1 /*
2 * Copyright (c) 1996, 2025, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2024, Alibaba Group Holding Limited. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation. Oracle designates this
9 * particular file as subject to the "Classpath" exception as provided
10 * by Oracle in the LICENSE file that accompanied this code.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
23 * or visit www.oracle.com if you need additional information or have any
24 * questions.
25 */
26
27 package java.io;
28
29 import java.lang.runtime.ExactConversionsSupport;
30
31 import java.util.ArrayList;
32 import java.util.Arrays;
33 import java.util.List;
34 import java.util.Objects;
35 import java.util.StringJoiner;
36
37 import jdk.internal.util.ByteArray;
38 import jdk.internal.access.JavaLangAccess;
39 import jdk.internal.access.SharedSecrets;
40
41 import static jdk.internal.util.ModifiedUtf.putChar;
42 import static jdk.internal.util.ModifiedUtf.utfLen;
43
44 /**
45 * An ObjectOutputStream writes primitive data types and graphs of Java objects
46 * to an OutputStream. The objects can be read (reconstituted) using an
47 * ObjectInputStream. Persistent storage of objects can be accomplished by
48 * using a file for the stream. If the stream is a network socket stream, the
49 * objects can be reconstituted on another host or in another process.
50 *
51 * <p>Only objects that support the java.io.Serializable interface can be
52 * written to streams. The class of each serializable object is encoded
53 * including the class name and signature of the class, the values of the
54 * object's fields and arrays, and the closure of any other objects referenced
55 * from the initial objects.
56 *
57 * <p>The method writeObject is used to write an object to the stream. Any
58 * object, including Strings and arrays, is written with writeObject. Multiple
59 * objects or primitives can be written to the stream. The objects must be
60 * read back from the corresponding ObjectInputstream with the same types and
61 * in the same order as they were written.
62 *
63 * <p>Primitive data types can also be written to the stream using the
64 * appropriate methods from DataOutput. Strings can also be written using the
65 * writeUTF method.
66 *
67 * <p>The default serialization mechanism for an object writes the class of the
68 * object, the class signature, and the values of all non-transient and
69 * non-static fields. References to other objects (except in transient or
70 * static fields) cause those objects to be written also. Multiple references
71 * to a single object are encoded using a reference sharing mechanism so that
72 * graphs of objects can be restored to the same shape as when the original was
73 * written.
74 *
75 * <p>For example to write an object that can be read by the example in
76 * {@link ObjectInputStream}:
77 * {@snippet lang="java":
78 * try (FileOutputStream fos = new FileOutputStream("t.tmp");
79 * ObjectOutputStream oos = new ObjectOutputStream(fos)) {
80 * oos.writeObject("Today");
81 * oos.writeObject(LocalDateTime.now());
82 * } catch (Exception ex) {
83 * // handle exception
84 * }
85 * }
86 *
87 * <p>Serializable classes that require special handling during the
88 * serialization and deserialization process should implement methods
89 * with the following signatures:
90 *
91 * {@snippet lang="java":
92 * private void readObject(java.io.ObjectInputStream stream)
93 * throws IOException, ClassNotFoundException;
94 * private void writeObject(java.io.ObjectOutputStream stream)
95 * throws IOException;
96 * private void readObjectNoData()
97 * throws ObjectStreamException;
98 * }
99 *
100 * <p>The method name, modifiers, return type, and number and type of
101 * parameters must match exactly for the method to be used by
102 * serialization or deserialization. The methods should only be
103 * declared to throw checked exceptions consistent with these
104 * signatures.
105 *
106 * <p>The writeObject method is responsible for writing the state of the object
107 * for its particular class so that the corresponding readObject method can
108 * restore it. The method does not need to concern itself with the state
109 * belonging to the object's superclasses or subclasses. State is saved by
110 * writing the individual fields to the ObjectOutputStream using the
111 * writeObject method or by using the methods for primitive data types
112 * supported by DataOutput.
113 *
114 * <p>Serialization does not write out the fields of any object that does not
115 * implement the java.io.Serializable interface. Subclasses of Objects that
116 * are not serializable can be serializable. In this case the non-serializable
117 * class must have a no-arg constructor to allow its fields to be initialized.
118 * In this case it is the responsibility of the subclass to save and restore
119 * the state of the non-serializable class. It is frequently the case that the
120 * fields of that class are accessible (public, package, or protected) or that
121 * there are get and set methods that can be used to restore the state.
122 *
123 * <p>Serialization of an object can be prevented by implementing writeObject
124 * and readObject methods that throw the NotSerializableException. The
125 * exception will be caught by the ObjectOutputStream and abort the
126 * serialization process.
127 *
128 * <p>Implementing the Externalizable interface allows the object to assume
129 * complete control over the contents and format of the object's serialized
130 * form. The methods of the Externalizable interface, writeExternal and
131 * readExternal, are called to save and restore the objects state. When
132 * implemented by a class they can write and read their own state using all of
133 * the methods of ObjectOutput and ObjectInput. It is the responsibility of
134 * the objects to handle any versioning that occurs.
135 *
136 * <p>Enum constants are serialized differently than ordinary serializable or
137 * externalizable objects. The serialized form of an enum constant consists
138 * solely of its name; field values of the constant are not transmitted. To
139 * serialize an enum constant, ObjectOutputStream writes the string returned by
140 * the constant's name method. Like other serializable or externalizable
141 * objects, enum constants can function as the targets of back references
142 * appearing subsequently in the serialization stream. The process by which
143 * enum constants are serialized cannot be customized; any class-specific
144 * writeObject and writeReplace methods defined by enum types are ignored
145 * during serialization. Similarly, any serialPersistentFields or
146 * serialVersionUID field declarations are also ignored--all enum types have a
147 * fixed serialVersionUID of 0L.
148 *
149 * <p>Primitive data, excluding serializable fields and externalizable data, is
150 * written to the ObjectOutputStream in block-data records. A block data record
151 * is composed of a header and data. The block data header consists of a marker
152 * and the number of bytes to follow the header. Consecutive primitive data
153 * writes are merged into one block-data record. The blocking factor used for
154 * a block-data record will be 1024 bytes. Each block-data record will be
155 * filled up to 1024 bytes, or be written whenever there is a termination of
156 * block-data mode. Calls to the ObjectOutputStream methods writeObject,
157 * defaultWriteObject and writeFields initially terminate any existing
158 * block-data record.
159 *
160 * <p>Records are serialized differently than ordinary serializable or externalizable
161 * objects, see <a href="ObjectInputStream.html#record-serialization">record serialization</a>.
162 *
163 * @spec serialization/index.html Java Object Serialization Specification
164 * @author Mike Warres
165 * @author Roger Riggs
166 * @see java.io.DataOutput
167 * @see java.io.ObjectInputStream
168 * @see java.io.Serializable
169 * @see java.io.Externalizable
170 * @see <a href="{@docRoot}/../specs/serialization/output.html">
171 * <cite>Java Object Serialization Specification,</cite> Section 2, "Object Output Classes"</a>
172 * @since 1.1
173 */
174 public class ObjectOutputStream
175 extends OutputStream implements ObjectOutput, ObjectStreamConstants
176 {
177 private static final JavaLangAccess JLA = SharedSecrets.getJavaLangAccess();
178
179 /** filter stream for handling block data conversion */
180 private final BlockDataOutputStream bout;
181 /** obj -> wire handle map */
182 private final HandleTable handles;
183 /** obj -> replacement obj map */
184 private final ReplaceTable subs;
185 /** stream protocol version */
186 private int protocol = PROTOCOL_VERSION_2;
187 /** recursion depth */
188 private int depth;
189
190 /** buffer for writing primitive field values */
191 private byte[] primVals;
192
193 /** if true, invoke writeObjectOverride() instead of writeObject() */
194 private final boolean enableOverride;
195 /** if true, invoke replaceObject() */
196 private boolean enableReplace;
197
198 // values below valid only during upcalls to writeObject()/writeExternal()
199 /**
200 * Context during upcalls to class-defined writeObject methods; holds
201 * object currently being serialized and descriptor for current class.
202 * Null when not during writeObject upcall.
203 */
204 private SerialCallbackContext curContext;
205 /** current PutField object */
206 private PutFieldImpl curPut;
207
208 /** custom storage for debug trace info */
209 private final DebugTraceInfoStack debugInfoStack;
210
211 /**
212 * value of "sun.io.serialization.extendedDebugInfo" property,
213 * as true or false for extended information about exception's place
214 */
215 private static final boolean extendedDebugInfo =
216 Boolean.getBoolean("sun.io.serialization.extendedDebugInfo");
217
218 /**
219 * Creates an ObjectOutputStream that writes to the specified OutputStream.
220 * This constructor writes the serialization stream header to the
221 * underlying stream; callers may wish to flush the stream immediately to
222 * ensure that constructors for receiving ObjectInputStreams will not block
223 * when reading the header.
224 *
225 * @param out output stream to write to
226 * @throws IOException if an I/O error occurs while writing stream header
227 * @throws NullPointerException if {@code out} is {@code null}
228 * @since 1.4
229 * @see ObjectOutputStream#ObjectOutputStream()
230 * @see ObjectOutputStream#putFields()
231 * @see ObjectInputStream#ObjectInputStream(InputStream)
232 */
233 @SuppressWarnings("this-escape")
234 public ObjectOutputStream(OutputStream out) throws IOException {
235 bout = new BlockDataOutputStream(out);
236 handles = new HandleTable(10, (float) 3.00);
237 subs = new ReplaceTable(10, (float) 3.00);
238 enableOverride = false;
239 writeStreamHeader();
240 bout.setBlockDataMode(true);
241 if (extendedDebugInfo) {
242 debugInfoStack = new DebugTraceInfoStack();
243 } else {
244 debugInfoStack = null;
245 }
246 }
247
248 /**
249 * Provide a way for subclasses that are completely reimplementing
250 * ObjectOutputStream to not have to allocate private data just used by
251 * this implementation of ObjectOutputStream.
252 *
253 * @throws IOException if an I/O error occurs while creating this stream
254 */
255 protected ObjectOutputStream() throws IOException {
256 bout = null;
257 handles = null;
258 subs = null;
259 enableOverride = true;
260 debugInfoStack = null;
261 }
262
263 /**
264 * Specify stream protocol version to use when writing the stream.
265 *
266 * <p>This routine provides a hook to enable the current version of
267 * Serialization to write in a format that is backwards compatible to a
268 * previous version of the stream format.
269 *
270 * <p>Every effort will be made to avoid introducing additional
271 * backwards incompatibilities; however, sometimes there is no
272 * other alternative.
273 *
274 * @param version use ProtocolVersion from java.io.ObjectStreamConstants.
275 * @throws IllegalStateException if called after any objects
276 * have been serialized.
277 * @throws IllegalArgumentException if invalid version is passed in.
278 * @throws IOException if I/O errors occur
279 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
280 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_2
281 * @since 1.2
282 */
283 public void useProtocolVersion(int version) throws IOException {
284 if (handles.size() != 0) {
285 // REMIND: implement better check for pristine stream?
286 throw new IllegalStateException("stream non-empty");
287 }
288 switch (version) {
289 case PROTOCOL_VERSION_1:
290 case PROTOCOL_VERSION_2:
291 protocol = version;
292 break;
293
294 default:
295 throw new IllegalArgumentException(
296 "unknown version: " + version);
297 }
298 }
299
300 /**
301 * Write the specified object to the ObjectOutputStream. The class of the
302 * object, the signature of the class, and the values of the non-transient
303 * and non-static fields of the class and all of its supertypes are
304 * written. Default serialization for a class can be overridden using the
305 * writeObject and the readObject methods. Objects referenced by this
306 * object are written transitively so that a complete equivalent graph of
307 * objects can be reconstructed by an ObjectInputStream.
308 *
309 * <p>Exceptions are thrown for problems with the OutputStream and for
310 * classes that should not be serialized. All exceptions are fatal to the
311 * OutputStream, which is left in an indeterminate state, and it is up to
312 * the caller to ignore or recover the stream state.
313 *
314 * @throws InvalidClassException Something is wrong with a class used by
315 * serialization.
316 * @throws NotSerializableException Some object to be serialized does not
317 * implement the java.io.Serializable interface.
318 * @throws IOException Any exception thrown by the underlying
319 * OutputStream.
320 */
321 public final void writeObject(Object obj) throws IOException {
322 if (enableOverride) {
323 writeObjectOverride(obj);
324 return;
325 }
326 try {
327 writeObject0(obj, false);
328 } catch (IOException ex) {
329 if (depth == 0) {
330 writeFatalException(ex);
331 }
332 throw ex;
333 }
334 }
335
336 /**
337 * Method used by subclasses to override the default writeObject method.
338 * This method is called by trusted subclasses of ObjectOutputStream that
339 * constructed ObjectOutputStream using the protected no-arg constructor.
340 * The subclass is expected to provide an override method with the modifier
341 * "final".
342 *
343 * @param obj object to be written to the underlying stream
344 * @throws IOException if there are I/O errors while writing to the
345 * underlying stream
346 * @see #ObjectOutputStream()
347 * @see #writeObject(Object)
348 * @since 1.2
349 */
350 protected void writeObjectOverride(Object obj) throws IOException {
351 }
352
353 /**
354 * Writes an "unshared" object to the ObjectOutputStream. This method is
355 * identical to writeObject, except that it always writes the given object
356 * as a new, unique object in the stream (as opposed to a back-reference
357 * pointing to a previously serialized instance). Specifically:
358 * <ul>
359 * <li>An object written via writeUnshared is always serialized in the
360 * same manner as a newly appearing object (an object that has not
361 * been written to the stream yet), regardless of whether or not the
362 * object has been written previously.
363 *
364 * <li>If writeObject is used to write an object that has been previously
365 * written with writeUnshared, the previous writeUnshared operation
366 * is treated as if it were a write of a separate object. In other
367 * words, ObjectOutputStream will never generate back-references to
368 * object data written by calls to writeUnshared.
369 * </ul>
370 * While writing an object via writeUnshared does not in itself guarantee a
371 * unique reference to the object when it is deserialized, it allows a
372 * single object to be defined multiple times in a stream, so that multiple
373 * calls to readUnshared by the receiver will not conflict. Note that the
374 * rules described above only apply to the base-level object written with
375 * writeUnshared, and not to any transitively referenced sub-objects in the
376 * object graph to be serialized.
377 *
378 * @param obj object to write to stream
379 * @throws NotSerializableException if an object in the graph to be
380 * serialized does not implement the Serializable interface
381 * @throws InvalidClassException if a problem exists with the class of an
382 * object to be serialized
383 * @throws IOException if an I/O error occurs during serialization
384 * @since 1.4
385 */
386 public void writeUnshared(Object obj) throws IOException {
387 try {
388 writeObject0(obj, true);
389 } catch (IOException ex) {
390 if (depth == 0) {
391 writeFatalException(ex);
392 }
393 throw ex;
394 }
395 }
396
397 /**
398 * Write the non-static and non-transient fields of the current class to
399 * this stream. This may only be called from the writeObject method of the
400 * class being serialized. It will throw the NotActiveException if it is
401 * called otherwise.
402 *
403 * @throws IOException if I/O errors occur while writing to the underlying
404 * {@code OutputStream}
405 */
406 public void defaultWriteObject() throws IOException {
407 SerialCallbackContext ctx = curContext;
408 if (ctx == null) {
409 throw new NotActiveException("not in call to writeObject");
410 }
411 Object curObj = ctx.getObj();
412 ObjectStreamClass curDesc = ctx.getDesc();
413 bout.setBlockDataMode(false);
414 defaultWriteFields(curObj, curDesc);
415 bout.setBlockDataMode(true);
416 }
417
418 /**
419 * Retrieve the object used to buffer persistent fields to be written to
420 * the stream. The fields will be written to the stream when writeFields
421 * method is called.
422 *
423 * @return an instance of the class Putfield that holds the serializable
424 * fields
425 * @throws IOException if I/O errors occur
426 * @since 1.2
427 */
428 public ObjectOutputStream.PutField putFields() throws IOException {
429 if (curPut == null) {
430 SerialCallbackContext ctx = curContext;
431 if (ctx == null) {
432 throw new NotActiveException("not in call to writeObject");
433 }
434 ctx.checkAndSetUsed();
435 ObjectStreamClass curDesc = ctx.getDesc();
436 curPut = new PutFieldImpl(curDesc);
437 }
438 return curPut;
439 }
440
441 /**
442 * Write the buffered fields to the stream.
443 *
444 * @throws IOException if I/O errors occur while writing to the underlying
445 * stream
446 * @throws NotActiveException Called when a classes writeObject method was
447 * not called to write the state of the object.
448 * @since 1.2
449 */
450 public void writeFields() throws IOException {
451 if (curPut == null) {
452 throw new NotActiveException("no current PutField object");
453 }
454 bout.setBlockDataMode(false);
455 curPut.writeFields();
456 bout.setBlockDataMode(true);
457 }
458
459 /**
460 * Reset will disregard the state of any objects already written to the
461 * stream. The state is reset to be the same as a new ObjectOutputStream.
462 * The current point in the stream is marked as reset so the corresponding
463 * ObjectInputStream will be reset at the same point. Objects previously
464 * written to the stream will not be referred to as already being in the
465 * stream. They will be written to the stream again.
466 *
467 * @throws IOException if reset() is invoked while serializing an object.
468 */
469 public void reset() throws IOException {
470 if (depth != 0) {
471 throw new IOException("stream active");
472 }
473 bout.setBlockDataMode(false);
474 bout.writeByte(TC_RESET);
475 clear();
476 bout.setBlockDataMode(true);
477 }
478
479 /**
480 * Subclasses may implement this method to allow class data to be stored in
481 * the stream. By default this method does nothing. The corresponding
482 * method in ObjectInputStream is resolveClass. This method is called
483 * exactly once for each unique class in the stream. The class name and
484 * signature will have already been written to the stream. This method may
485 * make free use of the ObjectOutputStream to save any representation of
486 * the class it deems suitable (for example, the bytes of the class file).
487 * The resolveClass method in the corresponding subclass of
488 * ObjectInputStream must read and use any data or objects written by
489 * annotateClass.
490 *
491 * @param cl the class to annotate custom data for
492 * @throws IOException Any exception thrown by the underlying
493 * OutputStream.
494 */
495 protected void annotateClass(Class<?> cl) throws IOException {
496 }
497
498 /**
499 * Subclasses may implement this method to store custom data in the stream
500 * along with descriptors for dynamic proxy classes.
501 *
502 * <p>This method is called exactly once for each unique proxy class
503 * descriptor in the stream. The default implementation of this method in
504 * {@code ObjectOutputStream} does nothing.
505 *
506 * <p>The corresponding method in {@code ObjectInputStream} is
507 * {@code resolveProxyClass}. For a given subclass of
508 * {@code ObjectOutputStream} that overrides this method, the
509 * {@code resolveProxyClass} method in the corresponding subclass of
510 * {@code ObjectInputStream} must read any data or objects written by
511 * {@code annotateProxyClass}.
512 *
513 * @param cl the proxy class to annotate custom data for
514 * @throws IOException any exception thrown by the underlying
515 * {@code OutputStream}
516 * @see ObjectInputStream#resolveProxyClass(String[])
517 * @since 1.3
518 */
519 protected void annotateProxyClass(Class<?> cl) throws IOException {
520 }
521
522 /**
523 * This method will allow trusted subclasses of ObjectOutputStream to
524 * substitute one object for another during serialization. Replacing
525 * objects is disabled until enableReplaceObject is called. The
526 * enableReplaceObject method checks that the stream requesting to do
527 * replacement can be trusted. The first occurrence of each object written
528 * into the serialization stream is passed to replaceObject. Subsequent
529 * references to the object are replaced by the object returned by the
530 * original call to replaceObject. To ensure that the private state of
531 * objects is not unintentionally exposed, only trusted streams may use
532 * replaceObject.
533 *
534 * <p>The ObjectOutputStream.writeObject method takes a parameter of type
535 * Object (as opposed to type Serializable) to allow for cases where
536 * non-serializable objects are replaced by serializable ones.
537 *
538 * <p>When a subclass is replacing objects it must ensure that either a
539 * complementary substitution must be made during deserialization or that
540 * the substituted object is compatible with every field where the
541 * reference will be stored. Objects whose type is not a subclass of the
542 * type of the field or array element abort the serialization by raising an
543 * exception and the object is not be stored.
544 *
545 * <p>This method is called only once when each object is first
546 * encountered. All subsequent references to the object will be redirected
547 * to the new object. This method should return the object to be
548 * substituted or the original object.
549 *
550 * <p>Null can be returned as the object to be substituted, but may cause
551 * {@link NullPointerException} in classes that contain references to the
552 * original object since they may be expecting an object instead of
553 * null.
554 *
555 * @param obj the object to be replaced
556 * @return the alternate object that replaced the specified one
557 * @throws IOException Any exception thrown by the underlying
558 * OutputStream.
559 */
560 protected Object replaceObject(Object obj) throws IOException {
561 return obj;
562 }
563
564 /**
565 * Enables the stream to do replacement of objects written to the stream. When
566 * enabled, the {@link #replaceObject} method is called for every object being
567 * serialized.
568 *
569 * @param enable true for enabling use of {@code replaceObject} for
570 * every object being serialized
571 * @return the previous setting before this method was invoked
572 */
573 protected boolean enableReplaceObject(boolean enable) {
574 if (enable == enableReplace) {
575 return enable;
576 }
577 enableReplace = enable;
578 return !enableReplace;
579 }
580
581 /**
582 * The writeStreamHeader method is provided so subclasses can append or
583 * prepend their own header to the stream. It writes the magic number and
584 * version to the stream.
585 *
586 * @throws IOException if I/O errors occur while writing to the underlying
587 * stream
588 */
589 protected void writeStreamHeader() throws IOException {
590 bout.writeShort(STREAM_MAGIC);
591 bout.writeShort(STREAM_VERSION);
592 }
593
594 /**
595 * Write the specified class descriptor to the ObjectOutputStream. Class
596 * descriptors are used to identify the classes of objects written to the
597 * stream. Subclasses of ObjectOutputStream may override this method to
598 * customize the way in which class descriptors are written to the
599 * serialization stream. The corresponding method in ObjectInputStream,
600 * {@link ObjectInputStream#readClassDescriptor readClassDescriptor}, should then be
601 * overridden to reconstitute the class descriptor from its custom stream representation.
602 * By default, this method writes class descriptors according to the format
603 * defined in the <a href="{@docRoot}/../specs/serialization/index.html">
604 * <cite>Java Object Serialization Specification</cite></a>.
605 *
606 * <p>Note that this method will only be called if the ObjectOutputStream
607 * is not using the old serialization stream format (set by calling
608 * ObjectOutputStream's {@code useProtocolVersion} method). If this
609 * serialization stream is using the old format
610 * ({@code PROTOCOL_VERSION_1}), the class descriptor will be written
611 * internally in a manner that cannot be overridden or customized.
612 *
613 * @param desc class descriptor to write to the stream
614 * @throws IOException If an I/O error has occurred.
615 * @spec serialization/index.html Java Object Serialization Specification
616 * @see java.io.ObjectInputStream#readClassDescriptor()
617 * @see #useProtocolVersion(int)
618 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
619 * @since 1.3
620 */
621 protected void writeClassDescriptor(ObjectStreamClass desc)
622 throws IOException
623 {
624 desc.writeNonProxy(this);
625 }
626
627 /**
628 * Writes a byte. This method will block until the byte is actually
629 * written.
630 *
631 * @param val the byte to be written to the stream
632 * @throws IOException If an I/O error has occurred.
633 */
634 @Override
635 public void write(int val) throws IOException {
636 bout.write(val);
637 }
638
639 /**
640 * Writes an array of bytes. This method will block until the bytes are
641 * actually written.
642 *
643 * @param buf the data to be written
644 * @throws IOException If an I/O error has occurred.
645 */
646 @Override
647 public void write(byte[] buf) throws IOException {
648 bout.write(buf, 0, buf.length, false);
649 }
650
651 /**
652 * Writes a sub array of bytes.
653 *
654 * @param buf the data to be written
655 * @param off the start offset in the data
656 * @param len the number of bytes that are written
657 * @throws IOException {@inheritDoc}
658 * @throws IndexOutOfBoundsException {@inheritDoc}
659 */
660 @Override
661 public void write(byte[] buf, int off, int len) throws IOException {
662 if (buf == null) {
663 throw new NullPointerException();
664 }
665 Objects.checkFromIndexSize(off, len, buf.length);
666 bout.write(buf, off, len, false);
667 }
668
669 /**
670 * Flushes the stream. This will write any buffered output bytes and flush
671 * through to the underlying stream.
672 *
673 * @throws IOException {@inheritDoc}
674 */
675 @Override
676 public void flush() throws IOException {
677 bout.flush();
678 }
679
680 /**
681 * Drain any buffered data in ObjectOutputStream. Similar to flush but
682 * does not propagate the flush to the underlying stream.
683 *
684 * @throws IOException if I/O errors occur while writing to the underlying
685 * stream
686 */
687 protected void drain() throws IOException {
688 bout.drain();
689 }
690
691 /**
692 * Closes the stream. This method must be called to release any resources
693 * associated with the stream.
694 *
695 * @throws IOException If an I/O error has occurred.
696 */
697 @Override
698 public void close() throws IOException {
699 flush();
700 clear();
701 bout.close();
702 }
703
704 /**
705 * Writes a boolean.
706 *
707 * @param val the boolean to be written
708 * @throws IOException if I/O errors occur while writing to the underlying
709 * stream
710 */
711 public void writeBoolean(boolean val) throws IOException {
712 bout.writeBoolean(val);
713 }
714
715 /**
716 * Writes an 8-bit byte.
717 *
718 * @param val the byte value to be written
719 * @throws IOException if I/O errors occur while writing to the underlying
720 * stream
721 */
722 public void writeByte(int val) throws IOException {
723 bout.writeByte(val);
724 }
725
726 /**
727 * Writes a 16-bit short.
728 *
729 * @param val the short value to be written
730 * @throws IOException if I/O errors occur while writing to the underlying
731 * stream
732 */
733 public void writeShort(int val) throws IOException {
734 bout.writeShort(val);
735 }
736
737 /**
738 * Writes a 16-bit char.
739 *
740 * @param val the char value to be written
741 * @throws IOException if I/O errors occur while writing to the underlying
742 * stream
743 */
744 public void writeChar(int val) throws IOException {
745 bout.writeChar(val);
746 }
747
748 /**
749 * Writes a 32-bit int.
750 *
751 * @param val the integer value to be written
752 * @throws IOException if I/O errors occur while writing to the underlying
753 * stream
754 */
755 public void writeInt(int val) throws IOException {
756 bout.writeInt(val);
757 }
758
759 /**
760 * Writes a 64-bit long.
761 *
762 * @param val the long value to be written
763 * @throws IOException if I/O errors occur while writing to the underlying
764 * stream
765 */
766 public void writeLong(long val) throws IOException {
767 bout.writeLong(val);
768 }
769
770 /**
771 * Writes a 32-bit float.
772 *
773 * @param val the float value to be written
774 * @throws IOException if I/O errors occur while writing to the underlying
775 * stream
776 */
777 public void writeFloat(float val) throws IOException {
778 bout.writeFloat(val);
779 }
780
781 /**
782 * Writes a 64-bit double.
783 *
784 * @param val the double value to be written
785 * @throws IOException if I/O errors occur while writing to the underlying
786 * stream
787 */
788 public void writeDouble(double val) throws IOException {
789 bout.writeDouble(val);
790 }
791
792 /**
793 * Writes a String as a sequence of bytes.
794 *
795 * @param str the String of bytes to be written
796 * @throws IOException if I/O errors occur while writing to the underlying
797 * stream
798 */
799 public void writeBytes(String str) throws IOException {
800 bout.writeBytes(str);
801 }
802
803 /**
804 * Writes a String as a sequence of chars.
805 *
806 * @param str the String of chars to be written
807 * @throws IOException if I/O errors occur while writing to the underlying
808 * stream
809 */
810 public void writeChars(String str) throws IOException {
811 bout.writeChars(str);
812 }
813
814 /**
815 * Primitive data write of this String in
816 * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
817 * format. Note that there is a
818 * significant difference between writing a String into the stream as
819 * primitive data or as an Object. A String instance written by writeObject
820 * is written into the stream as a String initially. Future writeObject()
821 * calls write references to the string into the stream.
822 *
823 * @param str the String to be written
824 * @throws IOException if I/O errors occur while writing to the underlying
825 * stream
826 */
827 public void writeUTF(String str) throws IOException {
828 bout.writeUTFInternal(str, false);
829 }
830
831 /**
832 * Provide programmatic access to the persistent fields to be written
833 * to ObjectOutput.
834 *
835 * @since 1.2
836 */
837 public abstract static class PutField {
838 /**
839 * Constructor for subclasses to call.
840 */
841 public PutField() {}
842
843 /**
844 * Put the value of the named boolean field into the persistent field.
845 *
846 * @param name the name of the serializable field
847 * @param val the value to assign to the field
848 * @throws IllegalArgumentException if {@code name} does not
849 * match the name of a serializable field for the class whose fields
850 * are being written, or if the type of the named field is not
851 * {@code boolean}
852 */
853 public abstract void put(String name, boolean val);
854
855 /**
856 * Put the value of the named byte field into the persistent field.
857 *
858 * @param name the name of the serializable field
859 * @param val the value to assign to the field
860 * @throws IllegalArgumentException if {@code name} does not
861 * match the name of a serializable field for the class whose fields
862 * are being written, or if the type of the named field is not
863 * {@code byte}
864 */
865 public abstract void put(String name, byte val);
866
867 /**
868 * Put the value of the named char field into the persistent field.
869 *
870 * @param name the name of the serializable field
871 * @param val the value to assign to the field
872 * @throws IllegalArgumentException if {@code name} does not
873 * match the name of a serializable field for the class whose fields
874 * are being written, or if the type of the named field is not
875 * {@code char}
876 */
877 public abstract void put(String name, char val);
878
879 /**
880 * Put the value of the named short field into the persistent field.
881 *
882 * @param name the name of the serializable field
883 * @param val the value to assign to the field
884 * @throws IllegalArgumentException if {@code name} does not
885 * match the name of a serializable field for the class whose fields
886 * are being written, or if the type of the named field is not
887 * {@code short}
888 */
889 public abstract void put(String name, short val);
890
891 /**
892 * Put the value of the named int field into the persistent field.
893 *
894 * @param name the name of the serializable field
895 * @param val the value to assign to the field
896 * @throws IllegalArgumentException if {@code name} does not
897 * match the name of a serializable field for the class whose fields
898 * are being written, or if the type of the named field is not
899 * {@code int}
900 */
901 public abstract void put(String name, int val);
902
903 /**
904 * Put the value of the named long field into the persistent field.
905 *
906 * @param name the name of the serializable field
907 * @param val the value to assign to the field
908 * @throws IllegalArgumentException if {@code name} does not
909 * match the name of a serializable field for the class whose fields
910 * are being written, or if the type of the named field is not
911 * {@code long}
912 */
913 public abstract void put(String name, long val);
914
915 /**
916 * Put the value of the named float field into the persistent field.
917 *
918 * @param name the name of the serializable field
919 * @param val the value to assign to the field
920 * @throws IllegalArgumentException if {@code name} does not
921 * match the name of a serializable field for the class whose fields
922 * are being written, or if the type of the named field is not
923 * {@code float}
924 */
925 public abstract void put(String name, float val);
926
927 /**
928 * Put the value of the named double field into the persistent field.
929 *
930 * @param name the name of the serializable field
931 * @param val the value to assign to the field
932 * @throws IllegalArgumentException if {@code name} does not
933 * match the name of a serializable field for the class whose fields
934 * are being written, or if the type of the named field is not
935 * {@code double}
936 */
937 public abstract void put(String name, double val);
938
939 /**
940 * Put the value of the named Object field into the persistent field.
941 *
942 * @param name the name of the serializable field
943 * @param val the value to assign to the field
944 * (which may be {@code null})
945 * @throws IllegalArgumentException if {@code name} does not
946 * match the name of a serializable field for the class whose fields
947 * are being written, or if the type of the named field is not a
948 * reference type
949 */
950 public abstract void put(String name, Object val);
951
952 /**
953 * Write the data and fields to the specified ObjectOutput stream,
954 * which must be the same stream that produced this
955 * {@code PutField} object.
956 *
957 * @param out the stream to write the data and fields to
958 * @throws IOException if I/O errors occur while writing to the
959 * underlying stream
960 * @throws IllegalArgumentException if the specified stream is not
961 * the same stream that produced this {@code PutField}
962 * object
963 * @deprecated This method does not write the values contained by this
964 * {@code PutField} object in a proper format, and may
965 * result in corruption of the serialization stream. The
966 * correct way to write {@code PutField} data is by
967 * calling the {@link java.io.ObjectOutputStream#writeFields()}
968 * method.
969 */
970 @Deprecated(forRemoval = true, since = "1.4")
971 public abstract void write(ObjectOutput out) throws IOException;
972 }
973
974
975 /**
976 * Returns protocol version in use.
977 */
978 int getProtocolVersion() {
979 return protocol;
980 }
981
982 /**
983 * Writes string without allowing it to be replaced in stream. Used by
984 * ObjectStreamClass to write class descriptor type strings.
985 */
986 void writeTypeString(String str) throws IOException {
987 int handle;
988 if (str == null) {
989 writeNull();
990 } else if ((handle = handles.lookup(str)) != -1) {
991 writeHandle(handle);
992 } else {
993 writeString(str, false);
994 }
995 }
996
997 /**
998 * Clears internal data structures.
999 */
1000 private void clear() {
1001 subs.clear();
1002 handles.clear();
1003 }
1004
1005 /**
1006 * Underlying writeObject/writeUnshared implementation.
1007 */
1008 private void writeObject0(Object obj, boolean unshared)
1009 throws IOException
1010 {
1011 boolean oldMode = bout.setBlockDataMode(false);
1012 depth++;
1013 try {
1014 // handle previously written and non-replaceable objects
1015 int h;
1016 if ((obj = subs.lookup(obj)) == null) {
1017 writeNull();
1018 return;
1019 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1020 writeHandle(h);
1021 return;
1022 } else if (obj instanceof Class) {
1023 writeClass((Class) obj, unshared);
1024 return;
1025 } else if (obj instanceof ObjectStreamClass) {
1026 writeClassDesc((ObjectStreamClass) obj, unshared);
1027 return;
1028 }
1029
1030 // check for replacement object
1031 Object orig = obj;
1032 Class<?> cl = obj.getClass();
1033 ObjectStreamClass desc;
1034 for (;;) {
1035 // REMIND: skip this check for strings/arrays?
1036 Class<?> repCl;
1037 desc = ObjectStreamClass.lookup(cl, true);
1038 if (!desc.hasWriteReplaceMethod() ||
1039 (obj = desc.invokeWriteReplace(obj)) == null ||
1040 (repCl = obj.getClass()) == cl)
1041 {
1042 break;
1043 }
1044 cl = repCl;
1045 }
1046 if (enableReplace) {
1047 Object rep = replaceObject(obj);
1048 if (rep != obj && rep != null) {
1049 cl = rep.getClass();
1050 desc = ObjectStreamClass.lookup(cl, true);
1051 }
1052 obj = rep;
1053 }
1054
1055 // if object replaced, run through original checks a second time
1056 if (obj != orig) {
1057 subs.assign(orig, obj);
1058 if (obj == null) {
1059 writeNull();
1060 return;
1061 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1062 writeHandle(h);
1063 return;
1064 } else if (obj instanceof Class) {
1065 writeClass((Class) obj, unshared);
1066 return;
1067 } else if (obj instanceof ObjectStreamClass) {
1068 writeClassDesc((ObjectStreamClass) obj, unshared);
1069 return;
1070 }
1071 }
1072
1073 // remaining cases
1074 if (obj instanceof String) {
1075 writeString((String) obj, unshared);
1076 } else if (cl.isArray()) {
1077 writeArray(obj, desc, unshared);
1078 } else if (obj instanceof Enum) {
1079 writeEnum((Enum<?>) obj, desc, unshared);
1080 } else if (obj instanceof Serializable) {
1081 writeOrdinaryObject(obj, desc, unshared);
1082 } else {
1083 if (extendedDebugInfo) {
1084 throw new NotSerializableException(
1085 cl.getName() + "\n" + debugInfoStack.toString());
1086 } else {
1087 throw new NotSerializableException(cl.getName());
1088 }
1089 }
1090 } finally {
1091 depth--;
1092 bout.setBlockDataMode(oldMode);
1093 }
1094 }
1095
1096 /**
1097 * Writes null code to stream.
1098 */
1099 private void writeNull() throws IOException {
1100 bout.writeByte(TC_NULL);
1101 }
1102
1103 /**
1104 * Writes given object handle to stream.
1105 */
1106 private void writeHandle(int handle) throws IOException {
1107 bout.writeByte(TC_REFERENCE);
1108 bout.writeInt(baseWireHandle + handle);
1109 }
1110
1111 /**
1112 * Writes representation of given class to stream.
1113 */
1114 private void writeClass(Class<?> cl, boolean unshared) throws IOException {
1115 bout.writeByte(TC_CLASS);
1116 writeClassDesc(ObjectStreamClass.lookup(cl, true), false);
1117 handles.assign(unshared ? null : cl);
1118 }
1119
1120 /**
1121 * Writes representation of given class descriptor to stream.
1122 */
1123 private void writeClassDesc(ObjectStreamClass desc, boolean unshared)
1124 throws IOException
1125 {
1126 int handle;
1127 if (desc == null) {
1128 writeNull();
1129 } else if (!unshared && (handle = handles.lookup(desc)) != -1) {
1130 writeHandle(handle);
1131 } else if (desc.isProxy()) {
1132 writeProxyDesc(desc, unshared);
1133 } else {
1134 writeNonProxyDesc(desc, unshared);
1135 }
1136 }
1137
1138 /**
1139 * Writes class descriptor representing a dynamic proxy class to stream.
1140 */
1141 private void writeProxyDesc(ObjectStreamClass desc, boolean unshared)
1142 throws IOException
1143 {
1144 bout.writeByte(TC_PROXYCLASSDESC);
1145 handles.assign(unshared ? null : desc);
1146
1147 Class<?> cl = desc.forClass();
1148 Class<?>[] ifaces = cl.getInterfaces();
1149 bout.writeInt(ifaces.length);
1150 for (int i = 0; i < ifaces.length; i++) {
1151 bout.writeUTF(ifaces[i].getName());
1152 }
1153
1154 bout.setBlockDataMode(true);
1155 annotateProxyClass(cl);
1156 bout.setBlockDataMode(false);
1157 bout.writeByte(TC_ENDBLOCKDATA);
1158
1159 writeClassDesc(desc.getSuperDesc(), false);
1160 }
1161
1162 /**
1163 * Writes class descriptor representing a standard (i.e., not a dynamic
1164 * proxy) class to stream.
1165 */
1166 private void writeNonProxyDesc(ObjectStreamClass desc, boolean unshared)
1167 throws IOException
1168 {
1169 bout.writeByte(TC_CLASSDESC);
1170 handles.assign(unshared ? null : desc);
1171
1172 if (protocol == PROTOCOL_VERSION_1) {
1173 // do not invoke class descriptor write hook with old protocol
1174 desc.writeNonProxy(this);
1175 } else {
1176 writeClassDescriptor(desc);
1177 }
1178
1179 Class<?> cl = desc.forClass();
1180 bout.setBlockDataMode(true);
1181 annotateClass(cl);
1182 bout.setBlockDataMode(false);
1183 bout.writeByte(TC_ENDBLOCKDATA);
1184
1185 writeClassDesc(desc.getSuperDesc(), false);
1186 }
1187
1188 /**
1189 * Writes given string to stream, using standard or long UTF format
1190 * depending on string length.
1191 */
1192 private void writeString(String str, boolean unshared) throws IOException {
1193 handles.assign(unshared ? null : str);
1194 bout.writeUTFInternal(str, true);
1195 }
1196
1197 /**
1198 * Writes given array object to stream.
1199 */
1200 private void writeArray(Object array,
1201 ObjectStreamClass desc,
1202 boolean unshared)
1203 throws IOException
1204 {
1205 bout.writeByte(TC_ARRAY);
1206 writeClassDesc(desc, false);
1207 handles.assign(unshared ? null : array);
1208
1209 Class<?> ccl = desc.forClass().getComponentType();
1210 if (ccl.isPrimitive()) {
1211 if (ccl == Integer.TYPE) {
1212 int[] ia = (int[]) array;
1213 bout.writeInt(ia.length);
1214 bout.writeInts(ia, 0, ia.length);
1215 } else if (ccl == Byte.TYPE) {
1216 byte[] ba = (byte[]) array;
1217 bout.writeInt(ba.length);
1218 bout.write(ba, 0, ba.length, true);
1219 } else if (ccl == Long.TYPE) {
1220 long[] ja = (long[]) array;
1221 bout.writeInt(ja.length);
1222 bout.writeLongs(ja, 0, ja.length);
1223 } else if (ccl == Float.TYPE) {
1224 float[] fa = (float[]) array;
1225 bout.writeInt(fa.length);
1226 bout.writeFloats(fa, 0, fa.length);
1227 } else if (ccl == Double.TYPE) {
1228 double[] da = (double[]) array;
1229 bout.writeInt(da.length);
1230 bout.writeDoubles(da, 0, da.length);
1231 } else if (ccl == Short.TYPE) {
1232 short[] sa = (short[]) array;
1233 bout.writeInt(sa.length);
1234 bout.writeShorts(sa, 0, sa.length);
1235 } else if (ccl == Character.TYPE) {
1236 char[] ca = (char[]) array;
1237 bout.writeInt(ca.length);
1238 bout.writeChars(ca, 0, ca.length);
1239 } else if (ccl == Boolean.TYPE) {
1240 boolean[] za = (boolean[]) array;
1241 bout.writeInt(za.length);
1242 bout.writeBooleans(za, 0, za.length);
1243 } else {
1244 throw new InternalError();
1245 }
1246 } else {
1247 Object[] objs = (Object[]) array;
1248 int len = objs.length;
1249 bout.writeInt(len);
1250 if (extendedDebugInfo) {
1251 debugInfoStack.push(
1252 "array (class \"" + array.getClass().getName() +
1253 "\", size: " + len + ")");
1254 }
1255 try {
1256 for (int i = 0; i < len; i++) {
1257 if (extendedDebugInfo) {
1258 debugInfoStack.push(
1259 "element of array (index: " + i + ")");
1260 }
1261 try {
1262 writeObject0(objs[i], false);
1263 } finally {
1264 if (extendedDebugInfo) {
1265 debugInfoStack.pop();
1266 }
1267 }
1268 }
1269 } finally {
1270 if (extendedDebugInfo) {
1271 debugInfoStack.pop();
1272 }
1273 }
1274 }
1275 }
1276
1277 /**
1278 * Writes given enum constant to stream.
1279 */
1280 private void writeEnum(Enum<?> en,
1281 ObjectStreamClass desc,
1282 boolean unshared)
1283 throws IOException
1284 {
1285 bout.writeByte(TC_ENUM);
1286 ObjectStreamClass sdesc = desc.getSuperDesc();
1287 writeClassDesc((sdesc.forClass() == Enum.class) ? desc : sdesc, false);
1288 handles.assign(unshared ? null : en);
1289 writeString(en.name(), false);
1290 }
1291
1292 /**
1293 * Writes representation of an "ordinary" (i.e., not a String, Class,
1294 * ObjectStreamClass, array, or enum constant) serializable object to the
1295 * stream.
1296 */
1297 private void writeOrdinaryObject(Object obj,
1298 ObjectStreamClass desc,
1299 boolean unshared)
1300 throws IOException
1301 {
1302 if (extendedDebugInfo) {
1303 debugInfoStack.push(
1304 (depth == 1 ? "root " : "") + "object (class \"" +
1305 obj.getClass().getName() + "\", " + obj.toString() + ")");
1306 }
1307 try {
1308 desc.checkSerialize();
1309
1310 bout.writeByte(TC_OBJECT);
1311 writeClassDesc(desc, false);
1312 handles.assign(unshared ? null : obj);
1313
1314 if (desc.isRecord()) {
1315 writeRecordData(obj, desc);
1316 } else if (desc.isExternalizable() && !desc.isProxy()) {
1317 writeExternalData((Externalizable) obj);
1318 } else {
1319 writeSerialData(obj, desc);
1320 }
1321 } finally {
1322 if (extendedDebugInfo) {
1323 debugInfoStack.pop();
1324 }
1325 }
1326 }
1327
1328 /**
1329 * Writes externalizable data of given object by invoking its
1330 * writeExternal() method.
1331 */
1332 private void writeExternalData(Externalizable obj) throws IOException {
1333 PutFieldImpl oldPut = curPut;
1334 curPut = null;
1335
1336 if (extendedDebugInfo) {
1337 debugInfoStack.push("writeExternal data");
1338 }
1339 SerialCallbackContext oldContext = curContext;
1340 try {
1341 curContext = null;
1342 if (protocol == PROTOCOL_VERSION_1) {
1343 obj.writeExternal(this);
1344 } else {
1345 bout.setBlockDataMode(true);
1346 obj.writeExternal(this);
1347 bout.setBlockDataMode(false);
1348 bout.writeByte(TC_ENDBLOCKDATA);
1349 }
1350 } finally {
1351 curContext = oldContext;
1352 if (extendedDebugInfo) {
1353 debugInfoStack.pop();
1354 }
1355 }
1356
1357 curPut = oldPut;
1358 }
1359
1360 /** Writes the record component values for the given record object. */
1361 private void writeRecordData(Object obj, ObjectStreamClass desc)
1362 throws IOException
1363 {
1364 assert obj.getClass().isRecord();
1365 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1366 if (slots.length != 1) {
1367 throw new InvalidClassException(
1368 "expected a single record slot length, but found: " + slots.length);
1369 }
1370
1371 defaultWriteFields(obj, desc); // #### seems unnecessary to use the accessors
1372 }
1373
1374 /**
1375 * Writes instance data for each serializable class of given object, from
1376 * superclass to subclass.
1377 */
1378 private void writeSerialData(Object obj, ObjectStreamClass desc)
1379 throws IOException
1380 {
1381 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1382 for (int i = 0; i < slots.length; i++) {
1383 ObjectStreamClass slotDesc = slots[i].desc;
1384 if (slotDesc.hasWriteObjectMethod()) {
1385 PutFieldImpl oldPut = curPut;
1386 curPut = null;
1387 SerialCallbackContext oldContext = curContext;
1388
1389 if (extendedDebugInfo) {
1390 debugInfoStack.push(
1391 "custom writeObject data (class \"" +
1392 slotDesc.getName() + "\")");
1393 }
1394 try {
1395 curContext = new SerialCallbackContext(obj, slotDesc);
1396 bout.setBlockDataMode(true);
1397 slotDesc.invokeWriteObject(obj, this);
1398 bout.setBlockDataMode(false);
1399 bout.writeByte(TC_ENDBLOCKDATA);
1400 } finally {
1401 curContext.setUsed();
1402 curContext = oldContext;
1403 if (extendedDebugInfo) {
1404 debugInfoStack.pop();
1405 }
1406 }
1407
1408 curPut = oldPut;
1409 } else {
1410 defaultWriteFields(obj, slotDesc);
1411 }
1412 }
1413 }
1414
1415 /**
1416 * Fetches and writes values of serializable fields of given object to
1417 * stream. The given class descriptor specifies which field values to
1418 * write, and in which order they should be written.
1419 */
1420 private void defaultWriteFields(Object obj, ObjectStreamClass desc)
1421 throws IOException
1422 {
1423 Class<?> cl = desc.forClass();
1424 if (cl != null && obj != null && !cl.isInstance(obj)) {
1425 throw new ClassCastException();
1426 }
1427
1428 desc.checkDefaultSerialize();
1429
1430 int primDataSize = desc.getPrimDataSize();
1431 if (primDataSize > 0) {
1432 if (primVals == null || primVals.length < primDataSize) {
1433 primVals = new byte[primDataSize];
1434 }
1435 desc.getPrimFieldValues(obj, primVals);
1436 bout.write(primVals, 0, primDataSize, false);
1437 }
1438
1439 int numObjFields = desc.getNumObjFields();
1440 if (numObjFields > 0) {
1441 ObjectStreamField[] fields = desc.getFields(false);
1442 Object[] objVals = new Object[numObjFields];
1443 int numPrimFields = fields.length - objVals.length;
1444 desc.getObjFieldValues(obj, objVals);
1445 for (int i = 0; i < objVals.length; i++) {
1446 if (extendedDebugInfo) {
1447 debugInfoStack.push(
1448 "field (class \"" + desc.getName() + "\", name: \"" +
1449 fields[numPrimFields + i].getName() + "\", type: \"" +
1450 fields[numPrimFields + i].getType() + "\")");
1451 }
1452 try {
1453 writeObject0(objVals[i],
1454 fields[numPrimFields + i].isUnshared());
1455 } finally {
1456 if (extendedDebugInfo) {
1457 debugInfoStack.pop();
1458 }
1459 }
1460 }
1461 }
1462 }
1463
1464 /**
1465 * Attempts to write to stream fatal IOException that has caused
1466 * serialization to abort.
1467 */
1468 private void writeFatalException(IOException ex) throws IOException {
1469 /*
1470 * Note: the serialization specification states that if a second
1471 * IOException occurs while attempting to serialize the original fatal
1472 * exception to the stream, then a StreamCorruptedException should be
1473 * thrown (section 2.1). However, due to a bug in previous
1474 * implementations of serialization, StreamCorruptedExceptions were
1475 * rarely (if ever) actually thrown--the "root" exceptions from
1476 * underlying streams were thrown instead. This historical behavior is
1477 * followed here for consistency.
1478 */
1479 clear();
1480 boolean oldMode = bout.setBlockDataMode(false);
1481 try {
1482 bout.writeByte(TC_EXCEPTION);
1483 writeObject0(ex, false);
1484 clear();
1485 } finally {
1486 bout.setBlockDataMode(oldMode);
1487 }
1488 }
1489
1490 /**
1491 * Default PutField implementation.
1492 */
1493 private class PutFieldImpl extends PutField {
1494
1495 /** class descriptor describing serializable fields */
1496 private final ObjectStreamClass desc;
1497 /** primitive field values */
1498 private final byte[] primVals;
1499 /** object field values */
1500 private final Object[] objVals;
1501
1502 /**
1503 * Creates PutFieldImpl object for writing fields defined in given
1504 * class descriptor.
1505 */
1506 PutFieldImpl(ObjectStreamClass desc) {
1507 this.desc = desc;
1508 primVals = new byte[desc.getPrimDataSize()];
1509 objVals = new Object[desc.getNumObjFields()];
1510 }
1511
1512 public void put(String name, boolean val) {
1513 ByteArray.setBoolean(primVals, getFieldOffset(name, Boolean.TYPE), val);
1514 }
1515
1516 public void put(String name, byte val) {
1517 primVals[getFieldOffset(name, Byte.TYPE)] = val;
1518 }
1519
1520 public void put(String name, char val) {
1521 ByteArray.setChar(primVals, getFieldOffset(name, Character.TYPE), val);
1522 }
1523
1524 public void put(String name, short val) {
1525 ByteArray.setShort(primVals, getFieldOffset(name, Short.TYPE), val);
1526 }
1527
1528 public void put(String name, int val) {
1529 ByteArray.setInt(primVals, getFieldOffset(name, Integer.TYPE), val);
1530 }
1531
1532 public void put(String name, float val) {
1533 ByteArray.setFloat(primVals, getFieldOffset(name, Float.TYPE), val);
1534 }
1535
1536 public void put(String name, long val) {
1537 ByteArray.setLong(primVals, getFieldOffset(name, Long.TYPE), val);
1538 }
1539
1540 public void put(String name, double val) {
1541 ByteArray.setDouble(primVals, getFieldOffset(name, Double.TYPE), val);
1542 }
1543
1544 public void put(String name, Object val) {
1545 objVals[getFieldOffset(name, Object.class)] = val;
1546 }
1547
1548 // deprecated in ObjectOutputStream.PutField
1549 public void write(ObjectOutput out) throws IOException {
1550 /*
1551 * Applications should *not* use this method to write PutField
1552 * data, as it will lead to stream corruption if the PutField
1553 * object writes any primitive data (since block data mode is not
1554 * unset/set properly, as is done in OOS.writeFields()). This
1555 * broken implementation is being retained solely for behavioral
1556 * compatibility, in order to support applications which use
1557 * OOS.PutField.write() for writing only non-primitive data.
1558 *
1559 * Serialization of unshared objects is not implemented here since
1560 * it is not necessary for backwards compatibility; also, unshared
1561 * semantics may not be supported by the given ObjectOutput
1562 * instance. Applications which write unshared objects using the
1563 * PutField API must use OOS.writeFields().
1564 */
1565 if (ObjectOutputStream.this != out) {
1566 throw new IllegalArgumentException("wrong stream");
1567 }
1568 out.write(primVals, 0, primVals.length);
1569
1570 ObjectStreamField[] fields = desc.getFields(false);
1571 int numPrimFields = fields.length - objVals.length;
1572 // REMIND: warn if numPrimFields > 0?
1573 for (int i = 0; i < objVals.length; i++) {
1574 if (fields[numPrimFields + i].isUnshared()) {
1575 throw new IOException("cannot write unshared object");
1576 }
1577 out.writeObject(objVals[i]);
1578 }
1579 }
1580
1581 /**
1582 * Writes buffered primitive data and object fields to stream.
1583 */
1584 void writeFields() throws IOException {
1585 bout.write(primVals, 0, primVals.length, false);
1586
1587 ObjectStreamField[] fields = desc.getFields(false);
1588 int numPrimFields = fields.length - objVals.length;
1589 for (int i = 0; i < objVals.length; i++) {
1590 if (extendedDebugInfo) {
1591 debugInfoStack.push(
1592 "field (class \"" + desc.getName() + "\", name: \"" +
1593 fields[numPrimFields + i].getName() + "\", type: \"" +
1594 fields[numPrimFields + i].getType() + "\")");
1595 }
1596 try {
1597 writeObject0(objVals[i],
1598 fields[numPrimFields + i].isUnshared());
1599 } finally {
1600 if (extendedDebugInfo) {
1601 debugInfoStack.pop();
1602 }
1603 }
1604 }
1605 }
1606
1607 /**
1608 * Returns offset of field with given name and type. A specified type
1609 * of null matches all types, Object.class matches all non-primitive
1610 * types, and any other non-null type matches assignable types only.
1611 * Throws IllegalArgumentException if no matching field found.
1612 */
1613 private int getFieldOffset(String name, Class<?> type) {
1614 ObjectStreamField field = desc.getField(name, type);
1615 if (field == null) {
1616 throw new IllegalArgumentException("no such field " + name +
1617 " with type " + type);
1618 }
1619 return field.getOffset();
1620 }
1621 }
1622
1623 /**
1624 * Buffered output stream with two modes: in default mode, outputs data in
1625 * same format as DataOutputStream; in "block data" mode, outputs data
1626 * bracketed by block data markers (see object serialization specification
1627 * for details).
1628 */
1629 private static final class BlockDataOutputStream
1630 extends OutputStream implements DataOutput
1631 {
1632 /** maximum data block length */
1633 private static final int MAX_BLOCK_SIZE = 1024;
1634 /** maximum data block header length */
1635 private static final int MAX_HEADER_SIZE = 5;
1636 /** (tunable) length of char buffer (for writing strings) */
1637 private static final int CHAR_BUF_SIZE = 256;
1638
1639 /** buffer for writing general/block data */
1640 private final byte[] buf = new byte[MAX_BLOCK_SIZE];
1641 /** buffer for writing block data headers */
1642 private final byte[] hbuf = new byte[MAX_HEADER_SIZE];
1643 /** char buffer for fast string writes */
1644 private final char[] cbuf = new char[CHAR_BUF_SIZE];
1645
1646 /** block data mode */
1647 private boolean blkmode = false;
1648 /** current offset into buf */
1649 private int pos = 0;
1650
1651 /** underlying output stream */
1652 private final OutputStream out;
1653 /** loopback stream (for data writes that span data blocks) */
1654 private final DataOutputStream dout;
1655
1656 /**
1657 * Creates new BlockDataOutputStream on top of given underlying stream.
1658 * Block data mode is turned off by default.
1659 */
1660 BlockDataOutputStream(OutputStream out) {
1661 this.out = out;
1662 dout = new DataOutputStream(this);
1663 }
1664
1665 /**
1666 * Sets block data mode to the given mode (true == on, false == off)
1667 * and returns the previous mode value. If the new mode is the same as
1668 * the old mode, no action is taken. If the new mode differs from the
1669 * old mode, any buffered data is flushed before switching to the new
1670 * mode.
1671 */
1672 boolean setBlockDataMode(boolean mode) throws IOException {
1673 if (blkmode == mode) {
1674 return blkmode;
1675 }
1676 drain();
1677 blkmode = mode;
1678 return !blkmode;
1679 }
1680
1681 /**
1682 * Returns true if the stream is currently in block data mode, false
1683 * otherwise.
1684 */
1685 boolean getBlockDataMode() {
1686 return blkmode;
1687 }
1688
1689 /* ----------------- generic output stream methods ----------------- */
1690 /*
1691 * The following methods are equivalent to their counterparts in
1692 * OutputStream, except that they partition written data into data
1693 * blocks when in block data mode.
1694 */
1695
1696 public void write(int b) throws IOException {
1697 if (pos >= MAX_BLOCK_SIZE) {
1698 drain();
1699 }
1700 buf[pos++] = (byte) b;
1701 }
1702
1703 public void write(byte[] b) throws IOException {
1704 write(b, 0, b.length, false);
1705 }
1706
1707 public void write(byte[] b, int off, int len) throws IOException {
1708 write(b, off, len, false);
1709 }
1710
1711 public void flush() throws IOException {
1712 drain();
1713 out.flush();
1714 }
1715
1716 public void close() throws IOException {
1717 flush();
1718 out.close();
1719 }
1720
1721 /**
1722 * Writes specified span of byte values from given array. If copy is
1723 * true, copies the values to an intermediate buffer before writing
1724 * them to underlying stream (to avoid exposing a reference to the
1725 * original byte array).
1726 */
1727 void write(byte[] b, int off, int len, boolean copy)
1728 throws IOException
1729 {
1730 if (!(copy || blkmode)) { // write directly
1731 drain();
1732 out.write(b, off, len);
1733 return;
1734 }
1735
1736 while (len > 0) {
1737 if (pos >= MAX_BLOCK_SIZE) {
1738 drain();
1739 }
1740 if (len >= MAX_BLOCK_SIZE && !copy && pos == 0) {
1741 // avoid unnecessary copy
1742 writeBlockHeader(MAX_BLOCK_SIZE);
1743 out.write(b, off, MAX_BLOCK_SIZE);
1744 off += MAX_BLOCK_SIZE;
1745 len -= MAX_BLOCK_SIZE;
1746 } else {
1747 int wlen = Math.min(len, MAX_BLOCK_SIZE - pos);
1748 System.arraycopy(b, off, buf, pos, wlen);
1749 pos += wlen;
1750 off += wlen;
1751 len -= wlen;
1752 }
1753 }
1754 }
1755
1756 /**
1757 * Writes all buffered data from this stream to the underlying stream,
1758 * but does not flush underlying stream.
1759 */
1760 void drain() throws IOException {
1761 if (pos == 0) {
1762 return;
1763 }
1764 if (blkmode) {
1765 writeBlockHeader(pos);
1766 }
1767 out.write(buf, 0, pos);
1768 pos = 0;
1769 }
1770
1771 /**
1772 * Writes block data header. Data blocks shorter than 256 bytes are
1773 * prefixed with a 2-byte header; all others start with a 5-byte
1774 * header.
1775 */
1776 private void writeBlockHeader(int len) throws IOException {
1777 if (len <= 0xFF) {
1778 hbuf[0] = TC_BLOCKDATA;
1779 hbuf[1] = (byte) len;
1780 out.write(hbuf, 0, 2);
1781 } else {
1782 hbuf[0] = TC_BLOCKDATALONG;
1783 ByteArray.setInt(hbuf, 1, len);
1784 out.write(hbuf, 0, 5);
1785 }
1786 }
1787
1788
1789 /* ----------------- primitive data output methods ----------------- */
1790 /*
1791 * The following methods are equivalent to their counterparts in
1792 * DataOutputStream, except that they partition written data into data
1793 * blocks when in block data mode.
1794 */
1795
1796 public void writeBoolean(boolean v) throws IOException {
1797 if (pos >= MAX_BLOCK_SIZE) {
1798 drain();
1799 }
1800 ByteArray.setBoolean(buf, pos++, v);
1801 }
1802
1803 public void writeByte(int v) throws IOException {
1804 if (pos >= MAX_BLOCK_SIZE) {
1805 drain();
1806 }
1807 buf[pos++] = (byte) v;
1808 }
1809
1810 public void writeChar(int v) throws IOException {
1811 if (pos + 2 <= MAX_BLOCK_SIZE) {
1812 ByteArray.setChar(buf, pos, (char) v);
1813 pos += 2;
1814 } else {
1815 dout.writeChar(v);
1816 }
1817 }
1818
1819 public void writeShort(int v) throws IOException {
1820 if (pos + 2 <= MAX_BLOCK_SIZE) {
1821 ByteArray.setShort(buf, pos, (short) v);
1822 pos += 2;
1823 } else {
1824 dout.writeShort(v);
1825 }
1826 }
1827
1828 public void writeInt(int v) throws IOException {
1829 if (pos + 4 <= MAX_BLOCK_SIZE) {
1830 ByteArray.setInt(buf, pos, v);
1831 pos += 4;
1832 } else {
1833 dout.writeInt(v);
1834 }
1835 }
1836
1837 public void writeFloat(float v) throws IOException {
1838 if (pos + 4 <= MAX_BLOCK_SIZE) {
1839 ByteArray.setFloat(buf, pos, v);
1840 pos += 4;
1841 } else {
1842 dout.writeFloat(v);
1843 }
1844 }
1845
1846 public void writeLong(long v) throws IOException {
1847 if (pos + 8 <= MAX_BLOCK_SIZE) {
1848 ByteArray.setLong(buf, pos, v);
1849 pos += 8;
1850 } else {
1851 dout.writeLong(v);
1852 }
1853 }
1854
1855 public void writeDouble(double v) throws IOException {
1856 if (pos + 8 <= MAX_BLOCK_SIZE) {
1857 ByteArray.setDouble(buf, pos, v);
1858 pos += 8;
1859 } else {
1860 dout.writeDouble(v);
1861 }
1862 }
1863
1864 @SuppressWarnings("deprecation")
1865 void writeBytes(String s, int len) throws IOException {
1866 int pos = this.pos;
1867 for (int strpos = 0; strpos < len;) {
1868 int rem = MAX_BLOCK_SIZE - pos;
1869 int csize = Math.min(len - strpos, rem);
1870 s.getBytes(strpos, strpos + csize, buf, pos);
1871 pos += csize;
1872 strpos += csize;
1873
1874 if (pos == MAX_BLOCK_SIZE) {
1875 this.pos = pos;
1876 drain();
1877 pos = 0;
1878 }
1879 }
1880 this.pos = pos;
1881 }
1882
1883 public void writeBytes(String s) throws IOException {
1884 writeBytes(s, s.length());
1885 }
1886
1887 public void writeChars(String s) throws IOException {
1888 int endoff = s.length();
1889 for (int off = 0; off < endoff; ) {
1890 int csize = Math.min(endoff - off, CHAR_BUF_SIZE);
1891 s.getChars(off, off + csize, cbuf, 0);
1892 writeChars(cbuf, 0, csize);
1893 off += csize;
1894 }
1895 }
1896
1897 public void writeUTF(String str) throws IOException {
1898 writeUTFInternal(str, false);
1899 }
1900
1901 private void writeUTFInternal(String str, boolean writeHeader) throws IOException {
1902 int strlen = str.length();
1903 int countNonZeroAscii = JLA.countNonZeroAscii(str);
1904 long utflen = utfLen(str, countNonZeroAscii);
1905 if (ExactConversionsSupport.isLongToCharExact(utflen)) {
1906 if(writeHeader) {
1907 writeByte(TC_STRING);
1908 }
1909 writeShort((short)utflen);
1910 } else {
1911 if(writeHeader) {
1912 writeByte(TC_LONGSTRING);
1913 }
1914 writeLong(utflen);
1915 }
1916
1917 if (countNonZeroAscii != 0) {
1918 writeBytes(str, countNonZeroAscii);
1919 }
1920 if (countNonZeroAscii != strlen) {
1921 writeMoreUTF(str, countNonZeroAscii);
1922 }
1923 }
1924
1925 private void writeMoreUTF(String str, int stroff) throws IOException {
1926 int pos = this.pos;
1927 for (int strlen = str.length(); stroff < strlen;) {
1928 char c = str.charAt(stroff++);
1929 int csize = c != 0 && c < 0x80 ? 1 : c >= 0x800 ? 3 : 2;
1930 if (pos + csize >= MAX_BLOCK_SIZE) {
1931 this.pos = pos;
1932 drain();
1933 pos = 0;
1934 }
1935 pos = putChar(buf, pos, c);
1936 }
1937 this.pos = pos;
1938 }
1939
1940
1941 /* -------------- primitive data array output methods -------------- */
1942 /*
1943 * The following methods write out spans of primitive data values.
1944 * Though equivalent to calling the corresponding primitive write
1945 * methods repeatedly, these methods are optimized for writing groups
1946 * of primitive data values more efficiently.
1947 */
1948
1949 void writeBooleans(boolean[] v, int off, int len) throws IOException {
1950 int endoff = off + len;
1951 while (off < endoff) {
1952 if (pos >= MAX_BLOCK_SIZE) {
1953 drain();
1954 }
1955 int stop = Math.min(endoff, off + (MAX_BLOCK_SIZE - pos));
1956 while (off < stop) {
1957 ByteArray.setBoolean(buf, pos++, v[off++]);
1958 }
1959 }
1960 }
1961
1962 void writeChars(char[] v, int off, int len) throws IOException {
1963 int limit = MAX_BLOCK_SIZE - 2;
1964 int endoff = off + len;
1965 while (off < endoff) {
1966 if (pos <= limit) {
1967 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
1968 int stop = Math.min(endoff, off + avail);
1969 while (off < stop) {
1970 ByteArray.setChar(buf, pos, v[off++]);
1971 pos += 2;
1972 }
1973 } else {
1974 dout.writeChar(v[off++]);
1975 }
1976 }
1977 }
1978
1979 void writeShorts(short[] v, int off, int len) throws IOException {
1980 int limit = MAX_BLOCK_SIZE - 2;
1981 int endoff = off + len;
1982 while (off < endoff) {
1983 if (pos <= limit) {
1984 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
1985 int stop = Math.min(endoff, off + avail);
1986 while (off < stop) {
1987 ByteArray.setShort(buf, pos, v[off++]);
1988 pos += 2;
1989 }
1990 } else {
1991 dout.writeShort(v[off++]);
1992 }
1993 }
1994 }
1995
1996 void writeInts(int[] v, int off, int len) throws IOException {
1997 int limit = MAX_BLOCK_SIZE - 4;
1998 int endoff = off + len;
1999 while (off < endoff) {
2000 if (pos <= limit) {
2001 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2002 int stop = Math.min(endoff, off + avail);
2003 while (off < stop) {
2004 ByteArray.setInt(buf, pos, v[off++]);
2005 pos += 4;
2006 }
2007 } else {
2008 dout.writeInt(v[off++]);
2009 }
2010 }
2011 }
2012
2013 void writeFloats(float[] v, int off, int len) throws IOException {
2014 int limit = MAX_BLOCK_SIZE - 4;
2015 int endoff = off + len;
2016 while (off < endoff) {
2017 if (pos <= limit) {
2018 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2019 int stop = Math.min(endoff, off + avail);
2020 while (off < stop) {
2021 ByteArray.setFloat(buf, pos, v[off++]);
2022 pos += 4;
2023 }
2024 } else {
2025 dout.writeFloat(v[off++]);
2026 }
2027 }
2028 }
2029
2030 void writeLongs(long[] v, int off, int len) throws IOException {
2031 int limit = MAX_BLOCK_SIZE - 8;
2032 int endoff = off + len;
2033 while (off < endoff) {
2034 if (pos <= limit) {
2035 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2036 int stop = Math.min(endoff, off + avail);
2037 while (off < stop) {
2038 ByteArray.setLong(buf, pos, v[off++]);
2039 pos += 8;
2040 }
2041 } else {
2042 dout.writeLong(v[off++]);
2043 }
2044 }
2045 }
2046
2047 void writeDoubles(double[] v, int off, int len) throws IOException {
2048 int limit = MAX_BLOCK_SIZE - 8;
2049 int endoff = off + len;
2050 while (off < endoff) {
2051 if (pos <= limit) {
2052 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2053 int stop = Math.min(endoff, off + avail);
2054 while (off < stop) {
2055 ByteArray.setDouble(buf, pos, v[off++]);
2056 pos += 8;
2057 }
2058 } else {
2059 dout.writeDouble(v[off++]);
2060 }
2061 }
2062 }
2063 }
2064
2065 /**
2066 * Lightweight identity hash table which maps objects to integer handles,
2067 * assigned in ascending order.
2068 */
2069 private static final class HandleTable {
2070
2071 /* number of mappings in table/next available handle */
2072 private int size;
2073 /* size threshold determining when to expand hash spine */
2074 private int threshold;
2075 /* factor for computing size threshold */
2076 private final float loadFactor;
2077 /* maps hash value -> candidate handle value */
2078 private int[] spine;
2079 /* maps handle value -> next candidate handle value */
2080 private int[] next;
2081 /* maps handle value -> associated object */
2082 private Object[] objs;
2083
2084 /**
2085 * Creates new HandleTable with given capacity and load factor.
2086 */
2087 HandleTable(int initialCapacity, float loadFactor) {
2088 this.loadFactor = loadFactor;
2089 spine = new int[initialCapacity];
2090 next = new int[initialCapacity];
2091 objs = new Object[initialCapacity];
2092 threshold = (int) (initialCapacity * loadFactor);
2093 clear();
2094 }
2095
2096 /**
2097 * Assigns next available handle to given object, and returns handle
2098 * value. Handles are assigned in ascending order starting at 0.
2099 */
2100 int assign(Object obj) {
2101 if (size >= next.length) {
2102 growEntries();
2103 }
2104 if (size >= threshold) {
2105 growSpine();
2106 }
2107 insert(obj, size);
2108 return size++;
2109 }
2110
2111 /**
2112 * Looks up and returns handle associated with given object, or -1 if
2113 * no mapping found.
2114 */
2115 int lookup(Object obj) {
2116 if (size == 0) {
2117 return -1;
2118 }
2119 int index = hash(obj) % spine.length;
2120 for (int i = spine[index]; i >= 0; i = next[i]) {
2121 if (objs[i] == obj) {
2122 return i;
2123 }
2124 }
2125 return -1;
2126 }
2127
2128 /**
2129 * Resets table to its initial (empty) state.
2130 */
2131 void clear() {
2132 Arrays.fill(spine, -1);
2133 Arrays.fill(objs, 0, size, null);
2134 size = 0;
2135 }
2136
2137 /**
2138 * Returns the number of mappings currently in table.
2139 */
2140 int size() {
2141 return size;
2142 }
2143
2144 /**
2145 * Inserts mapping object -> handle mapping into table. Assumes table
2146 * is large enough to accommodate new mapping.
2147 */
2148 private void insert(Object obj, int handle) {
2149 int index = hash(obj) % spine.length;
2150 objs[handle] = obj;
2151 next[handle] = spine[index];
2152 spine[index] = handle;
2153 }
2154
2155 /**
2156 * Expands the hash "spine" -- equivalent to increasing the number of
2157 * buckets in a conventional hash table.
2158 */
2159 private void growSpine() {
2160 spine = new int[(spine.length << 1) + 1];
2161 threshold = (int) (spine.length * loadFactor);
2162 Arrays.fill(spine, -1);
2163 for (int i = 0; i < size; i++) {
2164 insert(objs[i], i);
2165 }
2166 }
2167
2168 /**
2169 * Increases hash table capacity by lengthening entry arrays.
2170 */
2171 private void growEntries() {
2172 int newLength = (next.length << 1) + 1;
2173 int[] newNext = new int[newLength];
2174 System.arraycopy(next, 0, newNext, 0, size);
2175 next = newNext;
2176
2177 Object[] newObjs = new Object[newLength];
2178 System.arraycopy(objs, 0, newObjs, 0, size);
2179 objs = newObjs;
2180 }
2181
2182 /**
2183 * Returns hash value for given object.
2184 */
2185 private int hash(Object obj) {
2186 return System.identityHashCode(obj) & 0x7FFFFFFF;
2187 }
2188 }
2189
2190 /**
2191 * Lightweight identity hash table which maps objects to replacement
2192 * objects.
2193 */
2194 private static final class ReplaceTable {
2195
2196 /* maps object -> index */
2197 private final HandleTable htab;
2198 /* maps index -> replacement object */
2199 private Object[] reps;
2200
2201 /**
2202 * Creates new ReplaceTable with given capacity and load factor.
2203 */
2204 ReplaceTable(int initialCapacity, float loadFactor) {
2205 htab = new HandleTable(initialCapacity, loadFactor);
2206 reps = new Object[initialCapacity];
2207 }
2208
2209 /**
2210 * Enters mapping from object to replacement object.
2211 */
2212 void assign(Object obj, Object rep) {
2213 int index = htab.assign(obj);
2214 while (index >= reps.length) {
2215 grow();
2216 }
2217 reps[index] = rep;
2218 }
2219
2220 /**
2221 * Looks up and returns replacement for given object. If no
2222 * replacement is found, returns the lookup object itself.
2223 */
2224 Object lookup(Object obj) {
2225 int index = htab.lookup(obj);
2226 return (index >= 0) ? reps[index] : obj;
2227 }
2228
2229 /**
2230 * Resets table to its initial (empty) state.
2231 */
2232 void clear() {
2233 Arrays.fill(reps, 0, htab.size(), null);
2234 htab.clear();
2235 }
2236
2237 /**
2238 * Returns the number of mappings currently in table.
2239 */
2240 int size() {
2241 return htab.size();
2242 }
2243
2244 /**
2245 * Increases table capacity.
2246 */
2247 private void grow() {
2248 Object[] newReps = new Object[(reps.length << 1) + 1];
2249 System.arraycopy(reps, 0, newReps, 0, reps.length);
2250 reps = newReps;
2251 }
2252 }
2253
2254 /**
2255 * Stack to keep debug information about the state of the
2256 * serialization process, for embedding in exception messages.
2257 */
2258 private static final class DebugTraceInfoStack {
2259 private final List<String> stack;
2260
2261 DebugTraceInfoStack() {
2262 stack = new ArrayList<>();
2263 }
2264
2265 /**
2266 * Removes all of the elements from enclosed list.
2267 */
2268 void clear() {
2269 stack.clear();
2270 }
2271
2272 /**
2273 * Removes the object at the top of enclosed list.
2274 */
2275 void pop() {
2276 stack.remove(stack.size()-1);
2277 }
2278
2279 /**
2280 * Pushes a String onto the top of enclosed list.
2281 */
2282 void push(String entry) {
2283 stack.add("\t- " + entry);
2284 }
2285
2286 /**
2287 * Returns a string representation of this object
2288 */
2289 public String toString() {
2290 StringJoiner sj = new StringJoiner("\n");
2291 for (int i = stack.size() - 1; i >= 0; i--) {
2292 sj.add(stack.get(i));
2293 }
2294 return sj.toString();
2295 }
2296 }
2297
2298 }