1 /*
2 * Copyright (c) 1996, 2024, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2024, Alibaba Group Holding Limited. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation. Oracle designates this
9 * particular file as subject to the "Classpath" exception as provided
10 * by Oracle in the LICENSE file that accompanied this code.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
23 * or visit www.oracle.com if you need additional information or have any
24 * questions.
25 */
26
27 package java.io;
28
29 import java.security.AccessController;
30 import java.security.PrivilegedAction;
31 import java.util.ArrayList;
32 import java.util.Arrays;
33 import java.util.List;
34 import java.util.Objects;
35 import java.util.StringJoiner;
36
37 import jdk.internal.util.ByteArray;
38 import jdk.internal.access.JavaLangAccess;
39 import jdk.internal.access.SharedSecrets;
40 import sun.reflect.misc.ReflectUtil;
41
42 import static java.io.ObjectInputStream.TRACE;
43
44 import static jdk.internal.util.ModifiedUtf.putChar;
45 import static jdk.internal.util.ModifiedUtf.utfLen;
46
47 /**
48 * An ObjectOutputStream writes primitive data types and graphs of Java objects
49 * to an OutputStream. The objects can be read (reconstituted) using an
50 * ObjectInputStream. Persistent storage of objects can be accomplished by
51 * using a file for the stream. If the stream is a network socket stream, the
52 * objects can be reconstituted on another host or in another process.
53 *
54 * <p>Only objects that support the java.io.Serializable interface can be
55 * written to streams. The class of each serializable object is encoded
56 * including the class name and signature of the class, the values of the
57 * object's fields and arrays, and the closure of any other objects referenced
58 * from the initial objects.
59 *
60 * <p>The method writeObject is used to write an object to the stream. Any
61 * object, including Strings and arrays, is written with writeObject. Multiple
62 * objects or primitives can be written to the stream. The objects must be
63 * read back from the corresponding ObjectInputstream with the same types and
64 * in the same order as they were written.
65 *
66 * <p>Primitive data types can also be written to the stream using the
67 * appropriate methods from DataOutput. Strings can also be written using the
68 * writeUTF method.
69 *
70 * <p>The default serialization mechanism for an object writes the class of the
71 * object, the class signature, and the values of all non-transient and
72 * non-static fields. References to other objects (except in transient or
73 * static fields) cause those objects to be written also. Multiple references
74 * to a single object are encoded using a reference sharing mechanism so that
75 * graphs of objects can be restored to the same shape as when the original was
76 * written.
77 *
78 * <p>For example to write an object that can be read by the example in
79 * {@link ObjectInputStream}:
80 * {@snippet lang="java":
81 * try (FileOutputStream fos = new FileOutputStream("t.tmp");
82 * ObjectOutputStream oos = new ObjectOutputStream(fos)) {
83 * oos.writeObject("Today");
84 * oos.writeObject(LocalDateTime.now());
85 * } catch (Exception ex) {
86 * // handle exception
87 * }
88 * }
89 *
90 * <p>Serializable classes that require special handling during the
91 * serialization and deserialization process should implement methods
92 * with the following signatures:
93 *
94 * {@snippet lang="java":
95 * private void readObject(java.io.ObjectInputStream stream)
96 * throws IOException, ClassNotFoundException;
97 * private void writeObject(java.io.ObjectOutputStream stream)
98 * throws IOException;
99 * private void readObjectNoData()
100 * throws ObjectStreamException;
101 * }
102 *
103 * <p>The method name, modifiers, return type, and number and type of
104 * parameters must match exactly for the method to be used by
105 * serialization or deserialization. The methods should only be
106 * declared to throw checked exceptions consistent with these
107 * signatures.
108 *
109 * <p>The writeObject method is responsible for writing the state of the object
110 * for its particular class so that the corresponding readObject method can
111 * restore it. The method does not need to concern itself with the state
112 * belonging to the object's superclasses or subclasses. State is saved by
113 * writing the individual fields to the ObjectOutputStream using the
114 * writeObject method or by using the methods for primitive data types
115 * supported by DataOutput.
116 *
117 * <p>Serialization does not write out the fields of any object that does not
118 * implement the java.io.Serializable interface. Subclasses of Objects that
119 * are not serializable can be serializable. In this case the non-serializable
120 * class must have a no-arg constructor to allow its fields to be initialized.
121 * In this case it is the responsibility of the subclass to save and restore
122 * the state of the non-serializable class. It is frequently the case that the
123 * fields of that class are accessible (public, package, or protected) or that
124 * there are get and set methods that can be used to restore the state.
125 *
126 * <p>Serialization of an object can be prevented by implementing writeObject
127 * and readObject methods that throw the NotSerializableException. The
128 * exception will be caught by the ObjectOutputStream and abort the
129 * serialization process.
130 *
131 * <p>Implementing the Externalizable interface allows the object to assume
132 * complete control over the contents and format of the object's serialized
133 * form. The methods of the Externalizable interface, writeExternal and
134 * readExternal, are called to save and restore the objects state. When
135 * implemented by a class they can write and read their own state using all of
136 * the methods of ObjectOutput and ObjectInput. It is the responsibility of
137 * the objects to handle any versioning that occurs.
138 * Value classes implementing {@link Externalizable} cannot be serialized
139 * or deserialized, the value object is immutable and the state cannot be restored.
140 * Use {@link Serializable} {@code writeReplace} to delegate to another serializable
141 * object such as a record.
142 *
143 * Value objects cannot be {@code java.io.Externalizable}.
144 *
145 * <p>Enum constants are serialized differently than ordinary serializable or
146 * externalizable objects. The serialized form of an enum constant consists
147 * solely of its name; field values of the constant are not transmitted. To
148 * serialize an enum constant, ObjectOutputStream writes the string returned by
149 * the constant's name method. Like other serializable or externalizable
150 * objects, enum constants can function as the targets of back references
151 * appearing subsequently in the serialization stream. The process by which
152 * enum constants are serialized cannot be customized; any class-specific
153 * writeObject and writeReplace methods defined by enum types are ignored
154 * during serialization. Similarly, any serialPersistentFields or
155 * serialVersionUID field declarations are also ignored--all enum types have a
156 * fixed serialVersionUID of 0L.
157 *
158 * <p>Primitive data, excluding serializable fields and externalizable data, is
159 * written to the ObjectOutputStream in block-data records. A block data record
160 * is composed of a header and data. The block data header consists of a marker
161 * and the number of bytes to follow the header. Consecutive primitive data
162 * writes are merged into one block-data record. The blocking factor used for
163 * a block-data record will be 1024 bytes. Each block-data record will be
164 * filled up to 1024 bytes, or be written whenever there is a termination of
165 * block-data mode. Calls to the ObjectOutputStream methods writeObject,
166 * defaultWriteObject and writeFields initially terminate any existing
167 * block-data record.
168 *
169 * <a id="record-serialization"></a>
170 * <p>Records are serialized differently than ordinary serializable or externalizable
171 * objects, see <a href="ObjectInputStream.html#record-serialization">record serialization</a>.
172 *
173 * <a id="valueclass-serialization"></a>
174 * <p>Value classes are {@linkplain Serializable} through the use of the serialization proxy pattern.
175 * The serialization protocol does not support a standard serialized form for value classes.
176 * The value class delegates to a serialization proxy by supplying an alternate
177 * record or object to be serialized instead of the value class.
178 * When the proxy is deserialized it re-constructs the value object and returns the value object.
179 * For example,
180 * {@snippet lang="java" :
181 * value class ZipCode implements Serializable { // @highlight substring="value class"
182 * private static final long serialVersionUID = 1L;
183 * private int zipCode;
184 * public ZipCode(int zip) { this.zipCode = zip; }
185 * public int zipCode() { return zipCode; }
186 *
187 * public Object writeReplace() { // @highlight substring="writeReplace"
188 * return new ZipCodeProxy(zipCode);
189 * }
190 *
191 * private record ZipCodeProxy(int zipCode) implements Serializable {
192 * public Object readResolve() { // @highlight substring="readResolve"
193 * return new ZipCode(zipCode);
194 * }
195 * }
196 * }
197 * }
198 *
199 * @spec serialization/index.html Java Object Serialization Specification
200 * @author Mike Warres
201 * @author Roger Riggs
202 * @see java.io.DataOutput
203 * @see java.io.ObjectInputStream
204 * @see java.io.Serializable
205 * @see java.io.Externalizable
206 * @see <a href="{@docRoot}/../specs/serialization/output.html">
207 * <cite>Java Object Serialization Specification,</cite> Section 2, "Object Output Classes"</a>
208 * @since 1.1
209 */
210 public class ObjectOutputStream
211 extends OutputStream implements ObjectOutput, ObjectStreamConstants
212 {
213 private static final JavaLangAccess JLA = SharedSecrets.getJavaLangAccess();
214
215 private static class Caches {
216 /** cache of subclass security audit results */
217 static final ClassValue<Boolean> subclassAudits =
218 new ClassValue<>() {
219 @Override
220 protected Boolean computeValue(Class<?> type) {
221 return auditSubclass(type);
222 }
223 };
224 }
225
226 /** filter stream for handling block data conversion */
227 private final BlockDataOutputStream bout;
228 /** obj -> wire handle map */
229 private final HandleTable handles;
230 /** obj -> replacement obj map */
231 private final ReplaceTable subs;
232 /** stream protocol version */
233 private int protocol = PROTOCOL_VERSION_2;
234 /** recursion depth */
235 private int depth;
236
237 /** buffer for writing primitive field values */
238 private byte[] primVals;
239
240 /** if true, invoke writeObjectOverride() instead of writeObject() */
241 private final boolean enableOverride;
242 /** if true, invoke replaceObject() */
243 private boolean enableReplace;
244
245 // values below valid only during upcalls to writeObject()/writeExternal()
246 /**
247 * Context during upcalls to class-defined writeObject methods; holds
248 * object currently being serialized and descriptor for current class.
249 * Null when not during writeObject upcall.
250 */
251 private SerialCallbackContext curContext;
252 /** current PutField object */
253 private PutFieldImpl curPut;
254
255 /** custom storage for debug trace info */
256 private final DebugTraceInfoStack debugInfoStack;
257
258 /**
259 * value of "sun.io.serialization.extendedDebugInfo" property,
260 * as true or false for extended information about exception's place
261 */
262 @SuppressWarnings("removal")
263 private static final boolean extendedDebugInfo =
264 java.security.AccessController.doPrivileged(
265 new sun.security.action.GetBooleanAction(
266 "sun.io.serialization.extendedDebugInfo")).booleanValue();
267
268 /**
269 * Creates an ObjectOutputStream that writes to the specified OutputStream.
270 * This constructor writes the serialization stream header to the
271 * underlying stream; callers may wish to flush the stream immediately to
272 * ensure that constructors for receiving ObjectInputStreams will not block
273 * when reading the header.
274 *
275 * <p>If a security manager is installed, this constructor will check for
276 * the "enableSubclassImplementation" SerializablePermission when invoked
277 * directly or indirectly by the constructor of a subclass which overrides
278 * the ObjectOutputStream.putFields or ObjectOutputStream.writeUnshared
279 * methods.
280 *
281 * @param out output stream to write to
282 * @throws IOException if an I/O error occurs while writing stream header
283 * @throws SecurityException if untrusted subclass illegally overrides
284 * security-sensitive methods
285 * @throws NullPointerException if {@code out} is {@code null}
286 * @since 1.4
287 * @see ObjectOutputStream#ObjectOutputStream()
288 * @see ObjectOutputStream#putFields()
289 * @see ObjectInputStream#ObjectInputStream(InputStream)
290 */
291 @SuppressWarnings("this-escape")
292 public ObjectOutputStream(OutputStream out) throws IOException {
293 verifySubclass();
294 bout = new BlockDataOutputStream(out);
295 handles = new HandleTable(10, (float) 3.00);
296 subs = new ReplaceTable(10, (float) 3.00);
297 enableOverride = false;
298 writeStreamHeader();
299 bout.setBlockDataMode(true);
300 if (extendedDebugInfo) {
301 debugInfoStack = new DebugTraceInfoStack();
302 } else {
303 debugInfoStack = null;
304 }
305 }
306
307 /**
308 * Provide a way for subclasses that are completely reimplementing
309 * ObjectOutputStream to not have to allocate private data just used by
310 * this implementation of ObjectOutputStream.
311 *
312 * <p>If there is a security manager installed, this method first calls the
313 * security manager's {@code checkPermission} method with a
314 * {@code SerializablePermission("enableSubclassImplementation")}
315 * permission to ensure it's ok to enable subclassing.
316 *
317 * @throws SecurityException if a security manager exists and its
318 * {@code checkPermission} method denies enabling
319 * subclassing.
320 * @throws IOException if an I/O error occurs while creating this stream
321 * @see SecurityManager#checkPermission
322 * @see java.io.SerializablePermission
323 */
324 protected ObjectOutputStream() throws IOException, SecurityException {
325 @SuppressWarnings("removal")
326 SecurityManager sm = System.getSecurityManager();
327 if (sm != null) {
328 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
329 }
330 bout = null;
331 handles = null;
332 subs = null;
333 enableOverride = true;
334 debugInfoStack = null;
335 }
336
337 /**
338 * Specify stream protocol version to use when writing the stream.
339 *
340 * <p>This routine provides a hook to enable the current version of
341 * Serialization to write in a format that is backwards compatible to a
342 * previous version of the stream format.
343 *
344 * <p>Every effort will be made to avoid introducing additional
345 * backwards incompatibilities; however, sometimes there is no
346 * other alternative.
347 *
348 * @param version use ProtocolVersion from java.io.ObjectStreamConstants.
349 * @throws IllegalStateException if called after any objects
350 * have been serialized.
351 * @throws IllegalArgumentException if invalid version is passed in.
352 * @throws IOException if I/O errors occur
353 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
354 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_2
355 * @since 1.2
356 */
357 public void useProtocolVersion(int version) throws IOException {
358 if (handles.size() != 0) {
359 // REMIND: implement better check for pristine stream?
360 throw new IllegalStateException("stream non-empty");
361 }
362 switch (version) {
363 case PROTOCOL_VERSION_1:
364 case PROTOCOL_VERSION_2:
365 protocol = version;
366 break;
367
368 default:
369 throw new IllegalArgumentException(
370 "unknown version: " + version);
371 }
372 }
373
374 /**
375 * Write the specified object to the ObjectOutputStream. The class of the
376 * object, the signature of the class, and the values of the non-transient
377 * and non-static fields of the class and all of its supertypes are
378 * written. Default serialization for a class can be overridden using the
379 * writeObject and the readObject methods. Objects referenced by this
380 * object are written transitively so that a complete equivalent graph of
381 * objects can be reconstructed by an ObjectInputStream.
382 *
383 * <p>Serialization and deserialization of value classes is described in
384 * {@linkplain ObjectOutputStream##valueclass-serialization value class serialization}.
385 *
386 * <p>Exceptions are thrown for problems with the OutputStream and for
387 * classes that should not be serialized. All exceptions are fatal to the
388 * OutputStream, which is left in an indeterminate state, and it is up to
389 * the caller to ignore or recover the stream state.
390 *
391 * @throws InvalidClassException Something is wrong with a class used by
392 * serialization.
393 * @throws NotSerializableException Some object to be serialized does not
394 * implement the java.io.Serializable interface.
395 * @throws IOException Any exception thrown by the underlying
396 * OutputStream.
397 */
398 public final void writeObject(Object obj) throws IOException {
399 if (enableOverride) {
400 writeObjectOverride(obj);
401 return;
402 }
403 try {
404 writeObject0(obj, false);
405 } catch (IOException ex) {
406 if (depth == 0) {
407 writeFatalException(ex);
408 }
409 throw ex;
410 }
411 }
412
413 /**
414 * Method used by subclasses to override the default writeObject method.
415 * This method is called by trusted subclasses of ObjectOutputStream that
416 * constructed ObjectOutputStream using the protected no-arg constructor.
417 * The subclass is expected to provide an override method with the modifier
418 * "final".
419 *
420 * @param obj object to be written to the underlying stream
421 * @throws IOException if there are I/O errors while writing to the
422 * underlying stream
423 * @see #ObjectOutputStream()
424 * @see #writeObject(Object)
425 * @since 1.2
426 */
427 protected void writeObjectOverride(Object obj) throws IOException {
428 }
429
430 /**
431 * Writes an "unshared" object to the ObjectOutputStream. This method is
432 * identical to writeObject, except that it always writes the given object
433 * as a new, unique object in the stream (as opposed to a back-reference
434 * pointing to a previously serialized instance). Specifically:
435 * <ul>
436 * <li>An object written via writeUnshared is always serialized in the
437 * same manner as a newly appearing object (an object that has not
438 * been written to the stream yet), regardless of whether or not the
439 * object has been written previously.
440 *
441 * <li>If writeObject is used to write an object that has been previously
442 * written with writeUnshared, the previous writeUnshared operation
443 * is treated as if it were a write of a separate object. In other
444 * words, ObjectOutputStream will never generate back-references to
445 * object data written by calls to writeUnshared.
446 * </ul>
447 * While writing an object via writeUnshared does not in itself guarantee a
448 * unique reference to the object when it is deserialized, it allows a
449 * single object to be defined multiple times in a stream, so that multiple
450 * calls to readUnshared by the receiver will not conflict. Note that the
451 * rules described above only apply to the base-level object written with
452 * writeUnshared, and not to any transitively referenced sub-objects in the
453 * object graph to be serialized.
454 *
455 * <p>Serialization and deserialization of value classes is described in
456 * {@linkplain ObjectOutputStream##valueclass-serialization value class serialization}.
457 *
458 * <p>ObjectOutputStream subclasses which override this method can only be
459 * constructed in security contexts possessing the
460 * "enableSubclassImplementation" SerializablePermission; any attempt to
461 * instantiate such a subclass without this permission will cause a
462 * SecurityException to be thrown.
463 *
464 * @param obj object to write to stream
465 * @throws NotSerializableException if an object in the graph to be
466 * serialized does not implement the Serializable interface
467 * @throws InvalidClassException if a problem exists with the class of an
468 * object to be serialized
469 * @throws IOException if an I/O error occurs during serialization
470 * @since 1.4
471 */
472 public void writeUnshared(Object obj) throws IOException {
473 try {
474 writeObject0(obj, true);
475 } catch (IOException ex) {
476 if (depth == 0) {
477 writeFatalException(ex);
478 }
479 throw ex;
480 }
481 }
482
483 /**
484 * Write the non-static and non-transient fields of the current class to
485 * this stream. This may only be called from the writeObject method of the
486 * class being serialized. It will throw the NotActiveException if it is
487 * called otherwise.
488 *
489 * @throws IOException if I/O errors occur while writing to the underlying
490 * {@code OutputStream}
491 */
492 public void defaultWriteObject() throws IOException {
493 SerialCallbackContext ctx = curContext;
494 if (ctx == null) {
495 throw new NotActiveException("not in call to writeObject");
496 }
497 Object curObj = ctx.getObj();
498 ObjectStreamClass curDesc = ctx.getDesc();
499 bout.setBlockDataMode(false);
500 defaultWriteFields(curObj, curDesc);
501 bout.setBlockDataMode(true);
502 }
503
504 /**
505 * Retrieve the object used to buffer persistent fields to be written to
506 * the stream. The fields will be written to the stream when writeFields
507 * method is called.
508 *
509 * @return an instance of the class Putfield that holds the serializable
510 * fields
511 * @throws IOException if I/O errors occur
512 * @since 1.2
513 */
514 public ObjectOutputStream.PutField putFields() throws IOException {
515 if (curPut == null) {
516 SerialCallbackContext ctx = curContext;
517 if (ctx == null) {
518 throw new NotActiveException("not in call to writeObject");
519 }
520 ctx.checkAndSetUsed();
521 ObjectStreamClass curDesc = ctx.getDesc();
522 curPut = new PutFieldImpl(curDesc);
523 }
524 return curPut;
525 }
526
527 /**
528 * Write the buffered fields to the stream.
529 *
530 * @throws IOException if I/O errors occur while writing to the underlying
531 * stream
532 * @throws NotActiveException Called when a classes writeObject method was
533 * not called to write the state of the object.
534 * @since 1.2
535 */
536 public void writeFields() throws IOException {
537 if (curPut == null) {
538 throw new NotActiveException("no current PutField object");
539 }
540 bout.setBlockDataMode(false);
541 curPut.writeFields();
542 bout.setBlockDataMode(true);
543 }
544
545 /**
546 * Reset will disregard the state of any objects already written to the
547 * stream. The state is reset to be the same as a new ObjectOutputStream.
548 * The current point in the stream is marked as reset so the corresponding
549 * ObjectInputStream will be reset at the same point. Objects previously
550 * written to the stream will not be referred to as already being in the
551 * stream. They will be written to the stream again.
552 *
553 * @throws IOException if reset() is invoked while serializing an object.
554 */
555 public void reset() throws IOException {
556 if (depth != 0) {
557 throw new IOException("stream active");
558 }
559 bout.setBlockDataMode(false);
560 bout.writeByte(TC_RESET);
561 clear();
562 bout.setBlockDataMode(true);
563 }
564
565 /**
566 * Subclasses may implement this method to allow class data to be stored in
567 * the stream. By default this method does nothing. The corresponding
568 * method in ObjectInputStream is resolveClass. This method is called
569 * exactly once for each unique class in the stream. The class name and
570 * signature will have already been written to the stream. This method may
571 * make free use of the ObjectOutputStream to save any representation of
572 * the class it deems suitable (for example, the bytes of the class file).
573 * The resolveClass method in the corresponding subclass of
574 * ObjectInputStream must read and use any data or objects written by
575 * annotateClass.
576 *
577 * @param cl the class to annotate custom data for
578 * @throws IOException Any exception thrown by the underlying
579 * OutputStream.
580 */
581 protected void annotateClass(Class<?> cl) throws IOException {
582 }
583
584 /**
585 * Subclasses may implement this method to store custom data in the stream
586 * along with descriptors for dynamic proxy classes.
587 *
588 * <p>This method is called exactly once for each unique proxy class
589 * descriptor in the stream. The default implementation of this method in
590 * {@code ObjectOutputStream} does nothing.
591 *
592 * <p>The corresponding method in {@code ObjectInputStream} is
593 * {@code resolveProxyClass}. For a given subclass of
594 * {@code ObjectOutputStream} that overrides this method, the
595 * {@code resolveProxyClass} method in the corresponding subclass of
596 * {@code ObjectInputStream} must read any data or objects written by
597 * {@code annotateProxyClass}.
598 *
599 * @param cl the proxy class to annotate custom data for
600 * @throws IOException any exception thrown by the underlying
601 * {@code OutputStream}
602 * @see ObjectInputStream#resolveProxyClass(String[])
603 * @since 1.3
604 */
605 protected void annotateProxyClass(Class<?> cl) throws IOException {
606 }
607
608 /**
609 * This method will allow trusted subclasses of ObjectOutputStream to
610 * substitute one object for another during serialization. Replacing
611 * objects is disabled until enableReplaceObject is called. The
612 * enableReplaceObject method checks that the stream requesting to do
613 * replacement can be trusted. The first occurrence of each object written
614 * into the serialization stream is passed to replaceObject. Subsequent
615 * references to the object are replaced by the object returned by the
616 * original call to replaceObject. To ensure that the private state of
617 * objects is not unintentionally exposed, only trusted streams may use
618 * replaceObject.
619 *
620 * <p>The ObjectOutputStream.writeObject method takes a parameter of type
621 * Object (as opposed to type Serializable) to allow for cases where
622 * non-serializable objects are replaced by serializable ones.
623 *
624 * <p>When a subclass is replacing objects it must ensure that either a
625 * complementary substitution must be made during deserialization or that
626 * the substituted object is compatible with every field where the
627 * reference will be stored. Objects whose type is not a subclass of the
628 * type of the field or array element abort the serialization by raising an
629 * exception and the object is not be stored.
630 *
631 * <p>This method is called only once when each object is first
632 * encountered. All subsequent references to the object will be redirected
633 * to the new object. This method should return the object to be
634 * substituted or the original object.
635 *
636 * <p>Null can be returned as the object to be substituted, but may cause
637 * {@link NullPointerException} in classes that contain references to the
638 * original object since they may be expecting an object instead of
639 * null.
640 *
641 * @param obj the object to be replaced
642 * @return the alternate object that replaced the specified one
643 * @throws IOException Any exception thrown by the underlying
644 * OutputStream.
645 */
646 protected Object replaceObject(Object obj) throws IOException {
647 return obj;
648 }
649
650 /**
651 * Enables the stream to do replacement of objects written to the stream. When
652 * enabled, the {@link #replaceObject} method is called for every object being
653 * serialized.
654 *
655 * <p>If object replacement is currently not enabled, and
656 * {@code enable} is true, and there is a security manager installed,
657 * this method first calls the security manager's
658 * {@code checkPermission} method with the
659 * {@code SerializablePermission("enableSubstitution")} permission to
660 * ensure that the caller is permitted to enable the stream to do replacement
661 * of objects written to the stream.
662 *
663 * @param enable true for enabling use of {@code replaceObject} for
664 * every object being serialized
665 * @return the previous setting before this method was invoked
666 * @throws SecurityException if a security manager exists and its
667 * {@code checkPermission} method denies enabling the stream
668 * to do replacement of objects written to the stream.
669 * @see SecurityManager#checkPermission
670 * @see java.io.SerializablePermission
671 */
672 protected boolean enableReplaceObject(boolean enable)
673 throws SecurityException
674 {
675 if (enable == enableReplace) {
676 return enable;
677 }
678 if (enable) {
679 @SuppressWarnings("removal")
680 SecurityManager sm = System.getSecurityManager();
681 if (sm != null) {
682 sm.checkPermission(SUBSTITUTION_PERMISSION);
683 }
684 }
685 enableReplace = enable;
686 return !enableReplace;
687 }
688
689 /**
690 * The writeStreamHeader method is provided so subclasses can append or
691 * prepend their own header to the stream. It writes the magic number and
692 * version to the stream.
693 *
694 * @throws IOException if I/O errors occur while writing to the underlying
695 * stream
696 */
697 protected void writeStreamHeader() throws IOException {
698 bout.writeShort(STREAM_MAGIC);
699 bout.writeShort(STREAM_VERSION);
700 }
701
702 /**
703 * Write the specified class descriptor to the ObjectOutputStream. Class
704 * descriptors are used to identify the classes of objects written to the
705 * stream. Subclasses of ObjectOutputStream may override this method to
706 * customize the way in which class descriptors are written to the
707 * serialization stream. The corresponding method in ObjectInputStream,
708 * {@link ObjectInputStream#readClassDescriptor readClassDescriptor}, should then be overridden to
709 * reconstitute the class descriptor from its custom stream representation.
710 * By default, this method writes class descriptors according to the format
711 * defined in the <a href="{@docRoot}/../specs/serialization/index.html">
712 * <cite>Java Object Serialization Specification</cite></a>.
713 *
714 * <p>Note that this method will only be called if the ObjectOutputStream
715 * is not using the old serialization stream format (set by calling
716 * ObjectOutputStream's {@code useProtocolVersion} method). If this
717 * serialization stream is using the old format
718 * ({@code PROTOCOL_VERSION_1}), the class descriptor will be written
719 * internally in a manner that cannot be overridden or customized.
720 *
721 * @param desc class descriptor to write to the stream
722 * @throws IOException If an I/O error has occurred.
723 * @spec serialization/index.html Java Object Serialization Specification
724 * @see java.io.ObjectInputStream#readClassDescriptor()
725 * @see #useProtocolVersion(int)
726 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
727 * @since 1.3
728 */
729 protected void writeClassDescriptor(ObjectStreamClass desc)
730 throws IOException
731 {
732 desc.writeNonProxy(this);
733 }
734
735 /**
736 * Writes a byte. This method will block until the byte is actually
737 * written.
738 *
739 * @param val the byte to be written to the stream
740 * @throws IOException If an I/O error has occurred.
741 */
742 @Override
743 public void write(int val) throws IOException {
744 bout.write(val);
745 }
746
747 /**
748 * Writes an array of bytes. This method will block until the bytes are
749 * actually written.
750 *
751 * @param buf the data to be written
752 * @throws IOException If an I/O error has occurred.
753 */
754 @Override
755 public void write(byte[] buf) throws IOException {
756 bout.write(buf, 0, buf.length, false);
757 }
758
759 /**
760 * Writes a sub array of bytes.
761 *
762 * @param buf the data to be written
763 * @param off the start offset in the data
764 * @param len the number of bytes that are written
765 * @throws IOException {@inheritDoc}
766 * @throws IndexOutOfBoundsException {@inheritDoc}
767 */
768 @Override
769 public void write(byte[] buf, int off, int len) throws IOException {
770 if (buf == null) {
771 throw new NullPointerException();
772 }
773 Objects.checkFromIndexSize(off, len, buf.length);
774 bout.write(buf, off, len, false);
775 }
776
777 /**
778 * Flushes the stream. This will write any buffered output bytes and flush
779 * through to the underlying stream.
780 *
781 * @throws IOException {@inheritDoc}
782 */
783 @Override
784 public void flush() throws IOException {
785 bout.flush();
786 }
787
788 /**
789 * Drain any buffered data in ObjectOutputStream. Similar to flush but
790 * does not propagate the flush to the underlying stream.
791 *
792 * @throws IOException if I/O errors occur while writing to the underlying
793 * stream
794 */
795 protected void drain() throws IOException {
796 bout.drain();
797 }
798
799 /**
800 * Closes the stream. This method must be called to release any resources
801 * associated with the stream.
802 *
803 * @throws IOException If an I/O error has occurred.
804 */
805 @Override
806 public void close() throws IOException {
807 flush();
808 clear();
809 bout.close();
810 }
811
812 /**
813 * Writes a boolean.
814 *
815 * @param val the boolean to be written
816 * @throws IOException if I/O errors occur while writing to the underlying
817 * stream
818 */
819 public void writeBoolean(boolean val) throws IOException {
820 bout.writeBoolean(val);
821 }
822
823 /**
824 * Writes an 8-bit byte.
825 *
826 * @param val the byte value to be written
827 * @throws IOException if I/O errors occur while writing to the underlying
828 * stream
829 */
830 public void writeByte(int val) throws IOException {
831 bout.writeByte(val);
832 }
833
834 /**
835 * Writes a 16-bit short.
836 *
837 * @param val the short value to be written
838 * @throws IOException if I/O errors occur while writing to the underlying
839 * stream
840 */
841 public void writeShort(int val) throws IOException {
842 bout.writeShort(val);
843 }
844
845 /**
846 * Writes a 16-bit char.
847 *
848 * @param val the char value to be written
849 * @throws IOException if I/O errors occur while writing to the underlying
850 * stream
851 */
852 public void writeChar(int val) throws IOException {
853 bout.writeChar(val);
854 }
855
856 /**
857 * Writes a 32-bit int.
858 *
859 * @param val the integer value to be written
860 * @throws IOException if I/O errors occur while writing to the underlying
861 * stream
862 */
863 public void writeInt(int val) throws IOException {
864 bout.writeInt(val);
865 }
866
867 /**
868 * Writes a 64-bit long.
869 *
870 * @param val the long value to be written
871 * @throws IOException if I/O errors occur while writing to the underlying
872 * stream
873 */
874 public void writeLong(long val) throws IOException {
875 bout.writeLong(val);
876 }
877
878 /**
879 * Writes a 32-bit float.
880 *
881 * @param val the float value to be written
882 * @throws IOException if I/O errors occur while writing to the underlying
883 * stream
884 */
885 public void writeFloat(float val) throws IOException {
886 bout.writeFloat(val);
887 }
888
889 /**
890 * Writes a 64-bit double.
891 *
892 * @param val the double value to be written
893 * @throws IOException if I/O errors occur while writing to the underlying
894 * stream
895 */
896 public void writeDouble(double val) throws IOException {
897 bout.writeDouble(val);
898 }
899
900 /**
901 * Writes a String as a sequence of bytes.
902 *
903 * @param str the String of bytes to be written
904 * @throws IOException if I/O errors occur while writing to the underlying
905 * stream
906 */
907 public void writeBytes(String str) throws IOException {
908 bout.writeBytes(str);
909 }
910
911 /**
912 * Writes a String as a sequence of chars.
913 *
914 * @param str the String of chars to be written
915 * @throws IOException if I/O errors occur while writing to the underlying
916 * stream
917 */
918 public void writeChars(String str) throws IOException {
919 bout.writeChars(str);
920 }
921
922 /**
923 * Primitive data write of this String in
924 * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
925 * format. Note that there is a
926 * significant difference between writing a String into the stream as
927 * primitive data or as an Object. A String instance written by writeObject
928 * is written into the stream as a String initially. Future writeObject()
929 * calls write references to the string into the stream.
930 *
931 * @param str the String to be written
932 * @throws IOException if I/O errors occur while writing to the underlying
933 * stream
934 */
935 public void writeUTF(String str) throws IOException {
936 bout.writeUTFInternal(str, false);
937 }
938
939 /**
940 * Provide programmatic access to the persistent fields to be written
941 * to ObjectOutput.
942 *
943 * @since 1.2
944 */
945 public abstract static class PutField {
946 /**
947 * Constructor for subclasses to call.
948 */
949 public PutField() {}
950
951 /**
952 * Put the value of the named boolean field into the persistent field.
953 *
954 * @param name the name of the serializable field
955 * @param val the value to assign to the field
956 * @throws IllegalArgumentException if {@code name} does not
957 * match the name of a serializable field for the class whose fields
958 * are being written, or if the type of the named field is not
959 * {@code boolean}
960 */
961 public abstract void put(String name, boolean val);
962
963 /**
964 * Put the value of the named byte field into the persistent field.
965 *
966 * @param name the name of the serializable field
967 * @param val the value to assign to the field
968 * @throws IllegalArgumentException if {@code name} does not
969 * match the name of a serializable field for the class whose fields
970 * are being written, or if the type of the named field is not
971 * {@code byte}
972 */
973 public abstract void put(String name, byte val);
974
975 /**
976 * Put the value of the named char field into the persistent field.
977 *
978 * @param name the name of the serializable field
979 * @param val the value to assign to the field
980 * @throws IllegalArgumentException if {@code name} does not
981 * match the name of a serializable field for the class whose fields
982 * are being written, or if the type of the named field is not
983 * {@code char}
984 */
985 public abstract void put(String name, char val);
986
987 /**
988 * Put the value of the named short field into the persistent field.
989 *
990 * @param name the name of the serializable field
991 * @param val the value to assign to the field
992 * @throws IllegalArgumentException if {@code name} does not
993 * match the name of a serializable field for the class whose fields
994 * are being written, or if the type of the named field is not
995 * {@code short}
996 */
997 public abstract void put(String name, short val);
998
999 /**
1000 * Put the value of the named int field into the persistent field.
1001 *
1002 * @param name the name of the serializable field
1003 * @param val the value to assign to the field
1004 * @throws IllegalArgumentException if {@code name} does not
1005 * match the name of a serializable field for the class whose fields
1006 * are being written, or if the type of the named field is not
1007 * {@code int}
1008 */
1009 public abstract void put(String name, int val);
1010
1011 /**
1012 * Put the value of the named long field into the persistent field.
1013 *
1014 * @param name the name of the serializable field
1015 * @param val the value to assign to the field
1016 * @throws IllegalArgumentException if {@code name} does not
1017 * match the name of a serializable field for the class whose fields
1018 * are being written, or if the type of the named field is not
1019 * {@code long}
1020 */
1021 public abstract void put(String name, long val);
1022
1023 /**
1024 * Put the value of the named float field into the persistent field.
1025 *
1026 * @param name the name of the serializable field
1027 * @param val the value to assign to the field
1028 * @throws IllegalArgumentException if {@code name} does not
1029 * match the name of a serializable field for the class whose fields
1030 * are being written, or if the type of the named field is not
1031 * {@code float}
1032 */
1033 public abstract void put(String name, float val);
1034
1035 /**
1036 * Put the value of the named double field into the persistent field.
1037 *
1038 * @param name the name of the serializable field
1039 * @param val the value to assign to the field
1040 * @throws IllegalArgumentException if {@code name} does not
1041 * match the name of a serializable field for the class whose fields
1042 * are being written, or if the type of the named field is not
1043 * {@code double}
1044 */
1045 public abstract void put(String name, double val);
1046
1047 /**
1048 * Put the value of the named Object field into the persistent field.
1049 *
1050 * @param name the name of the serializable field
1051 * @param val the value to assign to the field
1052 * (which may be {@code null})
1053 * @throws IllegalArgumentException if {@code name} does not
1054 * match the name of a serializable field for the class whose fields
1055 * are being written, or if the type of the named field is not a
1056 * reference type
1057 */
1058 public abstract void put(String name, Object val);
1059
1060 /**
1061 * Write the data and fields to the specified ObjectOutput stream,
1062 * which must be the same stream that produced this
1063 * {@code PutField} object.
1064 *
1065 * @param out the stream to write the data and fields to
1066 * @throws IOException if I/O errors occur while writing to the
1067 * underlying stream
1068 * @throws IllegalArgumentException if the specified stream is not
1069 * the same stream that produced this {@code PutField}
1070 * object
1071 * @deprecated This method does not write the values contained by this
1072 * {@code PutField} object in a proper format, and may
1073 * result in corruption of the serialization stream. The
1074 * correct way to write {@code PutField} data is by
1075 * calling the {@link java.io.ObjectOutputStream#writeFields()}
1076 * method.
1077 */
1078 @Deprecated(forRemoval = true, since = "1.4")
1079 public abstract void write(ObjectOutput out) throws IOException;
1080 }
1081
1082
1083 /**
1084 * Returns protocol version in use.
1085 */
1086 int getProtocolVersion() {
1087 return protocol;
1088 }
1089
1090 /**
1091 * Writes string without allowing it to be replaced in stream. Used by
1092 * ObjectStreamClass to write class descriptor type strings.
1093 */
1094 void writeTypeString(String str) throws IOException {
1095 int handle;
1096 if (str == null) {
1097 writeNull();
1098 } else if ((handle = handles.lookup(str)) != -1) {
1099 writeHandle(handle);
1100 } else {
1101 writeString(str, false);
1102 }
1103 }
1104
1105 /**
1106 * Verifies that this (possibly subclass) instance can be constructed
1107 * without violating security constraints: the subclass must not override
1108 * security-sensitive non-final methods, or else the
1109 * "enableSubclassImplementation" SerializablePermission is checked.
1110 */
1111 private void verifySubclass() {
1112 Class<?> cl = getClass();
1113 if (cl == ObjectOutputStream.class) {
1114 return;
1115 }
1116 @SuppressWarnings("removal")
1117 SecurityManager sm = System.getSecurityManager();
1118 if (sm == null) {
1119 return;
1120 }
1121 boolean result = Caches.subclassAudits.get(cl);
1122 if (!result) {
1123 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
1124 }
1125 }
1126
1127 /**
1128 * Performs reflective checks on given subclass to verify that it doesn't
1129 * override security-sensitive non-final methods. Returns TRUE if subclass
1130 * is "safe", FALSE otherwise.
1131 */
1132 @SuppressWarnings("removal")
1133 private static Boolean auditSubclass(Class<?> subcl) {
1134 return AccessController.doPrivileged(
1135 new PrivilegedAction<>() {
1136 public Boolean run() {
1137 for (Class<?> cl = subcl;
1138 cl != ObjectOutputStream.class;
1139 cl = cl.getSuperclass())
1140 {
1141 try {
1142 cl.getDeclaredMethod(
1143 "writeUnshared", new Class<?>[] { Object.class });
1144 return Boolean.FALSE;
1145 } catch (NoSuchMethodException ex) {
1146 }
1147 try {
1148 cl.getDeclaredMethod("putFields", (Class<?>[]) null);
1149 return Boolean.FALSE;
1150 } catch (NoSuchMethodException ex) {
1151 }
1152 }
1153 return Boolean.TRUE;
1154 }
1155 }
1156 );
1157 }
1158
1159 /**
1160 * Clears internal data structures.
1161 */
1162 private void clear() {
1163 subs.clear();
1164 handles.clear();
1165 }
1166
1167 /**
1168 * Underlying writeObject/writeUnshared implementation.
1169 */
1170 private void writeObject0(Object obj, boolean unshared)
1171 throws IOException
1172 {
1173 boolean oldMode = bout.setBlockDataMode(false);
1174 depth++;
1175 try {
1176 // handle previously written and non-replaceable objects
1177 int h;
1178 if ((obj = subs.lookup(obj)) == null) {
1179 writeNull();
1180 return;
1181 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1182 writeHandle(h);
1183 return;
1184 } else if (obj instanceof Class) {
1185 writeClass((Class) obj, unshared);
1186 return;
1187 } else if (obj instanceof ObjectStreamClass) {
1188 writeClassDesc((ObjectStreamClass) obj, unshared);
1189 return;
1190 }
1191
1192 // check for replacement object
1193 Object orig = obj;
1194 Class<?> cl = obj.getClass();
1195 ObjectStreamClass desc;
1196 for (;;) {
1197 // REMIND: skip this check for strings/arrays?
1198 Class<?> repCl;
1199 desc = ObjectStreamClass.lookup(cl, true);
1200 if (!desc.hasWriteReplaceMethod() ||
1201 (obj = desc.invokeWriteReplace(obj)) == null ||
1202 (repCl = obj.getClass()) == cl)
1203 {
1204 break;
1205 }
1206 cl = repCl;
1207 }
1208 if (enableReplace) {
1209 Object rep = replaceObject(obj);
1210 if (rep != obj && rep != null) {
1211 cl = rep.getClass();
1212 desc = ObjectStreamClass.lookup(cl, true);
1213 }
1214 obj = rep;
1215 }
1216
1217 // if object replaced, run through original checks a second time
1218 if (obj != orig) {
1219 subs.assign(orig, obj);
1220 if (obj == null) {
1221 writeNull();
1222 return;
1223 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1224 writeHandle(h);
1225 return;
1226 } else if (obj instanceof Class) {
1227 writeClass((Class) obj, unshared);
1228 return;
1229 } else if (obj instanceof ObjectStreamClass) {
1230 writeClassDesc((ObjectStreamClass) obj, unshared);
1231 return;
1232 }
1233 }
1234
1235 // remaining cases
1236 if (obj instanceof String) {
1237 writeString((String) obj, unshared);
1238 } else if (cl.isArray()) {
1239 writeArray(obj, desc, unshared);
1240 } else if (obj instanceof Enum) {
1241 writeEnum((Enum<?>) obj, desc, unshared);
1242 } else if (obj instanceof Serializable) {
1243 writeOrdinaryObject(obj, desc, unshared);
1244 } else {
1245 if (extendedDebugInfo) {
1246 throw new NotSerializableException(
1247 cl.getName() + "\n" + debugInfoStack.toString());
1248 } else {
1249 throw new NotSerializableException(cl.getName());
1250 }
1251 }
1252 } finally {
1253 depth--;
1254 bout.setBlockDataMode(oldMode);
1255 }
1256 }
1257
1258 /**
1259 * Writes null code to stream.
1260 */
1261 private void writeNull() throws IOException {
1262 bout.writeByte(TC_NULL);
1263 }
1264
1265 /**
1266 * Writes given object handle to stream.
1267 */
1268 private void writeHandle(int handle) throws IOException {
1269 bout.writeByte(TC_REFERENCE);
1270 bout.writeInt(baseWireHandle + handle);
1271 }
1272
1273 /**
1274 * Writes representation of given class to stream.
1275 */
1276 private void writeClass(Class<?> cl, boolean unshared) throws IOException {
1277 bout.writeByte(TC_CLASS);
1278 writeClassDesc(ObjectStreamClass.lookup(cl, true), false);
1279 handles.assign(unshared ? null : cl);
1280 }
1281
1282 /**
1283 * Writes representation of given class descriptor to stream.
1284 */
1285 private void writeClassDesc(ObjectStreamClass desc, boolean unshared)
1286 throws IOException
1287 {
1288 int handle;
1289 if (desc == null) {
1290 writeNull();
1291 } else if (!unshared && (handle = handles.lookup(desc)) != -1) {
1292 writeHandle(handle);
1293 } else if (desc.isProxy()) {
1294 writeProxyDesc(desc, unshared);
1295 } else {
1296 writeNonProxyDesc(desc, unshared);
1297 }
1298 }
1299
1300 private boolean isCustomSubclass() {
1301 // Return true if this class is a custom subclass of ObjectOutputStream
1302 return getClass().getClassLoader()
1303 != ObjectOutputStream.class.getClassLoader();
1304 }
1305
1306 /**
1307 * Writes class descriptor representing a dynamic proxy class to stream.
1308 */
1309 private void writeProxyDesc(ObjectStreamClass desc, boolean unshared)
1310 throws IOException
1311 {
1312 bout.writeByte(TC_PROXYCLASSDESC);
1313 handles.assign(unshared ? null : desc);
1314
1315 Class<?> cl = desc.forClass();
1316 Class<?>[] ifaces = cl.getInterfaces();
1317 bout.writeInt(ifaces.length);
1318 for (int i = 0; i < ifaces.length; i++) {
1319 bout.writeUTF(ifaces[i].getName());
1320 }
1321
1322 bout.setBlockDataMode(true);
1323 if (isCustomSubclass()) {
1324 ReflectUtil.checkPackageAccess(cl);
1325 }
1326 annotateProxyClass(cl);
1327 bout.setBlockDataMode(false);
1328 bout.writeByte(TC_ENDBLOCKDATA);
1329
1330 writeClassDesc(desc.getSuperDesc(), false);
1331 }
1332
1333 /**
1334 * Writes class descriptor representing a standard (i.e., not a dynamic
1335 * proxy) class to stream.
1336 */
1337 private void writeNonProxyDesc(ObjectStreamClass desc, boolean unshared)
1338 throws IOException
1339 {
1340 bout.writeByte(TC_CLASSDESC);
1341 handles.assign(unshared ? null : desc);
1342
1343 if (protocol == PROTOCOL_VERSION_1) {
1344 // do not invoke class descriptor write hook with old protocol
1345 desc.writeNonProxy(this);
1346 } else {
1347 writeClassDescriptor(desc);
1348 }
1349
1350 Class<?> cl = desc.forClass();
1351 bout.setBlockDataMode(true);
1352 if (cl != null && isCustomSubclass()) {
1353 ReflectUtil.checkPackageAccess(cl);
1354 }
1355 annotateClass(cl);
1356 bout.setBlockDataMode(false);
1357 bout.writeByte(TC_ENDBLOCKDATA);
1358
1359 writeClassDesc(desc.getSuperDesc(), false);
1360 }
1361
1362 /**
1363 * Writes given string to stream, using standard or long UTF format
1364 * depending on string length.
1365 */
1366 private void writeString(String str, boolean unshared) throws IOException {
1367 handles.assign(unshared ? null : str);
1368 bout.writeUTFInternal(str, true);
1369 }
1370
1371 /**
1372 * Writes given array object to stream.
1373 */
1374 private void writeArray(Object array,
1375 ObjectStreamClass desc,
1376 boolean unshared)
1377 throws IOException
1378 {
1379 bout.writeByte(TC_ARRAY);
1380 writeClassDesc(desc, false);
1381 handles.assign(unshared ? null : array);
1382
1383 Class<?> ccl = desc.forClass().getComponentType();
1384 if (ccl.isPrimitive()) {
1385 if (ccl == Integer.TYPE) {
1386 int[] ia = (int[]) array;
1387 bout.writeInt(ia.length);
1388 bout.writeInts(ia, 0, ia.length);
1389 } else if (ccl == Byte.TYPE) {
1390 byte[] ba = (byte[]) array;
1391 bout.writeInt(ba.length);
1392 bout.write(ba, 0, ba.length, true);
1393 } else if (ccl == Long.TYPE) {
1394 long[] ja = (long[]) array;
1395 bout.writeInt(ja.length);
1396 bout.writeLongs(ja, 0, ja.length);
1397 } else if (ccl == Float.TYPE) {
1398 float[] fa = (float[]) array;
1399 bout.writeInt(fa.length);
1400 bout.writeFloats(fa, 0, fa.length);
1401 } else if (ccl == Double.TYPE) {
1402 double[] da = (double[]) array;
1403 bout.writeInt(da.length);
1404 bout.writeDoubles(da, 0, da.length);
1405 } else if (ccl == Short.TYPE) {
1406 short[] sa = (short[]) array;
1407 bout.writeInt(sa.length);
1408 bout.writeShorts(sa, 0, sa.length);
1409 } else if (ccl == Character.TYPE) {
1410 char[] ca = (char[]) array;
1411 bout.writeInt(ca.length);
1412 bout.writeChars(ca, 0, ca.length);
1413 } else if (ccl == Boolean.TYPE) {
1414 boolean[] za = (boolean[]) array;
1415 bout.writeInt(za.length);
1416 bout.writeBooleans(za, 0, za.length);
1417 } else {
1418 throw new InternalError();
1419 }
1420 } else {
1421 Object[] objs = (Object[]) array;
1422 int len = objs.length;
1423 bout.writeInt(len);
1424 if (extendedDebugInfo) {
1425 debugInfoStack.push(
1426 "array (class \"" + array.getClass().getName() +
1427 "\", size: " + len + ")");
1428 }
1429 try {
1430 for (int i = 0; i < len; i++) {
1431 if (extendedDebugInfo) {
1432 debugInfoStack.push(
1433 "element of array (index: " + i + ")");
1434 }
1435 try {
1436 writeObject0(objs[i], false);
1437 } finally {
1438 if (extendedDebugInfo) {
1439 debugInfoStack.pop();
1440 }
1441 }
1442 }
1443 } finally {
1444 if (extendedDebugInfo) {
1445 debugInfoStack.pop();
1446 }
1447 }
1448 }
1449 }
1450
1451 /**
1452 * Writes given enum constant to stream.
1453 */
1454 private void writeEnum(Enum<?> en,
1455 ObjectStreamClass desc,
1456 boolean unshared)
1457 throws IOException
1458 {
1459 bout.writeByte(TC_ENUM);
1460 ObjectStreamClass sdesc = desc.getSuperDesc();
1461 writeClassDesc((sdesc.forClass() == Enum.class) ? desc : sdesc, false);
1462 handles.assign(unshared ? null : en);
1463 writeString(en.name(), false);
1464 }
1465
1466 /**
1467 * Writes representation of an "ordinary" (i.e., not a String, Class,
1468 * ObjectStreamClass, array, or enum constant) serializable object to the
1469 * stream.
1470 */
1471 private void writeOrdinaryObject(Object obj,
1472 ObjectStreamClass desc,
1473 boolean unshared)
1474 throws IOException
1475 {
1476 if (extendedDebugInfo) {
1477 debugInfoStack.push(
1478 (depth == 1 ? "root " : "") + "object (class \"" +
1479 obj.getClass().getName() + "\", " + obj.toString() + ")");
1480 }
1481 try {
1482 desc.checkSerialize();
1483
1484 bout.writeByte(TC_OBJECT);
1485 writeClassDesc(desc, false);
1486 handles.assign(unshared ? null : obj);
1487
1488 if (desc.isRecord()) {
1489 writeRecordData(obj, desc);
1490 } else if (desc.isExternalizable() && !desc.isProxy()) {
1491 if (desc.isValue())
1492 throw new InvalidClassException("Externalizable not valid for value class "
1493 + desc.forClass().getName());
1494 writeExternalData((Externalizable) obj);
1495 } else {
1496 writeSerialData(obj, desc);
1497 }
1498 } finally {
1499 if (extendedDebugInfo) {
1500 debugInfoStack.pop();
1501 }
1502 }
1503 }
1504
1505 /**
1506 * Writes externalizable data of given object by invoking its
1507 * writeExternal() method.
1508 */
1509 private void writeExternalData(Externalizable obj) throws IOException {
1510 PutFieldImpl oldPut = curPut;
1511 curPut = null;
1512
1513 if (extendedDebugInfo) {
1514 debugInfoStack.push("writeExternal data");
1515 }
1516 SerialCallbackContext oldContext = curContext;
1517 try {
1518 curContext = null;
1519 if (protocol == PROTOCOL_VERSION_1) {
1520 obj.writeExternal(this);
1521 } else {
1522 bout.setBlockDataMode(true);
1523 obj.writeExternal(this);
1524 bout.setBlockDataMode(false);
1525 bout.writeByte(TC_ENDBLOCKDATA);
1526 }
1527 } finally {
1528 curContext = oldContext;
1529 if (extendedDebugInfo) {
1530 debugInfoStack.pop();
1531 }
1532 }
1533
1534 curPut = oldPut;
1535 }
1536
1537 /** Writes the record component values for the given record object. */
1538 private void writeRecordData(Object obj, ObjectStreamClass desc)
1539 throws IOException
1540 {
1541 assert obj.getClass().isRecord();
1542 List<ObjectStreamClass.ClassDataSlot> slots = desc.getClassDataLayout();
1543 if (slots.size() != 1) {
1544 throw new InvalidClassException(
1545 "expected a single record slot length, but found: " + slots.size());
1546 }
1547
1548 defaultWriteFields(obj, desc); // #### seems unnecessary to use the accessors
1549 }
1550
1551 /**
1552 * Writes instance data for each serializable class of given object, from
1553 * superclass to subclass.
1554 */
1555 private void writeSerialData(Object obj, ObjectStreamClass desc)
1556 throws IOException
1557 {
1558 List<ObjectStreamClass.ClassDataSlot> slots = desc.getClassDataLayout();
1559 for (int i = 0; i < slots.size(); i++) {
1560 ObjectStreamClass slotDesc = slots.get(i).desc;
1561 if (slotDesc.hasWriteObjectMethod()) {
1562 PutFieldImpl oldPut = curPut;
1563 curPut = null;
1564 SerialCallbackContext oldContext = curContext;
1565
1566 if (extendedDebugInfo) {
1567 debugInfoStack.push(
1568 "custom writeObject data (class \"" +
1569 slotDesc.getName() + "\")");
1570 }
1571 try {
1572 curContext = new SerialCallbackContext(obj, slotDesc);
1573 bout.setBlockDataMode(true);
1574 slotDesc.invokeWriteObject(obj, this);
1575 bout.setBlockDataMode(false);
1576 bout.writeByte(TC_ENDBLOCKDATA);
1577 } finally {
1578 curContext.setUsed();
1579 curContext = oldContext;
1580 if (extendedDebugInfo) {
1581 debugInfoStack.pop();
1582 }
1583 }
1584
1585 curPut = oldPut;
1586 } else {
1587 defaultWriteFields(obj, slotDesc);
1588 }
1589 }
1590 }
1591
1592 /**
1593 * Fetches and writes values of serializable fields of given object to
1594 * stream. The given class descriptor specifies which field values to
1595 * write, and in which order they should be written.
1596 */
1597 private void defaultWriteFields(Object obj, ObjectStreamClass desc)
1598 throws IOException
1599 {
1600 Class<?> cl = desc.forClass();
1601 if (cl != null && obj != null && !cl.isInstance(obj)) {
1602 throw new ClassCastException();
1603 }
1604
1605 desc.checkDefaultSerialize();
1606
1607 int primDataSize = desc.getPrimDataSize();
1608 if (primDataSize > 0) {
1609 if (primVals == null || primVals.length < primDataSize) {
1610 primVals = new byte[primDataSize];
1611 }
1612 desc.getPrimFieldValues(obj, primVals);
1613 bout.write(primVals, 0, primDataSize, false);
1614 }
1615
1616 int numObjFields = desc.getNumObjFields();
1617 if (numObjFields > 0) {
1618 ObjectStreamField[] fields = desc.getFields(false);
1619 Object[] objVals = new Object[numObjFields];
1620 int numPrimFields = fields.length - objVals.length;
1621 desc.getObjFieldValues(obj, objVals);
1622 for (int i = 0; i < objVals.length; i++) {
1623 if (extendedDebugInfo) {
1624 debugInfoStack.push(
1625 "field (class \"" + desc.getName() + "\", name: \"" +
1626 fields[numPrimFields + i].getName() + "\", type: \"" +
1627 fields[numPrimFields + i].getType() + "\")");
1628 }
1629 try {
1630 writeObject0(objVals[i],
1631 fields[numPrimFields + i].isUnshared());
1632 } finally {
1633 if (extendedDebugInfo) {
1634 debugInfoStack.pop();
1635 }
1636 }
1637 }
1638 }
1639 }
1640
1641 /**
1642 * Attempts to write to stream fatal IOException that has caused
1643 * serialization to abort.
1644 */
1645 private void writeFatalException(IOException ex) throws IOException {
1646 /*
1647 * Note: the serialization specification states that if a second
1648 * IOException occurs while attempting to serialize the original fatal
1649 * exception to the stream, then a StreamCorruptedException should be
1650 * thrown (section 2.1). However, due to a bug in previous
1651 * implementations of serialization, StreamCorruptedExceptions were
1652 * rarely (if ever) actually thrown--the "root" exceptions from
1653 * underlying streams were thrown instead. This historical behavior is
1654 * followed here for consistency.
1655 */
1656 clear();
1657 boolean oldMode = bout.setBlockDataMode(false);
1658 try {
1659 bout.writeByte(TC_EXCEPTION);
1660 writeObject0(ex, false);
1661 clear();
1662 } finally {
1663 bout.setBlockDataMode(oldMode);
1664 }
1665 }
1666
1667 /**
1668 * Default PutField implementation.
1669 */
1670 private class PutFieldImpl extends PutField {
1671
1672 /** class descriptor describing serializable fields */
1673 private final ObjectStreamClass desc;
1674 /** primitive field values */
1675 private final byte[] primVals;
1676 /** object field values */
1677 private final Object[] objVals;
1678
1679 /**
1680 * Creates PutFieldImpl object for writing fields defined in given
1681 * class descriptor.
1682 */
1683 PutFieldImpl(ObjectStreamClass desc) {
1684 this.desc = desc;
1685 primVals = new byte[desc.getPrimDataSize()];
1686 objVals = new Object[desc.getNumObjFields()];
1687 }
1688
1689 public void put(String name, boolean val) {
1690 ByteArray.setBoolean(primVals, getFieldOffset(name, Boolean.TYPE), val);
1691 }
1692
1693 public void put(String name, byte val) {
1694 primVals[getFieldOffset(name, Byte.TYPE)] = val;
1695 }
1696
1697 public void put(String name, char val) {
1698 ByteArray.setChar(primVals, getFieldOffset(name, Character.TYPE), val);
1699 }
1700
1701 public void put(String name, short val) {
1702 ByteArray.setShort(primVals, getFieldOffset(name, Short.TYPE), val);
1703 }
1704
1705 public void put(String name, int val) {
1706 ByteArray.setInt(primVals, getFieldOffset(name, Integer.TYPE), val);
1707 }
1708
1709 public void put(String name, float val) {
1710 ByteArray.setFloat(primVals, getFieldOffset(name, Float.TYPE), val);
1711 }
1712
1713 public void put(String name, long val) {
1714 ByteArray.setLong(primVals, getFieldOffset(name, Long.TYPE), val);
1715 }
1716
1717 public void put(String name, double val) {
1718 ByteArray.setDouble(primVals, getFieldOffset(name, Double.TYPE), val);
1719 }
1720
1721 public void put(String name, Object val) {
1722 objVals[getFieldOffset(name, Object.class)] = val;
1723 }
1724
1725 // deprecated in ObjectOutputStream.PutField
1726 public void write(ObjectOutput out) throws IOException {
1727 /*
1728 * Applications should *not* use this method to write PutField
1729 * data, as it will lead to stream corruption if the PutField
1730 * object writes any primitive data (since block data mode is not
1731 * unset/set properly, as is done in OOS.writeFields()). This
1732 * broken implementation is being retained solely for behavioral
1733 * compatibility, in order to support applications which use
1734 * OOS.PutField.write() for writing only non-primitive data.
1735 *
1736 * Serialization of unshared objects is not implemented here since
1737 * it is not necessary for backwards compatibility; also, unshared
1738 * semantics may not be supported by the given ObjectOutput
1739 * instance. Applications which write unshared objects using the
1740 * PutField API must use OOS.writeFields().
1741 */
1742 if (ObjectOutputStream.this != out) {
1743 throw new IllegalArgumentException("wrong stream");
1744 }
1745 out.write(primVals, 0, primVals.length);
1746
1747 ObjectStreamField[] fields = desc.getFields(false);
1748 int numPrimFields = fields.length - objVals.length;
1749 // REMIND: warn if numPrimFields > 0?
1750 for (int i = 0; i < objVals.length; i++) {
1751 if (fields[numPrimFields + i].isUnshared()) {
1752 throw new IOException("cannot write unshared object");
1753 }
1754 out.writeObject(objVals[i]);
1755 }
1756 }
1757
1758 /**
1759 * Writes buffered primitive data and object fields to stream.
1760 */
1761 void writeFields() throws IOException {
1762 bout.write(primVals, 0, primVals.length, false);
1763
1764 ObjectStreamField[] fields = desc.getFields(false);
1765 int numPrimFields = fields.length - objVals.length;
1766 for (int i = 0; i < objVals.length; i++) {
1767 if (extendedDebugInfo) {
1768 debugInfoStack.push(
1769 "field (class \"" + desc.getName() + "\", name: \"" +
1770 fields[numPrimFields + i].getName() + "\", type: \"" +
1771 fields[numPrimFields + i].getType() + "\")");
1772 }
1773 try {
1774 writeObject0(objVals[i],
1775 fields[numPrimFields + i].isUnshared());
1776 } finally {
1777 if (extendedDebugInfo) {
1778 debugInfoStack.pop();
1779 }
1780 }
1781 }
1782 }
1783
1784 /**
1785 * Returns offset of field with given name and type. A specified type
1786 * of null matches all types, Object.class matches all non-primitive
1787 * types, and any other non-null type matches assignable types only.
1788 * Throws IllegalArgumentException if no matching field found.
1789 */
1790 private int getFieldOffset(String name, Class<?> type) {
1791 ObjectStreamField field = desc.getField(name, type);
1792 if (field == null) {
1793 throw new IllegalArgumentException("no such field " + name +
1794 " with type " + type);
1795 }
1796 return field.getOffset();
1797 }
1798 }
1799
1800 /**
1801 * Buffered output stream with two modes: in default mode, outputs data in
1802 * same format as DataOutputStream; in "block data" mode, outputs data
1803 * bracketed by block data markers (see object serialization specification
1804 * for details).
1805 */
1806 private static final class BlockDataOutputStream
1807 extends OutputStream implements DataOutput
1808 {
1809 /** maximum data block length */
1810 private static final int MAX_BLOCK_SIZE = 1024;
1811 /** maximum data block header length */
1812 private static final int MAX_HEADER_SIZE = 5;
1813 /** (tunable) length of char buffer (for writing strings) */
1814 private static final int CHAR_BUF_SIZE = 256;
1815
1816 /** buffer for writing general/block data */
1817 private final byte[] buf = new byte[MAX_BLOCK_SIZE];
1818 /** buffer for writing block data headers */
1819 private final byte[] hbuf = new byte[MAX_HEADER_SIZE];
1820 /** char buffer for fast string writes */
1821 private final char[] cbuf = new char[CHAR_BUF_SIZE];
1822
1823 /** block data mode */
1824 private boolean blkmode = false;
1825 /** current offset into buf */
1826 private int pos = 0;
1827
1828 /** underlying output stream */
1829 private final OutputStream out;
1830 /** loopback stream (for data writes that span data blocks) */
1831 private final DataOutputStream dout;
1832
1833 /**
1834 * Creates new BlockDataOutputStream on top of given underlying stream.
1835 * Block data mode is turned off by default.
1836 */
1837 BlockDataOutputStream(OutputStream out) {
1838 this.out = out;
1839 dout = new DataOutputStream(this);
1840 }
1841
1842 /**
1843 * Sets block data mode to the given mode (true == on, false == off)
1844 * and returns the previous mode value. If the new mode is the same as
1845 * the old mode, no action is taken. If the new mode differs from the
1846 * old mode, any buffered data is flushed before switching to the new
1847 * mode.
1848 */
1849 boolean setBlockDataMode(boolean mode) throws IOException {
1850 if (blkmode == mode) {
1851 return blkmode;
1852 }
1853 drain();
1854 blkmode = mode;
1855 return !blkmode;
1856 }
1857
1858 /**
1859 * Returns true if the stream is currently in block data mode, false
1860 * otherwise.
1861 */
1862 boolean getBlockDataMode() {
1863 return blkmode;
1864 }
1865
1866 /* ----------------- generic output stream methods ----------------- */
1867 /*
1868 * The following methods are equivalent to their counterparts in
1869 * OutputStream, except that they partition written data into data
1870 * blocks when in block data mode.
1871 */
1872
1873 public void write(int b) throws IOException {
1874 if (pos >= MAX_BLOCK_SIZE) {
1875 drain();
1876 }
1877 buf[pos++] = (byte) b;
1878 }
1879
1880 public void write(byte[] b) throws IOException {
1881 write(b, 0, b.length, false);
1882 }
1883
1884 public void write(byte[] b, int off, int len) throws IOException {
1885 write(b, off, len, false);
1886 }
1887
1888 public void flush() throws IOException {
1889 drain();
1890 out.flush();
1891 }
1892
1893 public void close() throws IOException {
1894 flush();
1895 out.close();
1896 }
1897
1898 /**
1899 * Writes specified span of byte values from given array. If copy is
1900 * true, copies the values to an intermediate buffer before writing
1901 * them to underlying stream (to avoid exposing a reference to the
1902 * original byte array).
1903 */
1904 void write(byte[] b, int off, int len, boolean copy)
1905 throws IOException
1906 {
1907 if (!(copy || blkmode)) { // write directly
1908 drain();
1909 out.write(b, off, len);
1910 return;
1911 }
1912
1913 while (len > 0) {
1914 if (pos >= MAX_BLOCK_SIZE) {
1915 drain();
1916 }
1917 if (len >= MAX_BLOCK_SIZE && !copy && pos == 0) {
1918 // avoid unnecessary copy
1919 writeBlockHeader(MAX_BLOCK_SIZE);
1920 out.write(b, off, MAX_BLOCK_SIZE);
1921 off += MAX_BLOCK_SIZE;
1922 len -= MAX_BLOCK_SIZE;
1923 } else {
1924 int wlen = Math.min(len, MAX_BLOCK_SIZE - pos);
1925 System.arraycopy(b, off, buf, pos, wlen);
1926 pos += wlen;
1927 off += wlen;
1928 len -= wlen;
1929 }
1930 }
1931 }
1932
1933 /**
1934 * Writes all buffered data from this stream to the underlying stream,
1935 * but does not flush underlying stream.
1936 */
1937 void drain() throws IOException {
1938 if (pos == 0) {
1939 return;
1940 }
1941 if (blkmode) {
1942 writeBlockHeader(pos);
1943 }
1944 out.write(buf, 0, pos);
1945 pos = 0;
1946 }
1947
1948 /**
1949 * Writes block data header. Data blocks shorter than 256 bytes are
1950 * prefixed with a 2-byte header; all others start with a 5-byte
1951 * header.
1952 */
1953 private void writeBlockHeader(int len) throws IOException {
1954 if (len <= 0xFF) {
1955 hbuf[0] = TC_BLOCKDATA;
1956 hbuf[1] = (byte) len;
1957 out.write(hbuf, 0, 2);
1958 } else {
1959 hbuf[0] = TC_BLOCKDATALONG;
1960 ByteArray.setInt(hbuf, 1, len);
1961 out.write(hbuf, 0, 5);
1962 }
1963 }
1964
1965
1966 /* ----------------- primitive data output methods ----------------- */
1967 /*
1968 * The following methods are equivalent to their counterparts in
1969 * DataOutputStream, except that they partition written data into data
1970 * blocks when in block data mode.
1971 */
1972
1973 public void writeBoolean(boolean v) throws IOException {
1974 if (pos >= MAX_BLOCK_SIZE) {
1975 drain();
1976 }
1977 ByteArray.setBoolean(buf, pos++, v);
1978 }
1979
1980 public void writeByte(int v) throws IOException {
1981 if (pos >= MAX_BLOCK_SIZE) {
1982 drain();
1983 }
1984 buf[pos++] = (byte) v;
1985 }
1986
1987 public void writeChar(int v) throws IOException {
1988 if (pos + 2 <= MAX_BLOCK_SIZE) {
1989 ByteArray.setChar(buf, pos, (char) v);
1990 pos += 2;
1991 } else {
1992 dout.writeChar(v);
1993 }
1994 }
1995
1996 public void writeShort(int v) throws IOException {
1997 if (pos + 2 <= MAX_BLOCK_SIZE) {
1998 ByteArray.setShort(buf, pos, (short) v);
1999 pos += 2;
2000 } else {
2001 dout.writeShort(v);
2002 }
2003 }
2004
2005 public void writeInt(int v) throws IOException {
2006 if (pos + 4 <= MAX_BLOCK_SIZE) {
2007 ByteArray.setInt(buf, pos, v);
2008 pos += 4;
2009 } else {
2010 dout.writeInt(v);
2011 }
2012 }
2013
2014 public void writeFloat(float v) throws IOException {
2015 if (pos + 4 <= MAX_BLOCK_SIZE) {
2016 ByteArray.setFloat(buf, pos, v);
2017 pos += 4;
2018 } else {
2019 dout.writeFloat(v);
2020 }
2021 }
2022
2023 public void writeLong(long v) throws IOException {
2024 if (pos + 8 <= MAX_BLOCK_SIZE) {
2025 ByteArray.setLong(buf, pos, v);
2026 pos += 8;
2027 } else {
2028 dout.writeLong(v);
2029 }
2030 }
2031
2032 public void writeDouble(double v) throws IOException {
2033 if (pos + 8 <= MAX_BLOCK_SIZE) {
2034 ByteArray.setDouble(buf, pos, v);
2035 pos += 8;
2036 } else {
2037 dout.writeDouble(v);
2038 }
2039 }
2040
2041 @SuppressWarnings("deprecation")
2042 void writeBytes(String s, int len) throws IOException {
2043 int pos = this.pos;
2044 for (int strpos = 0; strpos < len;) {
2045 int rem = MAX_BLOCK_SIZE - pos;
2046 int csize = Math.min(len - strpos, rem);
2047 s.getBytes(strpos, strpos + csize, buf, pos);
2048 pos += csize;
2049 strpos += csize;
2050
2051 if (pos == MAX_BLOCK_SIZE) {
2052 this.pos = pos;
2053 drain();
2054 pos = 0;
2055 }
2056 }
2057 this.pos = pos;
2058 }
2059
2060 public void writeBytes(String s) throws IOException {
2061 writeBytes(s, s.length());
2062 }
2063
2064 public void writeChars(String s) throws IOException {
2065 int endoff = s.length();
2066 for (int off = 0; off < endoff; ) {
2067 int csize = Math.min(endoff - off, CHAR_BUF_SIZE);
2068 s.getChars(off, off + csize, cbuf, 0);
2069 writeChars(cbuf, 0, csize);
2070 off += csize;
2071 }
2072 }
2073
2074 public void writeUTF(String str) throws IOException {
2075 writeUTFInternal(str, false);
2076 }
2077
2078 private void writeUTFInternal(String str, boolean writeHeader) throws IOException {
2079 int strlen = str.length();
2080 int countNonZeroAscii = JLA.countNonZeroAscii(str);
2081 int utflen = utfLen(str, countNonZeroAscii);
2082 if (utflen <= 0xFFFF) {
2083 if(writeHeader) {
2084 writeByte(TC_STRING);
2085 }
2086 writeShort(utflen);
2087 } else {
2088 if(writeHeader) {
2089 writeByte(TC_LONGSTRING);
2090 }
2091 writeLong(utflen);
2092 }
2093
2094 if (countNonZeroAscii != 0) {
2095 writeBytes(str, countNonZeroAscii);
2096 }
2097 if (countNonZeroAscii != strlen) {
2098 writeMoreUTF(str, countNonZeroAscii);
2099 }
2100 }
2101
2102 private void writeMoreUTF(String str, int stroff) throws IOException {
2103 int pos = this.pos;
2104 for (int strlen = str.length(); stroff < strlen;) {
2105 char c = str.charAt(stroff++);
2106 int csize = c != 0 && c < 0x80 ? 1 : c >= 0x800 ? 3 : 2;
2107 if (pos + csize >= MAX_BLOCK_SIZE) {
2108 this.pos = pos;
2109 drain();
2110 pos = 0;
2111 }
2112 pos = putChar(buf, pos, c);
2113 }
2114 this.pos = pos;
2115 }
2116
2117
2118 /* -------------- primitive data array output methods -------------- */
2119 /*
2120 * The following methods write out spans of primitive data values.
2121 * Though equivalent to calling the corresponding primitive write
2122 * methods repeatedly, these methods are optimized for writing groups
2123 * of primitive data values more efficiently.
2124 */
2125
2126 void writeBooleans(boolean[] v, int off, int len) throws IOException {
2127 int endoff = off + len;
2128 while (off < endoff) {
2129 if (pos >= MAX_BLOCK_SIZE) {
2130 drain();
2131 }
2132 int stop = Math.min(endoff, off + (MAX_BLOCK_SIZE - pos));
2133 while (off < stop) {
2134 ByteArray.setBoolean(buf, pos++, v[off++]);
2135 }
2136 }
2137 }
2138
2139 void writeChars(char[] v, int off, int len) throws IOException {
2140 int limit = MAX_BLOCK_SIZE - 2;
2141 int endoff = off + len;
2142 while (off < endoff) {
2143 if (pos <= limit) {
2144 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2145 int stop = Math.min(endoff, off + avail);
2146 while (off < stop) {
2147 ByteArray.setChar(buf, pos, v[off++]);
2148 pos += 2;
2149 }
2150 } else {
2151 dout.writeChar(v[off++]);
2152 }
2153 }
2154 }
2155
2156 void writeShorts(short[] v, int off, int len) throws IOException {
2157 int limit = MAX_BLOCK_SIZE - 2;
2158 int endoff = off + len;
2159 while (off < endoff) {
2160 if (pos <= limit) {
2161 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2162 int stop = Math.min(endoff, off + avail);
2163 while (off < stop) {
2164 ByteArray.setShort(buf, pos, v[off++]);
2165 pos += 2;
2166 }
2167 } else {
2168 dout.writeShort(v[off++]);
2169 }
2170 }
2171 }
2172
2173 void writeInts(int[] v, int off, int len) throws IOException {
2174 int limit = MAX_BLOCK_SIZE - 4;
2175 int endoff = off + len;
2176 while (off < endoff) {
2177 if (pos <= limit) {
2178 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2179 int stop = Math.min(endoff, off + avail);
2180 while (off < stop) {
2181 ByteArray.setInt(buf, pos, v[off++]);
2182 pos += 4;
2183 }
2184 } else {
2185 dout.writeInt(v[off++]);
2186 }
2187 }
2188 }
2189
2190 void writeFloats(float[] v, int off, int len) throws IOException {
2191 int limit = MAX_BLOCK_SIZE - 4;
2192 int endoff = off + len;
2193 while (off < endoff) {
2194 if (pos <= limit) {
2195 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2196 int stop = Math.min(endoff, off + avail);
2197 while (off < stop) {
2198 ByteArray.setFloat(buf, pos, v[off++]);
2199 pos += 4;
2200 }
2201 } else {
2202 dout.writeFloat(v[off++]);
2203 }
2204 }
2205 }
2206
2207 void writeLongs(long[] v, int off, int len) throws IOException {
2208 int limit = MAX_BLOCK_SIZE - 8;
2209 int endoff = off + len;
2210 while (off < endoff) {
2211 if (pos <= limit) {
2212 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2213 int stop = Math.min(endoff, off + avail);
2214 while (off < stop) {
2215 ByteArray.setLong(buf, pos, v[off++]);
2216 pos += 8;
2217 }
2218 } else {
2219 dout.writeLong(v[off++]);
2220 }
2221 }
2222 }
2223
2224 void writeDoubles(double[] v, int off, int len) throws IOException {
2225 int limit = MAX_BLOCK_SIZE - 8;
2226 int endoff = off + len;
2227 while (off < endoff) {
2228 if (pos <= limit) {
2229 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2230 int stop = Math.min(endoff, off + avail);
2231 while (off < stop) {
2232 ByteArray.setDouble(buf, pos, v[off++]);
2233 pos += 8;
2234 }
2235 } else {
2236 dout.writeDouble(v[off++]);
2237 }
2238 }
2239 }
2240 }
2241
2242 /**
2243 * Lightweight identity hash table which maps objects to integer handles,
2244 * assigned in ascending order.
2245 */
2246 private static final class HandleTable {
2247
2248 /* number of mappings in table/next available handle */
2249 private int size;
2250 /* size threshold determining when to expand hash spine */
2251 private int threshold;
2252 /* factor for computing size threshold */
2253 private final float loadFactor;
2254 /* maps hash value -> candidate handle value */
2255 private int[] spine;
2256 /* maps handle value -> next candidate handle value */
2257 private int[] next;
2258 /* maps handle value -> associated object */
2259 private Object[] objs;
2260
2261 /**
2262 * Creates new HandleTable with given capacity and load factor.
2263 */
2264 HandleTable(int initialCapacity, float loadFactor) {
2265 this.loadFactor = loadFactor;
2266 spine = new int[initialCapacity];
2267 next = new int[initialCapacity];
2268 objs = new Object[initialCapacity];
2269 threshold = (int) (initialCapacity * loadFactor);
2270 clear();
2271 }
2272
2273 /**
2274 * Assigns next available handle to given object, and returns handle
2275 * value. Handles are assigned in ascending order starting at 0.
2276 */
2277 int assign(Object obj) {
2278 if (size >= next.length) {
2279 growEntries();
2280 }
2281 if (size >= threshold) {
2282 growSpine();
2283 }
2284 insert(obj, size);
2285 return size++;
2286 }
2287
2288 /**
2289 * Looks up and returns handle associated with given object, or -1 if
2290 * no mapping found.
2291 */
2292 int lookup(Object obj) {
2293 if (size == 0) {
2294 return -1;
2295 }
2296 int index = hash(obj) % spine.length;
2297 for (int i = spine[index]; i >= 0; i = next[i]) {
2298 if (objs[i] == obj) {
2299 return i;
2300 }
2301 }
2302 return -1;
2303 }
2304
2305 /**
2306 * Resets table to its initial (empty) state.
2307 */
2308 void clear() {
2309 Arrays.fill(spine, -1);
2310 Arrays.fill(objs, 0, size, null);
2311 size = 0;
2312 }
2313
2314 /**
2315 * Returns the number of mappings currently in table.
2316 */
2317 int size() {
2318 return size;
2319 }
2320
2321 /**
2322 * Inserts mapping object -> handle mapping into table. Assumes table
2323 * is large enough to accommodate new mapping.
2324 */
2325 private void insert(Object obj, int handle) {
2326 int index = hash(obj) % spine.length;
2327 objs[handle] = obj;
2328 next[handle] = spine[index];
2329 spine[index] = handle;
2330 }
2331
2332 /**
2333 * Expands the hash "spine" -- equivalent to increasing the number of
2334 * buckets in a conventional hash table.
2335 */
2336 private void growSpine() {
2337 spine = new int[(spine.length << 1) + 1];
2338 threshold = (int) (spine.length * loadFactor);
2339 Arrays.fill(spine, -1);
2340 for (int i = 0; i < size; i++) {
2341 insert(objs[i], i);
2342 }
2343 }
2344
2345 /**
2346 * Increases hash table capacity by lengthening entry arrays.
2347 */
2348 private void growEntries() {
2349 int newLength = (next.length << 1) + 1;
2350 int[] newNext = new int[newLength];
2351 System.arraycopy(next, 0, newNext, 0, size);
2352 next = newNext;
2353
2354 Object[] newObjs = new Object[newLength];
2355 System.arraycopy(objs, 0, newObjs, 0, size);
2356 objs = newObjs;
2357 }
2358
2359 /**
2360 * Returns hash value for given object.
2361 */
2362 private int hash(Object obj) {
2363 return System.identityHashCode(obj) & 0x7FFFFFFF;
2364 }
2365 }
2366
2367 /**
2368 * Lightweight identity hash table which maps objects to replacement
2369 * objects.
2370 */
2371 private static final class ReplaceTable {
2372
2373 /* maps object -> index */
2374 private final HandleTable htab;
2375 /* maps index -> replacement object */
2376 private Object[] reps;
2377
2378 /**
2379 * Creates new ReplaceTable with given capacity and load factor.
2380 */
2381 ReplaceTable(int initialCapacity, float loadFactor) {
2382 htab = new HandleTable(initialCapacity, loadFactor);
2383 reps = new Object[initialCapacity];
2384 }
2385
2386 /**
2387 * Enters mapping from object to replacement object.
2388 */
2389 void assign(Object obj, Object rep) {
2390 int index = htab.assign(obj);
2391 while (index >= reps.length) {
2392 grow();
2393 }
2394 reps[index] = rep;
2395 }
2396
2397 /**
2398 * Looks up and returns replacement for given object. If no
2399 * replacement is found, returns the lookup object itself.
2400 */
2401 Object lookup(Object obj) {
2402 int index = htab.lookup(obj);
2403 return (index >= 0) ? reps[index] : obj;
2404 }
2405
2406 /**
2407 * Resets table to its initial (empty) state.
2408 */
2409 void clear() {
2410 Arrays.fill(reps, 0, htab.size(), null);
2411 htab.clear();
2412 }
2413
2414 /**
2415 * Returns the number of mappings currently in table.
2416 */
2417 int size() {
2418 return htab.size();
2419 }
2420
2421 /**
2422 * Increases table capacity.
2423 */
2424 private void grow() {
2425 Object[] newReps = new Object[(reps.length << 1) + 1];
2426 System.arraycopy(reps, 0, newReps, 0, reps.length);
2427 reps = newReps;
2428 }
2429 }
2430
2431 /**
2432 * Stack to keep debug information about the state of the
2433 * serialization process, for embedding in exception messages.
2434 */
2435 private static final class DebugTraceInfoStack {
2436 private final List<String> stack;
2437
2438 DebugTraceInfoStack() {
2439 stack = new ArrayList<>();
2440 }
2441
2442 /**
2443 * Removes all of the elements from enclosed list.
2444 */
2445 void clear() {
2446 stack.clear();
2447 }
2448
2449 /**
2450 * Removes the object at the top of enclosed list.
2451 */
2452 void pop() {
2453 stack.remove(stack.size()-1);
2454 }
2455
2456 /**
2457 * Pushes a String onto the top of enclosed list.
2458 */
2459 void push(String entry) {
2460 stack.add("\t- " + entry);
2461 }
2462
2463 /**
2464 * Returns a string representation of this object
2465 */
2466 public String toString() {
2467 StringJoiner sj = new StringJoiner("\n");
2468 for (int i = stack.size() - 1; i >= 0; i--) {
2469 sj.add(stack.get(i));
2470 }
2471 return sj.toString();
2472 }
2473 }
2474
2475 }