1 /*
2 * Copyright (c) 1996, 2022, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.io;
27
28 import java.security.AccessController;
29 import java.security.PrivilegedAction;
30 import java.util.ArrayList;
31 import java.util.Arrays;
32 import java.util.List;
33 import java.util.Objects;
34 import java.util.StringJoiner;
35 import sun.reflect.misc.ReflectUtil;
36
37 /**
38 * An ObjectOutputStream writes primitive data types and graphs of Java objects
39 * to an OutputStream. The objects can be read (reconstituted) using an
40 * ObjectInputStream. Persistent storage of objects can be accomplished by
41 * using a file for the stream. If the stream is a network socket stream, the
42 * objects can be reconstituted on another host or in another process.
43 *
44 * <p>Only objects that support the java.io.Serializable interface can be
45 * written to streams. The class of each serializable object is encoded
46 * including the class name and signature of the class, the values of the
47 * object's fields and arrays, and the closure of any other objects referenced
48 * from the initial objects.
49 *
50 * <p>The method writeObject is used to write an object to the stream. Any
51 * object, including Strings and arrays, is written with writeObject. Multiple
52 * objects or primitives can be written to the stream. The objects must be
53 * read back from the corresponding ObjectInputstream with the same types and
54 * in the same order as they were written.
55 *
56 * <p>Primitive data types can also be written to the stream using the
57 * appropriate methods from DataOutput. Strings can also be written using the
58 * writeUTF method.
59 *
60 * <p>The default serialization mechanism for an object writes the class of the
61 * object, the class signature, and the values of all non-transient and
62 * non-static fields. References to other objects (except in transient or
63 * static fields) cause those objects to be written also. Multiple references
64 * to a single object are encoded using a reference sharing mechanism so that
65 * graphs of objects can be restored to the same shape as when the original was
66 * written.
67 *
68 * <p>For example to write an object that can be read by the example in
69 * {@link ObjectInputStream}:
70 * {@snippet lang="java":
71 * try (FileOutputStream fos = new FileOutputStream("t.tmp");
72 * ObjectOutputStream oos = new ObjectOutputStream(fos)) {
73 * oos.writeObject("Today");
74 * oos.writeObject(LocalDateTime.now());
75 * } catch (Exception ex) {
76 * // handle exception
77 * }
78 * }
79 *
80 * <p>Serializable classes that require special handling during the
81 * serialization and deserialization process should implement methods
82 * with the following signatures:
83 *
84 * {@snippet lang="java":
85 * private void readObject(java.io.ObjectInputStream stream)
86 * throws IOException, ClassNotFoundException;
87 * private void writeObject(java.io.ObjectOutputStream stream)
88 * throws IOException;
89 * private void readObjectNoData()
90 * throws ObjectStreamException;
91 * }
92 *
93 * <p>The method name, modifiers, return type, and number and type of
94 * parameters must match exactly for the method to be used by
95 * serialization or deserialization. The methods should only be
96 * declared to throw checked exceptions consistent with these
97 * signatures.
98 *
99 * <p>The writeObject method is responsible for writing the state of the object
100 * for its particular class so that the corresponding readObject method can
101 * restore it. The method does not need to concern itself with the state
102 * belonging to the object's superclasses or subclasses. State is saved by
103 * writing the individual fields to the ObjectOutputStream using the
104 * writeObject method or by using the methods for primitive data types
105 * supported by DataOutput.
106 *
107 * <p>Serialization does not write out the fields of any object that does not
108 * implement the java.io.Serializable interface. Subclasses of Objects that
109 * are not serializable can be serializable. In this case the non-serializable
110 * class must have a no-arg constructor to allow its fields to be initialized.
111 * In this case it is the responsibility of the subclass to save and restore
112 * the state of the non-serializable class. It is frequently the case that the
113 * fields of that class are accessible (public, package, or protected) or that
114 * there are get and set methods that can be used to restore the state.
115 *
116 * <p>Serialization of an object can be prevented by implementing writeObject
117 * and readObject methods that throw the NotSerializableException. The
118 * exception will be caught by the ObjectOutputStream and abort the
119 * serialization process.
120 *
121 * <p>Implementing the Externalizable interface allows the object to assume
122 * complete control over the contents and format of the object's serialized
123 * form. The methods of the Externalizable interface, writeExternal and
124 * readExternal, are called to save and restore the objects state. When
125 * implemented by a class they can write and read their own state using all of
126 * the methods of ObjectOutput and ObjectInput. It is the responsibility of
127 * the objects to handle any versioning that occurs.
128 *
129 * <p>Enum constants are serialized differently than ordinary serializable or
130 * externalizable objects. The serialized form of an enum constant consists
131 * solely of its name; field values of the constant are not transmitted. To
132 * serialize an enum constant, ObjectOutputStream writes the string returned by
133 * the constant's name method. Like other serializable or externalizable
134 * objects, enum constants can function as the targets of back references
135 * appearing subsequently in the serialization stream. The process by which
136 * enum constants are serialized cannot be customized; any class-specific
137 * writeObject and writeReplace methods defined by enum types are ignored
138 * during serialization. Similarly, any serialPersistentFields or
139 * serialVersionUID field declarations are also ignored--all enum types have a
140 * fixed serialVersionUID of 0L.
141 *
142 * <p>Primitive data, excluding serializable fields and externalizable data, is
143 * written to the ObjectOutputStream in block-data records. A block data record
144 * is composed of a header and data. The block data header consists of a marker
145 * and the number of bytes to follow the header. Consecutive primitive data
146 * writes are merged into one block-data record. The blocking factor used for
147 * a block-data record will be 1024 bytes. Each block-data record will be
148 * filled up to 1024 bytes, or be written whenever there is a termination of
149 * block-data mode. Calls to the ObjectOutputStream methods writeObject,
150 * defaultWriteObject and writeFields initially terminate any existing
151 * block-data record.
152 *
153 * <p>Records are serialized differently than ordinary serializable or externalizable
154 * objects, see <a href="ObjectInputStream.html#record-serialization">record serialization</a>.
155 *
156 * @author Mike Warres
157 * @author Roger Riggs
158 * @see java.io.DataOutput
159 * @see java.io.ObjectInputStream
160 * @see java.io.Serializable
161 * @see java.io.Externalizable
162 * @see <a href="{@docRoot}/../specs/serialization/output.html">
163 * <cite>Java Object Serialization Specification,</cite> Section 2, "Object Output Classes"</a>
164 * @since 1.1
165 */
166 public class ObjectOutputStream
167 extends OutputStream implements ObjectOutput, ObjectStreamConstants
168 {
169
170 private static class Caches {
171 /** cache of subclass security audit results */
172 static final ClassValue<Boolean> subclassAudits =
173 new ClassValue<>() {
174 @Override
175 protected Boolean computeValue(Class<?> type) {
176 return auditSubclass(type);
177 }
178 };
179 }
180
181 /** filter stream for handling block data conversion */
182 private final BlockDataOutputStream bout;
183 /** obj -> wire handle map */
184 private final HandleTable handles;
185 /** obj -> replacement obj map */
186 private final ReplaceTable subs;
187 /** stream protocol version */
188 private int protocol = PROTOCOL_VERSION_2;
189 /** recursion depth */
190 private int depth;
191
192 /** buffer for writing primitive field values */
193 private byte[] primVals;
194
195 /** if true, invoke writeObjectOverride() instead of writeObject() */
196 private final boolean enableOverride;
197 /** if true, invoke replaceObject() */
198 private boolean enableReplace;
199
200 // values below valid only during upcalls to writeObject()/writeExternal()
201 /**
202 * Context during upcalls to class-defined writeObject methods; holds
203 * object currently being serialized and descriptor for current class.
204 * Null when not during writeObject upcall.
205 */
206 private SerialCallbackContext curContext;
207 /** current PutField object */
208 private PutFieldImpl curPut;
209
210 /** custom storage for debug trace info */
211 private final DebugTraceInfoStack debugInfoStack;
212
213 /**
214 * value of "sun.io.serialization.extendedDebugInfo" property,
215 * as true or false for extended information about exception's place
216 */
217 @SuppressWarnings("removal")
218 private static final boolean extendedDebugInfo =
219 java.security.AccessController.doPrivileged(
220 new sun.security.action.GetBooleanAction(
221 "sun.io.serialization.extendedDebugInfo")).booleanValue();
222
223 /**
224 * Creates an ObjectOutputStream that writes to the specified OutputStream.
225 * This constructor writes the serialization stream header to the
226 * underlying stream; callers may wish to flush the stream immediately to
227 * ensure that constructors for receiving ObjectInputStreams will not block
228 * when reading the header.
229 *
230 * <p>If a security manager is installed, this constructor will check for
231 * the "enableSubclassImplementation" SerializablePermission when invoked
232 * directly or indirectly by the constructor of a subclass which overrides
233 * the ObjectOutputStream.putFields or ObjectOutputStream.writeUnshared
234 * methods.
235 *
236 * @param out output stream to write to
237 * @throws IOException if an I/O error occurs while writing stream header
238 * @throws SecurityException if untrusted subclass illegally overrides
239 * security-sensitive methods
240 * @throws NullPointerException if {@code out} is {@code null}
241 * @since 1.4
242 * @see ObjectOutputStream#ObjectOutputStream()
243 * @see ObjectOutputStream#putFields()
244 * @see ObjectInputStream#ObjectInputStream(InputStream)
245 */
246 public ObjectOutputStream(OutputStream out) throws IOException {
247 verifySubclass();
248 bout = new BlockDataOutputStream(out);
249 handles = new HandleTable(10, (float) 3.00);
250 subs = new ReplaceTable(10, (float) 3.00);
251 enableOverride = false;
252 writeStreamHeader();
253 bout.setBlockDataMode(true);
254 if (extendedDebugInfo) {
255 debugInfoStack = new DebugTraceInfoStack();
256 } else {
257 debugInfoStack = null;
258 }
259 }
260
261 /**
262 * Provide a way for subclasses that are completely reimplementing
263 * ObjectOutputStream to not have to allocate private data just used by
264 * this implementation of ObjectOutputStream.
265 *
266 * <p>If there is a security manager installed, this method first calls the
267 * security manager's {@code checkPermission} method with a
268 * {@code SerializablePermission("enableSubclassImplementation")}
269 * permission to ensure it's ok to enable subclassing.
270 *
271 * @throws SecurityException if a security manager exists and its
272 * {@code checkPermission} method denies enabling
273 * subclassing.
274 * @throws IOException if an I/O error occurs while creating this stream
275 * @see SecurityManager#checkPermission
276 * @see java.io.SerializablePermission
277 */
278 protected ObjectOutputStream() throws IOException, SecurityException {
279 @SuppressWarnings("removal")
280 SecurityManager sm = System.getSecurityManager();
281 if (sm != null) {
282 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
283 }
284 bout = null;
285 handles = null;
286 subs = null;
287 enableOverride = true;
288 debugInfoStack = null;
289 }
290
291 /**
292 * Specify stream protocol version to use when writing the stream.
293 *
294 * <p>This routine provides a hook to enable the current version of
295 * Serialization to write in a format that is backwards compatible to a
296 * previous version of the stream format.
297 *
298 * <p>Every effort will be made to avoid introducing additional
299 * backwards incompatibilities; however, sometimes there is no
300 * other alternative.
301 *
302 * @param version use ProtocolVersion from java.io.ObjectStreamConstants.
303 * @throws IllegalStateException if called after any objects
304 * have been serialized.
305 * @throws IllegalArgumentException if invalid version is passed in.
306 * @throws IOException if I/O errors occur
307 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
308 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_2
309 * @since 1.2
310 */
311 public void useProtocolVersion(int version) throws IOException {
312 if (handles.size() != 0) {
313 // REMIND: implement better check for pristine stream?
314 throw new IllegalStateException("stream non-empty");
315 }
316 switch (version) {
317 case PROTOCOL_VERSION_1:
318 case PROTOCOL_VERSION_2:
319 protocol = version;
320 break;
321
322 default:
323 throw new IllegalArgumentException(
324 "unknown version: " + version);
325 }
326 }
327
328 /**
329 * Write the specified object to the ObjectOutputStream. The class of the
330 * object, the signature of the class, and the values of the non-transient
331 * and non-static fields of the class and all of its supertypes are
332 * written. Default serialization for a class can be overridden using the
333 * writeObject and the readObject methods. Objects referenced by this
334 * object are written transitively so that a complete equivalent graph of
335 * objects can be reconstructed by an ObjectInputStream.
336 *
337 * <p>Exceptions are thrown for problems with the OutputStream and for
338 * classes that should not be serialized. All exceptions are fatal to the
339 * OutputStream, which is left in an indeterminate state, and it is up to
340 * the caller to ignore or recover the stream state.
341 *
342 * @throws InvalidClassException Something is wrong with a class used by
343 * serialization.
344 * @throws NotSerializableException Some object to be serialized does not
345 * implement the java.io.Serializable interface.
346 * @throws IOException Any exception thrown by the underlying
347 * OutputStream.
348 */
349 public final void writeObject(Object obj) throws IOException {
350 if (enableOverride) {
351 writeObjectOverride(obj);
352 return;
353 }
354 try {
355 writeObject0(obj, false);
356 } catch (IOException ex) {
357 if (depth == 0) {
358 writeFatalException(ex);
359 }
360 throw ex;
361 }
362 }
363
364 /**
365 * Method used by subclasses to override the default writeObject method.
366 * This method is called by trusted subclasses of ObjectOutputStream that
367 * constructed ObjectOutputStream using the protected no-arg constructor.
368 * The subclass is expected to provide an override method with the modifier
369 * "final".
370 *
371 * @param obj object to be written to the underlying stream
372 * @throws IOException if there are I/O errors while writing to the
373 * underlying stream
374 * @see #ObjectOutputStream()
375 * @see #writeObject(Object)
376 * @since 1.2
377 */
378 protected void writeObjectOverride(Object obj) throws IOException {
379 }
380
381 /**
382 * Writes an "unshared" object to the ObjectOutputStream. This method is
383 * identical to writeObject, except that it always writes the given object
384 * as a new, unique object in the stream (as opposed to a back-reference
385 * pointing to a previously serialized instance). Specifically:
386 * <ul>
387 * <li>An object written via writeUnshared is always serialized in the
388 * same manner as a newly appearing object (an object that has not
389 * been written to the stream yet), regardless of whether or not the
390 * object has been written previously.
391 *
392 * <li>If writeObject is used to write an object that has been previously
393 * written with writeUnshared, the previous writeUnshared operation
394 * is treated as if it were a write of a separate object. In other
395 * words, ObjectOutputStream will never generate back-references to
396 * object data written by calls to writeUnshared.
397 * </ul>
398 * While writing an object via writeUnshared does not in itself guarantee a
399 * unique reference to the object when it is deserialized, it allows a
400 * single object to be defined multiple times in a stream, so that multiple
401 * calls to readUnshared by the receiver will not conflict. Note that the
402 * rules described above only apply to the base-level object written with
403 * writeUnshared, and not to any transitively referenced sub-objects in the
404 * object graph to be serialized.
405 *
406 * <p>ObjectOutputStream subclasses which override this method can only be
407 * constructed in security contexts possessing the
408 * "enableSubclassImplementation" SerializablePermission; any attempt to
409 * instantiate such a subclass without this permission will cause a
410 * SecurityException to be thrown.
411 *
412 * @param obj object to write to stream
413 * @throws NotSerializableException if an object in the graph to be
414 * serialized does not implement the Serializable interface
415 * @throws InvalidClassException if a problem exists with the class of an
416 * object to be serialized
417 * @throws IOException if an I/O error occurs during serialization
418 * @since 1.4
419 */
420 public void writeUnshared(Object obj) throws IOException {
421 try {
422 writeObject0(obj, true);
423 } catch (IOException ex) {
424 if (depth == 0) {
425 writeFatalException(ex);
426 }
427 throw ex;
428 }
429 }
430
431 /**
432 * Write the non-static and non-transient fields of the current class to
433 * this stream. This may only be called from the writeObject method of the
434 * class being serialized. It will throw the NotActiveException if it is
435 * called otherwise.
436 *
437 * @throws IOException if I/O errors occur while writing to the underlying
438 * {@code OutputStream}
439 */
440 public void defaultWriteObject() throws IOException {
441 SerialCallbackContext ctx = curContext;
442 if (ctx == null) {
443 throw new NotActiveException("not in call to writeObject");
444 }
445 Object curObj = ctx.getObj();
446 ObjectStreamClass curDesc = ctx.getDesc();
447 bout.setBlockDataMode(false);
448 defaultWriteFields(curObj, curDesc);
449 bout.setBlockDataMode(true);
450 }
451
452 /**
453 * Retrieve the object used to buffer persistent fields to be written to
454 * the stream. The fields will be written to the stream when writeFields
455 * method is called.
456 *
457 * @return an instance of the class Putfield that holds the serializable
458 * fields
459 * @throws IOException if I/O errors occur
460 * @since 1.2
461 */
462 public ObjectOutputStream.PutField putFields() throws IOException {
463 if (curPut == null) {
464 SerialCallbackContext ctx = curContext;
465 if (ctx == null) {
466 throw new NotActiveException("not in call to writeObject");
467 }
468 ctx.checkAndSetUsed();
469 ObjectStreamClass curDesc = ctx.getDesc();
470 curPut = new PutFieldImpl(curDesc);
471 }
472 return curPut;
473 }
474
475 /**
476 * Write the buffered fields to the stream.
477 *
478 * @throws IOException if I/O errors occur while writing to the underlying
479 * stream
480 * @throws NotActiveException Called when a classes writeObject method was
481 * not called to write the state of the object.
482 * @since 1.2
483 */
484 public void writeFields() throws IOException {
485 if (curPut == null) {
486 throw new NotActiveException("no current PutField object");
487 }
488 bout.setBlockDataMode(false);
489 curPut.writeFields();
490 bout.setBlockDataMode(true);
491 }
492
493 /**
494 * Reset will disregard the state of any objects already written to the
495 * stream. The state is reset to be the same as a new ObjectOutputStream.
496 * The current point in the stream is marked as reset so the corresponding
497 * ObjectInputStream will be reset at the same point. Objects previously
498 * written to the stream will not be referred to as already being in the
499 * stream. They will be written to the stream again.
500 *
501 * @throws IOException if reset() is invoked while serializing an object.
502 */
503 public void reset() throws IOException {
504 if (depth != 0) {
505 throw new IOException("stream active");
506 }
507 bout.setBlockDataMode(false);
508 bout.writeByte(TC_RESET);
509 clear();
510 bout.setBlockDataMode(true);
511 }
512
513 /**
514 * Subclasses may implement this method to allow class data to be stored in
515 * the stream. By default this method does nothing. The corresponding
516 * method in ObjectInputStream is resolveClass. This method is called
517 * exactly once for each unique class in the stream. The class name and
518 * signature will have already been written to the stream. This method may
519 * make free use of the ObjectOutputStream to save any representation of
520 * the class it deems suitable (for example, the bytes of the class file).
521 * The resolveClass method in the corresponding subclass of
522 * ObjectInputStream must read and use any data or objects written by
523 * annotateClass.
524 *
525 * @param cl the class to annotate custom data for
526 * @throws IOException Any exception thrown by the underlying
527 * OutputStream.
528 */
529 protected void annotateClass(Class<?> cl) throws IOException {
530 }
531
532 /**
533 * Subclasses may implement this method to store custom data in the stream
534 * along with descriptors for dynamic proxy classes.
535 *
536 * <p>This method is called exactly once for each unique proxy class
537 * descriptor in the stream. The default implementation of this method in
538 * {@code ObjectOutputStream} does nothing.
539 *
540 * <p>The corresponding method in {@code ObjectInputStream} is
541 * {@code resolveProxyClass}. For a given subclass of
542 * {@code ObjectOutputStream} that overrides this method, the
543 * {@code resolveProxyClass} method in the corresponding subclass of
544 * {@code ObjectInputStream} must read any data or objects written by
545 * {@code annotateProxyClass}.
546 *
547 * @param cl the proxy class to annotate custom data for
548 * @throws IOException any exception thrown by the underlying
549 * {@code OutputStream}
550 * @see ObjectInputStream#resolveProxyClass(String[])
551 * @since 1.3
552 */
553 protected void annotateProxyClass(Class<?> cl) throws IOException {
554 }
555
556 /**
557 * This method will allow trusted subclasses of ObjectOutputStream to
558 * substitute one object for another during serialization. Replacing
559 * objects is disabled until enableReplaceObject is called. The
560 * enableReplaceObject method checks that the stream requesting to do
561 * replacement can be trusted. The first occurrence of each object written
562 * into the serialization stream is passed to replaceObject. Subsequent
563 * references to the object are replaced by the object returned by the
564 * original call to replaceObject. To ensure that the private state of
565 * objects is not unintentionally exposed, only trusted streams may use
566 * replaceObject.
567 *
568 * <p>The ObjectOutputStream.writeObject method takes a parameter of type
569 * Object (as opposed to type Serializable) to allow for cases where
570 * non-serializable objects are replaced by serializable ones.
571 *
572 * <p>When a subclass is replacing objects it must ensure that either a
573 * complementary substitution must be made during deserialization or that
574 * the substituted object is compatible with every field where the
575 * reference will be stored. Objects whose type is not a subclass of the
576 * type of the field or array element abort the serialization by raising an
577 * exception and the object is not be stored.
578 *
579 * <p>This method is called only once when each object is first
580 * encountered. All subsequent references to the object will be redirected
581 * to the new object. This method should return the object to be
582 * substituted or the original object.
583 *
584 * <p>Null can be returned as the object to be substituted, but may cause
585 * NullReferenceException in classes that contain references to the
586 * original object since they may be expecting an object instead of
587 * null.
588 *
589 * @param obj the object to be replaced
590 * @return the alternate object that replaced the specified one
591 * @throws IOException Any exception thrown by the underlying
592 * OutputStream.
593 */
594 protected Object replaceObject(Object obj) throws IOException {
595 return obj;
596 }
597
598 /**
599 * Enables the stream to do replacement of objects written to the stream. When
600 * enabled, the {@link #replaceObject} method is called for every object being
601 * serialized.
602 *
603 * <p>If object replacement is currently not enabled, and
604 * {@code enable} is true, and there is a security manager installed,
605 * this method first calls the security manager's
606 * {@code checkPermission} method with the
607 * {@code SerializablePermission("enableSubstitution")} permission to
608 * ensure that the caller is permitted to enable the stream to do replacement
609 * of objects written to the stream.
610 *
611 * @param enable true for enabling use of {@code replaceObject} for
612 * every object being serialized
613 * @return the previous setting before this method was invoked
614 * @throws SecurityException if a security manager exists and its
615 * {@code checkPermission} method denies enabling the stream
616 * to do replacement of objects written to the stream.
617 * @see SecurityManager#checkPermission
618 * @see java.io.SerializablePermission
619 */
620 protected boolean enableReplaceObject(boolean enable)
621 throws SecurityException
622 {
623 if (enable == enableReplace) {
624 return enable;
625 }
626 if (enable) {
627 @SuppressWarnings("removal")
628 SecurityManager sm = System.getSecurityManager();
629 if (sm != null) {
630 sm.checkPermission(SUBSTITUTION_PERMISSION);
631 }
632 }
633 enableReplace = enable;
634 return !enableReplace;
635 }
636
637 /**
638 * The writeStreamHeader method is provided so subclasses can append or
639 * prepend their own header to the stream. It writes the magic number and
640 * version to the stream.
641 *
642 * @throws IOException if I/O errors occur while writing to the underlying
643 * stream
644 */
645 protected void writeStreamHeader() throws IOException {
646 bout.writeShort(STREAM_MAGIC);
647 bout.writeShort(STREAM_VERSION);
648 }
649
650 /**
651 * Write the specified class descriptor to the ObjectOutputStream. Class
652 * descriptors are used to identify the classes of objects written to the
653 * stream. Subclasses of ObjectOutputStream may override this method to
654 * customize the way in which class descriptors are written to the
655 * serialization stream. The corresponding method in ObjectInputStream,
656 * {@link ObjectInputStream#readClassDescriptor readClassDescriptor}, should then be overridden to
657 * reconstitute the class descriptor from its custom stream representation.
658 * By default, this method writes class descriptors according to the format
659 * defined in the <a href="{@docRoot}/../specs/serialization/index.html">
660 * <cite>Java Object Serialization Specification</cite></a>.
661 *
662 * <p>Note that this method will only be called if the ObjectOutputStream
663 * is not using the old serialization stream format (set by calling
664 * ObjectOutputStream's {@code useProtocolVersion} method). If this
665 * serialization stream is using the old format
666 * ({@code PROTOCOL_VERSION_1}), the class descriptor will be written
667 * internally in a manner that cannot be overridden or customized.
668 *
669 * @param desc class descriptor to write to the stream
670 * @throws IOException If an I/O error has occurred.
671 * @see java.io.ObjectInputStream#readClassDescriptor()
672 * @see #useProtocolVersion(int)
673 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
674 * @since 1.3
675 */
676 protected void writeClassDescriptor(ObjectStreamClass desc)
677 throws IOException
678 {
679 desc.writeNonProxy(this);
680 }
681
682 /**
683 * Writes a byte. This method will block until the byte is actually
684 * written.
685 *
686 * @param val the byte to be written to the stream
687 * @throws IOException If an I/O error has occurred.
688 */
689 @Override
690 public void write(int val) throws IOException {
691 bout.write(val);
692 }
693
694 /**
695 * Writes an array of bytes. This method will block until the bytes are
696 * actually written.
697 *
698 * @param buf the data to be written
699 * @throws IOException If an I/O error has occurred.
700 */
701 @Override
702 public void write(byte[] buf) throws IOException {
703 bout.write(buf, 0, buf.length, false);
704 }
705
706 /**
707 * Writes a sub array of bytes.
708 *
709 * @param buf the data to be written
710 * @param off the start offset in the data
711 * @param len the number of bytes that are written
712 * @throws IOException {@inheritDoc}
713 * @throws IndexOutOfBoundsException {@inheritDoc}
714 */
715 @Override
716 public void write(byte[] buf, int off, int len) throws IOException {
717 if (buf == null) {
718 throw new NullPointerException();
719 }
720 Objects.checkFromIndexSize(off, len, buf.length);
721 bout.write(buf, off, len, false);
722 }
723
724 /**
725 * Flushes the stream. This will write any buffered output bytes and flush
726 * through to the underlying stream.
727 *
728 * @throws IOException {@inheritDoc}
729 */
730 @Override
731 public void flush() throws IOException {
732 bout.flush();
733 }
734
735 /**
736 * Drain any buffered data in ObjectOutputStream. Similar to flush but
737 * does not propagate the flush to the underlying stream.
738 *
739 * @throws IOException if I/O errors occur while writing to the underlying
740 * stream
741 */
742 protected void drain() throws IOException {
743 bout.drain();
744 }
745
746 /**
747 * Closes the stream. This method must be called to release any resources
748 * associated with the stream.
749 *
750 * @throws IOException If an I/O error has occurred.
751 */
752 @Override
753 public void close() throws IOException {
754 flush();
755 clear();
756 bout.close();
757 }
758
759 /**
760 * Writes a boolean.
761 *
762 * @param val the boolean to be written
763 * @throws IOException if I/O errors occur while writing to the underlying
764 * stream
765 */
766 public void writeBoolean(boolean val) throws IOException {
767 bout.writeBoolean(val);
768 }
769
770 /**
771 * Writes an 8 bit byte.
772 *
773 * @param val the byte value to be written
774 * @throws IOException if I/O errors occur while writing to the underlying
775 * stream
776 */
777 public void writeByte(int val) throws IOException {
778 bout.writeByte(val);
779 }
780
781 /**
782 * Writes a 16 bit short.
783 *
784 * @param val the short value to be written
785 * @throws IOException if I/O errors occur while writing to the underlying
786 * stream
787 */
788 public void writeShort(int val) throws IOException {
789 bout.writeShort(val);
790 }
791
792 /**
793 * Writes a 16 bit char.
794 *
795 * @param val the char value to be written
796 * @throws IOException if I/O errors occur while writing to the underlying
797 * stream
798 */
799 public void writeChar(int val) throws IOException {
800 bout.writeChar(val);
801 }
802
803 /**
804 * Writes a 32 bit int.
805 *
806 * @param val the integer value to be written
807 * @throws IOException if I/O errors occur while writing to the underlying
808 * stream
809 */
810 public void writeInt(int val) throws IOException {
811 bout.writeInt(val);
812 }
813
814 /**
815 * Writes a 64 bit long.
816 *
817 * @param val the long value to be written
818 * @throws IOException if I/O errors occur while writing to the underlying
819 * stream
820 */
821 public void writeLong(long val) throws IOException {
822 bout.writeLong(val);
823 }
824
825 /**
826 * Writes a 32 bit float.
827 *
828 * @param val the float value to be written
829 * @throws IOException if I/O errors occur while writing to the underlying
830 * stream
831 */
832 public void writeFloat(float val) throws IOException {
833 bout.writeFloat(val);
834 }
835
836 /**
837 * Writes a 64 bit double.
838 *
839 * @param val the double value to be written
840 * @throws IOException if I/O errors occur while writing to the underlying
841 * stream
842 */
843 public void writeDouble(double val) throws IOException {
844 bout.writeDouble(val);
845 }
846
847 /**
848 * Writes a String as a sequence of bytes.
849 *
850 * @param str the String of bytes to be written
851 * @throws IOException if I/O errors occur while writing to the underlying
852 * stream
853 */
854 public void writeBytes(String str) throws IOException {
855 bout.writeBytes(str);
856 }
857
858 /**
859 * Writes a String as a sequence of chars.
860 *
861 * @param str the String of chars to be written
862 * @throws IOException if I/O errors occur while writing to the underlying
863 * stream
864 */
865 public void writeChars(String str) throws IOException {
866 bout.writeChars(str);
867 }
868
869 /**
870 * Primitive data write of this String in
871 * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
872 * format. Note that there is a
873 * significant difference between writing a String into the stream as
874 * primitive data or as an Object. A String instance written by writeObject
875 * is written into the stream as a String initially. Future writeObject()
876 * calls write references to the string into the stream.
877 *
878 * @param str the String to be written
879 * @throws IOException if I/O errors occur while writing to the underlying
880 * stream
881 */
882 public void writeUTF(String str) throws IOException {
883 bout.writeUTF(str);
884 }
885
886 /**
887 * Provide programmatic access to the persistent fields to be written
888 * to ObjectOutput.
889 *
890 * @since 1.2
891 */
892 public abstract static class PutField {
893 /**
894 * Constructor for subclasses to call.
895 */
896 public PutField() {}
897
898 /**
899 * Put the value of the named boolean field into the persistent field.
900 *
901 * @param name the name of the serializable field
902 * @param val the value to assign to the field
903 * @throws IllegalArgumentException if {@code name} does not
904 * match the name of a serializable field for the class whose fields
905 * are being written, or if the type of the named field is not
906 * {@code boolean}
907 */
908 public abstract void put(String name, boolean val);
909
910 /**
911 * Put the value of the named byte field into the persistent field.
912 *
913 * @param name the name of the serializable field
914 * @param val the value to assign to the field
915 * @throws IllegalArgumentException if {@code name} does not
916 * match the name of a serializable field for the class whose fields
917 * are being written, or if the type of the named field is not
918 * {@code byte}
919 */
920 public abstract void put(String name, byte val);
921
922 /**
923 * Put the value of the named char field into the persistent field.
924 *
925 * @param name the name of the serializable field
926 * @param val the value to assign to the field
927 * @throws IllegalArgumentException if {@code name} does not
928 * match the name of a serializable field for the class whose fields
929 * are being written, or if the type of the named field is not
930 * {@code char}
931 */
932 public abstract void put(String name, char val);
933
934 /**
935 * Put the value of the named short field into the persistent field.
936 *
937 * @param name the name of the serializable field
938 * @param val the value to assign to the field
939 * @throws IllegalArgumentException if {@code name} does not
940 * match the name of a serializable field for the class whose fields
941 * are being written, or if the type of the named field is not
942 * {@code short}
943 */
944 public abstract void put(String name, short val);
945
946 /**
947 * Put the value of the named int field into the persistent field.
948 *
949 * @param name the name of the serializable field
950 * @param val the value to assign to the field
951 * @throws IllegalArgumentException if {@code name} does not
952 * match the name of a serializable field for the class whose fields
953 * are being written, or if the type of the named field is not
954 * {@code int}
955 */
956 public abstract void put(String name, int val);
957
958 /**
959 * Put the value of the named long field into the persistent field.
960 *
961 * @param name the name of the serializable field
962 * @param val the value to assign to the field
963 * @throws IllegalArgumentException if {@code name} does not
964 * match the name of a serializable field for the class whose fields
965 * are being written, or if the type of the named field is not
966 * {@code long}
967 */
968 public abstract void put(String name, long val);
969
970 /**
971 * Put the value of the named float field into the persistent field.
972 *
973 * @param name the name of the serializable field
974 * @param val the value to assign to the field
975 * @throws IllegalArgumentException if {@code name} does not
976 * match the name of a serializable field for the class whose fields
977 * are being written, or if the type of the named field is not
978 * {@code float}
979 */
980 public abstract void put(String name, float val);
981
982 /**
983 * Put the value of the named double field into the persistent field.
984 *
985 * @param name the name of the serializable field
986 * @param val the value to assign to the field
987 * @throws IllegalArgumentException if {@code name} does not
988 * match the name of a serializable field for the class whose fields
989 * are being written, or if the type of the named field is not
990 * {@code double}
991 */
992 public abstract void put(String name, double val);
993
994 /**
995 * Put the value of the named Object field into the persistent field.
996 *
997 * @param name the name of the serializable field
998 * @param val the value to assign to the field
999 * (which may be {@code null})
1000 * @throws IllegalArgumentException if {@code name} does not
1001 * match the name of a serializable field for the class whose fields
1002 * are being written, or if the type of the named field is not a
1003 * reference type
1004 */
1005 public abstract void put(String name, Object val);
1006
1007 /**
1008 * Write the data and fields to the specified ObjectOutput stream,
1009 * which must be the same stream that produced this
1010 * {@code PutField} object.
1011 *
1012 * @param out the stream to write the data and fields to
1013 * @throws IOException if I/O errors occur while writing to the
1014 * underlying stream
1015 * @throws IllegalArgumentException if the specified stream is not
1016 * the same stream that produced this {@code PutField}
1017 * object
1018 * @deprecated This method does not write the values contained by this
1019 * {@code PutField} object in a proper format, and may
1020 * result in corruption of the serialization stream. The
1021 * correct way to write {@code PutField} data is by
1022 * calling the {@link java.io.ObjectOutputStream#writeFields()}
1023 * method.
1024 */
1025 @Deprecated
1026 public abstract void write(ObjectOutput out) throws IOException;
1027 }
1028
1029
1030 /**
1031 * Returns protocol version in use.
1032 */
1033 int getProtocolVersion() {
1034 return protocol;
1035 }
1036
1037 /**
1038 * Writes string without allowing it to be replaced in stream. Used by
1039 * ObjectStreamClass to write class descriptor type strings.
1040 */
1041 void writeTypeString(String str) throws IOException {
1042 int handle;
1043 if (str == null) {
1044 writeNull();
1045 } else if ((handle = handles.lookup(str)) != -1) {
1046 writeHandle(handle);
1047 } else {
1048 writeString(str, false);
1049 }
1050 }
1051
1052 /**
1053 * Verifies that this (possibly subclass) instance can be constructed
1054 * without violating security constraints: the subclass must not override
1055 * security-sensitive non-final methods, or else the
1056 * "enableSubclassImplementation" SerializablePermission is checked.
1057 */
1058 private void verifySubclass() {
1059 Class<?> cl = getClass();
1060 if (cl == ObjectOutputStream.class) {
1061 return;
1062 }
1063 @SuppressWarnings("removal")
1064 SecurityManager sm = System.getSecurityManager();
1065 if (sm == null) {
1066 return;
1067 }
1068 boolean result = Caches.subclassAudits.get(cl);
1069 if (!result) {
1070 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
1071 }
1072 }
1073
1074 /**
1075 * Performs reflective checks on given subclass to verify that it doesn't
1076 * override security-sensitive non-final methods. Returns TRUE if subclass
1077 * is "safe", FALSE otherwise.
1078 */
1079 @SuppressWarnings("removal")
1080 private static Boolean auditSubclass(Class<?> subcl) {
1081 return AccessController.doPrivileged(
1082 new PrivilegedAction<>() {
1083 public Boolean run() {
1084 for (Class<?> cl = subcl;
1085 cl != ObjectOutputStream.class;
1086 cl = cl.getSuperclass())
1087 {
1088 try {
1089 cl.getDeclaredMethod(
1090 "writeUnshared", new Class<?>[] { Object.class });
1091 return Boolean.FALSE;
1092 } catch (NoSuchMethodException ex) {
1093 }
1094 try {
1095 cl.getDeclaredMethod("putFields", (Class<?>[]) null);
1096 return Boolean.FALSE;
1097 } catch (NoSuchMethodException ex) {
1098 }
1099 }
1100 return Boolean.TRUE;
1101 }
1102 }
1103 );
1104 }
1105
1106 /**
1107 * Clears internal data structures.
1108 */
1109 private void clear() {
1110 subs.clear();
1111 handles.clear();
1112 }
1113
1114 /**
1115 * Underlying writeObject/writeUnshared implementation.
1116 */
1117 private void writeObject0(Object obj, boolean unshared)
1118 throws IOException
1119 {
1120 boolean oldMode = bout.setBlockDataMode(false);
1121 depth++;
1122 try {
1123 // handle previously written and non-replaceable objects
1124 int h;
1125 if ((obj = subs.lookup(obj)) == null) {
1126 writeNull();
1127 return;
1128 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1129 writeHandle(h);
1130 return;
1131 } else if (obj instanceof Class) {
1132 writeClass((Class) obj, unshared);
1133 return;
1134 } else if (obj instanceof ObjectStreamClass) {
1135 writeClassDesc((ObjectStreamClass) obj, unshared);
1136 return;
1137 }
1138
1139 // check for replacement object
1140 Object orig = obj;
1141 Class<?> cl = obj.getClass();
1142 ObjectStreamClass desc;
1143 for (;;) {
1144 // REMIND: skip this check for strings/arrays?
1145 Class<?> repCl;
1146 desc = ObjectStreamClass.lookup(cl, true);
1147 if (!desc.hasWriteReplaceMethod() ||
1148 (obj = desc.invokeWriteReplace(obj)) == null ||
1149 (repCl = obj.getClass()) == cl)
1150 {
1151 break;
1152 }
1153 cl = repCl;
1154 }
1155 if (enableReplace) {
1156 Object rep = replaceObject(obj);
1157 if (rep != obj && rep != null) {
1158 cl = rep.getClass();
1159 desc = ObjectStreamClass.lookup(cl, true);
1160 }
1161 obj = rep;
1162 }
1163
1164 // if object replaced, run through original checks a second time
1165 if (obj != orig) {
1166 subs.assign(orig, obj);
1167 if (obj == null) {
1168 writeNull();
1169 return;
1170 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1171 writeHandle(h);
1172 return;
1173 } else if (obj instanceof Class) {
1174 writeClass((Class) obj, unshared);
1175 return;
1176 } else if (obj instanceof ObjectStreamClass) {
1177 writeClassDesc((ObjectStreamClass) obj, unshared);
1178 return;
1179 }
1180 }
1181
1182 // remaining cases
1183 if (obj instanceof String) {
1184 writeString((String) obj, unshared);
1185 } else if (cl.isArray()) {
1186 writeArray(obj, desc, unshared);
1187 } else if (obj instanceof Enum) {
1188 writeEnum((Enum<?>) obj, desc, unshared);
1189 } else if (obj instanceof Serializable) {
1190 writeOrdinaryObject(obj, desc, unshared);
1191 } else {
1192 if (extendedDebugInfo) {
1193 throw new NotSerializableException(
1194 cl.getName() + "\n" + debugInfoStack.toString());
1195 } else {
1196 throw new NotSerializableException(cl.getName());
1197 }
1198 }
1199 } finally {
1200 depth--;
1201 bout.setBlockDataMode(oldMode);
1202 }
1203 }
1204
1205 /**
1206 * Writes null code to stream.
1207 */
1208 private void writeNull() throws IOException {
1209 bout.writeByte(TC_NULL);
1210 }
1211
1212 /**
1213 * Writes given object handle to stream.
1214 */
1215 private void writeHandle(int handle) throws IOException {
1216 bout.writeByte(TC_REFERENCE);
1217 bout.writeInt(baseWireHandle + handle);
1218 }
1219
1220 /**
1221 * Writes representation of given class to stream.
1222 */
1223 private void writeClass(Class<?> cl, boolean unshared) throws IOException {
1224 bout.writeByte(TC_CLASS);
1225 writeClassDesc(ObjectStreamClass.lookup(cl, true), false);
1226 handles.assign(unshared ? null : cl);
1227 }
1228
1229 /**
1230 * Writes representation of given class descriptor to stream.
1231 */
1232 private void writeClassDesc(ObjectStreamClass desc, boolean unshared)
1233 throws IOException
1234 {
1235 int handle;
1236 if (desc == null) {
1237 writeNull();
1238 } else if (!unshared && (handle = handles.lookup(desc)) != -1) {
1239 writeHandle(handle);
1240 } else if (desc.isProxy()) {
1241 writeProxyDesc(desc, unshared);
1242 } else {
1243 writeNonProxyDesc(desc, unshared);
1244 }
1245 }
1246
1247 private boolean isCustomSubclass() {
1248 // Return true if this class is a custom subclass of ObjectOutputStream
1249 return getClass().getClassLoader()
1250 != ObjectOutputStream.class.getClassLoader();
1251 }
1252
1253 /**
1254 * Writes class descriptor representing a dynamic proxy class to stream.
1255 */
1256 private void writeProxyDesc(ObjectStreamClass desc, boolean unshared)
1257 throws IOException
1258 {
1259 bout.writeByte(TC_PROXYCLASSDESC);
1260 handles.assign(unshared ? null : desc);
1261
1262 Class<?> cl = desc.forClass();
1263 Class<?>[] ifaces = cl.getInterfaces();
1264 bout.writeInt(ifaces.length);
1265 for (int i = 0; i < ifaces.length; i++) {
1266 bout.writeUTF(ifaces[i].getName());
1267 }
1268
1269 bout.setBlockDataMode(true);
1270 if (cl != null && isCustomSubclass()) {
1271 ReflectUtil.checkPackageAccess(cl);
1272 }
1273 annotateProxyClass(cl);
1274 bout.setBlockDataMode(false);
1275 bout.writeByte(TC_ENDBLOCKDATA);
1276
1277 writeClassDesc(desc.getSuperDesc(), false);
1278 }
1279
1280 /**
1281 * Writes class descriptor representing a standard (i.e., not a dynamic
1282 * proxy) class to stream.
1283 */
1284 private void writeNonProxyDesc(ObjectStreamClass desc, boolean unshared)
1285 throws IOException
1286 {
1287 bout.writeByte(TC_CLASSDESC);
1288 handles.assign(unshared ? null : desc);
1289
1290 if (protocol == PROTOCOL_VERSION_1) {
1291 // do not invoke class descriptor write hook with old protocol
1292 desc.writeNonProxy(this);
1293 } else {
1294 writeClassDescriptor(desc);
1295 }
1296
1297 Class<?> cl = desc.forClass();
1298 bout.setBlockDataMode(true);
1299 if (cl != null && isCustomSubclass()) {
1300 ReflectUtil.checkPackageAccess(cl);
1301 }
1302 annotateClass(cl);
1303 bout.setBlockDataMode(false);
1304 bout.writeByte(TC_ENDBLOCKDATA);
1305
1306 writeClassDesc(desc.getSuperDesc(), false);
1307 }
1308
1309 /**
1310 * Writes given string to stream, using standard or long UTF format
1311 * depending on string length.
1312 */
1313 private void writeString(String str, boolean unshared) throws IOException {
1314 handles.assign(unshared ? null : str);
1315 long utflen = bout.getUTFLength(str);
1316 if (utflen <= 0xFFFF) {
1317 bout.writeByte(TC_STRING);
1318 bout.writeUTF(str, utflen);
1319 } else {
1320 bout.writeByte(TC_LONGSTRING);
1321 bout.writeLongUTF(str, utflen);
1322 }
1323 }
1324
1325 /**
1326 * Writes given array object to stream.
1327 */
1328 private void writeArray(Object array,
1329 ObjectStreamClass desc,
1330 boolean unshared)
1331 throws IOException
1332 {
1333 bout.writeByte(TC_ARRAY);
1334 writeClassDesc(desc, false);
1335 handles.assign(unshared ? null : array);
1336
1337 Class<?> ccl = desc.forClass().getComponentType();
1338 if (ccl.isPrimitive()) {
1339 if (ccl == Integer.TYPE) {
1340 int[] ia = (int[]) array;
1341 bout.writeInt(ia.length);
1342 bout.writeInts(ia, 0, ia.length);
1343 } else if (ccl == Byte.TYPE) {
1344 byte[] ba = (byte[]) array;
1345 bout.writeInt(ba.length);
1346 bout.write(ba, 0, ba.length, true);
1347 } else if (ccl == Long.TYPE) {
1348 long[] ja = (long[]) array;
1349 bout.writeInt(ja.length);
1350 bout.writeLongs(ja, 0, ja.length);
1351 } else if (ccl == Float.TYPE) {
1352 float[] fa = (float[]) array;
1353 bout.writeInt(fa.length);
1354 bout.writeFloats(fa, 0, fa.length);
1355 } else if (ccl == Double.TYPE) {
1356 double[] da = (double[]) array;
1357 bout.writeInt(da.length);
1358 bout.writeDoubles(da, 0, da.length);
1359 } else if (ccl == Short.TYPE) {
1360 short[] sa = (short[]) array;
1361 bout.writeInt(sa.length);
1362 bout.writeShorts(sa, 0, sa.length);
1363 } else if (ccl == Character.TYPE) {
1364 char[] ca = (char[]) array;
1365 bout.writeInt(ca.length);
1366 bout.writeChars(ca, 0, ca.length);
1367 } else if (ccl == Boolean.TYPE) {
1368 boolean[] za = (boolean[]) array;
1369 bout.writeInt(za.length);
1370 bout.writeBooleans(za, 0, za.length);
1371 } else {
1372 throw new InternalError();
1373 }
1374 } else {
1375 Object[] objs = (Object[]) array;
1376 int len = objs.length;
1377 bout.writeInt(len);
1378 if (extendedDebugInfo) {
1379 debugInfoStack.push(
1380 "array (class \"" + array.getClass().getName() +
1381 "\", size: " + len + ")");
1382 }
1383 try {
1384 for (int i = 0; i < len; i++) {
1385 if (extendedDebugInfo) {
1386 debugInfoStack.push(
1387 "element of array (index: " + i + ")");
1388 }
1389 try {
1390 writeObject0(objs[i], false);
1391 } finally {
1392 if (extendedDebugInfo) {
1393 debugInfoStack.pop();
1394 }
1395 }
1396 }
1397 } finally {
1398 if (extendedDebugInfo) {
1399 debugInfoStack.pop();
1400 }
1401 }
1402 }
1403 }
1404
1405 /**
1406 * Writes given enum constant to stream.
1407 */
1408 private void writeEnum(Enum<?> en,
1409 ObjectStreamClass desc,
1410 boolean unshared)
1411 throws IOException
1412 {
1413 bout.writeByte(TC_ENUM);
1414 ObjectStreamClass sdesc = desc.getSuperDesc();
1415 writeClassDesc((sdesc.forClass() == Enum.class) ? desc : sdesc, false);
1416 handles.assign(unshared ? null : en);
1417 writeString(en.name(), false);
1418 }
1419
1420 /**
1421 * Writes representation of an "ordinary" (i.e., not a String, Class,
1422 * ObjectStreamClass, array, or enum constant) serializable object to the
1423 * stream.
1424 */
1425 private void writeOrdinaryObject(Object obj,
1426 ObjectStreamClass desc,
1427 boolean unshared)
1428 throws IOException
1429 {
1430 if (extendedDebugInfo) {
1431 debugInfoStack.push(
1432 (depth == 1 ? "root " : "") + "object (class \"" +
1433 obj.getClass().getName() + "\", " + obj.toString() + ")");
1434 }
1435 try {
1436 desc.checkSerialize();
1437
1438 bout.writeByte(TC_OBJECT);
1439 writeClassDesc(desc, false);
1440 handles.assign(unshared ? null : obj);
1441
1442 if (desc.isRecord()) {
1443 writeRecordData(obj, desc);
1444 } else if (desc.isExternalizable() && !desc.isProxy()) {
1445 writeExternalData((Externalizable) obj);
1446 } else {
1447 writeSerialData(obj, desc);
1448 }
1449 } finally {
1450 if (extendedDebugInfo) {
1451 debugInfoStack.pop();
1452 }
1453 }
1454 }
1455
1456 /**
1457 * Writes externalizable data of given object by invoking its
1458 * writeExternal() method.
1459 */
1460 private void writeExternalData(Externalizable obj) throws IOException {
1461 PutFieldImpl oldPut = curPut;
1462 curPut = null;
1463
1464 if (extendedDebugInfo) {
1465 debugInfoStack.push("writeExternal data");
1466 }
1467 SerialCallbackContext oldContext = curContext;
1468 try {
1469 curContext = null;
1470 if (protocol == PROTOCOL_VERSION_1) {
1471 obj.writeExternal(this);
1472 } else {
1473 bout.setBlockDataMode(true);
1474 obj.writeExternal(this);
1475 bout.setBlockDataMode(false);
1476 bout.writeByte(TC_ENDBLOCKDATA);
1477 }
1478 } finally {
1479 curContext = oldContext;
1480 if (extendedDebugInfo) {
1481 debugInfoStack.pop();
1482 }
1483 }
1484
1485 curPut = oldPut;
1486 }
1487
1488 /** Writes the record component values for the given record object. */
1489 private void writeRecordData(Object obj, ObjectStreamClass desc)
1490 throws IOException
1491 {
1492 assert obj.getClass().isRecord();
1493 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1494 if (slots.length != 1) {
1495 throw new InvalidClassException(
1496 "expected a single record slot length, but found: " + slots.length);
1497 }
1498
1499 defaultWriteFields(obj, desc); // #### seems unnecessary to use the accessors
1500 }
1501
1502 /**
1503 * Writes instance data for each serializable class of given object, from
1504 * superclass to subclass.
1505 */
1506 private void writeSerialData(Object obj, ObjectStreamClass desc)
1507 throws IOException
1508 {
1509 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1510 for (int i = 0; i < slots.length; i++) {
1511 ObjectStreamClass slotDesc = slots[i].desc;
1512 if (slotDesc.hasWriteObjectMethod()) {
1513 PutFieldImpl oldPut = curPut;
1514 curPut = null;
1515 SerialCallbackContext oldContext = curContext;
1516
1517 if (extendedDebugInfo) {
1518 debugInfoStack.push(
1519 "custom writeObject data (class \"" +
1520 slotDesc.getName() + "\")");
1521 }
1522 try {
1523 curContext = new SerialCallbackContext(obj, slotDesc);
1524 bout.setBlockDataMode(true);
1525 slotDesc.invokeWriteObject(obj, this);
1526 bout.setBlockDataMode(false);
1527 bout.writeByte(TC_ENDBLOCKDATA);
1528 } finally {
1529 curContext.setUsed();
1530 curContext = oldContext;
1531 if (extendedDebugInfo) {
1532 debugInfoStack.pop();
1533 }
1534 }
1535
1536 curPut = oldPut;
1537 } else {
1538 defaultWriteFields(obj, slotDesc);
1539 }
1540 }
1541 }
1542
1543 /**
1544 * Fetches and writes values of serializable fields of given object to
1545 * stream. The given class descriptor specifies which field values to
1546 * write, and in which order they should be written.
1547 */
1548 private void defaultWriteFields(Object obj, ObjectStreamClass desc)
1549 throws IOException
1550 {
1551 Class<?> cl = desc.forClass();
1552 if (cl != null && obj != null && !cl.isInstance(obj)) {
1553 throw new ClassCastException();
1554 }
1555
1556 desc.checkDefaultSerialize();
1557
1558 int primDataSize = desc.getPrimDataSize();
1559 if (primDataSize > 0) {
1560 if (primVals == null || primVals.length < primDataSize) {
1561 primVals = new byte[primDataSize];
1562 }
1563 desc.getPrimFieldValues(obj, primVals);
1564 bout.write(primVals, 0, primDataSize, false);
1565 }
1566
1567 int numObjFields = desc.getNumObjFields();
1568 if (numObjFields > 0) {
1569 ObjectStreamField[] fields = desc.getFields(false);
1570 Object[] objVals = new Object[numObjFields];
1571 int numPrimFields = fields.length - objVals.length;
1572 desc.getObjFieldValues(obj, objVals);
1573 for (int i = 0; i < objVals.length; i++) {
1574 if (extendedDebugInfo) {
1575 debugInfoStack.push(
1576 "field (class \"" + desc.getName() + "\", name: \"" +
1577 fields[numPrimFields + i].getName() + "\", type: \"" +
1578 fields[numPrimFields + i].getType() + "\")");
1579 }
1580 try {
1581 writeObject0(objVals[i],
1582 fields[numPrimFields + i].isUnshared());
1583 } finally {
1584 if (extendedDebugInfo) {
1585 debugInfoStack.pop();
1586 }
1587 }
1588 }
1589 }
1590 }
1591
1592 /**
1593 * Attempts to write to stream fatal IOException that has caused
1594 * serialization to abort.
1595 */
1596 private void writeFatalException(IOException ex) throws IOException {
1597 /*
1598 * Note: the serialization specification states that if a second
1599 * IOException occurs while attempting to serialize the original fatal
1600 * exception to the stream, then a StreamCorruptedException should be
1601 * thrown (section 2.1). However, due to a bug in previous
1602 * implementations of serialization, StreamCorruptedExceptions were
1603 * rarely (if ever) actually thrown--the "root" exceptions from
1604 * underlying streams were thrown instead. This historical behavior is
1605 * followed here for consistency.
1606 */
1607 clear();
1608 boolean oldMode = bout.setBlockDataMode(false);
1609 try {
1610 bout.writeByte(TC_EXCEPTION);
1611 writeObject0(ex, false);
1612 clear();
1613 } finally {
1614 bout.setBlockDataMode(oldMode);
1615 }
1616 }
1617
1618 /**
1619 * Default PutField implementation.
1620 */
1621 private class PutFieldImpl extends PutField {
1622
1623 /** class descriptor describing serializable fields */
1624 private final ObjectStreamClass desc;
1625 /** primitive field values */
1626 private final byte[] primVals;
1627 /** object field values */
1628 private final Object[] objVals;
1629
1630 /**
1631 * Creates PutFieldImpl object for writing fields defined in given
1632 * class descriptor.
1633 */
1634 PutFieldImpl(ObjectStreamClass desc) {
1635 this.desc = desc;
1636 primVals = new byte[desc.getPrimDataSize()];
1637 objVals = new Object[desc.getNumObjFields()];
1638 }
1639
1640 public void put(String name, boolean val) {
1641 Bits.putBoolean(primVals, getFieldOffset(name, Boolean.TYPE), val);
1642 }
1643
1644 public void put(String name, byte val) {
1645 primVals[getFieldOffset(name, Byte.TYPE)] = val;
1646 }
1647
1648 public void put(String name, char val) {
1649 Bits.putChar(primVals, getFieldOffset(name, Character.TYPE), val);
1650 }
1651
1652 public void put(String name, short val) {
1653 Bits.putShort(primVals, getFieldOffset(name, Short.TYPE), val);
1654 }
1655
1656 public void put(String name, int val) {
1657 Bits.putInt(primVals, getFieldOffset(name, Integer.TYPE), val);
1658 }
1659
1660 public void put(String name, float val) {
1661 Bits.putFloat(primVals, getFieldOffset(name, Float.TYPE), val);
1662 }
1663
1664 public void put(String name, long val) {
1665 Bits.putLong(primVals, getFieldOffset(name, Long.TYPE), val);
1666 }
1667
1668 public void put(String name, double val) {
1669 Bits.putDouble(primVals, getFieldOffset(name, Double.TYPE), val);
1670 }
1671
1672 public void put(String name, Object val) {
1673 objVals[getFieldOffset(name, Object.class)] = val;
1674 }
1675
1676 // deprecated in ObjectOutputStream.PutField
1677 public void write(ObjectOutput out) throws IOException {
1678 /*
1679 * Applications should *not* use this method to write PutField
1680 * data, as it will lead to stream corruption if the PutField
1681 * object writes any primitive data (since block data mode is not
1682 * unset/set properly, as is done in OOS.writeFields()). This
1683 * broken implementation is being retained solely for behavioral
1684 * compatibility, in order to support applications which use
1685 * OOS.PutField.write() for writing only non-primitive data.
1686 *
1687 * Serialization of unshared objects is not implemented here since
1688 * it is not necessary for backwards compatibility; also, unshared
1689 * semantics may not be supported by the given ObjectOutput
1690 * instance. Applications which write unshared objects using the
1691 * PutField API must use OOS.writeFields().
1692 */
1693 if (ObjectOutputStream.this != out) {
1694 throw new IllegalArgumentException("wrong stream");
1695 }
1696 out.write(primVals, 0, primVals.length);
1697
1698 ObjectStreamField[] fields = desc.getFields(false);
1699 int numPrimFields = fields.length - objVals.length;
1700 // REMIND: warn if numPrimFields > 0?
1701 for (int i = 0; i < objVals.length; i++) {
1702 if (fields[numPrimFields + i].isUnshared()) {
1703 throw new IOException("cannot write unshared object");
1704 }
1705 out.writeObject(objVals[i]);
1706 }
1707 }
1708
1709 /**
1710 * Writes buffered primitive data and object fields to stream.
1711 */
1712 void writeFields() throws IOException {
1713 bout.write(primVals, 0, primVals.length, false);
1714
1715 ObjectStreamField[] fields = desc.getFields(false);
1716 int numPrimFields = fields.length - objVals.length;
1717 for (int i = 0; i < objVals.length; i++) {
1718 if (extendedDebugInfo) {
1719 debugInfoStack.push(
1720 "field (class \"" + desc.getName() + "\", name: \"" +
1721 fields[numPrimFields + i].getName() + "\", type: \"" +
1722 fields[numPrimFields + i].getType() + "\")");
1723 }
1724 try {
1725 writeObject0(objVals[i],
1726 fields[numPrimFields + i].isUnshared());
1727 } finally {
1728 if (extendedDebugInfo) {
1729 debugInfoStack.pop();
1730 }
1731 }
1732 }
1733 }
1734
1735 /**
1736 * Returns offset of field with given name and type. A specified type
1737 * of null matches all types, Object.class matches all non-primitive
1738 * types, and any other non-null type matches assignable types only.
1739 * Throws IllegalArgumentException if no matching field found.
1740 */
1741 private int getFieldOffset(String name, Class<?> type) {
1742 ObjectStreamField field = desc.getField(name, type);
1743 if (field == null) {
1744 throw new IllegalArgumentException("no such field " + name +
1745 " with type " + type);
1746 }
1747 return field.getOffset();
1748 }
1749 }
1750
1751 /**
1752 * Buffered output stream with two modes: in default mode, outputs data in
1753 * same format as DataOutputStream; in "block data" mode, outputs data
1754 * bracketed by block data markers (see object serialization specification
1755 * for details).
1756 */
1757 private static class BlockDataOutputStream
1758 extends OutputStream implements DataOutput
1759 {
1760 /** maximum data block length */
1761 private static final int MAX_BLOCK_SIZE = 1024;
1762 /** maximum data block header length */
1763 private static final int MAX_HEADER_SIZE = 5;
1764 /** (tunable) length of char buffer (for writing strings) */
1765 private static final int CHAR_BUF_SIZE = 256;
1766
1767 /** buffer for writing general/block data */
1768 private final byte[] buf = new byte[MAX_BLOCK_SIZE];
1769 /** buffer for writing block data headers */
1770 private final byte[] hbuf = new byte[MAX_HEADER_SIZE];
1771 /** char buffer for fast string writes */
1772 private final char[] cbuf = new char[CHAR_BUF_SIZE];
1773
1774 /** block data mode */
1775 private boolean blkmode = false;
1776 /** current offset into buf */
1777 private int pos = 0;
1778
1779 /** underlying output stream */
1780 private final OutputStream out;
1781 /** loopback stream (for data writes that span data blocks) */
1782 private final DataOutputStream dout;
1783
1784 /**
1785 * Creates new BlockDataOutputStream on top of given underlying stream.
1786 * Block data mode is turned off by default.
1787 */
1788 BlockDataOutputStream(OutputStream out) {
1789 this.out = out;
1790 dout = new DataOutputStream(this);
1791 }
1792
1793 /**
1794 * Sets block data mode to the given mode (true == on, false == off)
1795 * and returns the previous mode value. If the new mode is the same as
1796 * the old mode, no action is taken. If the new mode differs from the
1797 * old mode, any buffered data is flushed before switching to the new
1798 * mode.
1799 */
1800 boolean setBlockDataMode(boolean mode) throws IOException {
1801 if (blkmode == mode) {
1802 return blkmode;
1803 }
1804 drain();
1805 blkmode = mode;
1806 return !blkmode;
1807 }
1808
1809 /**
1810 * Returns true if the stream is currently in block data mode, false
1811 * otherwise.
1812 */
1813 boolean getBlockDataMode() {
1814 return blkmode;
1815 }
1816
1817 /* ----------------- generic output stream methods ----------------- */
1818 /*
1819 * The following methods are equivalent to their counterparts in
1820 * OutputStream, except that they partition written data into data
1821 * blocks when in block data mode.
1822 */
1823
1824 public void write(int b) throws IOException {
1825 if (pos >= MAX_BLOCK_SIZE) {
1826 drain();
1827 }
1828 buf[pos++] = (byte) b;
1829 }
1830
1831 public void write(byte[] b) throws IOException {
1832 write(b, 0, b.length, false);
1833 }
1834
1835 public void write(byte[] b, int off, int len) throws IOException {
1836 write(b, off, len, false);
1837 }
1838
1839 public void flush() throws IOException {
1840 drain();
1841 out.flush();
1842 }
1843
1844 public void close() throws IOException {
1845 flush();
1846 out.close();
1847 }
1848
1849 /**
1850 * Writes specified span of byte values from given array. If copy is
1851 * true, copies the values to an intermediate buffer before writing
1852 * them to underlying stream (to avoid exposing a reference to the
1853 * original byte array).
1854 */
1855 void write(byte[] b, int off, int len, boolean copy)
1856 throws IOException
1857 {
1858 if (!(copy || blkmode)) { // write directly
1859 drain();
1860 out.write(b, off, len);
1861 return;
1862 }
1863
1864 while (len > 0) {
1865 if (pos >= MAX_BLOCK_SIZE) {
1866 drain();
1867 }
1868 if (len >= MAX_BLOCK_SIZE && !copy && pos == 0) {
1869 // avoid unnecessary copy
1870 writeBlockHeader(MAX_BLOCK_SIZE);
1871 out.write(b, off, MAX_BLOCK_SIZE);
1872 off += MAX_BLOCK_SIZE;
1873 len -= MAX_BLOCK_SIZE;
1874 } else {
1875 int wlen = Math.min(len, MAX_BLOCK_SIZE - pos);
1876 System.arraycopy(b, off, buf, pos, wlen);
1877 pos += wlen;
1878 off += wlen;
1879 len -= wlen;
1880 }
1881 }
1882 }
1883
1884 /**
1885 * Writes all buffered data from this stream to the underlying stream,
1886 * but does not flush underlying stream.
1887 */
1888 void drain() throws IOException {
1889 if (pos == 0) {
1890 return;
1891 }
1892 if (blkmode) {
1893 writeBlockHeader(pos);
1894 }
1895 out.write(buf, 0, pos);
1896 pos = 0;
1897 }
1898
1899 /**
1900 * Writes block data header. Data blocks shorter than 256 bytes are
1901 * prefixed with a 2-byte header; all others start with a 5-byte
1902 * header.
1903 */
1904 private void writeBlockHeader(int len) throws IOException {
1905 if (len <= 0xFF) {
1906 hbuf[0] = TC_BLOCKDATA;
1907 hbuf[1] = (byte) len;
1908 out.write(hbuf, 0, 2);
1909 } else {
1910 hbuf[0] = TC_BLOCKDATALONG;
1911 Bits.putInt(hbuf, 1, len);
1912 out.write(hbuf, 0, 5);
1913 }
1914 }
1915
1916
1917 /* ----------------- primitive data output methods ----------------- */
1918 /*
1919 * The following methods are equivalent to their counterparts in
1920 * DataOutputStream, except that they partition written data into data
1921 * blocks when in block data mode.
1922 */
1923
1924 public void writeBoolean(boolean v) throws IOException {
1925 if (pos >= MAX_BLOCK_SIZE) {
1926 drain();
1927 }
1928 Bits.putBoolean(buf, pos++, v);
1929 }
1930
1931 public void writeByte(int v) throws IOException {
1932 if (pos >= MAX_BLOCK_SIZE) {
1933 drain();
1934 }
1935 buf[pos++] = (byte) v;
1936 }
1937
1938 public void writeChar(int v) throws IOException {
1939 if (pos + 2 <= MAX_BLOCK_SIZE) {
1940 Bits.putChar(buf, pos, (char) v);
1941 pos += 2;
1942 } else {
1943 dout.writeChar(v);
1944 }
1945 }
1946
1947 public void writeShort(int v) throws IOException {
1948 if (pos + 2 <= MAX_BLOCK_SIZE) {
1949 Bits.putShort(buf, pos, (short) v);
1950 pos += 2;
1951 } else {
1952 dout.writeShort(v);
1953 }
1954 }
1955
1956 public void writeInt(int v) throws IOException {
1957 if (pos + 4 <= MAX_BLOCK_SIZE) {
1958 Bits.putInt(buf, pos, v);
1959 pos += 4;
1960 } else {
1961 dout.writeInt(v);
1962 }
1963 }
1964
1965 public void writeFloat(float v) throws IOException {
1966 if (pos + 4 <= MAX_BLOCK_SIZE) {
1967 Bits.putFloat(buf, pos, v);
1968 pos += 4;
1969 } else {
1970 dout.writeFloat(v);
1971 }
1972 }
1973
1974 public void writeLong(long v) throws IOException {
1975 if (pos + 8 <= MAX_BLOCK_SIZE) {
1976 Bits.putLong(buf, pos, v);
1977 pos += 8;
1978 } else {
1979 dout.writeLong(v);
1980 }
1981 }
1982
1983 public void writeDouble(double v) throws IOException {
1984 if (pos + 8 <= MAX_BLOCK_SIZE) {
1985 Bits.putDouble(buf, pos, v);
1986 pos += 8;
1987 } else {
1988 dout.writeDouble(v);
1989 }
1990 }
1991
1992 public void writeBytes(String s) throws IOException {
1993 int endoff = s.length();
1994 int cpos = 0;
1995 int csize = 0;
1996 for (int off = 0; off < endoff; ) {
1997 if (cpos >= csize) {
1998 cpos = 0;
1999 csize = Math.min(endoff - off, CHAR_BUF_SIZE);
2000 s.getChars(off, off + csize, cbuf, 0);
2001 }
2002 if (pos >= MAX_BLOCK_SIZE) {
2003 drain();
2004 }
2005 int n = Math.min(csize - cpos, MAX_BLOCK_SIZE - pos);
2006 int stop = pos + n;
2007 while (pos < stop) {
2008 buf[pos++] = (byte) cbuf[cpos++];
2009 }
2010 off += n;
2011 }
2012 }
2013
2014 public void writeChars(String s) throws IOException {
2015 int endoff = s.length();
2016 for (int off = 0; off < endoff; ) {
2017 int csize = Math.min(endoff - off, CHAR_BUF_SIZE);
2018 s.getChars(off, off + csize, cbuf, 0);
2019 writeChars(cbuf, 0, csize);
2020 off += csize;
2021 }
2022 }
2023
2024 public void writeUTF(String s) throws IOException {
2025 writeUTF(s, getUTFLength(s));
2026 }
2027
2028
2029 /* -------------- primitive data array output methods -------------- */
2030 /*
2031 * The following methods write out spans of primitive data values.
2032 * Though equivalent to calling the corresponding primitive write
2033 * methods repeatedly, these methods are optimized for writing groups
2034 * of primitive data values more efficiently.
2035 */
2036
2037 void writeBooleans(boolean[] v, int off, int len) throws IOException {
2038 int endoff = off + len;
2039 while (off < endoff) {
2040 if (pos >= MAX_BLOCK_SIZE) {
2041 drain();
2042 }
2043 int stop = Math.min(endoff, off + (MAX_BLOCK_SIZE - pos));
2044 while (off < stop) {
2045 Bits.putBoolean(buf, pos++, v[off++]);
2046 }
2047 }
2048 }
2049
2050 void writeChars(char[] v, int off, int len) throws IOException {
2051 int limit = MAX_BLOCK_SIZE - 2;
2052 int endoff = off + len;
2053 while (off < endoff) {
2054 if (pos <= limit) {
2055 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2056 int stop = Math.min(endoff, off + avail);
2057 while (off < stop) {
2058 Bits.putChar(buf, pos, v[off++]);
2059 pos += 2;
2060 }
2061 } else {
2062 dout.writeChar(v[off++]);
2063 }
2064 }
2065 }
2066
2067 void writeShorts(short[] v, int off, int len) throws IOException {
2068 int limit = MAX_BLOCK_SIZE - 2;
2069 int endoff = off + len;
2070 while (off < endoff) {
2071 if (pos <= limit) {
2072 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2073 int stop = Math.min(endoff, off + avail);
2074 while (off < stop) {
2075 Bits.putShort(buf, pos, v[off++]);
2076 pos += 2;
2077 }
2078 } else {
2079 dout.writeShort(v[off++]);
2080 }
2081 }
2082 }
2083
2084 void writeInts(int[] v, int off, int len) throws IOException {
2085 int limit = MAX_BLOCK_SIZE - 4;
2086 int endoff = off + len;
2087 while (off < endoff) {
2088 if (pos <= limit) {
2089 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2090 int stop = Math.min(endoff, off + avail);
2091 while (off < stop) {
2092 Bits.putInt(buf, pos, v[off++]);
2093 pos += 4;
2094 }
2095 } else {
2096 dout.writeInt(v[off++]);
2097 }
2098 }
2099 }
2100
2101 void writeFloats(float[] v, int off, int len) throws IOException {
2102 int limit = MAX_BLOCK_SIZE - 4;
2103 int endoff = off + len;
2104 while (off < endoff) {
2105 if (pos <= limit) {
2106 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2107 int stop = Math.min(endoff, off + avail);
2108 while (off < stop) {
2109 Bits.putFloat(buf, pos, v[off++]);
2110 pos += 4;
2111 }
2112 } else {
2113 dout.writeFloat(v[off++]);
2114 }
2115 }
2116 }
2117
2118 void writeLongs(long[] v, int off, int len) throws IOException {
2119 int limit = MAX_BLOCK_SIZE - 8;
2120 int endoff = off + len;
2121 while (off < endoff) {
2122 if (pos <= limit) {
2123 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2124 int stop = Math.min(endoff, off + avail);
2125 while (off < stop) {
2126 Bits.putLong(buf, pos, v[off++]);
2127 pos += 8;
2128 }
2129 } else {
2130 dout.writeLong(v[off++]);
2131 }
2132 }
2133 }
2134
2135 void writeDoubles(double[] v, int off, int len) throws IOException {
2136 int limit = MAX_BLOCK_SIZE - 8;
2137 int endoff = off + len;
2138 while (off < endoff) {
2139 if (pos <= limit) {
2140 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2141 int stop = Math.min(endoff, off + avail);
2142 while (off < stop) {
2143 Bits.putDouble(buf, pos, v[off++]);
2144 pos += 8;
2145 }
2146 } else {
2147 dout.writeDouble(v[off++]);
2148 }
2149 }
2150 }
2151
2152 /**
2153 * Returns the length in bytes of the UTF encoding of the given string.
2154 */
2155 long getUTFLength(String s) {
2156 int len = s.length();
2157 long utflen = 0;
2158 for (int off = 0; off < len; ) {
2159 int csize = Math.min(len - off, CHAR_BUF_SIZE);
2160 s.getChars(off, off + csize, cbuf, 0);
2161 for (int cpos = 0; cpos < csize; cpos++) {
2162 char c = cbuf[cpos];
2163 if (c >= 0x0001 && c <= 0x007F) {
2164 utflen++;
2165 } else if (c > 0x07FF) {
2166 utflen += 3;
2167 } else {
2168 utflen += 2;
2169 }
2170 }
2171 off += csize;
2172 }
2173 return utflen;
2174 }
2175
2176 /**
2177 * Writes the given string in UTF format. This method is used in
2178 * situations where the UTF encoding length of the string is already
2179 * known; specifying it explicitly avoids a prescan of the string to
2180 * determine its UTF length.
2181 */
2182 void writeUTF(String s, long utflen) throws IOException {
2183 if (utflen > 0xFFFFL) {
2184 throw new UTFDataFormatException();
2185 }
2186 writeShort((int) utflen);
2187 if (utflen == (long) s.length()) {
2188 writeBytes(s);
2189 } else {
2190 writeUTFBody(s);
2191 }
2192 }
2193
2194 /**
2195 * Writes given string in "long" UTF format. "Long" UTF format is
2196 * identical to standard UTF, except that it uses an 8 byte header
2197 * (instead of the standard 2 bytes) to convey the UTF encoding length.
2198 */
2199 void writeLongUTF(String s) throws IOException {
2200 writeLongUTF(s, getUTFLength(s));
2201 }
2202
2203 /**
2204 * Writes given string in "long" UTF format, where the UTF encoding
2205 * length of the string is already known.
2206 */
2207 void writeLongUTF(String s, long utflen) throws IOException {
2208 writeLong(utflen);
2209 if (utflen == (long) s.length()) {
2210 writeBytes(s);
2211 } else {
2212 writeUTFBody(s);
2213 }
2214 }
2215
2216 /**
2217 * Writes the "body" (i.e., the UTF representation minus the 2-byte or
2218 * 8-byte length header) of the UTF encoding for the given string.
2219 */
2220 private void writeUTFBody(String s) throws IOException {
2221 int limit = MAX_BLOCK_SIZE - 3;
2222 int len = s.length();
2223 for (int off = 0; off < len; ) {
2224 int csize = Math.min(len - off, CHAR_BUF_SIZE);
2225 s.getChars(off, off + csize, cbuf, 0);
2226 for (int cpos = 0; cpos < csize; cpos++) {
2227 char c = cbuf[cpos];
2228 if (pos <= limit) {
2229 if (c <= 0x007F && c != 0) {
2230 buf[pos++] = (byte) c;
2231 } else if (c > 0x07FF) {
2232 buf[pos + 2] = (byte) (0x80 | ((c >> 0) & 0x3F));
2233 buf[pos + 1] = (byte) (0x80 | ((c >> 6) & 0x3F));
2234 buf[pos + 0] = (byte) (0xE0 | ((c >> 12) & 0x0F));
2235 pos += 3;
2236 } else {
2237 buf[pos + 1] = (byte) (0x80 | ((c >> 0) & 0x3F));
2238 buf[pos + 0] = (byte) (0xC0 | ((c >> 6) & 0x1F));
2239 pos += 2;
2240 }
2241 } else { // write one byte at a time to normalize block
2242 if (c <= 0x007F && c != 0) {
2243 write(c);
2244 } else if (c > 0x07FF) {
2245 write(0xE0 | ((c >> 12) & 0x0F));
2246 write(0x80 | ((c >> 6) & 0x3F));
2247 write(0x80 | ((c >> 0) & 0x3F));
2248 } else {
2249 write(0xC0 | ((c >> 6) & 0x1F));
2250 write(0x80 | ((c >> 0) & 0x3F));
2251 }
2252 }
2253 }
2254 off += csize;
2255 }
2256 }
2257 }
2258
2259 /**
2260 * Lightweight identity hash table which maps objects to integer handles,
2261 * assigned in ascending order.
2262 */
2263 private static class HandleTable {
2264
2265 /* number of mappings in table/next available handle */
2266 private int size;
2267 /* size threshold determining when to expand hash spine */
2268 private int threshold;
2269 /* factor for computing size threshold */
2270 private final float loadFactor;
2271 /* maps hash value -> candidate handle value */
2272 private int[] spine;
2273 /* maps handle value -> next candidate handle value */
2274 private int[] next;
2275 /* maps handle value -> associated object */
2276 private Object[] objs;
2277
2278 /**
2279 * Creates new HandleTable with given capacity and load factor.
2280 */
2281 HandleTable(int initialCapacity, float loadFactor) {
2282 this.loadFactor = loadFactor;
2283 spine = new int[initialCapacity];
2284 next = new int[initialCapacity];
2285 objs = new Object[initialCapacity];
2286 threshold = (int) (initialCapacity * loadFactor);
2287 clear();
2288 }
2289
2290 /**
2291 * Assigns next available handle to given object, and returns handle
2292 * value. Handles are assigned in ascending order starting at 0.
2293 */
2294 int assign(Object obj) {
2295 if (size >= next.length) {
2296 growEntries();
2297 }
2298 if (size >= threshold) {
2299 growSpine();
2300 }
2301 insert(obj, size);
2302 return size++;
2303 }
2304
2305 /**
2306 * Looks up and returns handle associated with given object, or -1 if
2307 * no mapping found.
2308 */
2309 int lookup(Object obj) {
2310 if (size == 0) {
2311 return -1;
2312 }
2313 int index = hash(obj) % spine.length;
2314 for (int i = spine[index]; i >= 0; i = next[i]) {
2315 if (objs[i] == obj) {
2316 return i;
2317 }
2318 }
2319 return -1;
2320 }
2321
2322 /**
2323 * Resets table to its initial (empty) state.
2324 */
2325 void clear() {
2326 Arrays.fill(spine, -1);
2327 Arrays.fill(objs, 0, size, null);
2328 size = 0;
2329 }
2330
2331 /**
2332 * Returns the number of mappings currently in table.
2333 */
2334 int size() {
2335 return size;
2336 }
2337
2338 /**
2339 * Inserts mapping object -> handle mapping into table. Assumes table
2340 * is large enough to accommodate new mapping.
2341 */
2342 private void insert(Object obj, int handle) {
2343 int index = hash(obj) % spine.length;
2344 objs[handle] = obj;
2345 next[handle] = spine[index];
2346 spine[index] = handle;
2347 }
2348
2349 /**
2350 * Expands the hash "spine" -- equivalent to increasing the number of
2351 * buckets in a conventional hash table.
2352 */
2353 private void growSpine() {
2354 spine = new int[(spine.length << 1) + 1];
2355 threshold = (int) (spine.length * loadFactor);
2356 Arrays.fill(spine, -1);
2357 for (int i = 0; i < size; i++) {
2358 insert(objs[i], i);
2359 }
2360 }
2361
2362 /**
2363 * Increases hash table capacity by lengthening entry arrays.
2364 */
2365 private void growEntries() {
2366 int newLength = (next.length << 1) + 1;
2367 int[] newNext = new int[newLength];
2368 System.arraycopy(next, 0, newNext, 0, size);
2369 next = newNext;
2370
2371 Object[] newObjs = new Object[newLength];
2372 System.arraycopy(objs, 0, newObjs, 0, size);
2373 objs = newObjs;
2374 }
2375
2376 /**
2377 * Returns hash value for given object.
2378 */
2379 private int hash(Object obj) {
2380 return System.identityHashCode(obj) & 0x7FFFFFFF;
2381 }
2382 }
2383
2384 /**
2385 * Lightweight identity hash table which maps objects to replacement
2386 * objects.
2387 */
2388 private static class ReplaceTable {
2389
2390 /* maps object -> index */
2391 private final HandleTable htab;
2392 /* maps index -> replacement object */
2393 private Object[] reps;
2394
2395 /**
2396 * Creates new ReplaceTable with given capacity and load factor.
2397 */
2398 ReplaceTable(int initialCapacity, float loadFactor) {
2399 htab = new HandleTable(initialCapacity, loadFactor);
2400 reps = new Object[initialCapacity];
2401 }
2402
2403 /**
2404 * Enters mapping from object to replacement object.
2405 */
2406 void assign(Object obj, Object rep) {
2407 int index = htab.assign(obj);
2408 while (index >= reps.length) {
2409 grow();
2410 }
2411 reps[index] = rep;
2412 }
2413
2414 /**
2415 * Looks up and returns replacement for given object. If no
2416 * replacement is found, returns the lookup object itself.
2417 */
2418 Object lookup(Object obj) {
2419 int index = htab.lookup(obj);
2420 return (index >= 0) ? reps[index] : obj;
2421 }
2422
2423 /**
2424 * Resets table to its initial (empty) state.
2425 */
2426 void clear() {
2427 Arrays.fill(reps, 0, htab.size(), null);
2428 htab.clear();
2429 }
2430
2431 /**
2432 * Returns the number of mappings currently in table.
2433 */
2434 int size() {
2435 return htab.size();
2436 }
2437
2438 /**
2439 * Increases table capacity.
2440 */
2441 private void grow() {
2442 Object[] newReps = new Object[(reps.length << 1) + 1];
2443 System.arraycopy(reps, 0, newReps, 0, reps.length);
2444 reps = newReps;
2445 }
2446 }
2447
2448 /**
2449 * Stack to keep debug information about the state of the
2450 * serialization process, for embedding in exception messages.
2451 */
2452 private static class DebugTraceInfoStack {
2453 private final List<String> stack;
2454
2455 DebugTraceInfoStack() {
2456 stack = new ArrayList<>();
2457 }
2458
2459 /**
2460 * Removes all of the elements from enclosed list.
2461 */
2462 void clear() {
2463 stack.clear();
2464 }
2465
2466 /**
2467 * Removes the object at the top of enclosed list.
2468 */
2469 void pop() {
2470 stack.remove(stack.size()-1);
2471 }
2472
2473 /**
2474 * Pushes a String onto the top of enclosed list.
2475 */
2476 void push(String entry) {
2477 stack.add("\t- " + entry);
2478 }
2479
2480 /**
2481 * Returns a string representation of this object
2482 */
2483 public String toString() {
2484 StringJoiner sj = new StringJoiner("\n");
2485 for (int i = stack.size() - 1; i >= 0; i--) {
2486 sj.add(stack.get(i));
2487 }
2488 return sj.toString();
2489 }
2490 }
2491
2492 }