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