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