1 /*
2 * Copyright (c) 1996, 2022, 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.security.AccessController;
29 import java.security.PrivilegedAction;
30 import java.util.ArrayList;
31 import java.util.Arrays;
32 import java.util.List;
33 import java.util.Objects;
34 import java.util.StringJoiner;
35 import sun.reflect.misc.ReflectUtil;
36
37 /**
38 * An ObjectOutputStream writes primitive data types and graphs of Java objects
39 * to an OutputStream. The objects can be read (reconstituted) using an
40 * ObjectInputStream. Persistent storage of objects can be accomplished by
41 * using a file for the stream. If the stream is a network socket stream, the
42 * objects can be reconstituted on another host or in another process.
43 *
44 * <p>Only objects that support the java.io.Serializable interface can be
45 * written to streams. The class of each serializable object is encoded
46 * including the class name and signature of the class, the values of the
47 * object's fields and arrays, and the closure of any other objects referenced
48 * from the initial objects.
49 *
50 * <p>The method writeObject is used to write an object to the stream. Any
51 * object, including Strings and arrays, is written with writeObject. Multiple
52 * objects or primitives can be written to the stream. The objects must be
53 * read back from the corresponding ObjectInputstream with the same types and
54 * in the same order as they were written.
55 *
56 * <p>Primitive data types can also be written to the stream using the
57 * appropriate methods from DataOutput. Strings can also be written using the
58 * writeUTF method.
59 *
60 * <p>The default serialization mechanism for an object writes the class of the
61 * object, the class signature, and the values of all non-transient and
62 * non-static fields. References to other objects (except in transient or
63 * static fields) cause those objects to be written also. Multiple references
64 * to a single object are encoded using a reference sharing mechanism so that
65 * graphs of objects can be restored to the same shape as when the original was
66 * written.
67 *
68 * <p>For example to write an object that can be read by the example in
69 * ObjectInputStream:
70 * <br>
71 * <pre>
72 * FileOutputStream fos = new FileOutputStream("t.tmp");
73 * ObjectOutputStream oos = new ObjectOutputStream(fos);
74 *
75 * oos.writeInt(12345);
76 * oos.writeObject("Today");
77 * oos.writeObject(new Date());
78 *
79 * oos.close();
80 * </pre>
81 *
82 * <p>Serializable classes that require special handling during the
83 * serialization and deserialization process should implement methods
84 * with the following signatures:
85 *
86 * <br>
87 * <pre>
88 * private void readObject(java.io.ObjectInputStream stream)
89 * throws IOException, ClassNotFoundException;
90 * private void writeObject(java.io.ObjectOutputStream stream)
91 * throws IOException
92 * private void readObjectNoData()
93 * throws ObjectStreamException;
94 * </pre>
95 *
96 * <p>The method name, modifiers, return type, and number and type of
97 * parameters must match exactly for the method to be used by
98 * serialization or deserialization. The methods should only be
99 * declared to throw checked exceptions consistent with these
100 * signatures.
101 *
102 * <p>The writeObject method is responsible for writing the state of the object
103 * for its particular class so that the corresponding readObject method can
104 * restore it. The method does not need to concern itself with the state
105 * belonging to the object's superclasses or subclasses. State is saved by
106 * writing the individual fields to the ObjectOutputStream using the
107 * writeObject method or by using the methods for primitive data types
108 * supported by DataOutput.
109 *
110 * <p>Serialization does not write out the fields of any object that does not
111 * implement the java.io.Serializable interface. Subclasses of Objects that
112 * are not serializable can be serializable. In this case the non-serializable
113 * class must have a no-arg constructor to allow its fields to be initialized.
114 * In this case it is the responsibility of the subclass to save and restore
115 * the state of the non-serializable class. It is frequently the case that the
116 * fields of that class are accessible (public, package, or protected) or that
117 * there are get and set methods that can be used to restore the state.
118 *
119 * <p>Serialization of an object can be prevented by implementing writeObject
120 * and readObject methods that throw the NotSerializableException. The
121 * exception will be caught by the ObjectOutputStream and abort the
122 * serialization process.
123 *
124 * <p>Implementing the Externalizable interface allows the object to assume
125 * complete control over the contents and format of the object's serialized
126 * form. The methods of the Externalizable interface, writeExternal and
127 * readExternal, are called to save and restore the objects state. When
128 * implemented by a class they can write and read their own state using all of
129 * the methods of ObjectOutput and ObjectInput. It is the responsibility of
130 * the objects to handle any versioning that occurs.
131 * Value classes implementing {@link Externalizable} cannot be serialized
132 * or deserialized, the value object is immutable and the state cannot be restored.
133 * Use {@link Serializable} {@code writeReplace} to delegate to another serializable
134 * object such as a record.
135 *
136 * Value objects cannot be {@code java.io.Externalizable}.
137 *
138 * <p>Enum constants are serialized differently than ordinary serializable or
139 * externalizable objects. The serialized form of an enum constant consists
140 * solely of its name; field values of the constant are not transmitted. To
141 * serialize an enum constant, ObjectOutputStream writes the string returned by
142 * the constant's name method. Like other serializable or externalizable
143 * objects, enum constants can function as the targets of back references
144 * appearing subsequently in the serialization stream. The process by which
145 * enum constants are serialized cannot be customized; any class-specific
146 * writeObject and writeReplace methods defined by enum types are ignored
147 * during serialization. Similarly, any serialPersistentFields or
148 * serialVersionUID field declarations are also ignored--all enum types have a
149 * fixed serialVersionUID of 0L.
150 *
151 * <p>Primitive data, excluding serializable fields and externalizable data, is
152 * written to the ObjectOutputStream in block-data records. A block data record
153 * is composed of a header and data. The block data header consists of a marker
154 * and the number of bytes to follow the header. Consecutive primitive data
155 * writes are merged into one block-data record. The blocking factor used for
156 * a block-data record will be 1024 bytes. Each block-data record will be
157 * filled up to 1024 bytes, or be written whenever there is a termination of
158 * block-data mode. Calls to the ObjectOutputStream methods writeObject,
159 * defaultWriteObject and writeFields initially terminate any existing
160 * block-data record.
161 *
162 * <p>Records are serialized differently than ordinary serializable or externalizable
163 * objects, see <a href="ObjectInputStream.html#record-serialization">record serialization</a>.
164 *
165 * @author Mike Warres
166 * @author Roger Riggs
167 * @see java.io.DataOutput
168 * @see java.io.ObjectInputStream
169 * @see java.io.Serializable
170 * @see java.io.Externalizable
171 * @see <a href="{@docRoot}/../specs/serialization/output.html">
172 * <cite>Java Object Serialization Specification,</cite> Section 2, "Object Output Classes"</a>
173 * @since 1.1
174 */
175 public class ObjectOutputStream
176 extends OutputStream implements ObjectOutput, ObjectStreamConstants
177 {
178
179 private static class Caches {
180 /** cache of subclass security audit results */
181 static final ClassValue<Boolean> subclassAudits =
182 new ClassValue<>() {
183 @Override
184 protected Boolean computeValue(Class<?> type) {
185 return auditSubclass(type);
186 }
187 };
188 }
189
190 /** filter stream for handling block data conversion */
191 private final BlockDataOutputStream bout;
192 /** obj -> wire handle map */
193 private final HandleTable handles;
194 /** obj -> replacement obj map */
195 private final ReplaceTable subs;
196 /** stream protocol version */
197 private int protocol = PROTOCOL_VERSION_2;
198 /** recursion depth */
199 private int depth;
200
201 /** buffer for writing primitive field values */
202 private byte[] primVals;
203
204 /** if true, invoke writeObjectOverride() instead of writeObject() */
205 private final boolean enableOverride;
206 /** if true, invoke replaceObject() */
207 private boolean enableReplace;
208
209 // values below valid only during upcalls to writeObject()/writeExternal()
210 /**
211 * Context during upcalls to class-defined writeObject methods; holds
212 * object currently being serialized and descriptor for current class.
213 * Null when not during writeObject upcall.
214 */
215 private SerialCallbackContext curContext;
216 /** current PutField object */
217 private PutFieldImpl curPut;
218
219 /** custom storage for debug trace info */
220 private final DebugTraceInfoStack debugInfoStack;
221
222 /**
223 * value of "sun.io.serialization.extendedDebugInfo" property,
224 * as true or false for extended information about exception's place
225 */
226 @SuppressWarnings("removal")
227 private static final boolean extendedDebugInfo =
228 java.security.AccessController.doPrivileged(
229 new sun.security.action.GetBooleanAction(
230 "sun.io.serialization.extendedDebugInfo")).booleanValue();
231
232 /**
233 * Creates an ObjectOutputStream that writes to the specified OutputStream.
234 * This constructor writes the serialization stream header to the
235 * underlying stream; callers may wish to flush the stream immediately to
236 * ensure that constructors for receiving ObjectInputStreams will not block
237 * when reading the header.
238 *
239 * <p>If a security manager is installed, this constructor will check for
240 * the "enableSubclassImplementation" SerializablePermission when invoked
241 * directly or indirectly by the constructor of a subclass which overrides
242 * the ObjectOutputStream.putFields or ObjectOutputStream.writeUnshared
243 * methods.
244 *
245 * @param out output stream to write to
246 * @throws IOException if an I/O error occurs while writing stream header
247 * @throws SecurityException if untrusted subclass illegally overrides
248 * security-sensitive methods
249 * @throws NullPointerException if {@code out} is {@code null}
250 * @since 1.4
251 * @see ObjectOutputStream#ObjectOutputStream()
252 * @see ObjectOutputStream#putFields()
253 * @see ObjectInputStream#ObjectInputStream(InputStream)
254 */
255 public ObjectOutputStream(OutputStream out) throws IOException {
256 verifySubclass();
257 bout = new BlockDataOutputStream(out);
258 handles = new HandleTable(10, (float) 3.00);
259 subs = new ReplaceTable(10, (float) 3.00);
260 enableOverride = false;
261 writeStreamHeader();
262 bout.setBlockDataMode(true);
263 if (extendedDebugInfo) {
264 debugInfoStack = new DebugTraceInfoStack();
265 } else {
266 debugInfoStack = null;
267 }
268 }
269
270 /**
271 * Provide a way for subclasses that are completely reimplementing
272 * ObjectOutputStream to not have to allocate private data just used by
273 * this implementation of ObjectOutputStream.
274 *
275 * <p>If there is a security manager installed, this method first calls the
276 * security manager's {@code checkPermission} method with a
277 * {@code SerializablePermission("enableSubclassImplementation")}
278 * permission to ensure it's ok to enable subclassing.
279 *
280 * @throws SecurityException if a security manager exists and its
281 * {@code checkPermission} method denies enabling
282 * subclassing.
283 * @throws IOException if an I/O error occurs while creating this stream
284 * @see SecurityManager#checkPermission
285 * @see java.io.SerializablePermission
286 */
287 protected ObjectOutputStream() throws IOException, SecurityException {
288 @SuppressWarnings("removal")
289 SecurityManager sm = System.getSecurityManager();
290 if (sm != null) {
291 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
292 }
293 bout = null;
294 handles = null;
295 subs = null;
296 enableOverride = true;
297 debugInfoStack = null;
298 }
299
300 /**
301 * Specify stream protocol version to use when writing the stream.
302 *
303 * <p>This routine provides a hook to enable the current version of
304 * Serialization to write in a format that is backwards compatible to a
305 * previous version of the stream format.
306 *
307 * <p>Every effort will be made to avoid introducing additional
308 * backwards incompatibilities; however, sometimes there is no
309 * other alternative.
310 *
311 * @param version use ProtocolVersion from java.io.ObjectStreamConstants.
312 * @throws IllegalStateException if called after any objects
313 * have been serialized.
314 * @throws IllegalArgumentException if invalid version is passed in.
315 * @throws IOException if I/O errors occur
316 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
317 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_2
318 * @since 1.2
319 */
320 public void useProtocolVersion(int version) throws IOException {
321 if (handles.size() != 0) {
322 // REMIND: implement better check for pristine stream?
323 throw new IllegalStateException("stream non-empty");
324 }
325 switch (version) {
326 case PROTOCOL_VERSION_1:
327 case PROTOCOL_VERSION_2:
328 protocol = version;
329 break;
330
331 default:
332 throw new IllegalArgumentException(
333 "unknown version: " + version);
334 }
335 }
336
337 /**
338 * Write the specified object to the ObjectOutputStream. The class of the
339 * object, the signature of the class, and the values of the non-transient
340 * and non-static fields of the class and all of its supertypes are
341 * written. Default serialization for a class can be overridden using the
342 * writeObject and the readObject methods. Objects referenced by this
343 * object are written transitively so that a complete equivalent graph of
344 * objects can be reconstructed by an ObjectInputStream.
345 *
346 * <p>Exceptions are thrown for problems with the OutputStream and for
347 * classes that should not be serialized. All exceptions are fatal to the
348 * OutputStream, which is left in an indeterminate state, and it is up to
349 * the caller to ignore or recover the stream state.
350 *
351 * @throws InvalidClassException Something is wrong with a class used by
352 * serialization.
353 * @throws NotSerializableException Some object to be serialized does not
354 * implement the java.io.Serializable interface.
355 * @throws IOException Any exception thrown by the underlying
356 * OutputStream.
357 */
358 public final void writeObject(Object obj) throws IOException {
359 if (enableOverride) {
360 writeObjectOverride(obj);
361 return;
362 }
363 try {
364 writeObject0(obj, false);
365 } catch (IOException ex) {
366 if (depth == 0) {
367 writeFatalException(ex);
368 }
369 throw ex;
370 }
371 }
372
373 /**
374 * Method used by subclasses to override the default writeObject method.
375 * This method is called by trusted subclasses of ObjectOutputStream that
376 * constructed ObjectOutputStream using the protected no-arg constructor.
377 * The subclass is expected to provide an override method with the modifier
378 * "final".
379 *
380 * @param obj object to be written to the underlying stream
381 * @throws IOException if there are I/O errors while writing to the
382 * underlying stream
383 * @see #ObjectOutputStream()
384 * @see #writeObject(Object)
385 * @since 1.2
386 */
387 protected void writeObjectOverride(Object obj) throws IOException {
388 }
389
390 /**
391 * Writes an "unshared" object to the ObjectOutputStream. This method is
392 * identical to writeObject, except that it always writes the given object
393 * as a new, unique object in the stream (as opposed to a back-reference
394 * pointing to a previously serialized instance). Specifically:
395 * <ul>
396 * <li>An object written via writeUnshared is always serialized in the
397 * same manner as a newly appearing object (an object that has not
398 * been written to the stream yet), regardless of whether or not the
399 * object has been written previously.
400 *
401 * <li>If writeObject is used to write an object that has been previously
402 * written with writeUnshared, the previous writeUnshared operation
403 * is treated as if it were a write of a separate object. In other
404 * words, ObjectOutputStream will never generate back-references to
405 * object data written by calls to writeUnshared.
406 * </ul>
407 * While writing an object via writeUnshared does not in itself guarantee a
408 * unique reference to the object when it is deserialized, it allows a
409 * single object to be defined multiple times in a stream, so that multiple
410 * calls to readUnshared by the receiver will not conflict. Note that the
411 * rules described above only apply to the base-level object written with
412 * writeUnshared, and not to any transitively referenced sub-objects in the
413 * object graph to be serialized.
414 *
415 * <p>ObjectOutputStream subclasses which override this method can only be
416 * constructed in security contexts possessing the
417 * "enableSubclassImplementation" SerializablePermission; any attempt to
418 * instantiate such a subclass without this permission will cause a
419 * SecurityException to be thrown.
420 *
421 * @param obj object to write to stream
422 * @throws NotSerializableException if an object in the graph to be
423 * serialized does not implement the Serializable interface
424 * @throws InvalidClassException if a problem exists with the class of an
425 * object to be serialized
426 * @throws IOException if an I/O error occurs during serialization
427 * @since 1.4
428 */
429 public void writeUnshared(Object obj) throws IOException {
430 try {
431 writeObject0(obj, true);
432 } catch (IOException ex) {
433 if (depth == 0) {
434 writeFatalException(ex);
435 }
436 throw ex;
437 }
438 }
439
440 /**
441 * Write the non-static and non-transient fields of the current class to
442 * this stream. This may only be called from the writeObject method of the
443 * class being serialized. It will throw the NotActiveException if it is
444 * called otherwise.
445 *
446 * @throws IOException if I/O errors occur while writing to the underlying
447 * {@code OutputStream}
448 */
449 public void defaultWriteObject() throws IOException {
450 SerialCallbackContext ctx = curContext;
451 if (ctx == null) {
452 throw new NotActiveException("not in call to writeObject");
453 }
454 Object curObj = ctx.getObj();
455 ObjectStreamClass curDesc = ctx.getDesc();
456 bout.setBlockDataMode(false);
457 defaultWriteFields(curObj, curDesc);
458 bout.setBlockDataMode(true);
459 }
460
461 /**
462 * Retrieve the object used to buffer persistent fields to be written to
463 * the stream. The fields will be written to the stream when writeFields
464 * method is called.
465 *
466 * @return an instance of the class Putfield that holds the serializable
467 * fields
468 * @throws IOException if I/O errors occur
469 * @since 1.2
470 */
471 public ObjectOutputStream.PutField putFields() throws IOException {
472 if (curPut == null) {
473 SerialCallbackContext ctx = curContext;
474 if (ctx == null) {
475 throw new NotActiveException("not in call to writeObject");
476 }
477 ctx.checkAndSetUsed();
478 ObjectStreamClass curDesc = ctx.getDesc();
479 curPut = new PutFieldImpl(curDesc);
480 }
481 return curPut;
482 }
483
484 /**
485 * Write the buffered fields to the stream.
486 *
487 * @throws IOException if I/O errors occur while writing to the underlying
488 * stream
489 * @throws NotActiveException Called when a classes writeObject method was
490 * not called to write the state of the object.
491 * @since 1.2
492 */
493 public void writeFields() throws IOException {
494 if (curPut == null) {
495 throw new NotActiveException("no current PutField object");
496 }
497 bout.setBlockDataMode(false);
498 curPut.writeFields();
499 bout.setBlockDataMode(true);
500 }
501
502 /**
503 * Reset will disregard the state of any objects already written to the
504 * stream. The state is reset to be the same as a new ObjectOutputStream.
505 * The current point in the stream is marked as reset so the corresponding
506 * ObjectInputStream will be reset at the same point. Objects previously
507 * written to the stream will not be referred to as already being in the
508 * stream. They will be written to the stream again.
509 *
510 * @throws IOException if reset() is invoked while serializing an object.
511 */
512 public void reset() throws IOException {
513 if (depth != 0) {
514 throw new IOException("stream active");
515 }
516 bout.setBlockDataMode(false);
517 bout.writeByte(TC_RESET);
518 clear();
519 bout.setBlockDataMode(true);
520 }
521
522 /**
523 * Subclasses may implement this method to allow class data to be stored in
524 * the stream. By default this method does nothing. The corresponding
525 * method in ObjectInputStream is resolveClass. This method is called
526 * exactly once for each unique class in the stream. The class name and
527 * signature will have already been written to the stream. This method may
528 * make free use of the ObjectOutputStream to save any representation of
529 * the class it deems suitable (for example, the bytes of the class file).
530 * The resolveClass method in the corresponding subclass of
531 * ObjectInputStream must read and use any data or objects written by
532 * annotateClass.
533 *
534 * @param cl the class to annotate custom data for
535 * @throws IOException Any exception thrown by the underlying
536 * OutputStream.
537 */
538 protected void annotateClass(Class<?> cl) throws IOException {
539 }
540
541 /**
542 * Subclasses may implement this method to store custom data in the stream
543 * along with descriptors for dynamic proxy classes.
544 *
545 * <p>This method is called exactly once for each unique proxy class
546 * descriptor in the stream. The default implementation of this method in
547 * {@code ObjectOutputStream} does nothing.
548 *
549 * <p>The corresponding method in {@code ObjectInputStream} is
550 * {@code resolveProxyClass}. For a given subclass of
551 * {@code ObjectOutputStream} that overrides this method, the
552 * {@code resolveProxyClass} method in the corresponding subclass of
553 * {@code ObjectInputStream} must read any data or objects written by
554 * {@code annotateProxyClass}.
555 *
556 * @param cl the proxy class to annotate custom data for
557 * @throws IOException any exception thrown by the underlying
558 * {@code OutputStream}
559 * @see ObjectInputStream#resolveProxyClass(String[])
560 * @since 1.3
561 */
562 protected void annotateProxyClass(Class<?> cl) throws IOException {
563 }
564
565 /**
566 * This method will allow trusted subclasses of ObjectOutputStream to
567 * substitute one object for another during serialization. Replacing
568 * objects is disabled until enableReplaceObject is called. The
569 * enableReplaceObject method checks that the stream requesting to do
570 * replacement can be trusted. The first occurrence of each object written
571 * into the serialization stream is passed to replaceObject. Subsequent
572 * references to the object are replaced by the object returned by the
573 * original call to replaceObject. To ensure that the private state of
574 * objects is not unintentionally exposed, only trusted streams may use
575 * replaceObject.
576 *
577 * <p>The ObjectOutputStream.writeObject method takes a parameter of type
578 * Object (as opposed to type Serializable) to allow for cases where
579 * non-serializable objects are replaced by serializable ones.
580 *
581 * <p>When a subclass is replacing objects it must ensure that either a
582 * complementary substitution must be made during deserialization or that
583 * the substituted object is compatible with every field where the
584 * reference will be stored. Objects whose type is not a subclass of the
585 * type of the field or array element abort the serialization by raising an
586 * exception and the object is not be stored.
587 *
588 * <p>This method is called only once when each object is first
589 * encountered. All subsequent references to the object will be redirected
590 * to the new object. This method should return the object to be
591 * substituted or the original object.
592 *
593 * <p>Null can be returned as the object to be substituted, but may cause
594 * NullReferenceException in classes that contain references to the
595 * original object since they may be expecting an object instead of
596 * null.
597 *
598 * @param obj the object to be replaced
599 * @return the alternate object that replaced the specified one
600 * @throws IOException Any exception thrown by the underlying
601 * OutputStream.
602 */
603 protected Object replaceObject(Object obj) throws IOException {
604 return obj;
605 }
606
607 /**
608 * Enables the stream to do replacement of objects written to the stream. When
609 * enabled, the {@link #replaceObject} method is called for every object being
610 * serialized.
611 *
612 * <p>If object replacement is currently not enabled, and
613 * {@code enable} is true, and there is a security manager installed,
614 * this method first calls the security manager's
615 * {@code checkPermission} method with the
616 * {@code SerializablePermission("enableSubstitution")} permission to
617 * ensure that the caller is permitted to enable the stream to do replacement
618 * of objects written to the stream.
619 *
620 * @param enable true for enabling use of {@code replaceObject} for
621 * every object being serialized
622 * @return the previous setting before this method was invoked
623 * @throws SecurityException if a security manager exists and its
624 * {@code checkPermission} method denies enabling the stream
625 * to do replacement of objects written to the stream.
626 * @see SecurityManager#checkPermission
627 * @see java.io.SerializablePermission
628 */
629 protected boolean enableReplaceObject(boolean enable)
630 throws SecurityException
631 {
632 if (enable == enableReplace) {
633 return enable;
634 }
635 if (enable) {
636 @SuppressWarnings("removal")
637 SecurityManager sm = System.getSecurityManager();
638 if (sm != null) {
639 sm.checkPermission(SUBSTITUTION_PERMISSION);
640 }
641 }
642 enableReplace = enable;
643 return !enableReplace;
644 }
645
646 /**
647 * The writeStreamHeader method is provided so subclasses can append or
648 * prepend their own header to the stream. It writes the magic number and
649 * version to the stream.
650 *
651 * @throws IOException if I/O errors occur while writing to the underlying
652 * stream
653 */
654 protected void writeStreamHeader() throws IOException {
655 bout.writeShort(STREAM_MAGIC);
656 bout.writeShort(STREAM_VERSION);
657 }
658
659 /**
660 * Write the specified class descriptor to the ObjectOutputStream. Class
661 * descriptors are used to identify the classes of objects written to the
662 * stream. Subclasses of ObjectOutputStream may override this method to
663 * customize the way in which class descriptors are written to the
664 * serialization stream. The corresponding method in ObjectInputStream,
665 * {@link ObjectInputStream#readClassDescriptor readClassDescriptor}, should then be overridden to
666 * reconstitute the class descriptor from its custom stream representation.
667 * By default, this method writes class descriptors according to the format
668 * defined in the <a href="{@docRoot}/../specs/serialization/index.html">
669 * <cite>Java Object Serialization Specification</cite></a>.
670 *
671 * <p>Note that this method will only be called if the ObjectOutputStream
672 * is not using the old serialization stream format (set by calling
673 * ObjectOutputStream's {@code useProtocolVersion} method). If this
674 * serialization stream is using the old format
675 * ({@code PROTOCOL_VERSION_1}), the class descriptor will be written
676 * internally in a manner that cannot be overridden or customized.
677 *
678 * @param desc class descriptor to write to the stream
679 * @throws IOException If an I/O error has occurred.
680 * @see java.io.ObjectInputStream#readClassDescriptor()
681 * @see #useProtocolVersion(int)
682 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
683 * @since 1.3
684 */
685 protected void writeClassDescriptor(ObjectStreamClass desc)
686 throws IOException
687 {
688 desc.writeNonProxy(this);
689 }
690
691 /**
692 * Writes a byte. This method will block until the byte is actually
693 * written.
694 *
695 * @param val the byte to be written to the stream
696 * @throws IOException If an I/O error has occurred.
697 */
698 @Override
699 public void write(int val) throws IOException {
700 bout.write(val);
701 }
702
703 /**
704 * Writes an array of bytes. This method will block until the bytes are
705 * actually written.
706 *
707 * @param buf the data to be written
708 * @throws IOException If an I/O error has occurred.
709 */
710 @Override
711 public void write(byte[] buf) throws IOException {
712 bout.write(buf, 0, buf.length, false);
713 }
714
715 /**
716 * Writes a sub array of bytes.
717 *
718 * @param buf the data to be written
719 * @param off the start offset in the data
720 * @param len the number of bytes that are written
721 * @throws IOException {@inheritDoc}
722 */
723 @Override
724 public void write(byte[] buf, int off, int len) throws IOException {
725 if (buf == null) {
726 throw new NullPointerException();
727 }
728 Objects.checkFromIndexSize(off, len, buf.length);
729 bout.write(buf, off, len, false);
730 }
731
732 /**
733 * Flushes the stream. This will write any buffered output bytes and flush
734 * through to the underlying stream.
735 *
736 * @throws IOException {@inheritDoc}
737 */
738 @Override
739 public void flush() throws IOException {
740 bout.flush();
741 }
742
743 /**
744 * Drain any buffered data in ObjectOutputStream. Similar to flush but
745 * does not propagate the flush to the underlying stream.
746 *
747 * @throws IOException if I/O errors occur while writing to the underlying
748 * stream
749 */
750 protected void drain() throws IOException {
751 bout.drain();
752 }
753
754 /**
755 * Closes the stream. This method must be called to release any resources
756 * associated with the stream.
757 *
758 * @throws IOException If an I/O error has occurred.
759 */
760 @Override
761 public void close() throws IOException {
762 flush();
763 clear();
764 bout.close();
765 }
766
767 /**
768 * Writes a boolean.
769 *
770 * @param val the boolean to be written
771 * @throws IOException if I/O errors occur while writing to the underlying
772 * stream
773 */
774 public void writeBoolean(boolean val) throws IOException {
775 bout.writeBoolean(val);
776 }
777
778 /**
779 * Writes an 8 bit byte.
780 *
781 * @param val the byte value to be written
782 * @throws IOException if I/O errors occur while writing to the underlying
783 * stream
784 */
785 public void writeByte(int val) throws IOException {
786 bout.writeByte(val);
787 }
788
789 /**
790 * Writes a 16 bit short.
791 *
792 * @param val the short value to be written
793 * @throws IOException if I/O errors occur while writing to the underlying
794 * stream
795 */
796 public void writeShort(int val) throws IOException {
797 bout.writeShort(val);
798 }
799
800 /**
801 * Writes a 16 bit char.
802 *
803 * @param val the char value to be written
804 * @throws IOException if I/O errors occur while writing to the underlying
805 * stream
806 */
807 public void writeChar(int val) throws IOException {
808 bout.writeChar(val);
809 }
810
811 /**
812 * Writes a 32 bit int.
813 *
814 * @param val the integer value to be written
815 * @throws IOException if I/O errors occur while writing to the underlying
816 * stream
817 */
818 public void writeInt(int val) throws IOException {
819 bout.writeInt(val);
820 }
821
822 /**
823 * Writes a 64 bit long.
824 *
825 * @param val the long value to be written
826 * @throws IOException if I/O errors occur while writing to the underlying
827 * stream
828 */
829 public void writeLong(long val) throws IOException {
830 bout.writeLong(val);
831 }
832
833 /**
834 * Writes a 32 bit float.
835 *
836 * @param val the float value to be written
837 * @throws IOException if I/O errors occur while writing to the underlying
838 * stream
839 */
840 public void writeFloat(float val) throws IOException {
841 bout.writeFloat(val);
842 }
843
844 /**
845 * Writes a 64 bit double.
846 *
847 * @param val the double value to be written
848 * @throws IOException if I/O errors occur while writing to the underlying
849 * stream
850 */
851 public void writeDouble(double val) throws IOException {
852 bout.writeDouble(val);
853 }
854
855 /**
856 * Writes a String as a sequence of bytes.
857 *
858 * @param str the String of bytes to be written
859 * @throws IOException if I/O errors occur while writing to the underlying
860 * stream
861 */
862 public void writeBytes(String str) throws IOException {
863 bout.writeBytes(str);
864 }
865
866 /**
867 * Writes a String as a sequence of chars.
868 *
869 * @param str the String of chars to be written
870 * @throws IOException if I/O errors occur while writing to the underlying
871 * stream
872 */
873 public void writeChars(String str) throws IOException {
874 bout.writeChars(str);
875 }
876
877 /**
878 * Primitive data write of this String in
879 * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
880 * format. Note that there is a
881 * significant difference between writing a String into the stream as
882 * primitive data or as an Object. A String instance written by writeObject
883 * is written into the stream as a String initially. Future writeObject()
884 * calls write references to the string into the stream.
885 *
886 * @param str the String to be written
887 * @throws IOException if I/O errors occur while writing to the underlying
888 * stream
889 */
890 public void writeUTF(String str) throws IOException {
891 bout.writeUTF(str);
892 }
893
894 /**
895 * Provide programmatic access to the persistent fields to be written
896 * to ObjectOutput.
897 *
898 * @since 1.2
899 */
900 public abstract static class PutField {
901 /**
902 * Constructor for subclasses to call.
903 */
904 public PutField() {}
905
906 /**
907 * Put the value of the named boolean field into the persistent field.
908 *
909 * @param name the name of the serializable field
910 * @param val the value to assign to the field
911 * @throws IllegalArgumentException if {@code name} does not
912 * match the name of a serializable field for the class whose fields
913 * are being written, or if the type of the named field is not
914 * {@code boolean}
915 */
916 public abstract void put(String name, boolean val);
917
918 /**
919 * Put the value of the named byte field into the persistent field.
920 *
921 * @param name the name of the serializable field
922 * @param val the value to assign to the field
923 * @throws IllegalArgumentException if {@code name} does not
924 * match the name of a serializable field for the class whose fields
925 * are being written, or if the type of the named field is not
926 * {@code byte}
927 */
928 public abstract void put(String name, byte val);
929
930 /**
931 * Put the value of the named char field into the persistent field.
932 *
933 * @param name the name of the serializable field
934 * @param val the value to assign to the field
935 * @throws IllegalArgumentException if {@code name} does not
936 * match the name of a serializable field for the class whose fields
937 * are being written, or if the type of the named field is not
938 * {@code char}
939 */
940 public abstract void put(String name, char val);
941
942 /**
943 * Put the value of the named short field into the persistent field.
944 *
945 * @param name the name of the serializable field
946 * @param val the value to assign to the field
947 * @throws IllegalArgumentException if {@code name} does not
948 * match the name of a serializable field for the class whose fields
949 * are being written, or if the type of the named field is not
950 * {@code short}
951 */
952 public abstract void put(String name, short val);
953
954 /**
955 * Put the value of the named int field into the persistent field.
956 *
957 * @param name the name of the serializable field
958 * @param val the value to assign to the field
959 * @throws IllegalArgumentException if {@code name} does not
960 * match the name of a serializable field for the class whose fields
961 * are being written, or if the type of the named field is not
962 * {@code int}
963 */
964 public abstract void put(String name, int val);
965
966 /**
967 * Put the value of the named long field into the persistent field.
968 *
969 * @param name the name of the serializable field
970 * @param val the value to assign to the field
971 * @throws IllegalArgumentException if {@code name} does not
972 * match the name of a serializable field for the class whose fields
973 * are being written, or if the type of the named field is not
974 * {@code long}
975 */
976 public abstract void put(String name, long val);
977
978 /**
979 * Put the value of the named float field into the persistent field.
980 *
981 * @param name the name of the serializable field
982 * @param val the value to assign to the field
983 * @throws IllegalArgumentException if {@code name} does not
984 * match the name of a serializable field for the class whose fields
985 * are being written, or if the type of the named field is not
986 * {@code float}
987 */
988 public abstract void put(String name, float val);
989
990 /**
991 * Put the value of the named double field into the persistent field.
992 *
993 * @param name the name of the serializable field
994 * @param val the value to assign to the field
995 * @throws IllegalArgumentException if {@code name} does not
996 * match the name of a serializable field for the class whose fields
997 * are being written, or if the type of the named field is not
998 * {@code double}
999 */
1000 public abstract void put(String name, double val);
1001
1002 /**
1003 * Put the value of the named Object field into the persistent field.
1004 *
1005 * @param name the name of the serializable field
1006 * @param val the value to assign to the field
1007 * (which may be {@code null})
1008 * @throws IllegalArgumentException if {@code name} does not
1009 * match the name of a serializable field for the class whose fields
1010 * are being written, or if the type of the named field is not a
1011 * reference type
1012 */
1013 public abstract void put(String name, Object val);
1014
1015 /**
1016 * Write the data and fields to the specified ObjectOutput stream,
1017 * which must be the same stream that produced this
1018 * {@code PutField} object.
1019 *
1020 * @param out the stream to write the data and fields to
1021 * @throws IOException if I/O errors occur while writing to the
1022 * underlying stream
1023 * @throws IllegalArgumentException if the specified stream is not
1024 * the same stream that produced this {@code PutField}
1025 * object
1026 * @deprecated This method does not write the values contained by this
1027 * {@code PutField} object in a proper format, and may
1028 * result in corruption of the serialization stream. The
1029 * correct way to write {@code PutField} data is by
1030 * calling the {@link java.io.ObjectOutputStream#writeFields()}
1031 * method.
1032 */
1033 @Deprecated
1034 public abstract void write(ObjectOutput out) throws IOException;
1035 }
1036
1037
1038 /**
1039 * Returns protocol version in use.
1040 */
1041 int getProtocolVersion() {
1042 return protocol;
1043 }
1044
1045 /**
1046 * Writes string without allowing it to be replaced in stream. Used by
1047 * ObjectStreamClass to write class descriptor type strings.
1048 */
1049 void writeTypeString(String str) throws IOException {
1050 int handle;
1051 if (str == null) {
1052 writeNull();
1053 } else if ((handle = handles.lookup(str)) != -1) {
1054 writeHandle(handle);
1055 } else {
1056 writeString(str, false);
1057 }
1058 }
1059
1060 /**
1061 * Verifies that this (possibly subclass) instance can be constructed
1062 * without violating security constraints: the subclass must not override
1063 * security-sensitive non-final methods, or else the
1064 * "enableSubclassImplementation" SerializablePermission is checked.
1065 */
1066 private void verifySubclass() {
1067 Class<?> cl = getClass();
1068 if (cl == ObjectOutputStream.class) {
1069 return;
1070 }
1071 @SuppressWarnings("removal")
1072 SecurityManager sm = System.getSecurityManager();
1073 if (sm == null) {
1074 return;
1075 }
1076 boolean result = Caches.subclassAudits.get(cl);
1077 if (!result) {
1078 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
1079 }
1080 }
1081
1082 /**
1083 * Performs reflective checks on given subclass to verify that it doesn't
1084 * override security-sensitive non-final methods. Returns TRUE if subclass
1085 * is "safe", FALSE otherwise.
1086 */
1087 @SuppressWarnings("removal")
1088 private static Boolean auditSubclass(Class<?> subcl) {
1089 return AccessController.doPrivileged(
1090 new PrivilegedAction<>() {
1091 public Boolean run() {
1092 for (Class<?> cl = subcl;
1093 cl != ObjectOutputStream.class;
1094 cl = cl.getSuperclass())
1095 {
1096 try {
1097 cl.getDeclaredMethod(
1098 "writeUnshared", new Class<?>[] { Object.class });
1099 return Boolean.FALSE;
1100 } catch (NoSuchMethodException ex) {
1101 }
1102 try {
1103 cl.getDeclaredMethod("putFields", (Class<?>[]) null);
1104 return Boolean.FALSE;
1105 } catch (NoSuchMethodException ex) {
1106 }
1107 }
1108 return Boolean.TRUE;
1109 }
1110 }
1111 );
1112 }
1113
1114 /**
1115 * Clears internal data structures.
1116 */
1117 private void clear() {
1118 subs.clear();
1119 handles.clear();
1120 }
1121
1122 /**
1123 * Underlying writeObject/writeUnshared implementation.
1124 */
1125 private void writeObject0(Object obj, boolean unshared)
1126 throws IOException
1127 {
1128 boolean oldMode = bout.setBlockDataMode(false);
1129 depth++;
1130 try {
1131 // handle previously written and non-replaceable objects
1132 int h;
1133 if ((obj = subs.lookup(obj)) == null) {
1134 writeNull();
1135 return;
1136 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1137 writeHandle(h);
1138 return;
1139 } else if (obj instanceof Class) {
1140 writeClass((Class) obj, unshared);
1141 return;
1142 } else if (obj instanceof ObjectStreamClass) {
1143 writeClassDesc((ObjectStreamClass) obj, unshared);
1144 return;
1145 }
1146
1147 // check for replacement object
1148 Object orig = obj;
1149 Class<?> cl = obj.getClass();
1150 ObjectStreamClass desc;
1151 for (;;) {
1152 // REMIND: skip this check for strings/arrays?
1153 Class<?> repCl;
1154 desc = ObjectStreamClass.lookup(cl, true);
1155 if (!desc.hasWriteReplaceMethod() ||
1156 (obj = desc.invokeWriteReplace(obj)) == null ||
1157 (repCl = obj.getClass()) == cl)
1158 {
1159 break;
1160 }
1161 cl = repCl;
1162 }
1163 if (enableReplace) {
1164 Object rep = replaceObject(obj);
1165 if (rep != obj && rep != null) {
1166 cl = rep.getClass();
1167 desc = ObjectStreamClass.lookup(cl, true);
1168 }
1169 obj = rep;
1170 }
1171
1172 // if object replaced, run through original checks a second time
1173 if (obj != orig) {
1174 subs.assign(orig, obj);
1175 if (obj == null) {
1176 writeNull();
1177 return;
1178 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1179 writeHandle(h);
1180 return;
1181 } else if (obj instanceof Class) {
1182 writeClass((Class) obj, unshared);
1183 return;
1184 } else if (obj instanceof ObjectStreamClass) {
1185 writeClassDesc((ObjectStreamClass) obj, unshared);
1186 return;
1187 }
1188 }
1189
1190 // remaining cases
1191 if (obj instanceof String) {
1192 writeString((String) obj, unshared);
1193 } else if (cl.isArray()) {
1194 writeArray(obj, desc, unshared);
1195 } else if (obj instanceof Enum) {
1196 writeEnum((Enum<?>) obj, desc, unshared);
1197 } else if (obj instanceof Serializable) {
1198 writeOrdinaryObject(obj, desc, unshared);
1199 } else {
1200 if (extendedDebugInfo) {
1201 throw new NotSerializableException(
1202 cl.getName() + "\n" + debugInfoStack.toString());
1203 } else {
1204 throw new NotSerializableException(cl.getName());
1205 }
1206 }
1207 } finally {
1208 depth--;
1209 bout.setBlockDataMode(oldMode);
1210 }
1211 }
1212
1213 /**
1214 * Writes null code to stream.
1215 */
1216 private void writeNull() throws IOException {
1217 bout.writeByte(TC_NULL);
1218 }
1219
1220 /**
1221 * Writes given object handle to stream.
1222 */
1223 private void writeHandle(int handle) throws IOException {
1224 bout.writeByte(TC_REFERENCE);
1225 bout.writeInt(baseWireHandle + handle);
1226 }
1227
1228 /**
1229 * Writes representation of given class to stream.
1230 */
1231 private void writeClass(Class<?> cl, boolean unshared) throws IOException {
1232 bout.writeByte(TC_CLASS);
1233 writeClassDesc(ObjectStreamClass.lookup(cl, true), false);
1234 handles.assign(unshared ? null : cl);
1235 }
1236
1237 /**
1238 * Writes representation of given class descriptor to stream.
1239 */
1240 private void writeClassDesc(ObjectStreamClass desc, boolean unshared)
1241 throws IOException
1242 {
1243 int handle;
1244 if (desc == null) {
1245 writeNull();
1246 } else if (!unshared && (handle = handles.lookup(desc)) != -1) {
1247 writeHandle(handle);
1248 } else if (desc.isProxy()) {
1249 writeProxyDesc(desc, unshared);
1250 } else {
1251 writeNonProxyDesc(desc, unshared);
1252 }
1253 }
1254
1255 private boolean isCustomSubclass() {
1256 // Return true if this class is a custom subclass of ObjectOutputStream
1257 return getClass().getClassLoader()
1258 != ObjectOutputStream.class.getClassLoader();
1259 }
1260
1261 /**
1262 * Writes class descriptor representing a dynamic proxy class to stream.
1263 */
1264 private void writeProxyDesc(ObjectStreamClass desc, boolean unshared)
1265 throws IOException
1266 {
1267 bout.writeByte(TC_PROXYCLASSDESC);
1268 handles.assign(unshared ? null : desc);
1269
1270 Class<?> cl = desc.forClass();
1271 Class<?>[] ifaces = cl.getInterfaces();
1272 bout.writeInt(ifaces.length);
1273 for (int i = 0; i < ifaces.length; i++) {
1274 bout.writeUTF(ifaces[i].getName());
1275 }
1276
1277 bout.setBlockDataMode(true);
1278 if (cl != null && isCustomSubclass()) {
1279 ReflectUtil.checkPackageAccess(cl);
1280 }
1281 annotateProxyClass(cl);
1282 bout.setBlockDataMode(false);
1283 bout.writeByte(TC_ENDBLOCKDATA);
1284
1285 writeClassDesc(desc.getSuperDesc(), false);
1286 }
1287
1288 /**
1289 * Writes class descriptor representing a standard (i.e., not a dynamic
1290 * proxy) class to stream.
1291 */
1292 private void writeNonProxyDesc(ObjectStreamClass desc, boolean unshared)
1293 throws IOException
1294 {
1295 bout.writeByte(TC_CLASSDESC);
1296 handles.assign(unshared ? null : desc);
1297
1298 if (protocol == PROTOCOL_VERSION_1) {
1299 // do not invoke class descriptor write hook with old protocol
1300 desc.writeNonProxy(this);
1301 } else {
1302 writeClassDescriptor(desc);
1303 }
1304
1305 Class<?> cl = desc.forClass();
1306 bout.setBlockDataMode(true);
1307 if (cl != null && isCustomSubclass()) {
1308 ReflectUtil.checkPackageAccess(cl);
1309 }
1310 annotateClass(cl);
1311 bout.setBlockDataMode(false);
1312 bout.writeByte(TC_ENDBLOCKDATA);
1313
1314 writeClassDesc(desc.getSuperDesc(), false);
1315 }
1316
1317 /**
1318 * Writes given string to stream, using standard or long UTF format
1319 * depending on string length.
1320 */
1321 private void writeString(String str, boolean unshared) throws IOException {
1322 handles.assign(unshared ? null : str);
1323 long utflen = bout.getUTFLength(str);
1324 if (utflen <= 0xFFFF) {
1325 bout.writeByte(TC_STRING);
1326 bout.writeUTF(str, utflen);
1327 } else {
1328 bout.writeByte(TC_LONGSTRING);
1329 bout.writeLongUTF(str, utflen);
1330 }
1331 }
1332
1333 /**
1334 * Writes given array object to stream.
1335 */
1336 private void writeArray(Object array,
1337 ObjectStreamClass desc,
1338 boolean unshared)
1339 throws IOException
1340 {
1341 bout.writeByte(TC_ARRAY);
1342 writeClassDesc(desc, false);
1343 handles.assign(unshared ? null : array);
1344
1345 Class<?> ccl = desc.forClass().getComponentType();
1346 if (ccl.isPrimitive()) {
1347 if (ccl == Integer.TYPE) {
1348 int[] ia = (int[]) array;
1349 bout.writeInt(ia.length);
1350 bout.writeInts(ia, 0, ia.length);
1351 } else if (ccl == Byte.TYPE) {
1352 byte[] ba = (byte[]) array;
1353 bout.writeInt(ba.length);
1354 bout.write(ba, 0, ba.length, true);
1355 } else if (ccl == Long.TYPE) {
1356 long[] ja = (long[]) array;
1357 bout.writeInt(ja.length);
1358 bout.writeLongs(ja, 0, ja.length);
1359 } else if (ccl == Float.TYPE) {
1360 float[] fa = (float[]) array;
1361 bout.writeInt(fa.length);
1362 bout.writeFloats(fa, 0, fa.length);
1363 } else if (ccl == Double.TYPE) {
1364 double[] da = (double[]) array;
1365 bout.writeInt(da.length);
1366 bout.writeDoubles(da, 0, da.length);
1367 } else if (ccl == Short.TYPE) {
1368 short[] sa = (short[]) array;
1369 bout.writeInt(sa.length);
1370 bout.writeShorts(sa, 0, sa.length);
1371 } else if (ccl == Character.TYPE) {
1372 char[] ca = (char[]) array;
1373 bout.writeInt(ca.length);
1374 bout.writeChars(ca, 0, ca.length);
1375 } else if (ccl == Boolean.TYPE) {
1376 boolean[] za = (boolean[]) array;
1377 bout.writeInt(za.length);
1378 bout.writeBooleans(za, 0, za.length);
1379 } else {
1380 throw new InternalError();
1381 }
1382 } else {
1383 Object[] objs = (Object[]) array;
1384 int len = objs.length;
1385 bout.writeInt(len);
1386 if (extendedDebugInfo) {
1387 debugInfoStack.push(
1388 "array (class \"" + array.getClass().getName() +
1389 "\", size: " + len + ")");
1390 }
1391 try {
1392 for (int i = 0; i < len; i++) {
1393 if (extendedDebugInfo) {
1394 debugInfoStack.push(
1395 "element of array (index: " + i + ")");
1396 }
1397 try {
1398 writeObject0(objs[i], false);
1399 } finally {
1400 if (extendedDebugInfo) {
1401 debugInfoStack.pop();
1402 }
1403 }
1404 }
1405 } finally {
1406 if (extendedDebugInfo) {
1407 debugInfoStack.pop();
1408 }
1409 }
1410 }
1411 }
1412
1413 /**
1414 * Writes given enum constant to stream.
1415 */
1416 private void writeEnum(Enum<?> en,
1417 ObjectStreamClass desc,
1418 boolean unshared)
1419 throws IOException
1420 {
1421 bout.writeByte(TC_ENUM);
1422 ObjectStreamClass sdesc = desc.getSuperDesc();
1423 writeClassDesc((sdesc.forClass() == Enum.class) ? desc : sdesc, false);
1424 handles.assign(unshared ? null : en);
1425 writeString(en.name(), false);
1426 }
1427
1428 /**
1429 * Writes representation of an "ordinary" (i.e., not a String, Class,
1430 * ObjectStreamClass, array, or enum constant) serializable object to the
1431 * stream.
1432 */
1433 private void writeOrdinaryObject(Object obj,
1434 ObjectStreamClass desc,
1435 boolean unshared)
1436 throws IOException
1437 {
1438 if (extendedDebugInfo) {
1439 debugInfoStack.push(
1440 (depth == 1 ? "root " : "") + "object (class \"" +
1441 obj.getClass().getName() + "\", " + obj.toString() + ")");
1442 }
1443 try {
1444 desc.checkSerialize();
1445
1446 bout.writeByte(TC_OBJECT);
1447 writeClassDesc(desc, false);
1448 handles.assign(unshared ? null : obj);
1449
1450 if (desc.isRecord()) {
1451 writeRecordData(obj, desc);
1452 } else if (desc.isExternalizable() && !desc.isProxy()) {
1453 if (desc.forClass().isValue())
1454 throw new NotSerializableException("Externalizable not valid for value class "
1455 + desc.forClass().getName());
1456 writeExternalData((Externalizable) obj);
1457 } else {
1458 writeSerialData(obj, desc);
1459 }
1460 } finally {
1461 if (extendedDebugInfo) {
1462 debugInfoStack.pop();
1463 }
1464 }
1465 }
1466
1467 /**
1468 * Writes externalizable data of given object by invoking its
1469 * writeExternal() method.
1470 */
1471 private void writeExternalData(Externalizable obj) throws IOException {
1472 PutFieldImpl oldPut = curPut;
1473 curPut = null;
1474
1475 if (extendedDebugInfo) {
1476 debugInfoStack.push("writeExternal data");
1477 }
1478 SerialCallbackContext oldContext = curContext;
1479 try {
1480 curContext = null;
1481 if (protocol == PROTOCOL_VERSION_1) {
1482 obj.writeExternal(this);
1483 } else {
1484 bout.setBlockDataMode(true);
1485 obj.writeExternal(this);
1486 bout.setBlockDataMode(false);
1487 bout.writeByte(TC_ENDBLOCKDATA);
1488 }
1489 } finally {
1490 curContext = oldContext;
1491 if (extendedDebugInfo) {
1492 debugInfoStack.pop();
1493 }
1494 }
1495
1496 curPut = oldPut;
1497 }
1498
1499 /** Writes the record component values for the given record object. */
1500 private void writeRecordData(Object obj, ObjectStreamClass desc)
1501 throws IOException
1502 {
1503 assert obj.getClass().isRecord();
1504 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1505 if (slots.length != 1) {
1506 throw new InvalidClassException(
1507 "expected a single record slot length, but found: " + slots.length);
1508 }
1509
1510 defaultWriteFields(obj, desc); // #### seems unnecessary to use the accessors
1511 }
1512
1513 /**
1514 * Writes instance data for each serializable class of given object, from
1515 * superclass to subclass.
1516 */
1517 private void writeSerialData(Object obj, ObjectStreamClass desc)
1518 throws IOException
1519 {
1520 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1521 for (int i = 0; i < slots.length; i++) {
1522 ObjectStreamClass slotDesc = slots[i].desc;
1523 if (slotDesc.hasWriteObjectMethod()) {
1524 PutFieldImpl oldPut = curPut;
1525 curPut = null;
1526 SerialCallbackContext oldContext = curContext;
1527
1528 if (extendedDebugInfo) {
1529 debugInfoStack.push(
1530 "custom writeObject data (class \"" +
1531 slotDesc.getName() + "\")");
1532 }
1533 try {
1534 curContext = new SerialCallbackContext(obj, slotDesc);
1535 bout.setBlockDataMode(true);
1536 slotDesc.invokeWriteObject(obj, this);
1537 bout.setBlockDataMode(false);
1538 bout.writeByte(TC_ENDBLOCKDATA);
1539 } finally {
1540 curContext.setUsed();
1541 curContext = oldContext;
1542 if (extendedDebugInfo) {
1543 debugInfoStack.pop();
1544 }
1545 }
1546
1547 curPut = oldPut;
1548 } else {
1549 defaultWriteFields(obj, slotDesc);
1550 }
1551 }
1552 }
1553
1554 /**
1555 * Fetches and writes values of serializable fields of given object to
1556 * stream. The given class descriptor specifies which field values to
1557 * write, and in which order they should be written.
1558 */
1559 private void defaultWriteFields(Object obj, ObjectStreamClass desc)
1560 throws IOException
1561 {
1562 Class<?> cl = desc.forClass();
1563 if (cl != null && obj != null && !cl.isInstance(obj)) {
1564 throw new ClassCastException();
1565 }
1566
1567 desc.checkDefaultSerialize();
1568
1569 int primDataSize = desc.getPrimDataSize();
1570 if (primDataSize > 0) {
1571 if (primVals == null || primVals.length < primDataSize) {
1572 primVals = new byte[primDataSize];
1573 }
1574 desc.getPrimFieldValues(obj, primVals);
1575 bout.write(primVals, 0, primDataSize, false);
1576 }
1577
1578 int numObjFields = desc.getNumObjFields();
1579 if (numObjFields > 0) {
1580 ObjectStreamField[] fields = desc.getFields(false);
1581 Object[] objVals = new Object[numObjFields];
1582 int numPrimFields = fields.length - objVals.length;
1583 desc.getObjFieldValues(obj, objVals);
1584 for (int i = 0; i < objVals.length; i++) {
1585 if (extendedDebugInfo) {
1586 debugInfoStack.push(
1587 "field (class \"" + desc.getName() + "\", name: \"" +
1588 fields[numPrimFields + i].getName() + "\", type: \"" +
1589 fields[numPrimFields + i].getType() + "\")");
1590 }
1591 try {
1592 writeObject0(objVals[i],
1593 fields[numPrimFields + i].isUnshared());
1594 } finally {
1595 if (extendedDebugInfo) {
1596 debugInfoStack.pop();
1597 }
1598 }
1599 }
1600 }
1601 }
1602
1603 /**
1604 * Attempts to write to stream fatal IOException that has caused
1605 * serialization to abort.
1606 */
1607 private void writeFatalException(IOException ex) throws IOException {
1608 /*
1609 * Note: the serialization specification states that if a second
1610 * IOException occurs while attempting to serialize the original fatal
1611 * exception to the stream, then a StreamCorruptedException should be
1612 * thrown (section 2.1). However, due to a bug in previous
1613 * implementations of serialization, StreamCorruptedExceptions were
1614 * rarely (if ever) actually thrown--the "root" exceptions from
1615 * underlying streams were thrown instead. This historical behavior is
1616 * followed here for consistency.
1617 */
1618 clear();
1619 boolean oldMode = bout.setBlockDataMode(false);
1620 try {
1621 bout.writeByte(TC_EXCEPTION);
1622 writeObject0(ex, false);
1623 clear();
1624 } finally {
1625 bout.setBlockDataMode(oldMode);
1626 }
1627 }
1628
1629 /**
1630 * Default PutField implementation.
1631 */
1632 private class PutFieldImpl extends PutField {
1633
1634 /** class descriptor describing serializable fields */
1635 private final ObjectStreamClass desc;
1636 /** primitive field values */
1637 private final byte[] primVals;
1638 /** object field values */
1639 private final Object[] objVals;
1640
1641 /**
1642 * Creates PutFieldImpl object for writing fields defined in given
1643 * class descriptor.
1644 */
1645 PutFieldImpl(ObjectStreamClass desc) {
1646 this.desc = desc;
1647 primVals = new byte[desc.getPrimDataSize()];
1648 objVals = new Object[desc.getNumObjFields()];
1649 }
1650
1651 public void put(String name, boolean val) {
1652 Bits.putBoolean(primVals, getFieldOffset(name, Boolean.TYPE), val);
1653 }
1654
1655 public void put(String name, byte val) {
1656 primVals[getFieldOffset(name, Byte.TYPE)] = val;
1657 }
1658
1659 public void put(String name, char val) {
1660 Bits.putChar(primVals, getFieldOffset(name, Character.TYPE), val);
1661 }
1662
1663 public void put(String name, short val) {
1664 Bits.putShort(primVals, getFieldOffset(name, Short.TYPE), val);
1665 }
1666
1667 public void put(String name, int val) {
1668 Bits.putInt(primVals, getFieldOffset(name, Integer.TYPE), val);
1669 }
1670
1671 public void put(String name, float val) {
1672 Bits.putFloat(primVals, getFieldOffset(name, Float.TYPE), val);
1673 }
1674
1675 public void put(String name, long val) {
1676 Bits.putLong(primVals, getFieldOffset(name, Long.TYPE), val);
1677 }
1678
1679 public void put(String name, double val) {
1680 Bits.putDouble(primVals, getFieldOffset(name, Double.TYPE), val);
1681 }
1682
1683 public void put(String name, Object val) {
1684 objVals[getFieldOffset(name, Object.class)] = val;
1685 }
1686
1687 // deprecated in ObjectOutputStream.PutField
1688 public void write(ObjectOutput out) throws IOException {
1689 /*
1690 * Applications should *not* use this method to write PutField
1691 * data, as it will lead to stream corruption if the PutField
1692 * object writes any primitive data (since block data mode is not
1693 * unset/set properly, as is done in OOS.writeFields()). This
1694 * broken implementation is being retained solely for behavioral
1695 * compatibility, in order to support applications which use
1696 * OOS.PutField.write() for writing only non-primitive data.
1697 *
1698 * Serialization of unshared objects is not implemented here since
1699 * it is not necessary for backwards compatibility; also, unshared
1700 * semantics may not be supported by the given ObjectOutput
1701 * instance. Applications which write unshared objects using the
1702 * PutField API must use OOS.writeFields().
1703 */
1704 if (ObjectOutputStream.this != out) {
1705 throw new IllegalArgumentException("wrong stream");
1706 }
1707 out.write(primVals, 0, primVals.length);
1708
1709 ObjectStreamField[] fields = desc.getFields(false);
1710 int numPrimFields = fields.length - objVals.length;
1711 // REMIND: warn if numPrimFields > 0?
1712 for (int i = 0; i < objVals.length; i++) {
1713 if (fields[numPrimFields + i].isUnshared()) {
1714 throw new IOException("cannot write unshared object");
1715 }
1716 out.writeObject(objVals[i]);
1717 }
1718 }
1719
1720 /**
1721 * Writes buffered primitive data and object fields to stream.
1722 */
1723 void writeFields() throws IOException {
1724 bout.write(primVals, 0, primVals.length, false);
1725
1726 ObjectStreamField[] fields = desc.getFields(false);
1727 int numPrimFields = fields.length - objVals.length;
1728 for (int i = 0; i < objVals.length; i++) {
1729 if (extendedDebugInfo) {
1730 debugInfoStack.push(
1731 "field (class \"" + desc.getName() + "\", name: \"" +
1732 fields[numPrimFields + i].getName() + "\", type: \"" +
1733 fields[numPrimFields + i].getType() + "\")");
1734 }
1735 try {
1736 writeObject0(objVals[i],
1737 fields[numPrimFields + i].isUnshared());
1738 } finally {
1739 if (extendedDebugInfo) {
1740 debugInfoStack.pop();
1741 }
1742 }
1743 }
1744 }
1745
1746 /**
1747 * Returns offset of field with given name and type. A specified type
1748 * of null matches all types, Object.class matches all non-primitive
1749 * types, and any other non-null type matches assignable types only.
1750 * Throws IllegalArgumentException if no matching field found.
1751 */
1752 private int getFieldOffset(String name, Class<?> type) {
1753 ObjectStreamField field = desc.getField(name, type);
1754 if (field == null) {
1755 throw new IllegalArgumentException("no such field " + name +
1756 " with type " + type);
1757 }
1758 return field.getOffset();
1759 }
1760 }
1761
1762 /**
1763 * Buffered output stream with two modes: in default mode, outputs data in
1764 * same format as DataOutputStream; in "block data" mode, outputs data
1765 * bracketed by block data markers (see object serialization specification
1766 * for details).
1767 */
1768 private static class BlockDataOutputStream
1769 extends OutputStream implements DataOutput
1770 {
1771 /** maximum data block length */
1772 private static final int MAX_BLOCK_SIZE = 1024;
1773 /** maximum data block header length */
1774 private static final int MAX_HEADER_SIZE = 5;
1775 /** (tunable) length of char buffer (for writing strings) */
1776 private static final int CHAR_BUF_SIZE = 256;
1777
1778 /** buffer for writing general/block data */
1779 private final byte[] buf = new byte[MAX_BLOCK_SIZE];
1780 /** buffer for writing block data headers */
1781 private final byte[] hbuf = new byte[MAX_HEADER_SIZE];
1782 /** char buffer for fast string writes */
1783 private final char[] cbuf = new char[CHAR_BUF_SIZE];
1784
1785 /** block data mode */
1786 private boolean blkmode = false;
1787 /** current offset into buf */
1788 private int pos = 0;
1789
1790 /** underlying output stream */
1791 private final OutputStream out;
1792 /** loopback stream (for data writes that span data blocks) */
1793 private final DataOutputStream dout;
1794
1795 /**
1796 * Creates new BlockDataOutputStream on top of given underlying stream.
1797 * Block data mode is turned off by default.
1798 */
1799 BlockDataOutputStream(OutputStream out) {
1800 this.out = out;
1801 dout = new DataOutputStream(this);
1802 }
1803
1804 /**
1805 * Sets block data mode to the given mode (true == on, false == off)
1806 * and returns the previous mode value. If the new mode is the same as
1807 * the old mode, no action is taken. If the new mode differs from the
1808 * old mode, any buffered data is flushed before switching to the new
1809 * mode.
1810 */
1811 boolean setBlockDataMode(boolean mode) throws IOException {
1812 if (blkmode == mode) {
1813 return blkmode;
1814 }
1815 drain();
1816 blkmode = mode;
1817 return !blkmode;
1818 }
1819
1820 /**
1821 * Returns true if the stream is currently in block data mode, false
1822 * otherwise.
1823 */
1824 boolean getBlockDataMode() {
1825 return blkmode;
1826 }
1827
1828 /* ----------------- generic output stream methods ----------------- */
1829 /*
1830 * The following methods are equivalent to their counterparts in
1831 * OutputStream, except that they partition written data into data
1832 * blocks when in block data mode.
1833 */
1834
1835 public void write(int b) throws IOException {
1836 if (pos >= MAX_BLOCK_SIZE) {
1837 drain();
1838 }
1839 buf[pos++] = (byte) b;
1840 }
1841
1842 public void write(byte[] b) throws IOException {
1843 write(b, 0, b.length, false);
1844 }
1845
1846 public void write(byte[] b, int off, int len) throws IOException {
1847 write(b, off, len, false);
1848 }
1849
1850 public void flush() throws IOException {
1851 drain();
1852 out.flush();
1853 }
1854
1855 public void close() throws IOException {
1856 flush();
1857 out.close();
1858 }
1859
1860 /**
1861 * Writes specified span of byte values from given array. If copy is
1862 * true, copies the values to an intermediate buffer before writing
1863 * them to underlying stream (to avoid exposing a reference to the
1864 * original byte array).
1865 */
1866 void write(byte[] b, int off, int len, boolean copy)
1867 throws IOException
1868 {
1869 if (!(copy || blkmode)) { // write directly
1870 drain();
1871 out.write(b, off, len);
1872 return;
1873 }
1874
1875 while (len > 0) {
1876 if (pos >= MAX_BLOCK_SIZE) {
1877 drain();
1878 }
1879 if (len >= MAX_BLOCK_SIZE && !copy && pos == 0) {
1880 // avoid unnecessary copy
1881 writeBlockHeader(MAX_BLOCK_SIZE);
1882 out.write(b, off, MAX_BLOCK_SIZE);
1883 off += MAX_BLOCK_SIZE;
1884 len -= MAX_BLOCK_SIZE;
1885 } else {
1886 int wlen = Math.min(len, MAX_BLOCK_SIZE - pos);
1887 System.arraycopy(b, off, buf, pos, wlen);
1888 pos += wlen;
1889 off += wlen;
1890 len -= wlen;
1891 }
1892 }
1893 }
1894
1895 /**
1896 * Writes all buffered data from this stream to the underlying stream,
1897 * but does not flush underlying stream.
1898 */
1899 void drain() throws IOException {
1900 if (pos == 0) {
1901 return;
1902 }
1903 if (blkmode) {
1904 writeBlockHeader(pos);
1905 }
1906 out.write(buf, 0, pos);
1907 pos = 0;
1908 }
1909
1910 /**
1911 * Writes block data header. Data blocks shorter than 256 bytes are
1912 * prefixed with a 2-byte header; all others start with a 5-byte
1913 * header.
1914 */
1915 private void writeBlockHeader(int len) throws IOException {
1916 if (len <= 0xFF) {
1917 hbuf[0] = TC_BLOCKDATA;
1918 hbuf[1] = (byte) len;
1919 out.write(hbuf, 0, 2);
1920 } else {
1921 hbuf[0] = TC_BLOCKDATALONG;
1922 Bits.putInt(hbuf, 1, len);
1923 out.write(hbuf, 0, 5);
1924 }
1925 }
1926
1927
1928 /* ----------------- primitive data output methods ----------------- */
1929 /*
1930 * The following methods are equivalent to their counterparts in
1931 * DataOutputStream, except that they partition written data into data
1932 * blocks when in block data mode.
1933 */
1934
1935 public void writeBoolean(boolean v) throws IOException {
1936 if (pos >= MAX_BLOCK_SIZE) {
1937 drain();
1938 }
1939 Bits.putBoolean(buf, pos++, v);
1940 }
1941
1942 public void writeByte(int v) throws IOException {
1943 if (pos >= MAX_BLOCK_SIZE) {
1944 drain();
1945 }
1946 buf[pos++] = (byte) v;
1947 }
1948
1949 public void writeChar(int v) throws IOException {
1950 if (pos + 2 <= MAX_BLOCK_SIZE) {
1951 Bits.putChar(buf, pos, (char) v);
1952 pos += 2;
1953 } else {
1954 dout.writeChar(v);
1955 }
1956 }
1957
1958 public void writeShort(int v) throws IOException {
1959 if (pos + 2 <= MAX_BLOCK_SIZE) {
1960 Bits.putShort(buf, pos, (short) v);
1961 pos += 2;
1962 } else {
1963 dout.writeShort(v);
1964 }
1965 }
1966
1967 public void writeInt(int v) throws IOException {
1968 if (pos + 4 <= MAX_BLOCK_SIZE) {
1969 Bits.putInt(buf, pos, v);
1970 pos += 4;
1971 } else {
1972 dout.writeInt(v);
1973 }
1974 }
1975
1976 public void writeFloat(float v) throws IOException {
1977 if (pos + 4 <= MAX_BLOCK_SIZE) {
1978 Bits.putFloat(buf, pos, v);
1979 pos += 4;
1980 } else {
1981 dout.writeFloat(v);
1982 }
1983 }
1984
1985 public void writeLong(long v) throws IOException {
1986 if (pos + 8 <= MAX_BLOCK_SIZE) {
1987 Bits.putLong(buf, pos, v);
1988 pos += 8;
1989 } else {
1990 dout.writeLong(v);
1991 }
1992 }
1993
1994 public void writeDouble(double v) throws IOException {
1995 if (pos + 8 <= MAX_BLOCK_SIZE) {
1996 Bits.putDouble(buf, pos, v);
1997 pos += 8;
1998 } else {
1999 dout.writeDouble(v);
2000 }
2001 }
2002
2003 public void writeBytes(String s) throws IOException {
2004 int endoff = s.length();
2005 int cpos = 0;
2006 int csize = 0;
2007 for (int off = 0; off < endoff; ) {
2008 if (cpos >= csize) {
2009 cpos = 0;
2010 csize = Math.min(endoff - off, CHAR_BUF_SIZE);
2011 s.getChars(off, off + csize, cbuf, 0);
2012 }
2013 if (pos >= MAX_BLOCK_SIZE) {
2014 drain();
2015 }
2016 int n = Math.min(csize - cpos, MAX_BLOCK_SIZE - pos);
2017 int stop = pos + n;
2018 while (pos < stop) {
2019 buf[pos++] = (byte) cbuf[cpos++];
2020 }
2021 off += n;
2022 }
2023 }
2024
2025 public void writeChars(String s) throws IOException {
2026 int endoff = s.length();
2027 for (int off = 0; off < endoff; ) {
2028 int csize = Math.min(endoff - off, CHAR_BUF_SIZE);
2029 s.getChars(off, off + csize, cbuf, 0);
2030 writeChars(cbuf, 0, csize);
2031 off += csize;
2032 }
2033 }
2034
2035 public void writeUTF(String s) throws IOException {
2036 writeUTF(s, getUTFLength(s));
2037 }
2038
2039
2040 /* -------------- primitive data array output methods -------------- */
2041 /*
2042 * The following methods write out spans of primitive data values.
2043 * Though equivalent to calling the corresponding primitive write
2044 * methods repeatedly, these methods are optimized for writing groups
2045 * of primitive data values more efficiently.
2046 */
2047
2048 void writeBooleans(boolean[] v, int off, int len) throws IOException {
2049 int endoff = off + len;
2050 while (off < endoff) {
2051 if (pos >= MAX_BLOCK_SIZE) {
2052 drain();
2053 }
2054 int stop = Math.min(endoff, off + (MAX_BLOCK_SIZE - pos));
2055 while (off < stop) {
2056 Bits.putBoolean(buf, pos++, v[off++]);
2057 }
2058 }
2059 }
2060
2061 void writeChars(char[] v, int off, int len) throws IOException {
2062 int limit = MAX_BLOCK_SIZE - 2;
2063 int endoff = off + len;
2064 while (off < endoff) {
2065 if (pos <= limit) {
2066 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2067 int stop = Math.min(endoff, off + avail);
2068 while (off < stop) {
2069 Bits.putChar(buf, pos, v[off++]);
2070 pos += 2;
2071 }
2072 } else {
2073 dout.writeChar(v[off++]);
2074 }
2075 }
2076 }
2077
2078 void writeShorts(short[] v, int off, int len) throws IOException {
2079 int limit = MAX_BLOCK_SIZE - 2;
2080 int endoff = off + len;
2081 while (off < endoff) {
2082 if (pos <= limit) {
2083 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2084 int stop = Math.min(endoff, off + avail);
2085 while (off < stop) {
2086 Bits.putShort(buf, pos, v[off++]);
2087 pos += 2;
2088 }
2089 } else {
2090 dout.writeShort(v[off++]);
2091 }
2092 }
2093 }
2094
2095 void writeInts(int[] v, int off, int len) throws IOException {
2096 int limit = MAX_BLOCK_SIZE - 4;
2097 int endoff = off + len;
2098 while (off < endoff) {
2099 if (pos <= limit) {
2100 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2101 int stop = Math.min(endoff, off + avail);
2102 while (off < stop) {
2103 Bits.putInt(buf, pos, v[off++]);
2104 pos += 4;
2105 }
2106 } else {
2107 dout.writeInt(v[off++]);
2108 }
2109 }
2110 }
2111
2112 void writeFloats(float[] v, int off, int len) throws IOException {
2113 int limit = MAX_BLOCK_SIZE - 4;
2114 int endoff = off + len;
2115 while (off < endoff) {
2116 if (pos <= limit) {
2117 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2118 int stop = Math.min(endoff, off + avail);
2119 while (off < stop) {
2120 Bits.putFloat(buf, pos, v[off++]);
2121 pos += 4;
2122 }
2123 } else {
2124 dout.writeFloat(v[off++]);
2125 }
2126 }
2127 }
2128
2129 void writeLongs(long[] v, int off, int len) throws IOException {
2130 int limit = MAX_BLOCK_SIZE - 8;
2131 int endoff = off + len;
2132 while (off < endoff) {
2133 if (pos <= limit) {
2134 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2135 int stop = Math.min(endoff, off + avail);
2136 while (off < stop) {
2137 Bits.putLong(buf, pos, v[off++]);
2138 pos += 8;
2139 }
2140 } else {
2141 dout.writeLong(v[off++]);
2142 }
2143 }
2144 }
2145
2146 void writeDoubles(double[] v, int off, int len) throws IOException {
2147 int limit = MAX_BLOCK_SIZE - 8;
2148 int endoff = off + len;
2149 while (off < endoff) {
2150 if (pos <= limit) {
2151 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2152 int stop = Math.min(endoff, off + avail);
2153 while (off < stop) {
2154 Bits.putDouble(buf, pos, v[off++]);
2155 pos += 8;
2156 }
2157 } else {
2158 dout.writeDouble(v[off++]);
2159 }
2160 }
2161 }
2162
2163 /**
2164 * Returns the length in bytes of the UTF encoding of the given string.
2165 */
2166 long getUTFLength(String s) {
2167 int len = s.length();
2168 long utflen = 0;
2169 for (int off = 0; off < len; ) {
2170 int csize = Math.min(len - off, CHAR_BUF_SIZE);
2171 s.getChars(off, off + csize, cbuf, 0);
2172 for (int cpos = 0; cpos < csize; cpos++) {
2173 char c = cbuf[cpos];
2174 if (c >= 0x0001 && c <= 0x007F) {
2175 utflen++;
2176 } else if (c > 0x07FF) {
2177 utflen += 3;
2178 } else {
2179 utflen += 2;
2180 }
2181 }
2182 off += csize;
2183 }
2184 return utflen;
2185 }
2186
2187 /**
2188 * Writes the given string in UTF format. This method is used in
2189 * situations where the UTF encoding length of the string is already
2190 * known; specifying it explicitly avoids a prescan of the string to
2191 * determine its UTF length.
2192 */
2193 void writeUTF(String s, long utflen) throws IOException {
2194 if (utflen > 0xFFFFL) {
2195 throw new UTFDataFormatException();
2196 }
2197 writeShort((int) utflen);
2198 if (utflen == (long) s.length()) {
2199 writeBytes(s);
2200 } else {
2201 writeUTFBody(s);
2202 }
2203 }
2204
2205 /**
2206 * Writes given string in "long" UTF format. "Long" UTF format is
2207 * identical to standard UTF, except that it uses an 8 byte header
2208 * (instead of the standard 2 bytes) to convey the UTF encoding length.
2209 */
2210 void writeLongUTF(String s) throws IOException {
2211 writeLongUTF(s, getUTFLength(s));
2212 }
2213
2214 /**
2215 * Writes given string in "long" UTF format, where the UTF encoding
2216 * length of the string is already known.
2217 */
2218 void writeLongUTF(String s, long utflen) throws IOException {
2219 writeLong(utflen);
2220 if (utflen == (long) s.length()) {
2221 writeBytes(s);
2222 } else {
2223 writeUTFBody(s);
2224 }
2225 }
2226
2227 /**
2228 * Writes the "body" (i.e., the UTF representation minus the 2-byte or
2229 * 8-byte length header) of the UTF encoding for the given string.
2230 */
2231 private void writeUTFBody(String s) throws IOException {
2232 int limit = MAX_BLOCK_SIZE - 3;
2233 int len = s.length();
2234 for (int off = 0; off < len; ) {
2235 int csize = Math.min(len - off, CHAR_BUF_SIZE);
2236 s.getChars(off, off + csize, cbuf, 0);
2237 for (int cpos = 0; cpos < csize; cpos++) {
2238 char c = cbuf[cpos];
2239 if (pos <= limit) {
2240 if (c <= 0x007F && c != 0) {
2241 buf[pos++] = (byte) c;
2242 } else if (c > 0x07FF) {
2243 buf[pos + 2] = (byte) (0x80 | ((c >> 0) & 0x3F));
2244 buf[pos + 1] = (byte) (0x80 | ((c >> 6) & 0x3F));
2245 buf[pos + 0] = (byte) (0xE0 | ((c >> 12) & 0x0F));
2246 pos += 3;
2247 } else {
2248 buf[pos + 1] = (byte) (0x80 | ((c >> 0) & 0x3F));
2249 buf[pos + 0] = (byte) (0xC0 | ((c >> 6) & 0x1F));
2250 pos += 2;
2251 }
2252 } else { // write one byte at a time to normalize block
2253 if (c <= 0x007F && c != 0) {
2254 write(c);
2255 } else if (c > 0x07FF) {
2256 write(0xE0 | ((c >> 12) & 0x0F));
2257 write(0x80 | ((c >> 6) & 0x3F));
2258 write(0x80 | ((c >> 0) & 0x3F));
2259 } else {
2260 write(0xC0 | ((c >> 6) & 0x1F));
2261 write(0x80 | ((c >> 0) & 0x3F));
2262 }
2263 }
2264 }
2265 off += csize;
2266 }
2267 }
2268 }
2269
2270 /**
2271 * Lightweight identity hash table which maps objects to integer handles,
2272 * assigned in ascending order.
2273 */
2274 private static class HandleTable {
2275
2276 /* number of mappings in table/next available handle */
2277 private int size;
2278 /* size threshold determining when to expand hash spine */
2279 private int threshold;
2280 /* factor for computing size threshold */
2281 private final float loadFactor;
2282 /* maps hash value -> candidate handle value */
2283 private int[] spine;
2284 /* maps handle value -> next candidate handle value */
2285 private int[] next;
2286 /* maps handle value -> associated object */
2287 private Object[] objs;
2288
2289 /**
2290 * Creates new HandleTable with given capacity and load factor.
2291 */
2292 HandleTable(int initialCapacity, float loadFactor) {
2293 this.loadFactor = loadFactor;
2294 spine = new int[initialCapacity];
2295 next = new int[initialCapacity];
2296 objs = new Object[initialCapacity];
2297 threshold = (int) (initialCapacity * loadFactor);
2298 clear();
2299 }
2300
2301 /**
2302 * Assigns next available handle to given object, and returns handle
2303 * value. Handles are assigned in ascending order starting at 0.
2304 */
2305 int assign(Object obj) {
2306 if (size >= next.length) {
2307 growEntries();
2308 }
2309 if (size >= threshold) {
2310 growSpine();
2311 }
2312 insert(obj, size);
2313 return size++;
2314 }
2315
2316 /**
2317 * Looks up and returns handle associated with given object, or -1 if
2318 * no mapping found.
2319 */
2320 int lookup(Object obj) {
2321 if (size == 0) {
2322 return -1;
2323 }
2324 int index = hash(obj) % spine.length;
2325 for (int i = spine[index]; i >= 0; i = next[i]) {
2326 if (objs[i] == obj) {
2327 return i;
2328 }
2329 }
2330 return -1;
2331 }
2332
2333 /**
2334 * Resets table to its initial (empty) state.
2335 */
2336 void clear() {
2337 Arrays.fill(spine, -1);
2338 Arrays.fill(objs, 0, size, null);
2339 size = 0;
2340 }
2341
2342 /**
2343 * Returns the number of mappings currently in table.
2344 */
2345 int size() {
2346 return size;
2347 }
2348
2349 /**
2350 * Inserts mapping object -> handle mapping into table. Assumes table
2351 * is large enough to accommodate new mapping.
2352 */
2353 private void insert(Object obj, int handle) {
2354 int index = hash(obj) % spine.length;
2355 objs[handle] = obj;
2356 next[handle] = spine[index];
2357 spine[index] = handle;
2358 }
2359
2360 /**
2361 * Expands the hash "spine" -- equivalent to increasing the number of
2362 * buckets in a conventional hash table.
2363 */
2364 private void growSpine() {
2365 spine = new int[(spine.length << 1) + 1];
2366 threshold = (int) (spine.length * loadFactor);
2367 Arrays.fill(spine, -1);
2368 for (int i = 0; i < size; i++) {
2369 insert(objs[i], i);
2370 }
2371 }
2372
2373 /**
2374 * Increases hash table capacity by lengthening entry arrays.
2375 */
2376 private void growEntries() {
2377 int newLength = (next.length << 1) + 1;
2378 int[] newNext = new int[newLength];
2379 System.arraycopy(next, 0, newNext, 0, size);
2380 next = newNext;
2381
2382 Object[] newObjs = new Object[newLength];
2383 System.arraycopy(objs, 0, newObjs, 0, size);
2384 objs = newObjs;
2385 }
2386
2387 /**
2388 * Returns hash value for given object.
2389 */
2390 private int hash(Object obj) {
2391 return System.identityHashCode(obj) & 0x7FFFFFFF;
2392 }
2393 }
2394
2395 /**
2396 * Lightweight identity hash table which maps objects to replacement
2397 * objects.
2398 */
2399 private static class ReplaceTable {
2400
2401 /* maps object -> index */
2402 private final HandleTable htab;
2403 /* maps index -> replacement object */
2404 private Object[] reps;
2405
2406 /**
2407 * Creates new ReplaceTable with given capacity and load factor.
2408 */
2409 ReplaceTable(int initialCapacity, float loadFactor) {
2410 htab = new HandleTable(initialCapacity, loadFactor);
2411 reps = new Object[initialCapacity];
2412 }
2413
2414 /**
2415 * Enters mapping from object to replacement object.
2416 */
2417 void assign(Object obj, Object rep) {
2418 int index = htab.assign(obj);
2419 while (index >= reps.length) {
2420 grow();
2421 }
2422 reps[index] = rep;
2423 }
2424
2425 /**
2426 * Looks up and returns replacement for given object. If no
2427 * replacement is found, returns the lookup object itself.
2428 */
2429 Object lookup(Object obj) {
2430 int index = htab.lookup(obj);
2431 return (index >= 0) ? reps[index] : obj;
2432 }
2433
2434 /**
2435 * Resets table to its initial (empty) state.
2436 */
2437 void clear() {
2438 Arrays.fill(reps, 0, htab.size(), null);
2439 htab.clear();
2440 }
2441
2442 /**
2443 * Returns the number of mappings currently in table.
2444 */
2445 int size() {
2446 return htab.size();
2447 }
2448
2449 /**
2450 * Increases table capacity.
2451 */
2452 private void grow() {
2453 Object[] newReps = new Object[(reps.length << 1) + 1];
2454 System.arraycopy(reps, 0, newReps, 0, reps.length);
2455 reps = newReps;
2456 }
2457 }
2458
2459 /**
2460 * Stack to keep debug information about the state of the
2461 * serialization process, for embedding in exception messages.
2462 */
2463 private static class DebugTraceInfoStack {
2464 private final List<String> stack;
2465
2466 DebugTraceInfoStack() {
2467 stack = new ArrayList<>();
2468 }
2469
2470 /**
2471 * Removes all of the elements from enclosed list.
2472 */
2473 void clear() {
2474 stack.clear();
2475 }
2476
2477 /**
2478 * Removes the object at the top of enclosed list.
2479 */
2480 void pop() {
2481 stack.remove(stack.size()-1);
2482 }
2483
2484 /**
2485 * Pushes a String onto the top of enclosed list.
2486 */
2487 void push(String entry) {
2488 stack.add("\t- " + entry);
2489 }
2490
2491 /**
2492 * Returns a string representation of this object
2493 */
2494 public String toString() {
2495 StringJoiner sj = new StringJoiner("\n");
2496 for (int i = stack.size() - 1; i >= 0; i--) {
2497 sj.add(stack.get(i));
2498 }
2499 return sj.toString();
2500 }
2501 }
2502
2503 }