjFields() {
1185 return numObjFields;
1186 }
1187
1188 /**
1189 * Fetches the serializable primitive field values of object obj and
1190 * marshals them into byte array buf starting at offset 0. It is the
1191 * responsibility of the caller to ensure that obj is of the proper type if
1192 * non-null.
1193 */
1194 void getPrimFieldValues(Object obj, byte[] buf) {
1195 fieldRefl.getPrimFieldValues(obj, buf);
1196 }
1197
1198 /**
1199 * Sets the serializable primitive fields of object obj using values
1200 * unmarshalled from byte array buf starting at offset 0. It is the
1201 * responsibility of the caller to ensure that obj is of the proper type if
1202 * non-null.
1203 */
1204 void setPrimFieldValues(Object obj, byte[] buf) {
1205 fieldRefl.setPrimFieldValues(obj, buf);
1206 }
1207
1208 /**
1209 * Fetches the serializable object field values of object obj and stores
1210 * them in array vals starting at offset 0. It is the responsibility of
1211 * the caller to ensure that obj is of the proper type if non-null.
1212 */
1213 void getObjFieldValues(Object obj, Object[] vals) {
1214 fieldRefl.getObjFieldValues(obj, vals);
1215 }
1216
1217 /**
1218 * Checks that the given values, from array vals starting at offset 0,
1219 * are assignable to the given serializable object fields.
1220 * @throws ClassCastException if any value is not assignable
1221 */
1222 void checkObjFieldValueTypes(Object obj, Object[] vals) {
1223 fieldRefl.checkObjectFieldValueTypes(obj, vals);
1224 }
1225
1226 /**
1227 * Sets the serializable object fields of object obj using values from
1228 * array vals starting at offset 0. It is the responsibility of the caller
1229 * to ensure that obj is of the proper type if non-null.
1230 */
1231 void setObjFieldValues(Object obj, Object[] vals) {
1232 fieldRefl.setObjFieldValues(obj, vals);
1233 }
1234
1235 /**
1236 * Calculates and sets serializable field offsets, as well as primitive
1237 * data size and object field count totals. Throws InvalidClassException
1238 * if fields are illegally ordered.
1239 */
1240 private void computeFieldOffsets() throws InvalidClassException {
1241 primDataSize = 0;
1242 numObjFields = 0;
1243 int firstObjIndex = -1;
1244
1245 for (int i = 0; i < fields.length; i++) {
1246 ObjectStreamField f = fields[i];
1247 switch (f.getTypeCode()) {
1248 case 'Z', 'B' -> f.setOffset(primDataSize++);
1249 case 'C', 'S' -> {
1250 f.setOffset(primDataSize);
1251 primDataSize += 2;
1252 }
1253 case 'I', 'F' -> {
1254 f.setOffset(primDataSize);
1255 primDataSize += 4;
1256 }
1257 case 'J', 'D' -> {
1258 f.setOffset(primDataSize);
1259 primDataSize += 8;
1260 }
1261 case '[', 'L' -> {
1262 f.setOffset(numObjFields++);
1263 if (firstObjIndex == -1) {
1264 firstObjIndex = i;
1265 }
1266 }
1267 default -> throw new InternalError();
1268 }
1269 }
1270 if (firstObjIndex != -1 &&
1271 firstObjIndex + numObjFields != fields.length)
1272 {
1273 throw new InvalidClassException(name, "illegal field order");
1274 }
1275 }
1276
1277 /**
1278 * If given class is the same as the class associated with this class
1279 * descriptor, returns reference to this class descriptor. Otherwise,
1280 * returns variant of this class descriptor bound to given class.
1281 */
1282 private ObjectStreamClass getVariantFor(Class<?> cl)
1283 throws InvalidClassException
1284 {
1285 if (this.cl == cl) {
1286 return this;
1287 }
1288 ObjectStreamClass desc = new ObjectStreamClass();
1289 if (isProxy) {
1290 desc.initProxy(cl, null, superDesc);
1291 } else {
1292 desc.initNonProxy(this, cl, null, superDesc);
1293 }
1294 return desc;
1295 }
1296
1297 /**
1298 * Returns public no-arg constructor of given class, or null if none found.
1299 * Access checks are disabled on the returned constructor (if any), since
1300 * the defining class may still be non-public.
1301 */
1302 private static Constructor<?> getExternalizableConstructor(Class<?> cl) {
1303 try {
1304 Constructor<?> cons = cl.getDeclaredConstructor((Class<?>[]) null);
1305 cons.setAccessible(true);
1306 return ((cons.getModifiers() & Modifier.PUBLIC) != 0) ?
1307 cons : null;
1308 } catch (NoSuchMethodException ex) {
1309 return null;
1310 }
1311 }
1312
1313 /**
1314 * Returns subclass-accessible no-arg constructor of first non-serializable
1315 * superclass, or null if none found. Access checks are disabled on the
1316 * returned constructor (if any).
1317 */
1318 private static Constructor<?> getSerializableConstructor(Class<?> cl) {
1319 return ReflectionFactory.getReflectionFactory().newConstructorForSerialization(cl);
1320 }
1321
1322 /**
1323 * Returns the canonical constructor for the given record class, or null if
1324 * the not found ( which should never happen for correctly generated record
1325 * classes ).
1326 */
1327 private static MethodHandle canonicalRecordCtr(Class<?> cls) {
1328 assert cls.isRecord() : "Expected record, got: " + cls;
1329 Class<?>[] paramTypes = Arrays.stream(cls.getRecordComponents())
1330 .map(RecordComponent::getType)
1331 .toArray(Class<?>[]::new);
1332 try {
1333 Constructor<?> ctr = cls.getDeclaredConstructor(paramTypes);
1334 ctr.setAccessible(true);
1335 return MethodHandles.lookup().unreflectConstructor(ctr);
1336 } catch (IllegalAccessException | NoSuchMethodException e) {
1337 return null;
1338 }
1339 }
1340
1341 /**
1342 * Returns the canonical constructor, if the local class equivalent of this
1343 * stream class descriptor is a record class, otherwise null.
1344 */
1345 MethodHandle getRecordConstructor() {
1346 return canonicalCtr;
1347 }
1348
1349 /**
1350 * Returns non-static, non-abstract method with given signature provided it
1351 * is defined by or accessible (via inheritance) by the given class, or
1352 * null if no match found. Access checks are disabled on the returned
1353 * method (if any).
1354 */
1355 private static Method getInheritableMethod(Class<?> cl, String name,
1356 Class<?>[] argTypes,
1357 Class<?> returnType)
1358 {
1359 Method meth = null;
1360 Class<?> defCl = cl;
1361 while (defCl != null) {
1362 try {
1363 meth = defCl.getDeclaredMethod(name, argTypes);
1364 break;
1365 } catch (NoSuchMethodException ex) {
1366 defCl = defCl.getSuperclass();
1367 }
1368 }
1369
1370 if ((meth == null) || (meth.getReturnType() != returnType)) {
1371 return null;
1372 }
1373 meth.setAccessible(true);
1374 int mods = meth.getModifiers();
1375 if ((mods & (Modifier.STATIC | Modifier.ABSTRACT)) != 0) {
1376 return null;
1377 } else if ((mods & (Modifier.PUBLIC | Modifier.PROTECTED)) != 0) {
1378 return meth;
1379 } else if ((mods & Modifier.PRIVATE) != 0) {
1380 return (cl == defCl) ? meth : null;
1381 } else {
1382 return packageEquals(cl, defCl) ? meth : null;
1383 }
1384 }
1385
1386 /**
1387 * Returns non-static private method with given signature defined by given
1388 * class, or null if none found. Access checks are disabled on the
1389 * returned method (if any).
1390 */
1391 private static Method getPrivateMethod(Class<?> cl, String name,
1392 Class<?>[] argTypes,
1393 Class<?> returnType)
1394 {
1395 try {
1396 Method meth = cl.getDeclaredMethod(name, argTypes);
1397 meth.setAccessible(true);
1398 int mods = meth.getModifiers();
1399 return ((meth.getReturnType() == returnType) &&
1400 ((mods & Modifier.STATIC) == 0) &&
1401 ((mods & Modifier.PRIVATE) != 0)) ? meth : null;
1402 } catch (NoSuchMethodException ex) {
1403 return null;
1404 }
1405 }
1406
1407 /**
1408 * Returns true if classes are defined in the same runtime package, false
1409 * otherwise.
1410 */
1411 private static boolean packageEquals(Class<?> cl1, Class<?> cl2) {
1412 return cl1.getClassLoader() == cl2.getClassLoader() &&
1413 cl1.getPackageName() == cl2.getPackageName();
1414 }
1415
1416 /**
1417 * Compares class names for equality, ignoring package names. Returns true
1418 * if class names equal, false otherwise.
1419 */
1420 private static boolean classNamesEqual(String name1, String name2) {
1421 int idx1 = name1.lastIndexOf('.') + 1;
1422 int idx2 = name2.lastIndexOf('.') + 1;
1423 int len1 = name1.length() - idx1;
1424 int len2 = name2.length() - idx2;
1425 return len1 == len2 &&
1426 name1.regionMatches(idx1, name2, idx2, len1);
1427 }
1428
1429 /**
1430 * Returns JVM type signature for given list of parameters and return type.
1431 */
1432 private static String getMethodSignature(Class<?>[] paramTypes,
1433 Class<?> retType)
1434 {
1435 StringBuilder sb = new StringBuilder();
1436 sb.append('(');
1437 for (int i = 0; i < paramTypes.length; i++) {
1438 sb.append(paramTypes[i].descriptorString());
1439 }
1440 sb.append(')');
1441 sb.append(retType.descriptorString());
1442 return sb.toString();
1443 }
1444
1445 /**
1446 * Convenience method for throwing an exception that is either a
1447 * RuntimeException, Error, or of some unexpected type (in which case it is
1448 * wrapped inside an IOException).
1449 */
1450 private static void throwMiscException(Throwable th) throws IOException {
1451 if (th instanceof RuntimeException) {
1452 throw (RuntimeException) th;
1453 } else if (th instanceof Error) {
1454 throw (Error) th;
1455 } else {
1456 throw new IOException("unexpected exception type", th);
1457 }
1458 }
1459
1460 /**
1461 * Returns ObjectStreamField array describing the serializable fields of
1462 * the given class. Serializable fields backed by an actual field of the
1463 * class are represented by ObjectStreamFields with corresponding non-null
1464 * Field objects. Throws InvalidClassException if the (explicitly
1465 * declared) serializable fields are invalid.
1466 */
1467 private static ObjectStreamField[] getSerialFields(Class<?> cl)
1468 throws InvalidClassException
1469 {
1470 if (!Serializable.class.isAssignableFrom(cl))
1471 return NO_FIELDS;
1472
1473 ObjectStreamField[] fields;
1474 if (cl.isRecord()) {
1475 fields = getDefaultSerialFields(cl);
1476 Arrays.sort(fields);
1477 } else if (!Externalizable.class.isAssignableFrom(cl) &&
1478 !Proxy.isProxyClass(cl) &&
1479 !cl.isInterface()) {
1480 if ((fields = getDeclaredSerialFields(cl)) == null) {
1481 fields = getDefaultSerialFields(cl);
1482 }
1483 Arrays.sort(fields);
1484 } else {
1485 fields = NO_FIELDS;
1486 }
1487 return fields;
1488 }
1489
1490 /**
1491 * Returns serializable fields of given class as defined explicitly by a
1492 * "serialPersistentFields" field, or null if no appropriate
1493 * "serialPersistentFields" field is defined. Serializable fields backed
1494 * by an actual field of the class are represented by ObjectStreamFields
1495 * with corresponding non-null Field objects. For compatibility with past
1496 * releases, a "serialPersistentFields" field with a null value is
1497 * considered equivalent to not declaring "serialPersistentFields". Throws
1498 * InvalidClassException if the declared serializable fields are
1499 * invalid--e.g., if multiple fields share the same name.
1500 */
1501 private static ObjectStreamField[] getDeclaredSerialFields(Class<?> cl)
1502 throws InvalidClassException
1503 {
1504 ObjectStreamField[] serialPersistentFields = null;
1505 try {
1506 Field f = cl.getDeclaredField("serialPersistentFields");
1507 int mask = Modifier.PRIVATE | Modifier.STATIC | Modifier.FINAL;
1508 if ((f.getModifiers() & mask) == mask) {
1509 f.setAccessible(true);
1510 serialPersistentFields = (ObjectStreamField[]) f.get(null);
1511 }
1512 } catch (Exception ex) {
1513 }
1514 if (serialPersistentFields == null) {
1515 return null;
1516 } else if (serialPersistentFields.length == 0) {
1517 return NO_FIELDS;
1518 }
1519
1520 ObjectStreamField[] boundFields =
1521 new ObjectStreamField[serialPersistentFields.length];
1522 Set<String> fieldNames = HashSet.newHashSet(serialPersistentFields.length);
1523
1524 for (int i = 0; i < serialPersistentFields.length; i++) {
1525 ObjectStreamField spf = serialPersistentFields[i];
1526
1527 String fname = spf.getName();
1528 if (fieldNames.contains(fname)) {
1529 throw new InvalidClassException(
1530 "multiple serializable fields named " + fname);
1531 }
1532 fieldNames.add(fname);
1533
1534 try {
1535 Field f = cl.getDeclaredField(fname);
1536 if ((f.getType() == spf.getType()) &&
1537 ((f.getModifiers() & Modifier.STATIC) == 0))
1538 {
1539 boundFields[i] =
1540 new ObjectStreamField(f, spf.isUnshared(), true);
1541 }
1542 } catch (NoSuchFieldException ex) {
1543 }
1544 if (boundFields[i] == null) {
1545 boundFields[i] = new ObjectStreamField(
1546 fname, spf.getType(), spf.isUnshared());
1547 }
1548 }
1549 return boundFields;
1550 }
1551
1552 /**
1553 * Returns array of ObjectStreamFields corresponding to all non-static
1554 * non-transient fields declared by given class. Each ObjectStreamField
1555 * contains a Field object for the field it represents. If no default
1556 * serializable fields exist, NO_FIELDS is returned.
1557 */
1558 private static ObjectStreamField[] getDefaultSerialFields(Class<?> cl) {
1559 Field[] clFields = cl.getDeclaredFields();
1560 ArrayList<ObjectStreamField> list = new ArrayList<>();
1561 int mask = Modifier.STATIC | Modifier.TRANSIENT;
1562
1563 for (int i = 0; i < clFields.length; i++) {
1564 if ((clFields[i].getModifiers() & mask) == 0) {
1565 list.add(new ObjectStreamField(clFields[i], false, true));
1566 }
1567 }
1568 int size = list.size();
1569 return (size == 0) ? NO_FIELDS :
1570 list.toArray(new ObjectStreamField[size]);
1571 }
1572
1573 /**
1574 * Returns explicit serial version UID value declared by given class, or
1575 * null if none.
1576 */
1577 private static Long getDeclaredSUID(Class<?> cl) {
1578 try {
1579 Field f = cl.getDeclaredField("serialVersionUID");
1580 int mask = Modifier.STATIC | Modifier.FINAL;
1581 if ((f.getModifiers() & mask) == mask) {
1582 f.setAccessible(true);
1583 return f.getLong(null);
1584 }
1585 } catch (Exception ex) {
1586 }
1587 return null;
1588 }
1589
1590 /**
1591 * Computes the default serial version UID value for the given class.
1592 */
1593 private static long computeDefaultSUID(Class<?> cl) {
1594 if (!Serializable.class.isAssignableFrom(cl) || Proxy.isProxyClass(cl))
1595 {
1596 return 0L;
1597 }
1598
1599 try {
1600 ByteArrayOutputStream bout = new ByteArrayOutputStream();
1601 DataOutputStream dout = new DataOutputStream(bout);
1602
1603 dout.writeUTF(cl.getName());
1604
1605 int classMods = cl.getModifiers() &
1606 (Modifier.PUBLIC | Modifier.FINAL |
1607 Modifier.INTERFACE | Modifier.ABSTRACT);
1608
1609 /*
1610 * compensate for javac bug in which ABSTRACT bit was set for an
1611 * interface only if the interface declared methods
1612 */
1613 Method[] methods = cl.getDeclaredMethods();
1614 if ((classMods & Modifier.INTERFACE) != 0) {
1615 classMods = (methods.length > 0) ?
1616 (classMods | Modifier.ABSTRACT) :
1617 (classMods & ~Modifier.ABSTRACT);
1618 }
1619 dout.writeInt(classMods);
1620
1621 if (!cl.isArray()) {
1622 /*
1623 * compensate for change in 1.2FCS in which
1624 * Class.getInterfaces() was modified to return Cloneable and
1625 * Serializable for array classes.
1626 */
1627 Class<?>[] interfaces = cl.getInterfaces();
1628 String[] ifaceNames = new String[interfaces.length];
1629 for (int i = 0; i < interfaces.length; i++) {
1630 ifaceNames[i] = interfaces[i].getName();
1631 }
1632 Arrays.sort(ifaceNames);
1633 for (int i = 0; i < ifaceNames.length; i++) {
1634 dout.writeUTF(ifaceNames[i]);
1635 }
1636 }
1637
1638 Field[] fields = cl.getDeclaredFields();
1639 MemberSignature[] fieldSigs = new MemberSignature[fields.length];
1640 for (int i = 0; i < fields.length; i++) {
1641 fieldSigs[i] = new MemberSignature(fields[i]);
1642 }
1643 Arrays.sort(fieldSigs, new Comparator<>() {
1644 public int compare(MemberSignature ms1, MemberSignature ms2) {
1645 return ms1.name.compareTo(ms2.name);
1646 }
1647 });
1648 for (int i = 0; i < fieldSigs.length; i++) {
1649 MemberSignature sig = fieldSigs[i];
1650 int mods = sig.member.getModifiers() &
1651 (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
1652 Modifier.STATIC | Modifier.FINAL | Modifier.VOLATILE |
1653 Modifier.TRANSIENT);
1654 if (((mods & Modifier.PRIVATE) == 0) ||
1655 ((mods & (Modifier.STATIC | Modifier.TRANSIENT)) == 0))
1656 {
1657 dout.writeUTF(sig.name);
1658 dout.writeInt(mods);
1659 dout.writeUTF(sig.signature);
1660 }
1661 }
1662
1663 if (hasStaticInitializer(cl)) {
1664 dout.writeUTF("<clinit>");
1665 dout.writeInt(Modifier.STATIC);
1666 dout.writeUTF("()V");
1667 }
1668
1669 Constructor<?>[] cons = cl.getDeclaredConstructors();
1670 MemberSignature[] consSigs = new MemberSignature[cons.length];
1671 for (int i = 0; i < cons.length; i++) {
1672 consSigs[i] = new MemberSignature(cons[i]);
1673 }
1674 Arrays.sort(consSigs, new Comparator<>() {
1675 public int compare(MemberSignature ms1, MemberSignature ms2) {
1676 return ms1.signature.compareTo(ms2.signature);
1677 }
1678 });
1679 for (int i = 0; i < consSigs.length; i++) {
1680 MemberSignature sig = consSigs[i];
1681 int mods = sig.member.getModifiers() &
1682 (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
1683 Modifier.STATIC | Modifier.FINAL |
1684 Modifier.SYNCHRONIZED | Modifier.NATIVE |
1685 Modifier.ABSTRACT | Modifier.STRICT);
1686 if ((mods & Modifier.PRIVATE) == 0) {
1687 dout.writeUTF("<init>");
1688 dout.writeInt(mods);
1689 dout.writeUTF(sig.signature.replace('/', '.'));
1690 }
1691 }
1692
1693 MemberSignature[] methSigs = new MemberSignature[methods.length];
1694 for (int i = 0; i < methods.length; i++) {
1695 methSigs[i] = new MemberSignature(methods[i]);
1696 }
1697 Arrays.sort(methSigs, new Comparator<>() {
1698 public int compare(MemberSignature ms1, MemberSignature ms2) {
1699 int comp = ms1.name.compareTo(ms2.name);
1700 if (comp == 0) {
1701 comp = ms1.signature.compareTo(ms2.signature);
1702 }
1703 return comp;
1704 }
1705 });
1706 for (int i = 0; i < methSigs.length; i++) {
1707 MemberSignature sig = methSigs[i];
1708 int mods = sig.member.getModifiers() &
1709 (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
1710 Modifier.STATIC | Modifier.FINAL |
1711 Modifier.SYNCHRONIZED | Modifier.NATIVE |
1712 Modifier.ABSTRACT | Modifier.STRICT);
1713 if ((mods & Modifier.PRIVATE) == 0) {
1714 dout.writeUTF(sig.name);
1715 dout.writeInt(mods);
1716 dout.writeUTF(sig.signature.replace('/', '.'));
1717 }
1718 }
1719
1720 dout.flush();
1721
1722 MessageDigest md = MessageDigest.getInstance("SHA");
1723 byte[] hashBytes = md.digest(bout.toByteArray());
1724 long hash = 0;
1725 for (int i = Math.min(hashBytes.length, 8) - 1; i >= 0; i--) {
1726 hash = (hash << 8) | (hashBytes[i] & 0xFF);
1727 }
1728 return hash;
1729 } catch (IOException ex) {
1730 throw new InternalError(ex);
1731 } catch (NoSuchAlgorithmException ex) {
1732 throw new SecurityException(ex.getMessage());
1733 }
1734 }
1735
1736 /**
1737 * Returns true if the given class defines a static initializer method,
1738 * false otherwise.
1739 */
1740 private static native boolean hasStaticInitializer(Class<?> cl);
1741
1742 /**
1743 * Class for computing and caching field/constructor/method signatures
1744 * during serialVersionUID calculation.
1745 */
1746 private static final class MemberSignature {
1747
1748 public final Member member;
1749 public final String name;
1750 public final String signature;
1751
1752 public MemberSignature(Field field) {
1753 member = field;
1754 name = field.getName();
1755 signature = field.getType().descriptorString();
1756 }
1757
1758 public MemberSignature(Constructor<?> cons) {
1759 member = cons;
1760 name = cons.getName();
1761 signature = getMethodSignature(
1762 cons.getParameterTypes(), Void.TYPE);
1763 }
1764
1765 public MemberSignature(Method meth) {
1766 member = meth;
1767 name = meth.getName();
1768 signature = getMethodSignature(
1769 meth.getParameterTypes(), meth.getReturnType());
1770 }
1771 }
1772
1773 /**
1774 * Class for setting and retrieving serializable field values in batch.
1775 */
1776 // REMIND: dynamically generate these?
1777 private static final class FieldReflector {
1778
1779 /** handle for performing unsafe operations */
1780 private static final Unsafe UNSAFE = Unsafe.getUnsafe();
1781
1782 /** fields to operate on */
1783 private final ObjectStreamField[] fields;
1784 /** number of primitive fields */
1785 private final int numPrimFields;
1786 /** unsafe field keys for reading fields - may contain dupes */
1787 private final long[] readKeys;
1788 /** unsafe fields keys for writing fields - no dupes */
1789 private final long[] writeKeys;
1790 /** field data offsets */
1791 private final int[] offsets;
1792 /** field type codes */
1793 private final char[] typeCodes;
1794 /** field types */
1795 private final Class<?>[] types;
1796
1797 /**
1798 * Constructs FieldReflector capable of setting/getting values from the
1799 * subset of fields whose ObjectStreamFields contain non-null
1800 * reflective Field objects. ObjectStreamFields with null Fields are
1801 * treated as filler, for which get operations return default values
1802 * and set operations discard given values.
1803 */
1804 FieldReflector(ObjectStreamField[] fields) {
1805 this.fields = fields;
1806 int nfields = fields.length;
1807 readKeys = new long[nfields];
1808 writeKeys = new long[nfields];
1809 offsets = new int[nfields];
1810 typeCodes = new char[nfields];
1811 ArrayList<Class<?>> typeList = new ArrayList<>();
1812 Set<Long> usedKeys = new HashSet<>();
1813
1814
1815 for (int i = 0; i < nfields; i++) {
1816 ObjectStreamField f = fields[i];
1817 Field rf = f.getField();
1818 long key = (rf != null) ?
1819 UNSAFE.objectFieldOffset(rf) : Unsafe.INVALID_FIELD_OFFSET;
1820 readKeys[i] = key;
1821 writeKeys[i] = usedKeys.add(key) ?
1822 key : Unsafe.INVALID_FIELD_OFFSET;
1823 offsets[i] = f.getOffset();
1824 typeCodes[i] = f.getTypeCode();
1825 if (!f.isPrimitive()) {
1826 typeList.add((rf != null) ? rf.getType() : null);
1827 }
1828 }
1829
1830 types = typeList.toArray(new Class<?>[typeList.size()]);
1831 numPrimFields = nfields - types.length;
1832 }
1833
1834 /**
1835 * Returns list of ObjectStreamFields representing fields operated on
1836 * by this reflector. The shared/unshared values and Field objects
1837 * contained by ObjectStreamFields in the list reflect their bindings
1838 * to locally defined serializable fields.
1839 */
1840 ObjectStreamField[] getFields() {
1841 return fields;
1842 }
1843
1844 /**
1845 * Fetches the serializable primitive field values of object obj and
1846 * marshals them into byte array buf starting at offset 0. The caller
1847 * is responsible for ensuring that obj is of the proper type.
1848 */
1849 void getPrimFieldValues(Object obj, byte[] buf) {
1850 if (obj == null) {
1851 throw new NullPointerException();
1852 }
1853 /* assuming checkDefaultSerialize() has been called on the class
1854 * descriptor this FieldReflector was obtained from, no field keys
1855 * in array should be equal to Unsafe.INVALID_FIELD_OFFSET.
1856 */
1857 for (int i = 0; i < numPrimFields; i++) {
1858 long key = readKeys[i];
1859 int off = offsets[i];
1860 switch (typeCodes[i]) {
1861 case 'Z' -> ByteArray.setBoolean(buf, off, UNSAFE.getBoolean(obj, key));
1862 case 'B' -> buf[off] = UNSAFE.getByte(obj, key);
1863 case 'C' -> ByteArray.setChar(buf, off, UNSAFE.getChar(obj, key));
1864 case 'S' -> ByteArray.setShort(buf, off, UNSAFE.getShort(obj, key));
1865 case 'I' -> ByteArray.setInt(buf, off, UNSAFE.getInt(obj, key));
1866 case 'F' -> ByteArray.setFloat(buf, off, UNSAFE.getFloat(obj, key));
1867 case 'J' -> ByteArray.setLong(buf, off, UNSAFE.getLong(obj, key));
1868 case 'D' -> ByteArray.setDouble(buf, off, UNSAFE.getDouble(obj, key));
1869 default -> throw new InternalError();
1870 }
1871 }
1872 }
1873
1874 /**
1875 * Sets the serializable primitive fields of object obj using values
1876 * unmarshalled from byte array buf starting at offset 0. The caller
1877 * is responsible for ensuring that obj is of the proper type.
1878 */
1879 void setPrimFieldValues(Object obj, byte[] buf) {
1880 if (obj == null) {
1881 throw new NullPointerException();
1882 }
1883 for (int i = 0; i < numPrimFields; i++) {
1884 long key = writeKeys[i];
1885 if (key == Unsafe.INVALID_FIELD_OFFSET) {
1886 continue; // discard value
1887 }
1888 int off = offsets[i];
1889 switch (typeCodes[i]) {
1890 case 'Z' -> UNSAFE.putBoolean(obj, key, ByteArray.getBoolean(buf, off));
1891 case 'B' -> UNSAFE.putByte(obj, key, buf[off]);
1892 case 'C' -> UNSAFE.putChar(obj, key, ByteArray.getChar(buf, off));
1893 case 'S' -> UNSAFE.putShort(obj, key, ByteArray.getShort(buf, off));
1894 case 'I' -> UNSAFE.putInt(obj, key, ByteArray.getInt(buf, off));
1895 case 'F' -> UNSAFE.putFloat(obj, key, ByteArray.getFloat(buf, off));
1896 case 'J' -> UNSAFE.putLong(obj, key, ByteArray.getLong(buf, off));
1897 case 'D' -> UNSAFE.putDouble(obj, key, ByteArray.getDouble(buf, off));
1898 default -> throw new InternalError();
1899 }
1900 }
1901 }
1902
1903 /**
1904 * Fetches the serializable object field values of object obj and
1905 * stores them in array vals starting at offset 0. The caller is
1906 * responsible for ensuring that obj is of the proper type.
1907 */
1908 void getObjFieldValues(Object obj, Object[] vals) {
1909 if (obj == null) {
1910 throw new NullPointerException();
1911 }
1912 /* assuming checkDefaultSerialize() has been called on the class
1913 * descriptor this FieldReflector was obtained from, no field keys
1914 * in array should be equal to Unsafe.INVALID_FIELD_OFFSET.
1915 */
1916 for (int i = numPrimFields; i < fields.length; i++) {
1917 vals[offsets[i]] = switch (typeCodes[i]) {
1918 case 'L', '[' -> UNSAFE.getReference(obj, readKeys[i]);
1919 default -> throw new InternalError();
1920 };
1921 }
1922 }
1923
1924 /**
1925 * Checks that the given values, from array vals starting at offset 0,
1926 * are assignable to the given serializable object fields.
1927 * @throws ClassCastException if any value is not assignable
1928 */
1929 void checkObjectFieldValueTypes(Object obj, Object[] vals) {
1930 setObjFieldValues(obj, vals, true);
1931 }
1932
1933 /**
1934 * Sets the serializable object fields of object obj using values from
1935 * array vals starting at offset 0. The caller is responsible for
1936 * ensuring that obj is of the proper type; however, attempts to set a
1937 * field with a value of the wrong type will trigger an appropriate
1938 * ClassCastException.
1939 */
1940 void setObjFieldValues(Object obj, Object[] vals) {
1941 setObjFieldValues(obj, vals, false);
1942 }
1943
1944 private void setObjFieldValues(Object obj, Object[] vals, boolean dryRun) {
1945 if (obj == null) {
1946 throw new NullPointerException();
1947 }
1948 for (int i = numPrimFields; i < fields.length; i++) {
1949 long key = writeKeys[i];
1950 if (key == Unsafe.INVALID_FIELD_OFFSET) {
1951 continue; // discard value
1952 }
1953 switch (typeCodes[i]) {
1954 case 'L', '[' -> {
1955 Object val = vals[offsets[i]];
1956 if (val != null &&
1957 !types[i - numPrimFields].isInstance(val))
1958 {
1959 Field f = fields[i].getField();
1960 throw new ClassCastException(
1961 "cannot assign instance of " +
1962 val.getClass().getName() + " to field " +
1963 f.getDeclaringClass().getName() + "." +
1964 f.getName() + " of type " +
1965 f.getType().getName() + " in instance of " +
1966 obj.getClass().getName());
1967 }
1968 if (!dryRun)
1969 UNSAFE.putReference(obj, key, val);
1970 }
1971 default -> throw new InternalError();
1972 }
1973 }
1974 }
1975 }
1976
1977 /**
1978 * Matches given set of serializable fields with serializable fields
1979 * described by the given local class descriptor, and returns a
1980 * FieldReflector instance capable of setting/getting values from the
1981 * subset of fields that match (non-matching fields are treated as filler,
1982 * for which get operations return default values and set operations
1983 * discard given values). Throws InvalidClassException if unresolvable
1984 * type conflicts exist between the two sets of fields.
1985 */
1986 private static FieldReflector getReflector(ObjectStreamField[] fields,
1987 ObjectStreamClass localDesc)
1988 throws InvalidClassException
1989 {
1990 // class irrelevant if no fields
1991 Class<?> cl = (localDesc != null && fields.length > 0) ?
1992 localDesc.cl : Void.class;
1993
1994 var clReflectors = Caches.reflectors.get(cl);
1995 var key = new FieldReflectorKey(fields);
1996 var reflector = clReflectors.get(key);
1997 if (reflector == null) {
1998 reflector = new FieldReflector(matchFields(fields, localDesc));
1999 var oldReflector = clReflectors.putIfAbsent(key, reflector);
2000 if (oldReflector != null) {
2001 reflector = oldReflector;
2002 }
2003 }
2004 return reflector;
2005 }
2006
2007 /**
2008 * FieldReflector cache lookup key. Keys are considered equal if they
2009 * refer to equivalent field formats.
2010 */
2011 private static class FieldReflectorKey {
2012
2013 private final String[] sigs;
2014 private final int hash;
2015
2016 FieldReflectorKey(ObjectStreamField[] fields)
2017 {
2018 sigs = new String[2 * fields.length];
2019 for (int i = 0, j = 0; i < fields.length; i++) {
2020 ObjectStreamField f = fields[i];
2021 sigs[j++] = f.getName();
2022 sigs[j++] = f.getSignature();
2023 }
2024 hash = Arrays.hashCode(sigs);
2025 }
2026
2027 public int hashCode() {
2028 return hash;
2029 }
2030
2031 public boolean equals(Object obj) {
2032 return obj == this ||
2033 obj instanceof FieldReflectorKey other &&
2034 Arrays.equals(sigs, other.sigs);
2035 }
2036 }
2037
2038 /**
2039 * Matches given set of serializable fields with serializable fields
2040 * obtained from the given local class descriptor (which contain bindings
2041 * to reflective Field objects). Returns list of ObjectStreamFields in
2042 * which each ObjectStreamField whose signature matches that of a local
2043 * field contains a Field object for that field; unmatched
2044 * ObjectStreamFields contain null Field objects. Shared/unshared settings
2045 * of the returned ObjectStreamFields also reflect those of matched local
2046 * ObjectStreamFields. Throws InvalidClassException if unresolvable type
2047 * conflicts exist between the two sets of fields.
2048 */
2049 private static ObjectStreamField[] matchFields(ObjectStreamField[] fields,
2050 ObjectStreamClass localDesc)
2051 throws InvalidClassException
2052 {
2053 ObjectStreamField[] localFields = (localDesc != null) ?
2054 localDesc.fields : NO_FIELDS;
2055
2056 /*
2057 * Even if fields == localFields, we cannot simply return localFields
2058 * here. In previous implementations of serialization,
2059 * ObjectStreamField.getType() returned Object.class if the
2060 * ObjectStreamField represented a non-primitive field and belonged to
2061 * a non-local class descriptor. To preserve this (questionable)
2062 * behavior, the ObjectStreamField instances returned by matchFields
2063 * cannot report non-primitive types other than Object.class; hence
2064 * localFields cannot be returned directly.
2065 */
2066
2067 ObjectStreamField[] matches = new ObjectStreamField[fields.length];
2068 for (int i = 0; i < fields.length; i++) {
2069 ObjectStreamField f = fields[i], m = null;
2070 for (int j = 0; j < localFields.length; j++) {
2071 ObjectStreamField lf = localFields[j];
2072 if (f.getName().equals(lf.getName())) {
2073 if ((f.isPrimitive() || lf.isPrimitive()) &&
2074 f.getTypeCode() != lf.getTypeCode())
2075 {
2076 throw new InvalidClassException(localDesc.name,
2077 "incompatible types for field " + f.getName());
2078 }
2079 if (lf.getField() != null) {
2080 m = new ObjectStreamField(
2081 lf.getField(), lf.isUnshared(), false);
2082 } else {
2083 m = new ObjectStreamField(
2084 lf.getName(), lf.getSignature(), lf.isUnshared());
2085 }
2086 }
2087 }
2088 if (m == null) {
2089 m = new ObjectStreamField(
2090 f.getName(), f.getSignature(), false);
2091 }
2092 m.setOffset(f.getOffset());
2093 matches[i] = m;
2094 }
2095 return matches;
2096 }
2097
2098 /**
2099 * A LRA cache of record deserialization constructors.
2100 */
2101 @SuppressWarnings("serial")
2102 private static final class DeserializationConstructorsCache
2103 extends ConcurrentHashMap<DeserializationConstructorsCache.Key, MethodHandle> {
2104
2105 // keep max. 10 cached entries - when the 11th element is inserted the oldest
2106 // is removed and 10 remains - 11 is the biggest map size where internal
2107 // table of 16 elements is sufficient (inserting 12th element would resize it to 32)
2108 private static final int MAX_SIZE = 10;
2109 private Key.Impl first, last; // first and last in FIFO queue
2110
2111 DeserializationConstructorsCache() {
2112 // start small - if there is more than one shape of ObjectStreamClass
2113 // deserialized, there will typically be two (current version and previous version)
2114 super(2);
2115 }
2116
2117 MethodHandle get(ObjectStreamField[] fields) {
2118 return get(new Key.Lookup(fields));
2119 }
2120
2121 synchronized MethodHandle putIfAbsentAndGet(ObjectStreamField[] fields, MethodHandle mh) {
2122 Key.Impl key = new Key.Impl(fields);
2123 var oldMh = putIfAbsent(key, mh);
2124 if (oldMh != null) return oldMh;
2125 // else we did insert new entry -> link the new key as last
2126 if (last == null) {
2127 last = first = key;
2128 } else {
2129 last = (last.next = key);
2130 }
2131 // may need to remove first
2132 if (size() > MAX_SIZE) {
2133 assert first != null;
2134 remove(first);
2135 first = first.next;
2136 if (first == null) {
2137 last = null;
2138 }
2139 }
2140 return mh;
2141 }
2142
2143 // a key composed of ObjectStreamField[] names and types
2144 abstract static class Key {
2145 abstract int length();
2146 abstract String fieldName(int i);
2147 abstract Class<?> fieldType(int i);
2148
2149 @Override
2150 public final int hashCode() {
2151 int n = length();
2152 int h = 0;
2153 for (int i = 0; i < n; i++) h = h * 31 + fieldType(i).hashCode();
2154 for (int i = 0; i < n; i++) h = h * 31 + fieldName(i).hashCode();
2155 return h;
2156 }
2157
2158 @Override
2159 public final boolean equals(Object obj) {
2160 if (!(obj instanceof Key other)) return false;
2161 int n = length();
2162 if (n != other.length()) return false;
2163 for (int i = 0; i < n; i++) if (fieldType(i) != other.fieldType(i)) return false;
2164 for (int i = 0; i < n; i++) if (!fieldName(i).equals(other.fieldName(i))) return false;
2165 return true;
2166 }
2167
2168 // lookup key - just wraps ObjectStreamField[]
2169 static final class Lookup extends Key {
2170 final ObjectStreamField[] fields;
2171
2172 Lookup(ObjectStreamField[] fields) { this.fields = fields; }
2173
2174 @Override
2175 int length() { return fields.length; }
2176
2177 @Override
2178 String fieldName(int i) { return fields[i].getName(); }
2179
2180 @Override
2181 Class<?> fieldType(int i) { return fields[i].getType(); }
2182 }
2183
2184 // real key - copies field names and types and forms FIFO queue in cache
2185 static final class Impl extends Key {
2186 Impl next;
2187 final String[] fieldNames;
2188 final Class<?>[] fieldTypes;
2189
2190 Impl(ObjectStreamField[] fields) {
2191 this.fieldNames = new String[fields.length];
2192 this.fieldTypes = new Class<?>[fields.length];
2193 for (int i = 0; i < fields.length; i++) {
2194 fieldNames[i] = fields[i].getName();
2195 fieldTypes[i] = fields[i].getType();
2196 }
2197 }
2198
2199 @Override
2200 int length() { return fieldNames.length; }
2201
2202 @Override
2203 String fieldName(int i) { return fieldNames[i]; }
2204
2205 @Override
2206 Class<?> fieldType(int i) { return fieldTypes[i]; }
2207 }
2208 }
2209 }
2210
2211 /** Record specific support for retrieving and binding stream field values. */
2212 static final class RecordSupport {
2213 /**
2214 * Returns canonical record constructor adapted to take two arguments:
2215 * {@code (byte[] primValues, Object[] objValues)}
2216 * and return
2217 * {@code Object}
2218 */
2219 static MethodHandle deserializationCtr(ObjectStreamClass desc) {
2220 // check the cached value 1st
2221 MethodHandle mh = desc.deserializationCtr;
2222 if (mh != null) return mh;
2223 mh = desc.deserializationCtrs.get(desc.getFields(false));
2224 if (mh != null) return desc.deserializationCtr = mh;
2225
2226 // retrieve record components
2227 RecordComponent[] recordComponents = desc.forClass().getRecordComponents();
2228
2229 // retrieve the canonical constructor
2230 // (T1, T2, ..., Tn):TR
2231 mh = desc.getRecordConstructor();
2232
2233 // change return type to Object
2234 // (T1, T2, ..., Tn):TR -> (T1, T2, ..., Tn):Object
2235 mh = mh.asType(mh.type().changeReturnType(Object.class));
2236
2237 // drop last 2 arguments representing primValues and objValues arrays
2238 // (T1, T2, ..., Tn):Object -> (T1, T2, ..., Tn, byte[], Object[]):Object
2239 mh = MethodHandles.dropArguments(mh, mh.type().parameterCount(), byte[].class, Object[].class);
2240
2241 for (int i = recordComponents.length-1; i >= 0; i--) {
2242 String name = recordComponents[i].getName();
2243 Class<?> type = recordComponents[i].getType();
2244 // obtain stream field extractor that extracts argument at
2245 // position i (Ti+1) from primValues and objValues arrays
2246 // (byte[], Object[]):Ti+1
2247 MethodHandle combiner = streamFieldExtractor(name, type, desc);
2248 // fold byte[] privValues and Object[] objValues into argument at position i (Ti+1)
2249 // (..., Ti, Ti+1, byte[], Object[]):Object -> (..., Ti, byte[], Object[]):Object
2250 mh = MethodHandles.foldArguments(mh, i, combiner);
2251 }
2252 // what we are left with is a MethodHandle taking just the primValues
2253 // and objValues arrays and returning the constructed record instance
2254 // (byte[], Object[]):Object
2255
2256 // store it into cache and return the 1st value stored
2257 return desc.deserializationCtr =
2258 desc.deserializationCtrs.putIfAbsentAndGet(desc.getFields(false), mh);
2259 }
2260
2261 /** Returns the number of primitive fields for the given descriptor. */
2262 private static int numberPrimValues(ObjectStreamClass desc) {
2263 ObjectStreamField[] fields = desc.getFields();
2264 int primValueCount = 0;
2265 for (int i = 0; i < fields.length; i++) {
2266 if (fields[i].isPrimitive())
2267 primValueCount++;
2268 else
2269 break; // can be no more
2270 }
2271 return primValueCount;
2272 }
2273
2274 /**
2275 * Returns extractor MethodHandle taking the primValues and objValues arrays
2276 * and extracting the argument of canonical constructor with given name and type
2277 * or producing default value for the given type if the field is absent.
2278 */
2279 private static MethodHandle streamFieldExtractor(String pName,
2280 Class<?> pType,
2281 ObjectStreamClass desc) {
2282 ObjectStreamField[] fields = desc.getFields(false);
2283
2284 for (int i = 0; i < fields.length; i++) {
2285 ObjectStreamField f = fields[i];
2286 String fName = f.getName();
2287 if (!fName.equals(pName))
2288 continue;
2289
2290 Class<?> fType = f.getField().getType();
2291 if (!pType.isAssignableFrom(fType))
2292 throw new InternalError(fName + " unassignable, pType:" + pType + ", fType:" + fType);
2293
2294 if (f.isPrimitive()) {
2295 // (byte[], int):fType
2296 MethodHandle mh = PRIM_VALUE_EXTRACTORS.get(fType);
2297 if (mh == null) {
2298 throw new InternalError("Unexpected type: " + fType);
2299 }
2300 // bind offset
2301 // (byte[], int):fType -> (byte[]):fType
2302 mh = MethodHandles.insertArguments(mh, 1, f.getOffset());
2303 // drop objValues argument
2304 // (byte[]):fType -> (byte[], Object[]):fType
2305 mh = MethodHandles.dropArguments(mh, 1, Object[].class);
2306 // adapt return type to pType
2307 // (byte[], Object[]):fType -> (byte[], Object[]):pType
2308 if (pType != fType) {
2309 mh = mh.asType(mh.type().changeReturnType(pType));
2310 }
2311 return mh;
2312 } else { // reference
2313 // (Object[], int):Object
2314 MethodHandle mh = MethodHandles.arrayElementGetter(Object[].class);
2315 // bind index
2316 // (Object[], int):Object -> (Object[]):Object
2317 mh = MethodHandles.insertArguments(mh, 1, i - numberPrimValues(desc));
2318 // drop primValues argument
2319 // (Object[]):Object -> (byte[], Object[]):Object
2320 mh = MethodHandles.dropArguments(mh, 0, byte[].class);
2321 // adapt return type to pType
2322 // (byte[], Object[]):Object -> (byte[], Object[]):pType
2323 if (pType != Object.class) {
2324 mh = mh.asType(mh.type().changeReturnType(pType));
2325 }
2326 return mh;
2327 }
2328 }
2329
2330 // return default value extractor if no field matches pName
2331 return MethodHandles.empty(MethodType.methodType(pType, byte[].class, Object[].class));
2332 }
2333
2334 private static final Map<Class<?>, MethodHandle> PRIM_VALUE_EXTRACTORS;
2335 static {
2336 var lkp = MethodHandles.lookup();
2337 try {
2338 PRIM_VALUE_EXTRACTORS = Map.of(
2339 byte.class, MethodHandles.arrayElementGetter(byte[].class),
2340 short.class, lkp.findStatic(ByteArray.class, "getShort", MethodType.methodType(short.class, byte[].class, int.class)),
2341 int.class, lkp.findStatic(ByteArray.class, "getInt", MethodType.methodType(int.class, byte[].class, int.class)),
2342 long.class, lkp.findStatic(ByteArray.class, "getLong", MethodType.methodType(long.class, byte[].class, int.class)),
2343 float.class, lkp.findStatic(ByteArray.class, "getFloat", MethodType.methodType(float.class, byte[].class, int.class)),
2344 double.class, lkp.findStatic(ByteArray.class, "getDouble", MethodType.methodType(double.class, byte[].class, int.class)),
2345 char.class, lkp.findStatic(ByteArray.class, "getChar", MethodType.methodType(char.class, byte[].class, int.class)),
2346 boolean.class, lkp.findStatic(ByteArray.class, "getBoolean", MethodType.methodType(boolean.class, byte[].class, int.class))
2347 );
2348 } catch (NoSuchMethodException | IllegalAccessException e) {
2349 throw new InternalError("Can't lookup " + ByteArray.class.getName() + ".getXXX", e);
2350 }
2351 }
2352 }
2353 }