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