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 * Value classes implementing {@link Externalizable} cannot be serialized
131 * or deserialized, the value object is immutable and the state cannot be restored.
132 * Use {@link Serializable} {@code writeReplace} to delegate to another serializable
133 * object such as a record.
134 *
135 * Value objects cannot be {@code java.io.Externalizable}.
136 *
137 * <p>Enum constants are serialized differently than ordinary serializable or
138 * externalizable objects. The serialized form of an enum constant consists
139 * solely of its name; field values of the constant are not transmitted. To
140 * serialize an enum constant, ObjectOutputStream writes the string returned by
141 * the constant's name method. Like other serializable or externalizable
142 * objects, enum constants can function as the targets of back references
143 * appearing subsequently in the serialization stream. The process by which
144 * enum constants are serialized cannot be customized; any class-specific
145 * writeObject and writeReplace methods defined by enum types are ignored
146 * during serialization. Similarly, any serialPersistentFields or
147 * serialVersionUID field declarations are also ignored--all enum types have a
148 * fixed serialVersionUID of 0L.
149 *
150 * <p>Primitive data, excluding serializable fields and externalizable data, is
151 * written to the ObjectOutputStream in block-data records. A block data record
152 * is composed of a header and data. The block data header consists of a marker
153 * and the number of bytes to follow the header. Consecutive primitive data
154 * writes are merged into one block-data record. The blocking factor used for
155 * a block-data record will be 1024 bytes. Each block-data record will be
156 * filled up to 1024 bytes, or be written whenever there is a termination of
157 * block-data mode. Calls to the ObjectOutputStream methods writeObject,
158 * defaultWriteObject and writeFields initially terminate any existing
159 * block-data record.
160 *
161 * <p>Records are serialized differently than ordinary serializable or externalizable
162 * objects, see <a href="ObjectInputStream.html#record-serialization">record serialization</a>.
163 *
164 * @spec serialization/index.html Java Object Serialization Specification
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 * {@link NullPointerException} 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 * @spec serialization/index.html Java Object Serialization Specification
681 * @see java.io.ObjectInputStream#readClassDescriptor()
682 * @see #useProtocolVersion(int)
683 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
684 * @since 1.3
685 */
686 protected void writeClassDescriptor(ObjectStreamClass desc)
687 throws IOException
688 {
689 desc.writeNonProxy(this);
690 }
691
692 /**
693 * Writes a byte. This method will block until the byte is actually
694 * written.
695 *
696 * @param val the byte to be written to the stream
697 * @throws IOException If an I/O error has occurred.
698 */
699 @Override
700 public void write(int val) throws IOException {
701 bout.write(val);
702 }
703
704 /**
705 * Writes an array of bytes. This method will block until the bytes are
706 * actually written.
707 *
708 * @param buf the data to be written
709 * @throws IOException If an I/O error has occurred.
710 */
711 @Override
712 public void write(byte[] buf) throws IOException {
713 bout.write(buf, 0, buf.length, false);
714 }
715
716 /**
717 * Writes a sub array of bytes.
718 *
719 * @param buf the data to be written
720 * @param off the start offset in the data
721 * @param len the number of bytes that are written
722 * @throws IOException {@inheritDoc}
723 * @throws IndexOutOfBoundsException {@inheritDoc}
724 */
725 @Override
726 public void write(byte[] buf, int off, int len) throws IOException {
727 if (buf == null) {
728 throw new NullPointerException();
729 }
730 Objects.checkFromIndexSize(off, len, buf.length);
731 bout.write(buf, off, len, false);
732 }
733
734 /**
735 * Flushes the stream. This will write any buffered output bytes and flush
736 * through to the underlying stream.
737 *
738 * @throws IOException {@inheritDoc}
739 */
740 @Override
741 public void flush() throws IOException {
742 bout.flush();
743 }
744
745 /**
746 * Drain any buffered data in ObjectOutputStream. Similar to flush but
747 * does not propagate the flush to the underlying stream.
748 *
749 * @throws IOException if I/O errors occur while writing to the underlying
750 * stream
751 */
752 protected void drain() throws IOException {
753 bout.drain();
754 }
755
756 /**
757 * Closes the stream. This method must be called to release any resources
758 * associated with the stream.
759 *
760 * @throws IOException If an I/O error has occurred.
761 */
762 @Override
763 public void close() throws IOException {
764 flush();
765 clear();
766 bout.close();
767 }
768
769 /**
770 * Writes a boolean.
771 *
772 * @param val the boolean to be written
773 * @throws IOException if I/O errors occur while writing to the underlying
774 * stream
775 */
776 public void writeBoolean(boolean val) throws IOException {
777 bout.writeBoolean(val);
778 }
779
780 /**
781 * Writes an 8-bit byte.
782 *
783 * @param val the byte value to be written
784 * @throws IOException if I/O errors occur while writing to the underlying
785 * stream
786 */
787 public void writeByte(int val) throws IOException {
788 bout.writeByte(val);
789 }
790
791 /**
792 * Writes a 16-bit short.
793 *
794 * @param val the short value to be written
795 * @throws IOException if I/O errors occur while writing to the underlying
796 * stream
797 */
798 public void writeShort(int val) throws IOException {
799 bout.writeShort(val);
800 }
801
802 /**
803 * Writes a 16-bit char.
804 *
805 * @param val the char value to be written
806 * @throws IOException if I/O errors occur while writing to the underlying
807 * stream
808 */
809 public void writeChar(int val) throws IOException {
810 bout.writeChar(val);
811 }
812
813 /**
814 * Writes a 32-bit int.
815 *
816 * @param val the integer value to be written
817 * @throws IOException if I/O errors occur while writing to the underlying
818 * stream
819 */
820 public void writeInt(int val) throws IOException {
821 bout.writeInt(val);
822 }
823
824 /**
825 * Writes a 64-bit long.
826 *
827 * @param val the long value to be written
828 * @throws IOException if I/O errors occur while writing to the underlying
829 * stream
830 */
831 public void writeLong(long val) throws IOException {
832 bout.writeLong(val);
833 }
834
835 /**
836 * Writes a 32-bit float.
837 *
838 * @param val the float value to be written
839 * @throws IOException if I/O errors occur while writing to the underlying
840 * stream
841 */
842 public void writeFloat(float val) throws IOException {
843 bout.writeFloat(val);
844 }
845
846 /**
847 * Writes a 64-bit double.
848 *
849 * @param val the double value to be written
850 * @throws IOException if I/O errors occur while writing to the underlying
851 * stream
852 */
853 public void writeDouble(double val) throws IOException {
854 bout.writeDouble(val);
855 }
856
857 /**
858 * Writes a String as a sequence of bytes.
859 *
860 * @param str the String of bytes to be written
861 * @throws IOException if I/O errors occur while writing to the underlying
862 * stream
863 */
864 public void writeBytes(String str) throws IOException {
865 bout.writeBytes(str);
866 }
867
868 /**
869 * Writes a String as a sequence of chars.
870 *
871 * @param str the String of chars to be written
872 * @throws IOException if I/O errors occur while writing to the underlying
873 * stream
874 */
875 public void writeChars(String str) throws IOException {
876 bout.writeChars(str);
877 }
878
879 /**
880 * Primitive data write of this String in
881 * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
882 * format. Note that there is a
883 * significant difference between writing a String into the stream as
884 * primitive data or as an Object. A String instance written by writeObject
885 * is written into the stream as a String initially. Future writeObject()
886 * calls write references to the string into the stream.
887 *
888 * @param str the String to be written
889 * @throws IOException if I/O errors occur while writing to the underlying
890 * stream
891 */
892 public void writeUTF(String str) throws IOException {
893 bout.writeUTF(str);
894 }
895
896 /**
897 * Provide programmatic access to the persistent fields to be written
898 * to ObjectOutput.
899 *
900 * @since 1.2
901 */
902 public abstract static class PutField {
903 /**
904 * Constructor for subclasses to call.
905 */
906 public PutField() {}
907
908 /**
909 * Put the value of the named boolean field into the persistent field.
910 *
911 * @param name the name of the serializable field
912 * @param val the value to assign to the field
913 * @throws IllegalArgumentException if {@code name} does not
914 * match the name of a serializable field for the class whose fields
915 * are being written, or if the type of the named field is not
916 * {@code boolean}
917 */
918 public abstract void put(String name, boolean val);
919
920 /**
921 * Put the value of the named byte field into the persistent field.
922 *
923 * @param name the name of the serializable field
924 * @param val the value to assign to the field
925 * @throws IllegalArgumentException if {@code name} does not
926 * match the name of a serializable field for the class whose fields
927 * are being written, or if the type of the named field is not
928 * {@code byte}
929 */
930 public abstract void put(String name, byte val);
931
932 /**
933 * Put the value of the named char field into the persistent field.
934 *
935 * @param name the name of the serializable field
936 * @param val the value to assign to the field
937 * @throws IllegalArgumentException if {@code name} does not
938 * match the name of a serializable field for the class whose fields
939 * are being written, or if the type of the named field is not
940 * {@code char}
941 */
942 public abstract void put(String name, char val);
943
944 /**
945 * Put the value of the named short field into the persistent field.
946 *
947 * @param name the name of the serializable field
948 * @param val the value to assign to the field
949 * @throws IllegalArgumentException if {@code name} does not
950 * match the name of a serializable field for the class whose fields
951 * are being written, or if the type of the named field is not
952 * {@code short}
953 */
954 public abstract void put(String name, short val);
955
956 /**
957 * Put the value of the named int field into the persistent field.
958 *
959 * @param name the name of the serializable field
960 * @param val the value to assign to the field
961 * @throws IllegalArgumentException if {@code name} does not
962 * match the name of a serializable field for the class whose fields
963 * are being written, or if the type of the named field is not
964 * {@code int}
965 */
966 public abstract void put(String name, int val);
967
968 /**
969 * Put the value of the named long field into the persistent field.
970 *
971 * @param name the name of the serializable field
972 * @param val the value to assign to the field
973 * @throws IllegalArgumentException if {@code name} does not
974 * match the name of a serializable field for the class whose fields
975 * are being written, or if the type of the named field is not
976 * {@code long}
977 */
978 public abstract void put(String name, long val);
979
980 /**
981 * Put the value of the named float field into the persistent field.
982 *
983 * @param name the name of the serializable field
984 * @param val the value to assign to the field
985 * @throws IllegalArgumentException if {@code name} does not
986 * match the name of a serializable field for the class whose fields
987 * are being written, or if the type of the named field is not
988 * {@code float}
989 */
990 public abstract void put(String name, float val);
991
992 /**
993 * Put the value of the named double field into the persistent field.
994 *
995 * @param name the name of the serializable field
996 * @param val the value to assign to the field
997 * @throws IllegalArgumentException if {@code name} does not
998 * match the name of a serializable field for the class whose fields
999 * are being written, or if the type of the named field is not
1000 * {@code double}
1001 */
1002 public abstract void put(String name, double val);
1003
1004 /**
1005 * Put the value of the named Object field into the persistent field.
1006 *
1007 * @param name the name of the serializable field
1008 * @param val the value to assign to the field
1009 * (which may be {@code null})
1010 * @throws IllegalArgumentException if {@code name} does not
1011 * match the name of a serializable field for the class whose fields
1012 * are being written, or if the type of the named field is not a
1013 * reference type
1014 */
1015 public abstract void put(String name, Object val);
1016
1017 /**
1018 * Write the data and fields to the specified ObjectOutput stream,
1019 * which must be the same stream that produced this
1020 * {@code PutField} object.
1021 *
1022 * @param out the stream to write the data and fields to
1023 * @throws IOException if I/O errors occur while writing to the
1024 * underlying stream
1025 * @throws IllegalArgumentException if the specified stream is not
1026 * the same stream that produced this {@code PutField}
1027 * object
1028 * @deprecated This method does not write the values contained by this
1029 * {@code PutField} object in a proper format, and may
1030 * result in corruption of the serialization stream. The
1031 * correct way to write {@code PutField} data is by
1032 * calling the {@link java.io.ObjectOutputStream#writeFields()}
1033 * method.
1034 */
1035 @Deprecated
1036 public abstract void write(ObjectOutput out) throws IOException;
1037 }
1038
1039
1040 /**
1041 * Returns protocol version in use.
1042 */
1043 int getProtocolVersion() {
1044 return protocol;
1045 }
1046
1047 /**
1048 * Writes string without allowing it to be replaced in stream. Used by
1049 * ObjectStreamClass to write class descriptor type strings.
1050 */
1051 void writeTypeString(String str) throws IOException {
1052 int handle;
1053 if (str == null) {
1054 writeNull();
1055 } else if ((handle = handles.lookup(str)) != -1) {
1056 writeHandle(handle);
1057 } else {
1058 writeString(str, false);
1059 }
1060 }
1061
1062 /**
1063 * Verifies that this (possibly subclass) instance can be constructed
1064 * without violating security constraints: the subclass must not override
1065 * security-sensitive non-final methods, or else the
1066 * "enableSubclassImplementation" SerializablePermission is checked.
1067 */
1068 private void verifySubclass() {
1069 Class<?> cl = getClass();
1070 if (cl == ObjectOutputStream.class) {
1071 return;
1072 }
1073 @SuppressWarnings("removal")
1074 SecurityManager sm = System.getSecurityManager();
1075 if (sm == null) {
1076 return;
1077 }
1078 boolean result = Caches.subclassAudits.get(cl);
1079 if (!result) {
1080 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
1081 }
1082 }
1083
1084 /**
1085 * Performs reflective checks on given subclass to verify that it doesn't
1086 * override security-sensitive non-final methods. Returns TRUE if subclass
1087 * is "safe", FALSE otherwise.
1088 */
1089 @SuppressWarnings("removal")
1090 private static Boolean auditSubclass(Class<?> subcl) {
1091 return AccessController.doPrivileged(
1092 new PrivilegedAction<>() {
1093 public Boolean run() {
1094 for (Class<?> cl = subcl;
1095 cl != ObjectOutputStream.class;
1096 cl = cl.getSuperclass())
1097 {
1098 try {
1099 cl.getDeclaredMethod(
1100 "writeUnshared", new Class<?>[] { Object.class });
1101 return Boolean.FALSE;
1102 } catch (NoSuchMethodException ex) {
1103 }
1104 try {
1105 cl.getDeclaredMethod("putFields", (Class<?>[]) null);
1106 return Boolean.FALSE;
1107 } catch (NoSuchMethodException ex) {
1108 }
1109 }
1110 return Boolean.TRUE;
1111 }
1112 }
1113 );
1114 }
1115
1116 /**
1117 * Clears internal data structures.
1118 */
1119 private void clear() {
1120 subs.clear();
1121 handles.clear();
1122 }
1123
1124 /**
1125 * Underlying writeObject/writeUnshared implementation.
1126 */
1127 private void writeObject0(Object obj, boolean unshared)
1128 throws IOException
1129 {
1130 boolean oldMode = bout.setBlockDataMode(false);
1131 depth++;
1132 try {
1133 // handle previously written and non-replaceable objects
1134 int h;
1135 if ((obj = subs.lookup(obj)) == null) {
1136 writeNull();
1137 return;
1138 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1139 writeHandle(h);
1140 return;
1141 } else if (obj instanceof Class) {
1142 writeClass((Class) obj, unshared);
1143 return;
1144 } else if (obj instanceof ObjectStreamClass) {
1145 writeClassDesc((ObjectStreamClass) obj, unshared);
1146 return;
1147 }
1148
1149 // check for replacement object
1150 Object orig = obj;
1151 Class<?> cl = obj.getClass();
1152 ObjectStreamClass desc;
1153 for (;;) {
1154 // REMIND: skip this check for strings/arrays?
1155 Class<?> repCl;
1156 desc = ObjectStreamClass.lookup(cl, true);
1157 if (!desc.hasWriteReplaceMethod() ||
1158 (obj = desc.invokeWriteReplace(obj)) == null ||
1159 (repCl = obj.getClass()) == cl)
1160 {
1161 break;
1162 }
1163 cl = repCl;
1164 }
1165 if (enableReplace) {
1166 Object rep = replaceObject(obj);
1167 if (rep != obj && rep != null) {
1168 cl = rep.getClass();
1169 desc = ObjectStreamClass.lookup(cl, true);
1170 }
1171 obj = rep;
1172 }
1173
1174 // if object replaced, run through original checks a second time
1175 if (obj != orig) {
1176 subs.assign(orig, obj);
1177 if (obj == null) {
1178 writeNull();
1179 return;
1180 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1181 writeHandle(h);
1182 return;
1183 } else if (obj instanceof Class) {
1184 writeClass((Class) obj, unshared);
1185 return;
1186 } else if (obj instanceof ObjectStreamClass) {
1187 writeClassDesc((ObjectStreamClass) obj, unshared);
1188 return;
1189 }
1190 }
1191
1192 // remaining cases
1193 if (obj instanceof String) {
1194 writeString((String) obj, unshared);
1195 } else if (cl.isArray()) {
1196 writeArray(obj, desc, unshared);
1197 } else if (obj instanceof Enum) {
1198 writeEnum((Enum<?>) obj, desc, unshared);
1199 } else if (obj instanceof Serializable) {
1200 writeOrdinaryObject(obj, desc, unshared);
1201 } else {
1202 if (extendedDebugInfo) {
1203 throw new NotSerializableException(
1204 cl.getName() + "\n" + debugInfoStack.toString());
1205 } else {
1206 throw new NotSerializableException(cl.getName());
1207 }
1208 }
1209 } finally {
1210 depth--;
1211 bout.setBlockDataMode(oldMode);
1212 }
1213 }
1214
1215 /**
1216 * Writes null code to stream.
1217 */
1218 private void writeNull() throws IOException {
1219 bout.writeByte(TC_NULL);
1220 }
1221
1222 /**
1223 * Writes given object handle to stream.
1224 */
1225 private void writeHandle(int handle) throws IOException {
1226 bout.writeByte(TC_REFERENCE);
1227 bout.writeInt(baseWireHandle + handle);
1228 }
1229
1230 /**
1231 * Writes representation of given class to stream.
1232 */
1233 private void writeClass(Class<?> cl, boolean unshared) throws IOException {
1234 bout.writeByte(TC_CLASS);
1235 writeClassDesc(ObjectStreamClass.lookup(cl, true), false);
1236 handles.assign(unshared ? null : cl);
1237 }
1238
1239 /**
1240 * Writes representation of given class descriptor to stream.
1241 */
1242 private void writeClassDesc(ObjectStreamClass desc, boolean unshared)
1243 throws IOException
1244 {
1245 int handle;
1246 if (desc == null) {
1247 writeNull();
1248 } else if (!unshared && (handle = handles.lookup(desc)) != -1) {
1249 writeHandle(handle);
1250 } else if (desc.isProxy()) {
1251 writeProxyDesc(desc, unshared);
1252 } else {
1253 writeNonProxyDesc(desc, unshared);
1254 }
1255 }
1256
1257 private boolean isCustomSubclass() {
1258 // Return true if this class is a custom subclass of ObjectOutputStream
1259 return getClass().getClassLoader()
1260 != ObjectOutputStream.class.getClassLoader();
1261 }
1262
1263 /**
1264 * Writes class descriptor representing a dynamic proxy class to stream.
1265 */
1266 private void writeProxyDesc(ObjectStreamClass desc, boolean unshared)
1267 throws IOException
1268 {
1269 bout.writeByte(TC_PROXYCLASSDESC);
1270 handles.assign(unshared ? null : desc);
1271
1272 Class<?> cl = desc.forClass();
1273 Class<?>[] ifaces = cl.getInterfaces();
1274 bout.writeInt(ifaces.length);
1275 for (int i = 0; i < ifaces.length; i++) {
1276 bout.writeUTF(ifaces[i].getName());
1277 }
1278
1279 bout.setBlockDataMode(true);
1280 if (cl != null && isCustomSubclass()) {
1281 ReflectUtil.checkPackageAccess(cl);
1282 }
1283 annotateProxyClass(cl);
1284 bout.setBlockDataMode(false);
1285 bout.writeByte(TC_ENDBLOCKDATA);
1286
1287 writeClassDesc(desc.getSuperDesc(), false);
1288 }
1289
1290 /**
1291 * Writes class descriptor representing a standard (i.e., not a dynamic
1292 * proxy) class to stream.
1293 */
1294 private void writeNonProxyDesc(ObjectStreamClass desc, boolean unshared)
1295 throws IOException
1296 {
1297 bout.writeByte(TC_CLASSDESC);
1298 handles.assign(unshared ? null : desc);
1299
1300 if (protocol == PROTOCOL_VERSION_1) {
1301 // do not invoke class descriptor write hook with old protocol
1302 desc.writeNonProxy(this);
1303 } else {
1304 writeClassDescriptor(desc);
1305 }
1306
1307 Class<?> cl = desc.forClass();
1308 bout.setBlockDataMode(true);
1309 if (cl != null && isCustomSubclass()) {
1310 ReflectUtil.checkPackageAccess(cl);
1311 }
1312 annotateClass(cl);
1313 bout.setBlockDataMode(false);
1314 bout.writeByte(TC_ENDBLOCKDATA);
1315
1316 writeClassDesc(desc.getSuperDesc(), false);
1317 }
1318
1319 /**
1320 * Writes given string to stream, using standard or long UTF format
1321 * depending on string length.
1322 */
1323 private void writeString(String str, boolean unshared) throws IOException {
1324 handles.assign(unshared ? null : str);
1325 long utflen = bout.getUTFLength(str);
1326 if (utflen <= 0xFFFF) {
1327 bout.writeByte(TC_STRING);
1328 bout.writeUTF(str, utflen);
1329 } else {
1330 bout.writeByte(TC_LONGSTRING);
1331 bout.writeLongUTF(str, utflen);
1332 }
1333 }
1334
1335 /**
1336 * Writes given array object to stream.
1337 */
1338 private void writeArray(Object array,
1339 ObjectStreamClass desc,
1340 boolean unshared)
1341 throws IOException
1342 {
1343 bout.writeByte(TC_ARRAY);
1344 writeClassDesc(desc, false);
1345 handles.assign(unshared ? null : array);
1346
1347 Class<?> ccl = desc.forClass().getComponentType();
1348 if (ccl.isPrimitive()) {
1349 if (ccl == Integer.TYPE) {
1350 int[] ia = (int[]) array;
1351 bout.writeInt(ia.length);
1352 bout.writeInts(ia, 0, ia.length);
1353 } else if (ccl == Byte.TYPE) {
1354 byte[] ba = (byte[]) array;
1355 bout.writeInt(ba.length);
1356 bout.write(ba, 0, ba.length, true);
1357 } else if (ccl == Long.TYPE) {
1358 long[] ja = (long[]) array;
1359 bout.writeInt(ja.length);
1360 bout.writeLongs(ja, 0, ja.length);
1361 } else if (ccl == Float.TYPE) {
1362 float[] fa = (float[]) array;
1363 bout.writeInt(fa.length);
1364 bout.writeFloats(fa, 0, fa.length);
1365 } else if (ccl == Double.TYPE) {
1366 double[] da = (double[]) array;
1367 bout.writeInt(da.length);
1368 bout.writeDoubles(da, 0, da.length);
1369 } else if (ccl == Short.TYPE) {
1370 short[] sa = (short[]) array;
1371 bout.writeInt(sa.length);
1372 bout.writeShorts(sa, 0, sa.length);
1373 } else if (ccl == Character.TYPE) {
1374 char[] ca = (char[]) array;
1375 bout.writeInt(ca.length);
1376 bout.writeChars(ca, 0, ca.length);
1377 } else if (ccl == Boolean.TYPE) {
1378 boolean[] za = (boolean[]) array;
1379 bout.writeInt(za.length);
1380 bout.writeBooleans(za, 0, za.length);
1381 } else {
1382 throw new InternalError();
1383 }
1384 } else {
1385 Object[] objs = (Object[]) array;
1386 int len = objs.length;
1387 bout.writeInt(len);
1388 if (extendedDebugInfo) {
1389 debugInfoStack.push(
1390 "array (class \"" + array.getClass().getName() +
1391 "\", size: " + len + ")");
1392 }
1393 try {
1394 for (int i = 0; i < len; i++) {
1395 if (extendedDebugInfo) {
1396 debugInfoStack.push(
1397 "element of array (index: " + i + ")");
1398 }
1399 try {
1400 writeObject0(objs[i], false);
1401 } finally {
1402 if (extendedDebugInfo) {
1403 debugInfoStack.pop();
1404 }
1405 }
1406 }
1407 } finally {
1408 if (extendedDebugInfo) {
1409 debugInfoStack.pop();
1410 }
1411 }
1412 }
1413 }
1414
1415 /**
1416 * Writes given enum constant to stream.
1417 */
1418 private void writeEnum(Enum<?> en,
1419 ObjectStreamClass desc,
1420 boolean unshared)
1421 throws IOException
1422 {
1423 bout.writeByte(TC_ENUM);
1424 ObjectStreamClass sdesc = desc.getSuperDesc();
1425 writeClassDesc((sdesc.forClass() == Enum.class) ? desc : sdesc, false);
1426 handles.assign(unshared ? null : en);
1427 writeString(en.name(), false);
1428 }
1429
1430 /**
1431 * Writes representation of an "ordinary" (i.e., not a String, Class,
1432 * ObjectStreamClass, array, or enum constant) serializable object to the
1433 * stream.
1434 */
1435 private void writeOrdinaryObject(Object obj,
1436 ObjectStreamClass desc,
1437 boolean unshared)
1438 throws IOException
1439 {
1440 if (extendedDebugInfo) {
1441 debugInfoStack.push(
1442 (depth == 1 ? "root " : "") + "object (class \"" +
1443 obj.getClass().getName() + "\", " + obj.toString() + ")");
1444 }
1445 try {
1446 desc.checkSerialize();
1447
1448 bout.writeByte(TC_OBJECT);
1449 writeClassDesc(desc, false);
1450 handles.assign(unshared ? null : obj);
1451
1452 if (desc.isRecord()) {
1453 writeRecordData(obj, desc);
1454 } else if (desc.isExternalizable() && !desc.isProxy()) {
1455 if (desc.forClass().isValue())
1456 throw new NotSerializableException("Externalizable not valid for value class "
1457 + desc.forClass().getName());
1458 writeExternalData((Externalizable) obj);
1459 } else {
1460 writeSerialData(obj, desc);
1461 }
1462 } finally {
1463 if (extendedDebugInfo) {
1464 debugInfoStack.pop();
1465 }
1466 }
1467 }
1468
1469 /**
1470 * Writes externalizable data of given object by invoking its
1471 * writeExternal() method.
1472 */
1473 private void writeExternalData(Externalizable obj) throws IOException {
1474 PutFieldImpl oldPut = curPut;
1475 curPut = null;
1476
1477 if (extendedDebugInfo) {
1478 debugInfoStack.push("writeExternal data");
1479 }
1480 SerialCallbackContext oldContext = curContext;
1481 try {
1482 curContext = null;
1483 if (protocol == PROTOCOL_VERSION_1) {
1484 obj.writeExternal(this);
1485 } else {
1486 bout.setBlockDataMode(true);
1487 obj.writeExternal(this);
1488 bout.setBlockDataMode(false);
1489 bout.writeByte(TC_ENDBLOCKDATA);
1490 }
1491 } finally {
1492 curContext = oldContext;
1493 if (extendedDebugInfo) {
1494 debugInfoStack.pop();
1495 }
1496 }
1497
1498 curPut = oldPut;
1499 }
1500
1501 /** Writes the record component values for the given record object. */
1502 private void writeRecordData(Object obj, ObjectStreamClass desc)
1503 throws IOException
1504 {
1505 assert obj.getClass().isRecord();
1506 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1507 if (slots.length != 1) {
1508 throw new InvalidClassException(
1509 "expected a single record slot length, but found: " + slots.length);
1510 }
1511
1512 defaultWriteFields(obj, desc); // #### seems unnecessary to use the accessors
1513 }
1514
1515 /**
1516 * Writes instance data for each serializable class of given object, from
1517 * superclass to subclass.
1518 */
1519 private void writeSerialData(Object obj, ObjectStreamClass desc)
1520 throws IOException
1521 {
1522 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1523 for (int i = 0; i < slots.length; i++) {
1524 ObjectStreamClass slotDesc = slots[i].desc;
1525 if (slotDesc.hasWriteObjectMethod()) {
1526 PutFieldImpl oldPut = curPut;
1527 curPut = null;
1528 SerialCallbackContext oldContext = curContext;
1529
1530 if (extendedDebugInfo) {
1531 debugInfoStack.push(
1532 "custom writeObject data (class \"" +
1533 slotDesc.getName() + "\")");
1534 }
1535 try {
1536 curContext = new SerialCallbackContext(obj, slotDesc);
1537 bout.setBlockDataMode(true);
1538 slotDesc.invokeWriteObject(obj, this);
1539 bout.setBlockDataMode(false);
1540 bout.writeByte(TC_ENDBLOCKDATA);
1541 } finally {
1542 curContext.setUsed();
1543 curContext = oldContext;
1544 if (extendedDebugInfo) {
1545 debugInfoStack.pop();
1546 }
1547 }
1548
1549 curPut = oldPut;
1550 } else {
1551 defaultWriteFields(obj, slotDesc);
1552 }
1553 }
1554 }
1555
1556 /**
1557 * Fetches and writes values of serializable fields of given object to
1558 * stream. The given class descriptor specifies which field values to
1559 * write, and in which order they should be written.
1560 */
1561 private void defaultWriteFields(Object obj, ObjectStreamClass desc)
1562 throws IOException
1563 {
1564 Class<?> cl = desc.forClass();
1565 if (cl != null && obj != null && !cl.isInstance(obj)) {
1566 throw new ClassCastException();
1567 }
1568
1569 desc.checkDefaultSerialize();
1570
1571 int primDataSize = desc.getPrimDataSize();
1572 if (primDataSize > 0) {
1573 if (primVals == null || primVals.length < primDataSize) {
1574 primVals = new byte[primDataSize];
1575 }
1576 desc.getPrimFieldValues(obj, primVals);
1577 bout.write(primVals, 0, primDataSize, false);
1578 }
1579
1580 int numObjFields = desc.getNumObjFields();
1581 if (numObjFields > 0) {
1582 ObjectStreamField[] fields = desc.getFields(false);
1583 Object[] objVals = new Object[numObjFields];
1584 int numPrimFields = fields.length - objVals.length;
1585 desc.getObjFieldValues(obj, objVals);
1586 for (int i = 0; i < objVals.length; i++) {
1587 if (extendedDebugInfo) {
1588 debugInfoStack.push(
1589 "field (class \"" + desc.getName() + "\", name: \"" +
1590 fields[numPrimFields + i].getName() + "\", type: \"" +
1591 fields[numPrimFields + i].getType() + "\")");
1592 }
1593 try {
1594 writeObject0(objVals[i],
1595 fields[numPrimFields + i].isUnshared());
1596 } finally {
1597 if (extendedDebugInfo) {
1598 debugInfoStack.pop();
1599 }
1600 }
1601 }
1602 }
1603 }
1604
1605 /**
1606 * Attempts to write to stream fatal IOException that has caused
1607 * serialization to abort.
1608 */
1609 private void writeFatalException(IOException ex) throws IOException {
1610 /*
1611 * Note: the serialization specification states that if a second
1612 * IOException occurs while attempting to serialize the original fatal
1613 * exception to the stream, then a StreamCorruptedException should be
1614 * thrown (section 2.1). However, due to a bug in previous
1615 * implementations of serialization, StreamCorruptedExceptions were
1616 * rarely (if ever) actually thrown--the "root" exceptions from
1617 * underlying streams were thrown instead. This historical behavior is
1618 * followed here for consistency.
1619 */
1620 clear();
1621 boolean oldMode = bout.setBlockDataMode(false);
1622 try {
1623 bout.writeByte(TC_EXCEPTION);
1624 writeObject0(ex, false);
1625 clear();
1626 } finally {
1627 bout.setBlockDataMode(oldMode);
1628 }
1629 }
1630
1631 /**
1632 * Default PutField implementation.
1633 */
1634 private class PutFieldImpl extends PutField {
1635
1636 /** class descriptor describing serializable fields */
1637 private final ObjectStreamClass desc;
1638 /** primitive field values */
1639 private final byte[] primVals;
1640 /** object field values */
1641 private final Object[] objVals;
1642
1643 /**
1644 * Creates PutFieldImpl object for writing fields defined in given
1645 * class descriptor.
1646 */
1647 PutFieldImpl(ObjectStreamClass desc) {
1648 this.desc = desc;
1649 primVals = new byte[desc.getPrimDataSize()];
1650 objVals = new Object[desc.getNumObjFields()];
1651 }
1652
1653 public void put(String name, boolean val) {
1654 ByteArray.setBoolean(primVals, getFieldOffset(name, Boolean.TYPE), val);
1655 }
1656
1657 public void put(String name, byte val) {
1658 primVals[getFieldOffset(name, Byte.TYPE)] = val;
1659 }
1660
1661 public void put(String name, char val) {
1662 ByteArray.setChar(primVals, getFieldOffset(name, Character.TYPE), val);
1663 }
1664
1665 public void put(String name, short val) {
1666 ByteArray.setShort(primVals, getFieldOffset(name, Short.TYPE), val);
1667 }
1668
1669 public void put(String name, int val) {
1670 ByteArray.setInt(primVals, getFieldOffset(name, Integer.TYPE), val);
1671 }
1672
1673 public void put(String name, float val) {
1674 ByteArray.setFloat(primVals, getFieldOffset(name, Float.TYPE), val);
1675 }
1676
1677 public void put(String name, long val) {
1678 ByteArray.setLong(primVals, getFieldOffset(name, Long.TYPE), val);
1679 }
1680
1681 public void put(String name, double val) {
1682 ByteArray.setDouble(primVals, getFieldOffset(name, Double.TYPE), val);
1683 }
1684
1685 public void put(String name, Object val) {
1686 objVals[getFieldOffset(name, Object.class)] = val;
1687 }
1688
1689 // deprecated in ObjectOutputStream.PutField
1690 public void write(ObjectOutput out) throws IOException {
1691 /*
1692 * Applications should *not* use this method to write PutField
1693 * data, as it will lead to stream corruption if the PutField
1694 * object writes any primitive data (since block data mode is not
1695 * unset/set properly, as is done in OOS.writeFields()). This
1696 * broken implementation is being retained solely for behavioral
1697 * compatibility, in order to support applications which use
1698 * OOS.PutField.write() for writing only non-primitive data.
1699 *
1700 * Serialization of unshared objects is not implemented here since
1701 * it is not necessary for backwards compatibility; also, unshared
1702 * semantics may not be supported by the given ObjectOutput
1703 * instance. Applications which write unshared objects using the
1704 * PutField API must use OOS.writeFields().
1705 */
1706 if (ObjectOutputStream.this != out) {
1707 throw new IllegalArgumentException("wrong stream");
1708 }
1709 out.write(primVals, 0, primVals.length);
1710
1711 ObjectStreamField[] fields = desc.getFields(false);
1712 int numPrimFields = fields.length - objVals.length;
1713 // REMIND: warn if numPrimFields > 0?
1714 for (int i = 0; i < objVals.length; i++) {
1715 if (fields[numPrimFields + i].isUnshared()) {
1716 throw new IOException("cannot write unshared object");
1717 }
1718 out.writeObject(objVals[i]);
1719 }
1720 }
1721
1722 /**
1723 * Writes buffered primitive data and object fields to stream.
1724 */
1725 void writeFields() throws IOException {
1726 bout.write(primVals, 0, primVals.length, false);
1727
1728 ObjectStreamField[] fields = desc.getFields(false);
1729 int numPrimFields = fields.length - objVals.length;
1730 for (int i = 0; i < objVals.length; i++) {
1731 if (extendedDebugInfo) {
1732 debugInfoStack.push(
1733 "field (class \"" + desc.getName() + "\", name: \"" +
1734 fields[numPrimFields + i].getName() + "\", type: \"" +
1735 fields[numPrimFields + i].getType() + "\")");
1736 }
1737 try {
1738 writeObject0(objVals[i],
1739 fields[numPrimFields + i].isUnshared());
1740 } finally {
1741 if (extendedDebugInfo) {
1742 debugInfoStack.pop();
1743 }
1744 }
1745 }
1746 }
1747
1748 /**
1749 * Returns offset of field with given name and type. A specified type
1750 * of null matches all types, Object.class matches all non-primitive
1751 * types, and any other non-null type matches assignable types only.
1752 * Throws IllegalArgumentException if no matching field found.
1753 */
1754 private int getFieldOffset(String name, Class<?> type) {
1755 ObjectStreamField field = desc.getField(name, type);
1756 if (field == null) {
1757 throw new IllegalArgumentException("no such field " + name +
1758 " with type " + type);
1759 }
1760 return field.getOffset();
1761 }
1762 }
1763
1764 /**
1765 * Buffered output stream with two modes: in default mode, outputs data in
1766 * same format as DataOutputStream; in "block data" mode, outputs data
1767 * bracketed by block data markers (see object serialization specification
1768 * for details).
1769 */
1770 private static final class BlockDataOutputStream
1771 extends OutputStream implements DataOutput
1772 {
1773 /** maximum data block length */
1774 private static final int MAX_BLOCK_SIZE = 1024;
1775 /** maximum data block header length */
1776 private static final int MAX_HEADER_SIZE = 5;
1777 /** (tunable) length of char buffer (for writing strings) */
1778 private static final int CHAR_BUF_SIZE = 256;
1779
1780 /** buffer for writing general/block data */
1781 private final byte[] buf = new byte[MAX_BLOCK_SIZE];
1782 /** buffer for writing block data headers */
1783 private final byte[] hbuf = new byte[MAX_HEADER_SIZE];
1784 /** char buffer for fast string writes */
1785 private final char[] cbuf = new char[CHAR_BUF_SIZE];
1786
1787 /** block data mode */
1788 private boolean blkmode = false;
1789 /** current offset into buf */
1790 private int pos = 0;
1791
1792 /** underlying output stream */
1793 private final OutputStream out;
1794 /** loopback stream (for data writes that span data blocks) */
1795 private final DataOutputStream dout;
1796
1797 /**
1798 * Creates new BlockDataOutputStream on top of given underlying stream.
1799 * Block data mode is turned off by default.
1800 */
1801 BlockDataOutputStream(OutputStream out) {
1802 this.out = out;
1803 dout = new DataOutputStream(this);
1804 }
1805
1806 /**
1807 * Sets block data mode to the given mode (true == on, false == off)
1808 * and returns the previous mode value. If the new mode is the same as
1809 * the old mode, no action is taken. If the new mode differs from the
1810 * old mode, any buffered data is flushed before switching to the new
1811 * mode.
1812 */
1813 boolean setBlockDataMode(boolean mode) throws IOException {
1814 if (blkmode == mode) {
1815 return blkmode;
1816 }
1817 drain();
1818 blkmode = mode;
1819 return !blkmode;
1820 }
1821
1822 /**
1823 * Returns true if the stream is currently in block data mode, false
1824 * otherwise.
1825 */
1826 boolean getBlockDataMode() {
1827 return blkmode;
1828 }
1829
1830 /* ----------------- generic output stream methods ----------------- */
1831 /*
1832 * The following methods are equivalent to their counterparts in
1833 * OutputStream, except that they partition written data into data
1834 * blocks when in block data mode.
1835 */
1836
1837 public void write(int b) throws IOException {
1838 if (pos >= MAX_BLOCK_SIZE) {
1839 drain();
1840 }
1841 buf[pos++] = (byte) b;
1842 }
1843
1844 public void write(byte[] b) throws IOException {
1845 write(b, 0, b.length, false);
1846 }
1847
1848 public void write(byte[] b, int off, int len) throws IOException {
1849 write(b, off, len, false);
1850 }
1851
1852 public void flush() throws IOException {
1853 drain();
1854 out.flush();
1855 }
1856
1857 public void close() throws IOException {
1858 flush();
1859 out.close();
1860 }
1861
1862 /**
1863 * Writes specified span of byte values from given array. If copy is
1864 * true, copies the values to an intermediate buffer before writing
1865 * them to underlying stream (to avoid exposing a reference to the
1866 * original byte array).
1867 */
1868 void write(byte[] b, int off, int len, boolean copy)
1869 throws IOException
1870 {
1871 if (!(copy || blkmode)) { // write directly
1872 drain();
1873 out.write(b, off, len);
1874 return;
1875 }
1876
1877 while (len > 0) {
1878 if (pos >= MAX_BLOCK_SIZE) {
1879 drain();
1880 }
1881 if (len >= MAX_BLOCK_SIZE && !copy && pos == 0) {
1882 // avoid unnecessary copy
1883 writeBlockHeader(MAX_BLOCK_SIZE);
1884 out.write(b, off, MAX_BLOCK_SIZE);
1885 off += MAX_BLOCK_SIZE;
1886 len -= MAX_BLOCK_SIZE;
1887 } else {
1888 int wlen = Math.min(len, MAX_BLOCK_SIZE - pos);
1889 System.arraycopy(b, off, buf, pos, wlen);
1890 pos += wlen;
1891 off += wlen;
1892 len -= wlen;
1893 }
1894 }
1895 }
1896
1897 /**
1898 * Writes all buffered data from this stream to the underlying stream,
1899 * but does not flush underlying stream.
1900 */
1901 void drain() throws IOException {
1902 if (pos == 0) {
1903 return;
1904 }
1905 if (blkmode) {
1906 writeBlockHeader(pos);
1907 }
1908 out.write(buf, 0, pos);
1909 pos = 0;
1910 }
1911
1912 /**
1913 * Writes block data header. Data blocks shorter than 256 bytes are
1914 * prefixed with a 2-byte header; all others start with a 5-byte
1915 * header.
1916 */
1917 private void writeBlockHeader(int len) throws IOException {
1918 if (len <= 0xFF) {
1919 hbuf[0] = TC_BLOCKDATA;
1920 hbuf[1] = (byte) len;
1921 out.write(hbuf, 0, 2);
1922 } else {
1923 hbuf[0] = TC_BLOCKDATALONG;
1924 ByteArray.setInt(hbuf, 1, len);
1925 out.write(hbuf, 0, 5);
1926 }
1927 }
1928
1929
1930 /* ----------------- primitive data output methods ----------------- */
1931 /*
1932 * The following methods are equivalent to their counterparts in
1933 * DataOutputStream, except that they partition written data into data
1934 * blocks when in block data mode.
1935 */
1936
1937 public void writeBoolean(boolean v) throws IOException {
1938 if (pos >= MAX_BLOCK_SIZE) {
1939 drain();
1940 }
1941 ByteArray.setBoolean(buf, pos++, v);
1942 }
1943
1944 public void writeByte(int v) throws IOException {
1945 if (pos >= MAX_BLOCK_SIZE) {
1946 drain();
1947 }
1948 buf[pos++] = (byte) v;
1949 }
1950
1951 public void writeChar(int v) throws IOException {
1952 if (pos + 2 <= MAX_BLOCK_SIZE) {
1953 ByteArray.setChar(buf, pos, (char) v);
1954 pos += 2;
1955 } else {
1956 dout.writeChar(v);
1957 }
1958 }
1959
1960 public void writeShort(int v) throws IOException {
1961 if (pos + 2 <= MAX_BLOCK_SIZE) {
1962 ByteArray.setShort(buf, pos, (short) v);
1963 pos += 2;
1964 } else {
1965 dout.writeShort(v);
1966 }
1967 }
1968
1969 public void writeInt(int v) throws IOException {
1970 if (pos + 4 <= MAX_BLOCK_SIZE) {
1971 ByteArray.setInt(buf, pos, v);
1972 pos += 4;
1973 } else {
1974 dout.writeInt(v);
1975 }
1976 }
1977
1978 public void writeFloat(float v) throws IOException {
1979 if (pos + 4 <= MAX_BLOCK_SIZE) {
1980 ByteArray.setFloat(buf, pos, v);
1981 pos += 4;
1982 } else {
1983 dout.writeFloat(v);
1984 }
1985 }
1986
1987 public void writeLong(long v) throws IOException {
1988 if (pos + 8 <= MAX_BLOCK_SIZE) {
1989 ByteArray.setLong(buf, pos, v);
1990 pos += 8;
1991 } else {
1992 dout.writeLong(v);
1993 }
1994 }
1995
1996 public void writeDouble(double v) throws IOException {
1997 if (pos + 8 <= MAX_BLOCK_SIZE) {
1998 ByteArray.setDouble(buf, pos, v);
1999 pos += 8;
2000 } else {
2001 dout.writeDouble(v);
2002 }
2003 }
2004
2005 public void writeBytes(String s) throws IOException {
2006 int endoff = s.length();
2007 int cpos = 0;
2008 int csize = 0;
2009 for (int off = 0; off < endoff; ) {
2010 if (cpos >= csize) {
2011 cpos = 0;
2012 csize = Math.min(endoff - off, CHAR_BUF_SIZE);
2013 s.getChars(off, off + csize, cbuf, 0);
2014 }
2015 if (pos >= MAX_BLOCK_SIZE) {
2016 drain();
2017 }
2018 int n = Math.min(csize - cpos, MAX_BLOCK_SIZE - pos);
2019 int stop = pos + n;
2020 while (pos < stop) {
2021 buf[pos++] = (byte) cbuf[cpos++];
2022 }
2023 off += n;
2024 }
2025 }
2026
2027 public void writeChars(String s) throws IOException {
2028 int endoff = s.length();
2029 for (int off = 0; off < endoff; ) {
2030 int csize = Math.min(endoff - off, CHAR_BUF_SIZE);
2031 s.getChars(off, off + csize, cbuf, 0);
2032 writeChars(cbuf, 0, csize);
2033 off += csize;
2034 }
2035 }
2036
2037 public void writeUTF(String s) throws IOException {
2038 writeUTF(s, getUTFLength(s));
2039 }
2040
2041
2042 /* -------------- primitive data array output methods -------------- */
2043 /*
2044 * The following methods write out spans of primitive data values.
2045 * Though equivalent to calling the corresponding primitive write
2046 * methods repeatedly, these methods are optimized for writing groups
2047 * of primitive data values more efficiently.
2048 */
2049
2050 void writeBooleans(boolean[] v, int off, int len) throws IOException {
2051 int endoff = off + len;
2052 while (off < endoff) {
2053 if (pos >= MAX_BLOCK_SIZE) {
2054 drain();
2055 }
2056 int stop = Math.min(endoff, off + (MAX_BLOCK_SIZE - pos));
2057 while (off < stop) {
2058 ByteArray.setBoolean(buf, pos++, v[off++]);
2059 }
2060 }
2061 }
2062
2063 void writeChars(char[] v, int off, int len) throws IOException {
2064 int limit = MAX_BLOCK_SIZE - 2;
2065 int endoff = off + len;
2066 while (off < endoff) {
2067 if (pos <= limit) {
2068 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2069 int stop = Math.min(endoff, off + avail);
2070 while (off < stop) {
2071 ByteArray.setChar(buf, pos, v[off++]);
2072 pos += 2;
2073 }
2074 } else {
2075 dout.writeChar(v[off++]);
2076 }
2077 }
2078 }
2079
2080 void writeShorts(short[] v, int off, int len) throws IOException {
2081 int limit = MAX_BLOCK_SIZE - 2;
2082 int endoff = off + len;
2083 while (off < endoff) {
2084 if (pos <= limit) {
2085 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2086 int stop = Math.min(endoff, off + avail);
2087 while (off < stop) {
2088 ByteArray.setShort(buf, pos, v[off++]);
2089 pos += 2;
2090 }
2091 } else {
2092 dout.writeShort(v[off++]);
2093 }
2094 }
2095 }
2096
2097 void writeInts(int[] v, int off, int len) throws IOException {
2098 int limit = MAX_BLOCK_SIZE - 4;
2099 int endoff = off + len;
2100 while (off < endoff) {
2101 if (pos <= limit) {
2102 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2103 int stop = Math.min(endoff, off + avail);
2104 while (off < stop) {
2105 ByteArray.setInt(buf, pos, v[off++]);
2106 pos += 4;
2107 }
2108 } else {
2109 dout.writeInt(v[off++]);
2110 }
2111 }
2112 }
2113
2114 void writeFloats(float[] v, int off, int len) throws IOException {
2115 int limit = MAX_BLOCK_SIZE - 4;
2116 int endoff = off + len;
2117 while (off < endoff) {
2118 if (pos <= limit) {
2119 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2120 int stop = Math.min(endoff, off + avail);
2121 while (off < stop) {
2122 ByteArray.setFloat(buf, pos, v[off++]);
2123 pos += 4;
2124 }
2125 } else {
2126 dout.writeFloat(v[off++]);
2127 }
2128 }
2129 }
2130
2131 void writeLongs(long[] v, int off, int len) throws IOException {
2132 int limit = MAX_BLOCK_SIZE - 8;
2133 int endoff = off + len;
2134 while (off < endoff) {
2135 if (pos <= limit) {
2136 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2137 int stop = Math.min(endoff, off + avail);
2138 while (off < stop) {
2139 ByteArray.setLong(buf, pos, v[off++]);
2140 pos += 8;
2141 }
2142 } else {
2143 dout.writeLong(v[off++]);
2144 }
2145 }
2146 }
2147
2148 void writeDoubles(double[] v, int off, int len) throws IOException {
2149 int limit = MAX_BLOCK_SIZE - 8;
2150 int endoff = off + len;
2151 while (off < endoff) {
2152 if (pos <= limit) {
2153 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2154 int stop = Math.min(endoff, off + avail);
2155 while (off < stop) {
2156 ByteArray.setDouble(buf, pos, v[off++]);
2157 pos += 8;
2158 }
2159 } else {
2160 dout.writeDouble(v[off++]);
2161 }
2162 }
2163 }
2164
2165 /**
2166 * Returns the length in bytes of the UTF encoding of the given string.
2167 */
2168 long getUTFLength(String s) {
2169 int len = s.length();
2170 long utflen = 0;
2171 for (int off = 0; off < len; ) {
2172 int csize = Math.min(len - off, CHAR_BUF_SIZE);
2173 s.getChars(off, off + csize, cbuf, 0);
2174 for (int cpos = 0; cpos < csize; cpos++) {
2175 char c = cbuf[cpos];
2176 if (c >= 0x0001 && c <= 0x007F) {
2177 utflen++;
2178 } else if (c > 0x07FF) {
2179 utflen += 3;
2180 } else {
2181 utflen += 2;
2182 }
2183 }
2184 off += csize;
2185 }
2186 return utflen;
2187 }
2188
2189 /**
2190 * Writes the given string in UTF format. This method is used in
2191 * situations where the UTF encoding length of the string is already
2192 * known; specifying it explicitly avoids a prescan of the string to
2193 * determine its UTF length.
2194 */
2195 void writeUTF(String s, long utflen) throws IOException {
2196 if (utflen > 0xFFFFL) {
2197 throw new UTFDataFormatException();
2198 }
2199 writeShort((int) utflen);
2200 if (utflen == (long) s.length()) {
2201 writeBytes(s);
2202 } else {
2203 writeUTFBody(s);
2204 }
2205 }
2206
2207 /**
2208 * Writes given string in "long" UTF format. "Long" UTF format is
2209 * identical to standard UTF, except that it uses an 8 byte header
2210 * (instead of the standard 2 bytes) to convey the UTF encoding length.
2211 */
2212 void writeLongUTF(String s) throws IOException {
2213 writeLongUTF(s, getUTFLength(s));
2214 }
2215
2216 /**
2217 * Writes given string in "long" UTF format, where the UTF encoding
2218 * length of the string is already known.
2219 */
2220 void writeLongUTF(String s, long utflen) throws IOException {
2221 writeLong(utflen);
2222 if (utflen == (long) s.length()) {
2223 writeBytes(s);
2224 } else {
2225 writeUTFBody(s);
2226 }
2227 }
2228
2229 /**
2230 * Writes the "body" (i.e., the UTF representation minus the 2-byte or
2231 * 8-byte length header) of the UTF encoding for the given string.
2232 */
2233 private void writeUTFBody(String s) throws IOException {
2234 int limit = MAX_BLOCK_SIZE - 3;
2235 int len = s.length();
2236 for (int off = 0; off < len; ) {
2237 int csize = Math.min(len - off, CHAR_BUF_SIZE);
2238 s.getChars(off, off + csize, cbuf, 0);
2239 for (int cpos = 0; cpos < csize; cpos++) {
2240 char c = cbuf[cpos];
2241 if (pos <= limit) {
2242 if (c <= 0x007F && c != 0) {
2243 buf[pos++] = (byte) c;
2244 } else if (c > 0x07FF) {
2245 buf[pos + 2] = (byte) (0x80 | ((c >> 0) & 0x3F));
2246 buf[pos + 1] = (byte) (0x80 | ((c >> 6) & 0x3F));
2247 buf[pos + 0] = (byte) (0xE0 | ((c >> 12) & 0x0F));
2248 pos += 3;
2249 } else {
2250 buf[pos + 1] = (byte) (0x80 | ((c >> 0) & 0x3F));
2251 buf[pos + 0] = (byte) (0xC0 | ((c >> 6) & 0x1F));
2252 pos += 2;
2253 }
2254 } else { // write one byte at a time to normalize block
2255 if (c <= 0x007F && c != 0) {
2256 write(c);
2257 } else if (c > 0x07FF) {
2258 write(0xE0 | ((c >> 12) & 0x0F));
2259 write(0x80 | ((c >> 6) & 0x3F));
2260 write(0x80 | ((c >> 0) & 0x3F));
2261 } else {
2262 write(0xC0 | ((c >> 6) & 0x1F));
2263 write(0x80 | ((c >> 0) & 0x3F));
2264 }
2265 }
2266 }
2267 off += csize;
2268 }
2269 }
2270 }
2271
2272 /**
2273 * Lightweight identity hash table which maps objects to integer handles,
2274 * assigned in ascending order.
2275 */
2276 private static final class HandleTable {
2277
2278 /* number of mappings in table/next available handle */
2279 private int size;
2280 /* size threshold determining when to expand hash spine */
2281 private int threshold;
2282 /* factor for computing size threshold */
2283 private final float loadFactor;
2284 /* maps hash value -> candidate handle value */
2285 private int[] spine;
2286 /* maps handle value -> next candidate handle value */
2287 private int[] next;
2288 /* maps handle value -> associated object */
2289 private Object[] objs;
2290
2291 /**
2292 * Creates new HandleTable with given capacity and load factor.
2293 */
2294 HandleTable(int initialCapacity, float loadFactor) {
2295 this.loadFactor = loadFactor;
2296 spine = new int[initialCapacity];
2297 next = new int[initialCapacity];
2298 objs = new Object[initialCapacity];
2299 threshold = (int) (initialCapacity * loadFactor);
2300 clear();
2301 }
2302
2303 /**
2304 * Assigns next available handle to given object, and returns handle
2305 * value. Handles are assigned in ascending order starting at 0.
2306 */
2307 int assign(Object obj) {
2308 if (size >= next.length) {
2309 growEntries();
2310 }
2311 if (size >= threshold) {
2312 growSpine();
2313 }
2314 insert(obj, size);
2315 return size++;
2316 }
2317
2318 /**
2319 * Looks up and returns handle associated with given object, or -1 if
2320 * no mapping found.
2321 */
2322 int lookup(Object obj) {
2323 if (size == 0) {
2324 return -1;
2325 }
2326 int index = hash(obj) % spine.length;
2327 for (int i = spine[index]; i >= 0; i = next[i]) {
2328 if (objs[i] == obj) {
2329 return i;
2330 }
2331 }
2332 return -1;
2333 }
2334
2335 /**
2336 * Resets table to its initial (empty) state.
2337 */
2338 void clear() {
2339 Arrays.fill(spine, -1);
2340 Arrays.fill(objs, 0, size, null);
2341 size = 0;
2342 }
2343
2344 /**
2345 * Returns the number of mappings currently in table.
2346 */
2347 int size() {
2348 return size;
2349 }
2350
2351 /**
2352 * Inserts mapping object -> handle mapping into table. Assumes table
2353 * is large enough to accommodate new mapping.
2354 */
2355 private void insert(Object obj, int handle) {
2356 int index = hash(obj) % spine.length;
2357 objs[handle] = obj;
2358 next[handle] = spine[index];
2359 spine[index] = handle;
2360 }
2361
2362 /**
2363 * Expands the hash "spine" -- equivalent to increasing the number of
2364 * buckets in a conventional hash table.
2365 */
2366 private void growSpine() {
2367 spine = new int[(spine.length << 1) + 1];
2368 threshold = (int) (spine.length * loadFactor);
2369 Arrays.fill(spine, -1);
2370 for (int i = 0; i < size; i++) {
2371 insert(objs[i], i);
2372 }
2373 }
2374
2375 /**
2376 * Increases hash table capacity by lengthening entry arrays.
2377 */
2378 private void growEntries() {
2379 int newLength = (next.length << 1) + 1;
2380 int[] newNext = new int[newLength];
2381 System.arraycopy(next, 0, newNext, 0, size);
2382 next = newNext;
2383
2384 Object[] newObjs = new Object[newLength];
2385 System.arraycopy(objs, 0, newObjs, 0, size);
2386 objs = newObjs;
2387 }
2388
2389 /**
2390 * Returns hash value for given object.
2391 */
2392 private int hash(Object obj) {
2393 return System.identityHashCode(obj) & 0x7FFFFFFF;
2394 }
2395 }
2396
2397 /**
2398 * Lightweight identity hash table which maps objects to replacement
2399 * objects.
2400 */
2401 private static final class ReplaceTable {
2402
2403 /* maps object -> index */
2404 private final HandleTable htab;
2405 /* maps index -> replacement object */
2406 private Object[] reps;
2407
2408 /**
2409 * Creates new ReplaceTable with given capacity and load factor.
2410 */
2411 ReplaceTable(int initialCapacity, float loadFactor) {
2412 htab = new HandleTable(initialCapacity, loadFactor);
2413 reps = new Object[initialCapacity];
2414 }
2415
2416 /**
2417 * Enters mapping from object to replacement object.
2418 */
2419 void assign(Object obj, Object rep) {
2420 int index = htab.assign(obj);
2421 while (index >= reps.length) {
2422 grow();
2423 }
2424 reps[index] = rep;
2425 }
2426
2427 /**
2428 * Looks up and returns replacement for given object. If no
2429 * replacement is found, returns the lookup object itself.
2430 */
2431 Object lookup(Object obj) {
2432 int index = htab.lookup(obj);
2433 return (index >= 0) ? reps[index] : obj;
2434 }
2435
2436 /**
2437 * Resets table to its initial (empty) state.
2438 */
2439 void clear() {
2440 Arrays.fill(reps, 0, htab.size(), null);
2441 htab.clear();
2442 }
2443
2444 /**
2445 * Returns the number of mappings currently in table.
2446 */
2447 int size() {
2448 return htab.size();
2449 }
2450
2451 /**
2452 * Increases table capacity.
2453 */
2454 private void grow() {
2455 Object[] newReps = new Object[(reps.length << 1) + 1];
2456 System.arraycopy(reps, 0, newReps, 0, reps.length);
2457 reps = newReps;
2458 }
2459 }
2460
2461 /**
2462 * Stack to keep debug information about the state of the
2463 * serialization process, for embedding in exception messages.
2464 */
2465 private static final class DebugTraceInfoStack {
2466 private final List<String> stack;
2467
2468 DebugTraceInfoStack() {
2469 stack = new ArrayList<>();
2470 }
2471
2472 /**
2473 * Removes all of the elements from enclosed list.
2474 */
2475 void clear() {
2476 stack.clear();
2477 }
2478
2479 /**
2480 * Removes the object at the top of enclosed list.
2481 */
2482 void pop() {
2483 stack.remove(stack.size()-1);
2484 }
2485
2486 /**
2487 * Pushes a String onto the top of enclosed list.
2488 */
2489 void push(String entry) {
2490 stack.add("\t- " + entry);
2491 }
2492
2493 /**
2494 * Returns a string representation of this object
2495 */
2496 public String toString() {
2497 StringJoiner sj = new StringJoiner("\n");
2498 for (int i = stack.size() - 1; i >= 0; i--) {
2499 sj.add(stack.get(i));
2500 }
2501 return sj.toString();
2502 }
2503 }
2504
2505 }