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