1 /*
2 * Copyright 1996-2006 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any 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.concurrent.ConcurrentHashMap;
36 import java.util.concurrent.ConcurrentMap;
37 import static java.io.ObjectStreamClass.processQueue;
38
39 /**
40 * An ObjectOutputStream writes primitive data types and graphs of Java objects
41 * to an OutputStream. The objects can be read (reconstituted) using an
42 * ObjectInputStream. Persistent storage of objects can be accomplished by
43 * using a file for the stream. If the stream is a network socket stream, the
44 * objects can be reconstituted on another host or in another process.
45 *
46 * <p>Only objects that support the java.io.Serializable interface can be
47 * written to streams. The class of each serializable object is encoded
48 * including the class name and signature of the class, the values of the
49 * object's fields and arrays, and the closure of any other objects referenced
50 * from the initial objects.
51 *
52 * <p>The method writeObject is used to write an object to the stream. Any
53 * object, including Strings and arrays, is written with writeObject. Multiple
54 * objects or primitives can be written to the stream. The objects must be
55 * read back from the corresponding ObjectInputstream with the same types and
56 * in the same order as they were written.
57 *
58 * <p>Primitive data types can also be written to the stream using the
59 * appropriate methods from DataOutput. Strings can also be written using the
60 * writeUTF method.
61 *
62 * <p>The default serialization mechanism for an object writes the class of the
63 * object, the class signature, and the values of all non-transient and
64 * non-static fields. References to other objects (except in transient or
65 * static fields) cause those objects to be written also. Multiple references
66 * to a single object are encoded using a reference sharing mechanism so that
67 * graphs of objects can be restored to the same shape as when the original was
68 * written.
69 *
70 * <p>For example to write an object that can be read by the example in
71 * ObjectInputStream:
72 * <br>
73 * <pre>
74 * FileOutputStream fos = new FileOutputStream("t.tmp");
75 * ObjectOutputStream oos = new ObjectOutputStream(fos);
76 *
77 * oos.writeInt(12345);
78 * oos.writeObject("Today");
79 * oos.writeObject(new Date());
80 *
81 * oos.close();
82 * </pre>
83 *
84 * <p>Classes that require special handling during the serialization and
85 * deserialization process must implement special methods with these exact
86 * signatures:
87 * <br>
88 * <pre>
89 * private void readObject(java.io.ObjectInputStream stream)
90 * throws IOException, ClassNotFoundException;
91 * private void writeObject(java.io.ObjectOutputStream stream)
92 * throws IOException
93 * private void readObjectNoData()
94 * throws ObjectStreamException;
95 * </pre>
96 *
97 * <p>The writeObject method is responsible for writing the state of the object
98 * for its particular class so that the corresponding readObject method can
99 * restore it. The method does not need to concern itself with the state
100 * belonging to the object's superclasses or subclasses. State is saved by
101 * writing the individual fields to the ObjectOutputStream using the
102 * writeObject method or by using the methods for primitive data types
103 * supported by DataOutput.
104 *
105 * <p>Serialization does not write out the fields of any object that does not
106 * implement the java.io.Serializable interface. Subclasses of Objects that
107 * are not serializable can be serializable. In this case the non-serializable
108 * class must have a no-arg constructor to allow its fields to be initialized.
109 * In this case it is the responsibility of the subclass to save and restore
110 * the state of the non-serializable class. It is frequently the case that the
111 * fields of that class are accessible (public, package, or protected) or that
112 * there are get and set methods that can be used to restore the state.
113 *
114 * <p>Serialization of an object can be prevented by implementing writeObject
115 * and readObject methods that throw the NotSerializableException. The
116 * exception will be caught by the ObjectOutputStream and abort the
117 * serialization process.
118 *
119 * <p>Implementing the Externalizable interface allows the object to assume
120 * complete control over the contents and format of the object's serialized
121 * form. The methods of the Externalizable interface, writeExternal and
122 * readExternal, are called to save and restore the objects state. When
123 * implemented by a class they can write and read their own state using all of
124 * the methods of ObjectOutput and ObjectInput. It is the responsibility of
125 * the objects to handle any versioning that occurs.
126 *
127 * <p>Enum constants are serialized differently than ordinary serializable or
128 * externalizable objects. The serialized form of an enum constant consists
129 * solely of its name; field values of the constant are not transmitted. To
130 * serialize an enum constant, ObjectOutputStream writes the string returned by
131 * the constant's name method. Like other serializable or externalizable
132 * objects, enum constants can function as the targets of back references
133 * appearing subsequently in the serialization stream. The process by which
134 * enum constants are serialized cannot be customized; any class-specific
135 * writeObject and writeReplace methods defined by enum types are ignored
136 * during serialization. Similarly, any serialPersistentFields or
137 * serialVersionUID field declarations are also ignored--all enum types have a
138 * fixed serialVersionUID of 0L.
139 *
140 * <p>Primitive data, excluding serializable fields and externalizable data, is
141 * written to the ObjectOutputStream in block-data records. A block data record
142 * is composed of a header and data. The block data header consists of a marker
143 * and the number of bytes to follow the header. Consecutive primitive data
144 * writes are merged into one block-data record. The blocking factor used for
145 * a block-data record will be 1024 bytes. Each block-data record will be
146 * filled up to 1024 bytes, or be written whenever there is a termination of
147 * block-data mode. Calls to the ObjectOutputStream methods writeObject,
148 * defaultWriteObject and writeFields initially terminate any existing
149 * block-data record.
150 *
151 * @author Mike Warres
152 * @author Roger Riggs
153 * @see java.io.DataOutput
154 * @see java.io.ObjectInputStream
155 * @see java.io.Serializable
156 * @see java.io.Externalizable
157 * @see <a href="../../../platform/serialization/spec/output.html">Object Serialization Specification, Section 2, Object Output Classes</a>
158 * @since JDK1.1
159 */
160 public class ObjectOutputStream
161 extends OutputStream implements ObjectOutput, ObjectStreamConstants
162 {
163
164 private static class Caches {
165 /** cache of subclass security audit results */
166 static final ConcurrentMap<WeakClassKey,Boolean> subclassAudits =
167 new ConcurrentHashMap<WeakClassKey,Boolean>();
168
169 /** queue for WeakReferences to audited subclasses */
170 static final ReferenceQueue<Class<?>> subclassAuditsQueue =
171 new ReferenceQueue<Class<?>>();
172 }
173
174 /** filter stream for handling block data conversion */
175 private final BlockDataOutputStream bout;
176 /** obj -> wire handle map */
177 private final HandleTable handles;
178 /** obj -> replacement obj map */
179 private final ReplaceTable subs;
180 /** stream protocol version */
181 private int protocol = PROTOCOL_VERSION_2;
182 /** recursion depth */
183 private int depth;
184
185 /** buffer for writing primitive field values */
186 private byte[] primVals;
187
188 /** if true, invoke writeObjectOverride() instead of writeObject() */
189 private final boolean enableOverride;
190 /** if true, invoke replaceObject() */
191 private boolean enableReplace;
192
193 // values below valid only during upcalls to writeObject()/writeExternal()
194 /** object currently being serialized */
195 private Object curObj;
196 /** descriptor for current class (null if in writeExternal()) */
197 private ObjectStreamClass curDesc;
198 /** current PutField object */
199 private PutFieldImpl curPut;
200
201 /** custom storage for debug trace info */
202 private final DebugTraceInfoStack debugInfoStack;
203
204 /**
205 * value of "sun.io.serialization.extendedDebugInfo" property,
206 * as true or false for extended information about exception's place
207 */
208 private static final boolean extendedDebugInfo =
209 java.security.AccessController.doPrivileged(
210 new sun.security.action.GetBooleanAction(
211 "sun.io.serialization.extendedDebugInfo")).booleanValue();
212
213 /**
214 * Creates an ObjectOutputStream that writes to the specified OutputStream.
215 * This constructor writes the serialization stream header to the
216 * underlying stream; callers may wish to flush the stream immediately to
217 * ensure that constructors for receiving ObjectInputStreams will not block
218 * when reading the header.
219 *
220 * <p>If a security manager is installed, this constructor will check for
221 * the "enableSubclassImplementation" SerializablePermission when invoked
222 * directly or indirectly by the constructor of a subclass which overrides
223 * the ObjectOutputStream.putFields or ObjectOutputStream.writeUnshared
224 * methods.
225 *
226 * @param out output stream to write to
227 * @throws IOException if an I/O error occurs while writing stream header
228 * @throws SecurityException if untrusted subclass illegally overrides
229 * security-sensitive methods
230 * @throws NullPointerException if <code>out</code> is <code>null</code>
231 * @since 1.4
232 * @see ObjectOutputStream#ObjectOutputStream()
233 * @see ObjectOutputStream#putFields()
234 * @see ObjectInputStream#ObjectInputStream(InputStream)
235 */
236 public ObjectOutputStream(OutputStream out) throws IOException {
237 verifySubclass();
238 bout = new BlockDataOutputStream(out);
239 handles = new HandleTable(10, (float) 3.00);
240 subs = new ReplaceTable(10, (float) 3.00);
241 enableOverride = false;
242 writeStreamHeader();
243 bout.setBlockDataMode(true);
244 if (extendedDebugInfo) {
245 debugInfoStack = new DebugTraceInfoStack();
246 } else {
247 debugInfoStack = null;
248 }
249 }
250
251 /**
252 * Provide a way for subclasses that are completely reimplementing
253 * ObjectOutputStream to not have to allocate private data just used by
254 * this implementation of ObjectOutputStream.
255 *
256 * <p>If there is a security manager installed, this method first calls the
257 * security manager's <code>checkPermission</code> method with a
258 * <code>SerializablePermission("enableSubclassImplementation")</code>
259 * permission to ensure it's ok to enable subclassing.
260 *
261 * @throws SecurityException if a security manager exists and its
262 * <code>checkPermission</code> method denies enabling
263 * subclassing.
264 * @see SecurityManager#checkPermission
265 * @see java.io.SerializablePermission
266 */
267 protected ObjectOutputStream() throws IOException, SecurityException {
268 SecurityManager sm = System.getSecurityManager();
269 if (sm != null) {
270 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
271 }
272 bout = null;
273 handles = null;
274 subs = null;
275 enableOverride = true;
276 debugInfoStack = null;
277 }
278
279 /**
280 * Specify stream protocol version to use when writing the stream.
281 *
282 * <p>This routine provides a hook to enable the current version of
283 * Serialization to write in a format that is backwards compatible to a
284 * previous version of the stream format.
285 *
286 * <p>Every effort will be made to avoid introducing additional
287 * backwards incompatibilities; however, sometimes there is no
288 * other alternative.
289 *
290 * @param version use ProtocolVersion from java.io.ObjectStreamConstants.
291 * @throws IllegalStateException if called after any objects
292 * have been serialized.
293 * @throws IllegalArgumentException if invalid version is passed in.
294 * @throws IOException if I/O errors occur
295 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
296 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_2
297 * @since 1.2
298 */
299 public void useProtocolVersion(int version) throws IOException {
300 if (handles.size() != 0) {
301 // REMIND: implement better check for pristine stream?
302 throw new IllegalStateException("stream non-empty");
303 }
304 switch (version) {
305 case PROTOCOL_VERSION_1:
306 case PROTOCOL_VERSION_2:
307 protocol = version;
308 break;
309
310 default:
311 throw new IllegalArgumentException(
312 "unknown version: " + version);
313 }
314 }
315
316 /**
317 * Write the specified object to the ObjectOutputStream. The class of the
318 * object, the signature of the class, and the values of the non-transient
319 * and non-static fields of the class and all of its supertypes are
320 * written. Default serialization for a class can be overridden using the
321 * writeObject and the readObject methods. Objects referenced by this
322 * object are written transitively so that a complete equivalent graph of
323 * objects can be reconstructed by an ObjectInputStream.
324 *
325 * <p>Exceptions are thrown for problems with the OutputStream and for
326 * classes that should not be serialized. All exceptions are fatal to the
327 * OutputStream, which is left in an indeterminate state, and it is up to
328 * the caller to ignore or recover the stream state.
329 *
330 * @throws InvalidClassException Something is wrong with a class used by
331 * serialization.
332 * @throws NotSerializableException Some object to be serialized does not
333 * implement the java.io.Serializable interface.
334 * @throws IOException Any exception thrown by the underlying
335 * OutputStream.
336 */
337 public final void writeObject(Object obj) throws IOException {
338 if (enableOverride) {
339 writeObjectOverride(obj);
340 return;
341 }
342 try {
343 writeObject0(obj, false);
344 } catch (IOException ex) {
345 if (depth == 0) {
346 writeFatalException(ex);
347 }
348 throw ex;
349 }
350 }
351
352 /**
353 * Method used by subclasses to override the default writeObject method.
354 * This method is called by trusted subclasses of ObjectInputStream that
355 * constructed ObjectInputStream using the protected no-arg constructor.
356 * The subclass is expected to provide an override method with the modifier
357 * "final".
358 *
359 * @param obj object to be written to the underlying stream
360 * @throws IOException if there are I/O errors while writing to the
361 * underlying stream
362 * @see #ObjectOutputStream()
363 * @see #writeObject(Object)
364 * @since 1.2
365 */
366 protected void writeObjectOverride(Object obj) throws IOException {
367 }
368
369 /**
370 * Writes an "unshared" object to the ObjectOutputStream. This method is
371 * identical to writeObject, except that it always writes the given object
372 * as a new, unique object in the stream (as opposed to a back-reference
373 * pointing to a previously serialized instance). Specifically:
374 * <ul>
375 * <li>An object written via writeUnshared is always serialized in the
376 * same manner as a newly appearing object (an object that has not
377 * been written to the stream yet), regardless of whether or not the
378 * object has been written previously.
379 *
380 * <li>If writeObject is used to write an object that has been previously
381 * written with writeUnshared, the previous writeUnshared operation
382 * is treated as if it were a write of a separate object. In other
383 * words, ObjectOutputStream will never generate back-references to
384 * object data written by calls to writeUnshared.
385 * </ul>
386 * While writing an object via writeUnshared does not in itself guarantee a
387 * unique reference to the object when it is deserialized, it allows a
388 * single object to be defined multiple times in a stream, so that multiple
389 * calls to readUnshared by the receiver will not conflict. Note that the
390 * rules described above only apply to the base-level object written with
391 * writeUnshared, and not to any transitively referenced sub-objects in the
392 * object graph to be serialized.
393 *
394 * <p>ObjectOutputStream subclasses which override this method can only be
395 * constructed in security contexts possessing the
396 * "enableSubclassImplementation" SerializablePermission; any attempt to
397 * instantiate such a subclass without this permission will cause a
398 * SecurityException to be thrown.
399 *
400 * @param obj object to write to stream
401 * @throws NotSerializableException if an object in the graph to be
402 * serialized does not implement the Serializable interface
403 * @throws InvalidClassException if a problem exists with the class of an
404 * object to be serialized
405 * @throws IOException if an I/O error occurs during serialization
406 * @since 1.4
407 */
408 public void writeUnshared(Object obj) throws IOException {
409 try {
410 writeObject0(obj, true);
411 } catch (IOException ex) {
412 if (depth == 0) {
413 writeFatalException(ex);
414 }
415 throw ex;
416 }
417 }
418
419 /**
420 * Write the non-static and non-transient fields of the current class to
421 * this stream. This may only be called from the writeObject method of the
422 * class being serialized. It will throw the NotActiveException if it is
423 * called otherwise.
424 *
425 * @throws IOException if I/O errors occur while writing to the underlying
426 * <code>OutputStream</code>
427 */
428 public void defaultWriteObject() throws IOException {
429 if (curObj == null || curDesc == null) {
430 throw new NotActiveException("not in call to writeObject");
431 }
432 bout.setBlockDataMode(false);
433 defaultWriteFields(curObj, curDesc);
434 bout.setBlockDataMode(true);
435 }
436
437 /**
438 * Retrieve the object used to buffer persistent fields to be written to
439 * the stream. The fields will be written to the stream when writeFields
440 * method is called.
441 *
442 * @return an instance of the class Putfield that holds the serializable
443 * fields
444 * @throws IOException if I/O errors occur
445 * @since 1.2
446 */
447 public ObjectOutputStream.PutField putFields() throws IOException {
448 if (curPut == null) {
449 if (curObj == null || curDesc == null) {
450 throw new NotActiveException("not in call to writeObject");
451 }
452 curPut = new PutFieldImpl(curDesc);
453 }
454 return curPut;
455 }
456
457 /**
458 * Write the buffered fields to the stream.
459 *
460 * @throws IOException if I/O errors occur while writing to the underlying
461 * stream
462 * @throws NotActiveException Called when a classes writeObject method was
463 * not called to write the state of the object.
464 * @since 1.2
465 */
466 public void writeFields() throws IOException {
467 if (curPut == null) {
468 throw new NotActiveException("no current PutField object");
469 }
470 bout.setBlockDataMode(false);
471 curPut.writeFields();
472 bout.setBlockDataMode(true);
473 }
474
475 /**
476 * Reset will disregard the state of any objects already written to the
477 * stream. The state is reset to be the same as a new ObjectOutputStream.
478 * The current point in the stream is marked as reset so the corresponding
479 * ObjectInputStream will be reset at the same point. Objects previously
480 * written to the stream will not be refered to as already being in the
481 * stream. They will be written to the stream again.
482 *
483 * @throws IOException if reset() is invoked while serializing an object.
484 */
485 public void reset() throws IOException {
486 if (depth != 0) {
487 throw new IOException("stream active");
488 }
489 bout.setBlockDataMode(false);
490 bout.writeByte(TC_RESET);
491 clear();
492 bout.setBlockDataMode(true);
493 }
494
495 /**
496 * Subclasses may implement this method to allow class data to be stored in
497 * the stream. By default this method does nothing. The corresponding
498 * method in ObjectInputStream is resolveClass. This method is called
499 * exactly once for each unique class in the stream. The class name and
500 * signature will have already been written to the stream. This method may
501 * make free use of the ObjectOutputStream to save any representation of
502 * the class it deems suitable (for example, the bytes of the class file).
503 * The resolveClass method in the corresponding subclass of
504 * ObjectInputStream must read and use any data or objects written by
505 * annotateClass.
506 *
507 * @param cl the class to annotate custom data for
508 * @throws IOException Any exception thrown by the underlying
509 * OutputStream.
510 */
511 protected void annotateClass(Class<?> cl) throws IOException {
512 }
513
514 /**
515 * Subclasses may implement this method to store custom data in the stream
516 * along with descriptors for dynamic proxy classes.
517 *
518 * <p>This method is called exactly once for each unique proxy class
519 * descriptor in the stream. The default implementation of this method in
520 * <code>ObjectOutputStream</code> does nothing.
521 *
522 * <p>The corresponding method in <code>ObjectInputStream</code> is
523 * <code>resolveProxyClass</code>. For a given subclass of
524 * <code>ObjectOutputStream</code> that overrides this method, the
525 * <code>resolveProxyClass</code> method in the corresponding subclass of
526 * <code>ObjectInputStream</code> must read any data or objects written by
527 * <code>annotateProxyClass</code>.
528 *
529 * @param cl the proxy class to annotate custom data for
530 * @throws IOException any exception thrown by the underlying
531 * <code>OutputStream</code>
532 * @see ObjectInputStream#resolveProxyClass(String[])
533 * @since 1.3
534 */
535 protected void annotateProxyClass(Class<?> cl) throws IOException {
536 }
537
538 /**
539 * This method will allow trusted subclasses of ObjectOutputStream to
540 * substitute one object for another during serialization. Replacing
541 * objects is disabled until enableReplaceObject is called. The
542 * enableReplaceObject method checks that the stream requesting to do
543 * replacement can be trusted. The first occurrence of each object written
544 * into the serialization stream is passed to replaceObject. Subsequent
545 * references to the object are replaced by the object returned by the
546 * original call to replaceObject. To ensure that the private state of
547 * objects is not unintentionally exposed, only trusted streams may use
548 * replaceObject.
549 *
550 * <p>The ObjectOutputStream.writeObject method takes a parameter of type
551 * Object (as opposed to type Serializable) to allow for cases where
552 * non-serializable objects are replaced by serializable ones.
553 *
554 * <p>When a subclass is replacing objects it must insure that either a
555 * complementary substitution must be made during deserialization or that
556 * the substituted object is compatible with every field where the
557 * reference will be stored. Objects whose type is not a subclass of the
558 * type of the field or array element abort the serialization by raising an
559 * exception and the object is not be stored.
560 *
561 * <p>This method is called only once when each object is first
562 * encountered. All subsequent references to the object will be redirected
563 * to the new object. This method should return the object to be
564 * substituted or the original object.
565 *
566 * <p>Null can be returned as the object to be substituted, but may cause
567 * NullReferenceException in classes that contain references to the
568 * original object since they may be expecting an object instead of
569 * null.
570 *
571 * @param obj the object to be replaced
572 * @return the alternate object that replaced the specified one
573 * @throws IOException Any exception thrown by the underlying
574 * OutputStream.
575 */
576 protected Object replaceObject(Object obj) throws IOException {
577 return obj;
578 }
579
580 /**
581 * Enable the stream to do replacement of objects in the stream. When
582 * enabled, the replaceObject method is called for every object being
583 * serialized.
584 *
585 * <p>If <code>enable</code> is true, and there is a security manager
586 * installed, this method first calls the security manager's
587 * <code>checkPermission</code> method with a
588 * <code>SerializablePermission("enableSubstitution")</code> permission to
589 * ensure it's ok to enable the stream to do replacement of objects in the
590 * stream.
591 *
592 * @param enable boolean parameter to enable replacement of objects
593 * @return the previous setting before this method was invoked
594 * @throws SecurityException if a security manager exists and its
595 * <code>checkPermission</code> method denies enabling the stream
596 * to do replacement of objects in the stream.
597 * @see SecurityManager#checkPermission
598 * @see java.io.SerializablePermission
599 */
600 protected boolean enableReplaceObject(boolean enable)
601 throws SecurityException
602 {
603 if (enable == enableReplace) {
604 return enable;
605 }
606 if (enable) {
607 SecurityManager sm = System.getSecurityManager();
608 if (sm != null) {
609 sm.checkPermission(SUBSTITUTION_PERMISSION);
610 }
611 }
612 enableReplace = enable;
613 return !enableReplace;
614 }
615
616 /**
617 * The writeStreamHeader method is provided so subclasses can append or
618 * prepend their own header to the stream. It writes the magic number and
619 * version to the stream.
620 *
621 * @throws IOException if I/O errors occur while writing to the underlying
622 * stream
623 */
624 protected void writeStreamHeader() throws IOException {
625 bout.writeShort(STREAM_MAGIC);
626 bout.writeShort(STREAM_VERSION);
627 }
628
629 /**
630 * Write the specified class descriptor to the ObjectOutputStream. Class
631 * descriptors are used to identify the classes of objects written to the
632 * stream. Subclasses of ObjectOutputStream may override this method to
633 * customize the way in which class descriptors are written to the
634 * serialization stream. The corresponding method in ObjectInputStream,
635 * <code>readClassDescriptor</code>, should then be overridden to
636 * reconstitute the class descriptor from its custom stream representation.
637 * By default, this method writes class descriptors according to the format
638 * defined in the Object Serialization specification.
639 *
640 * <p>Note that this method will only be called if the ObjectOutputStream
641 * is not using the old serialization stream format (set by calling
642 * ObjectOutputStream's <code>useProtocolVersion</code> method). If this
643 * serialization stream is using the old format
644 * (<code>PROTOCOL_VERSION_1</code>), the class descriptor will be written
645 * internally in a manner that cannot be overridden or customized.
646 *
647 * @param desc class descriptor to write to the stream
648 * @throws IOException If an I/O error has occurred.
649 * @see java.io.ObjectInputStream#readClassDescriptor()
650 * @see #useProtocolVersion(int)
651 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1
652 * @since 1.3
653 */
654 protected void writeClassDescriptor(ObjectStreamClass desc)
655 throws IOException
656 {
657 desc.writeNonProxy(this);
658 }
659
660 /**
661 * Writes a byte. This method will block until the byte is actually
662 * written.
663 *
664 * @param val the byte to be written to the stream
665 * @throws IOException If an I/O error has occurred.
666 */
667 public void write(int val) throws IOException {
668 bout.write(val);
669 }
670
671 /**
672 * Writes an array of bytes. This method will block until the bytes are
673 * actually written.
674 *
675 * @param buf the data to be written
676 * @throws IOException If an I/O error has occurred.
677 */
678 public void write(byte[] buf) throws IOException {
679 bout.write(buf, 0, buf.length, false);
680 }
681
682 /**
683 * Writes a sub array of bytes.
684 *
685 * @param buf the data to be written
686 * @param off the start offset in the data
687 * @param len the number of bytes that are written
688 * @throws IOException If an I/O error has occurred.
689 */
690 public void write(byte[] buf, int off, int len) throws IOException {
691 if (buf == null) {
692 throw new NullPointerException();
693 }
694 int endoff = off + len;
695 if (off < 0 || len < 0 || endoff > buf.length || endoff < 0) {
696 throw new IndexOutOfBoundsException();
697 }
698 bout.write(buf, off, len, false);
699 }
700
701 /**
702 * Flushes the stream. This will write any buffered output bytes and flush
703 * through to the underlying stream.
704 *
705 * @throws IOException If an I/O error has occurred.
706 */
707 public void flush() throws IOException {
708 bout.flush();
709 }
710
711 /**
712 * Drain any buffered data in ObjectOutputStream. Similar to flush but
713 * does not propagate the flush to the underlying stream.
714 *
715 * @throws IOException if I/O errors occur while writing to the underlying
716 * stream
717 */
718 protected void drain() throws IOException {
719 bout.drain();
720 }
721
722 /**
723 * Closes the stream. This method must be called to release any resources
724 * associated with the stream.
725 *
726 * @throws IOException If an I/O error has occurred.
727 */
728 public void close() throws IOException {
729 flush();
730 clear();
731 bout.close();
732 }
733
734 /**
735 * Writes a boolean.
736 *
737 * @param val the boolean to be written
738 * @throws IOException if I/O errors occur while writing to the underlying
739 * stream
740 */
741 public void writeBoolean(boolean val) throws IOException {
742 bout.writeBoolean(val);
743 }
744
745 /**
746 * Writes an 8 bit byte.
747 *
748 * @param val the byte value to be written
749 * @throws IOException if I/O errors occur while writing to the underlying
750 * stream
751 */
752 public void writeByte(int val) throws IOException {
753 bout.writeByte(val);
754 }
755
756 /**
757 * Writes a 16 bit short.
758 *
759 * @param val the short value to be written
760 * @throws IOException if I/O errors occur while writing to the underlying
761 * stream
762 */
763 public void writeShort(int val) throws IOException {
764 bout.writeShort(val);
765 }
766
767 /**
768 * Writes a 16 bit char.
769 *
770 * @param val the char value to be written
771 * @throws IOException if I/O errors occur while writing to the underlying
772 * stream
773 */
774 public void writeChar(int val) throws IOException {
775 bout.writeChar(val);
776 }
777
778 /**
779 * Writes a 32 bit int.
780 *
781 * @param val the integer value to be written
782 * @throws IOException if I/O errors occur while writing to the underlying
783 * stream
784 */
785 public void writeInt(int val) throws IOException {
786 bout.writeInt(val);
787 }
788
789 /**
790 * Writes a 64 bit long.
791 *
792 * @param val the long value to be written
793 * @throws IOException if I/O errors occur while writing to the underlying
794 * stream
795 */
796 public void writeLong(long val) throws IOException {
797 bout.writeLong(val);
798 }
799
800 /**
801 * Writes a 32 bit float.
802 *
803 * @param val the float value to be written
804 * @throws IOException if I/O errors occur while writing to the underlying
805 * stream
806 */
807 public void writeFloat(float val) throws IOException {
808 bout.writeFloat(val);
809 }
810
811 /**
812 * Writes a 64 bit double.
813 *
814 * @param val the double value to be written
815 * @throws IOException if I/O errors occur while writing to the underlying
816 * stream
817 */
818 public void writeDouble(double val) throws IOException {
819 bout.writeDouble(val);
820 }
821
822 /**
823 * Writes a String as a sequence of bytes.
824 *
825 * @param str the String of bytes to be written
826 * @throws IOException if I/O errors occur while writing to the underlying
827 * stream
828 */
829 public void writeBytes(String str) throws IOException {
830 bout.writeBytes(str);
831 }
832
833 /**
834 * Writes a String as a sequence of chars.
835 *
836 * @param str the String of chars to be written
837 * @throws IOException if I/O errors occur while writing to the underlying
838 * stream
839 */
840 public void writeChars(String str) throws IOException {
841 bout.writeChars(str);
842 }
843
844 /**
845 * Primitive data write of this String in
846 * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
847 * format. Note that there is a
848 * significant difference between writing a String into the stream as
849 * primitive data or as an Object. A String instance written by writeObject
850 * is written into the stream as a String initially. Future writeObject()
851 * calls write references to the string into the stream.
852 *
853 * @param str the String to be written
854 * @throws IOException if I/O errors occur while writing to the underlying
855 * stream
856 */
857 public void writeUTF(String str) throws IOException {
858 bout.writeUTF(str);
859 }
860
861 /**
862 * Provide programmatic access to the persistent fields to be written
863 * to ObjectOutput.
864 *
865 * @since 1.2
866 */
867 public static abstract class PutField {
868
869 /**
870 * Put the value of the named boolean field into the persistent field.
871 *
872 * @param name the name of the serializable field
873 * @param val the value to assign to the field
874 * @throws IllegalArgumentException if <code>name</code> does not
875 * match the name of a serializable field for the class whose fields
876 * are being written, or if the type of the named field is not
877 * <code>boolean</code>
878 */
879 public abstract void put(String name, boolean val);
880
881 /**
882 * Put the value of the named byte field into the persistent field.
883 *
884 * @param name the name of the serializable field
885 * @param val the value to assign to the field
886 * @throws IllegalArgumentException if <code>name</code> does not
887 * match the name of a serializable field for the class whose fields
888 * are being written, or if the type of the named field is not
889 * <code>byte</code>
890 */
891 public abstract void put(String name, byte val);
892
893 /**
894 * Put the value of the named char field into the persistent field.
895 *
896 * @param name the name of the serializable field
897 * @param val the value to assign to the field
898 * @throws IllegalArgumentException if <code>name</code> does not
899 * match the name of a serializable field for the class whose fields
900 * are being written, or if the type of the named field is not
901 * <code>char</code>
902 */
903 public abstract void put(String name, char val);
904
905 /**
906 * Put the value of the named short field into the persistent field.
907 *
908 * @param name the name of the serializable field
909 * @param val the value to assign to the field
910 * @throws IllegalArgumentException if <code>name</code> does not
911 * match the name of a serializable field for the class whose fields
912 * are being written, or if the type of the named field is not
913 * <code>short</code>
914 */
915 public abstract void put(String name, short val);
916
917 /**
918 * Put the value of the named int field into the persistent field.
919 *
920 * @param name the name of the serializable field
921 * @param val the value to assign to the field
922 * @throws IllegalArgumentException if <code>name</code> does not
923 * match the name of a serializable field for the class whose fields
924 * are being written, or if the type of the named field is not
925 * <code>int</code>
926 */
927 public abstract void put(String name, int val);
928
929 /**
930 * Put the value of the named long field into the persistent field.
931 *
932 * @param name the name of the serializable field
933 * @param val the value to assign to the field
934 * @throws IllegalArgumentException if <code>name</code> does not
935 * match the name of a serializable field for the class whose fields
936 * are being written, or if the type of the named field is not
937 * <code>long</code>
938 */
939 public abstract void put(String name, long val);
940
941 /**
942 * Put the value of the named float field into the persistent field.
943 *
944 * @param name the name of the serializable field
945 * @param val the value to assign to the field
946 * @throws IllegalArgumentException if <code>name</code> does not
947 * match the name of a serializable field for the class whose fields
948 * are being written, or if the type of the named field is not
949 * <code>float</code>
950 */
951 public abstract void put(String name, float val);
952
953 /**
954 * Put the value of the named double field into the persistent field.
955 *
956 * @param name the name of the serializable field
957 * @param val the value to assign to the field
958 * @throws IllegalArgumentException if <code>name</code> does not
959 * match the name of a serializable field for the class whose fields
960 * are being written, or if the type of the named field is not
961 * <code>double</code>
962 */
963 public abstract void put(String name, double val);
964
965 /**
966 * Put the value of the named Object field into the persistent field.
967 *
968 * @param name the name of the serializable field
969 * @param val the value to assign to the field
970 * (which may be <code>null</code>)
971 * @throws IllegalArgumentException if <code>name</code> does not
972 * match the name of a serializable field for the class whose fields
973 * are being written, or if the type of the named field is not a
974 * reference type
975 */
976 public abstract void put(String name, Object val);
977
978 /**
979 * Write the data and fields to the specified ObjectOutput stream,
980 * which must be the same stream that produced this
981 * <code>PutField</code> object.
982 *
983 * @param out the stream to write the data and fields to
984 * @throws IOException if I/O errors occur while writing to the
985 * underlying stream
986 * @throws IllegalArgumentException if the specified stream is not
987 * the same stream that produced this <code>PutField</code>
988 * object
989 * @deprecated This method does not write the values contained by this
990 * <code>PutField</code> object in a proper format, and may
991 * result in corruption of the serialization stream. The
992 * correct way to write <code>PutField</code> data is by
993 * calling the {@link java.io.ObjectOutputStream#writeFields()}
994 * method.
995 */
996 @Deprecated
997 public abstract void write(ObjectOutput out) throws IOException;
998 }
999
1000
1001 /**
1002 * Returns protocol version in use.
1003 */
1004 int getProtocolVersion() {
1005 return protocol;
1006 }
1007
1008 /**
1009 * Writes string without allowing it to be replaced in stream. Used by
1010 * ObjectStreamClass to write class descriptor type strings.
1011 */
1012 void writeTypeString(String str) throws IOException {
1013 int handle;
1014 if (str == null) {
1015 writeNull();
1016 } else if ((handle = handles.lookup(str)) != -1) {
1017 writeHandle(handle);
1018 } else {
1019 writeString(str, false);
1020 }
1021 }
1022
1023 /**
1024 * Verifies that this (possibly subclass) instance can be constructed
1025 * without violating security constraints: the subclass must not override
1026 * security-sensitive non-final methods, or else the
1027 * "enableSubclassImplementation" SerializablePermission is checked.
1028 */
1029 private void verifySubclass() {
1030 Class cl = getClass();
1031 if (cl == ObjectOutputStream.class) {
1032 return;
1033 }
1034 SecurityManager sm = System.getSecurityManager();
1035 if (sm == null) {
1036 return;
1037 }
1038 processQueue(Caches.subclassAuditsQueue, Caches.subclassAudits);
1039 WeakClassKey key = new WeakClassKey(cl, Caches.subclassAuditsQueue);
1040 Boolean result = Caches.subclassAudits.get(key);
1041 if (result == null) {
1042 result = Boolean.valueOf(auditSubclass(cl));
1043 Caches.subclassAudits.putIfAbsent(key, result);
1044 }
1045 if (result.booleanValue()) {
1046 return;
1047 }
1048 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
1049 }
1050
1051 /**
1052 * Performs reflective checks on given subclass to verify that it doesn't
1053 * override security-sensitive non-final methods. Returns true if subclass
1054 * is "safe", false otherwise.
1055 */
1056 private static boolean auditSubclass(final Class subcl) {
1057 Boolean result = AccessController.doPrivileged(
1058 new PrivilegedAction<Boolean>() {
1059 public Boolean run() {
1060 for (Class cl = subcl;
1061 cl != ObjectOutputStream.class;
1062 cl = cl.getSuperclass())
1063 {
1064 try {
1065 cl.getDeclaredMethod(
1066 "writeUnshared", new Class[] { Object.class });
1067 return Boolean.FALSE;
1068 } catch (NoSuchMethodException ex) {
1069 }
1070 try {
1071 cl.getDeclaredMethod("putFields", (Class[]) null);
1072 return Boolean.FALSE;
1073 } catch (NoSuchMethodException ex) {
1074 }
1075 }
1076 return Boolean.TRUE;
1077 }
1078 }
1079 );
1080 return result.booleanValue();
1081 }
1082
1083 /**
1084 * Clears internal data structures.
1085 */
1086 private void clear() {
1087 subs.clear();
1088 handles.clear();
1089 }
1090
1091 /**
1092 * Underlying writeObject/writeUnshared implementation.
1093 */
1094 private void writeObject0(Object obj, boolean unshared)
1095 throws IOException
1096 {
1097 boolean oldMode = bout.setBlockDataMode(false);
1098 depth++;
1099 try {
1100 // handle previously written and non-replaceable objects
1101 int h;
1102 if ((obj = subs.lookup(obj)) == null) {
1103 writeNull();
1104 return;
1105 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1106 writeHandle(h);
1107 return;
1108 } else if (obj instanceof Class) {
1109 writeClass((Class) obj, unshared);
1110 return;
1111 } else if (obj instanceof ObjectStreamClass) {
1112 writeClassDesc((ObjectStreamClass) obj, unshared);
1113 return;
1114 }
1115
1116 // check for replacement object
1117 Object orig = obj;
1118 Class cl = obj.getClass();
1119 ObjectStreamClass desc;
1120 for (;;) {
1121 // REMIND: skip this check for strings/arrays?
1122 Class repCl;
1123 desc = ObjectStreamClass.lookup(cl, true);
1124 if (!desc.hasWriteReplaceMethod() ||
1125 (obj = desc.invokeWriteReplace(obj)) == null ||
1126 (repCl = obj.getClass()) == cl)
1127 {
1128 break;
1129 }
1130 cl = repCl;
1131 }
1132 if (enableReplace) {
1133 Object rep = replaceObject(obj);
1134 if (rep != obj && rep != null) {
1135 cl = rep.getClass();
1136 desc = ObjectStreamClass.lookup(cl, true);
1137 }
1138 obj = rep;
1139 }
1140
1141 // if object replaced, run through original checks a second time
1142 if (obj != orig) {
1143 subs.assign(orig, obj);
1144 if (obj == null) {
1145 writeNull();
1146 return;
1147 } else if (!unshared && (h = handles.lookup(obj)) != -1) {
1148 writeHandle(h);
1149 return;
1150 } else if (obj instanceof Class) {
1151 writeClass((Class) obj, unshared);
1152 return;
1153 } else if (obj instanceof ObjectStreamClass) {
1154 writeClassDesc((ObjectStreamClass) obj, unshared);
1155 return;
1156 }
1157 }
1158
1159 // remaining cases
1160 if (obj instanceof String) {
1161 writeString((String) obj, unshared);
1162 } else if (cl.isArray()) {
1163 writeArray(obj, desc, unshared);
1164 } else if (obj instanceof Enum) {
1165 writeEnum((Enum) obj, desc, unshared);
1166 } else if (obj instanceof Serializable) {
1167 writeOrdinaryObject(obj, desc, unshared);
1168 } else {
1169 if (extendedDebugInfo) {
1170 throw new NotSerializableException(
1171 cl.getName() + "\n" + debugInfoStack.toString());
1172 } else {
1173 throw new NotSerializableException(cl.getName());
1174 }
1175 }
1176 } finally {
1177 depth--;
1178 bout.setBlockDataMode(oldMode);
1179 }
1180 }
1181
1182 /**
1183 * Writes null code to stream.
1184 */
1185 private void writeNull() throws IOException {
1186 bout.writeByte(TC_NULL);
1187 }
1188
1189 /**
1190 * Writes given object handle to stream.
1191 */
1192 private void writeHandle(int handle) throws IOException {
1193 bout.writeByte(TC_REFERENCE);
1194 bout.writeInt(baseWireHandle + handle);
1195 }
1196
1197 /**
1198 * Writes representation of given class to stream.
1199 */
1200 private void writeClass(Class cl, boolean unshared) throws IOException {
1201 bout.writeByte(TC_CLASS);
1202 writeClassDesc(ObjectStreamClass.lookup(cl, true), false);
1203 handles.assign(unshared ? null : cl);
1204 }
1205
1206 /**
1207 * Writes representation of given class descriptor to stream.
1208 */
1209 private void writeClassDesc(ObjectStreamClass desc, boolean unshared)
1210 throws IOException
1211 {
1212 int handle;
1213 if (desc == null) {
1214 writeNull();
1215 } else if (!unshared && (handle = handles.lookup(desc)) != -1) {
1216 writeHandle(handle);
1217 } else if (desc.isProxy()) {
1218 writeProxyDesc(desc, unshared);
1219 } else {
1220 writeNonProxyDesc(desc, unshared);
1221 }
1222 }
1223
1224 /**
1225 * Writes class descriptor representing a dynamic proxy class to stream.
1226 */
1227 private void writeProxyDesc(ObjectStreamClass desc, boolean unshared)
1228 throws IOException
1229 {
1230 bout.writeByte(TC_PROXYCLASSDESC);
1231 handles.assign(unshared ? null : desc);
1232
1233 Class cl = desc.forClass();
1234 Class[] ifaces = cl.getInterfaces();
1235 bout.writeInt(ifaces.length);
1236 for (int i = 0; i < ifaces.length; i++) {
1237 bout.writeUTF(ifaces[i].getName());
1238 }
1239
1240 bout.setBlockDataMode(true);
1241 annotateProxyClass(cl);
1242 bout.setBlockDataMode(false);
1243 bout.writeByte(TC_ENDBLOCKDATA);
1244
1245 writeClassDesc(desc.getSuperDesc(), false);
1246 }
1247
1248 /**
1249 * Writes class descriptor representing a standard (i.e., not a dynamic
1250 * proxy) class to stream.
1251 */
1252 private void writeNonProxyDesc(ObjectStreamClass desc, boolean unshared)
1253 throws IOException
1254 {
1255 bout.writeByte(TC_CLASSDESC);
1256 handles.assign(unshared ? null : desc);
1257
1258 if (protocol == PROTOCOL_VERSION_1) {
1259 // do not invoke class descriptor write hook with old protocol
1260 desc.writeNonProxy(this);
1261 } else {
1262 writeClassDescriptor(desc);
1263 }
1264
1265 Class cl = desc.forClass();
1266 bout.setBlockDataMode(true);
1267 annotateClass(cl);
1268 bout.setBlockDataMode(false);
1269 bout.writeByte(TC_ENDBLOCKDATA);
1270
1271 writeClassDesc(desc.getSuperDesc(), false);
1272 }
1273
1274 /**
1275 * Writes given string to stream, using standard or long UTF format
1276 * depending on string length.
1277 */
1278 private void writeString(String str, boolean unshared) throws IOException {
1279 handles.assign(unshared ? null : str);
1280 long utflen = bout.getUTFLength(str);
1281 if (utflen <= 0xFFFF) {
1282 bout.writeByte(TC_STRING);
1283 bout.writeUTF(str, utflen);
1284 } else {
1285 bout.writeByte(TC_LONGSTRING);
1286 bout.writeLongUTF(str, utflen);
1287 }
1288 }
1289
1290 /**
1291 * Writes given array object to stream.
1292 */
1293 private void writeArray(Object array,
1294 ObjectStreamClass desc,
1295 boolean unshared)
1296 throws IOException
1297 {
1298 bout.writeByte(TC_ARRAY);
1299 writeClassDesc(desc, false);
1300 handles.assign(unshared ? null : array);
1301
1302 Class ccl = desc.forClass().getComponentType();
1303 if (ccl.isPrimitive()) {
1304 if (ccl == Integer.TYPE) {
1305 int[] ia = (int[]) array;
1306 bout.writeInt(ia.length);
1307 bout.writeInts(ia, 0, ia.length);
1308 } else if (ccl == Byte.TYPE) {
1309 byte[] ba = (byte[]) array;
1310 bout.writeInt(ba.length);
1311 bout.write(ba, 0, ba.length, true);
1312 } else if (ccl == Long.TYPE) {
1313 long[] ja = (long[]) array;
1314 bout.writeInt(ja.length);
1315 bout.writeLongs(ja, 0, ja.length);
1316 } else if (ccl == Float.TYPE) {
1317 float[] fa = (float[]) array;
1318 bout.writeInt(fa.length);
1319 bout.writeFloats(fa, 0, fa.length);
1320 } else if (ccl == Double.TYPE) {
1321 double[] da = (double[]) array;
1322 bout.writeInt(da.length);
1323 bout.writeDoubles(da, 0, da.length);
1324 } else if (ccl == Short.TYPE) {
1325 short[] sa = (short[]) array;
1326 bout.writeInt(sa.length);
1327 bout.writeShorts(sa, 0, sa.length);
1328 } else if (ccl == Character.TYPE) {
1329 char[] ca = (char[]) array;
1330 bout.writeInt(ca.length);
1331 bout.writeChars(ca, 0, ca.length);
1332 } else if (ccl == Boolean.TYPE) {
1333 boolean[] za = (boolean[]) array;
1334 bout.writeInt(za.length);
1335 bout.writeBooleans(za, 0, za.length);
1336 } else {
1337 throw new InternalError();
1338 }
1339 } else {
1340 Object[] objs = (Object[]) array;
1341 int len = objs.length;
1342 bout.writeInt(len);
1343 if (extendedDebugInfo) {
1344 debugInfoStack.push(
1345 "array (class \"" + array.getClass().getName() +
1346 "\", size: " + len + ")");
1347 }
1348 try {
1349 for (int i = 0; i < len; i++) {
1350 if (extendedDebugInfo) {
1351 debugInfoStack.push(
1352 "element of array (index: " + i + ")");
1353 }
1354 try {
1355 writeObject0(objs[i], false);
1356 } finally {
1357 if (extendedDebugInfo) {
1358 debugInfoStack.pop();
1359 }
1360 }
1361 }
1362 } finally {
1363 if (extendedDebugInfo) {
1364 debugInfoStack.pop();
1365 }
1366 }
1367 }
1368 }
1369
1370 /**
1371 * Writes given enum constant to stream.
1372 */
1373 private void writeEnum(Enum en,
1374 ObjectStreamClass desc,
1375 boolean unshared)
1376 throws IOException
1377 {
1378 bout.writeByte(TC_ENUM);
1379 ObjectStreamClass sdesc = desc.getSuperDesc();
1380 writeClassDesc((sdesc.forClass() == Enum.class) ? desc : sdesc, false);
1381 handles.assign(unshared ? null : en);
1382 writeString(en.name(), false);
1383 }
1384
1385 /**
1386 * Writes representation of a "ordinary" (i.e., not a String, Class,
1387 * ObjectStreamClass, array, or enum constant) serializable object to the
1388 * stream.
1389 */
1390 private void writeOrdinaryObject(Object obj,
1391 ObjectStreamClass desc,
1392 boolean unshared)
1393 throws IOException
1394 {
1395 if (extendedDebugInfo) {
1396 debugInfoStack.push(
1397 (depth == 1 ? "root " : "") + "object (class \"" +
1398 obj.getClass().getName() + "\", " + obj.toString() + ")");
1399 }
1400 try {
1401 desc.checkSerialize();
1402
1403 bout.writeByte(TC_OBJECT);
1404 writeClassDesc(desc, false);
1405 handles.assign(unshared ? null : obj);
1406 if (desc.isExternalizable() && !desc.isProxy()) {
1407 writeExternalData((Externalizable) obj);
1408 } else {
1409 writeSerialData(obj, desc);
1410 }
1411 } finally {
1412 if (extendedDebugInfo) {
1413 debugInfoStack.pop();
1414 }
1415 }
1416 }
1417
1418 /**
1419 * Writes externalizable data of given object by invoking its
1420 * writeExternal() method.
1421 */
1422 private void writeExternalData(Externalizable obj) throws IOException {
1423 Object oldObj = curObj;
1424 ObjectStreamClass oldDesc = curDesc;
1425 PutFieldImpl oldPut = curPut;
1426 curObj = obj;
1427 curDesc = null;
1428 curPut = null;
1429
1430 if (extendedDebugInfo) {
1431 debugInfoStack.push("writeExternal data");
1432 }
1433 try {
1434 if (protocol == PROTOCOL_VERSION_1) {
1435 obj.writeExternal(this);
1436 } else {
1437 bout.setBlockDataMode(true);
1438 obj.writeExternal(this);
1439 bout.setBlockDataMode(false);
1440 bout.writeByte(TC_ENDBLOCKDATA);
1441 }
1442 } finally {
1443 if (extendedDebugInfo) {
1444 debugInfoStack.pop();
1445 }
1446 }
1447
1448 curObj = oldObj;
1449 curDesc = oldDesc;
1450 curPut = oldPut;
1451 }
1452
1453 /**
1454 * Writes instance data for each serializable class of given object, from
1455 * superclass to subclass.
1456 */
1457 private void writeSerialData(Object obj, ObjectStreamClass desc)
1458 throws IOException
1459 {
1460 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout();
1461 for (int i = 0; i < slots.length; i++) {
1462 ObjectStreamClass slotDesc = slots[i].desc;
1463 if (slotDesc.hasWriteObjectMethod()) {
1464 Object oldObj = curObj;
1465 ObjectStreamClass oldDesc = curDesc;
1466 PutFieldImpl oldPut = curPut;
1467 curObj = obj;
1468 curDesc = slotDesc;
1469 curPut = null;
1470
1471 if (extendedDebugInfo) {
1472 debugInfoStack.push(
1473 "custom writeObject data (class \"" +
1474 slotDesc.getName() + "\")");
1475 }
1476 try {
1477 bout.setBlockDataMode(true);
1478 slotDesc.invokeWriteObject(obj, this);
1479 bout.setBlockDataMode(false);
1480 bout.writeByte(TC_ENDBLOCKDATA);
1481 } finally {
1482 if (extendedDebugInfo) {
1483 debugInfoStack.pop();
1484 }
1485 }
1486
1487 curObj = oldObj;
1488 curDesc = oldDesc;
1489 curPut = oldPut;
1490 } else {
1491 defaultWriteFields(obj, slotDesc);
1492 }
1493 }
1494 }
1495
1496 /**
1497 * Fetches and writes values of serializable fields of given object to
1498 * stream. The given class descriptor specifies which field values to
1499 * write, and in which order they should be written.
1500 */
1501 private void defaultWriteFields(Object obj, ObjectStreamClass desc)
1502 throws IOException
1503 {
1504 // REMIND: perform conservative isInstance check here?
1505 desc.checkDefaultSerialize();
1506
1507 int primDataSize = desc.getPrimDataSize();
1508 if (primVals == null || primVals.length < primDataSize) {
1509 primVals = new byte[primDataSize];
1510 }
1511 desc.getPrimFieldValues(obj, primVals);
1512 bout.write(primVals, 0, primDataSize, false);
1513
1514 ObjectStreamField[] fields = desc.getFields(false);
1515 Object[] objVals = new Object[desc.getNumObjFields()];
1516 int numPrimFields = fields.length - objVals.length;
1517 desc.getObjFieldValues(obj, objVals);
1518 for (int i = 0; i < objVals.length; i++) {
1519 if (extendedDebugInfo) {
1520 debugInfoStack.push(
1521 "field (class \"" + desc.getName() + "\", name: \"" +
1522 fields[numPrimFields + i].getName() + "\", type: \"" +
1523 fields[numPrimFields + i].getType() + "\")");
1524 }
1525 try {
1526 writeObject0(objVals[i],
1527 fields[numPrimFields + i].isUnshared());
1528 } finally {
1529 if (extendedDebugInfo) {
1530 debugInfoStack.pop();
1531 }
1532 }
1533 }
1534 }
1535
1536 /**
1537 * Attempts to write to stream fatal IOException that has caused
1538 * serialization to abort.
1539 */
1540 private void writeFatalException(IOException ex) throws IOException {
1541 /*
1542 * Note: the serialization specification states that if a second
1543 * IOException occurs while attempting to serialize the original fatal
1544 * exception to the stream, then a StreamCorruptedException should be
1545 * thrown (section 2.1). However, due to a bug in previous
1546 * implementations of serialization, StreamCorruptedExceptions were
1547 * rarely (if ever) actually thrown--the "root" exceptions from
1548 * underlying streams were thrown instead. This historical behavior is
1549 * followed here for consistency.
1550 */
1551 clear();
1552 boolean oldMode = bout.setBlockDataMode(false);
1553 try {
1554 bout.writeByte(TC_EXCEPTION);
1555 writeObject0(ex, false);
1556 clear();
1557 } finally {
1558 bout.setBlockDataMode(oldMode);
1559 }
1560 }
1561
1562 /**
1563 * Converts specified span of float values into byte values.
1564 */
1565 // REMIND: remove once hotspot inlines Float.floatToIntBits
1566 private static native void floatsToBytes(float[] src, int srcpos,
1567 byte[] dst, int dstpos,
1568 int nfloats);
1569
1570 /**
1571 * Converts specified span of double values into byte values.
1572 */
1573 // REMIND: remove once hotspot inlines Double.doubleToLongBits
1574 private static native void doublesToBytes(double[] src, int srcpos,
1575 byte[] dst, int dstpos,
1576 int ndoubles);
1577
1578 /**
1579 * Default PutField implementation.
1580 */
1581 private class PutFieldImpl extends PutField {
1582
1583 /** class descriptor describing serializable fields */
1584 private final ObjectStreamClass desc;
1585 /** primitive field values */
1586 private final byte[] primVals;
1587 /** object field values */
1588 private final Object[] objVals;
1589
1590 /**
1591 * Creates PutFieldImpl object for writing fields defined in given
1592 * class descriptor.
1593 */
1594 PutFieldImpl(ObjectStreamClass desc) {
1595 this.desc = desc;
1596 primVals = new byte[desc.getPrimDataSize()];
1597 objVals = new Object[desc.getNumObjFields()];
1598 }
1599
1600 public void put(String name, boolean val) {
1601 Bits.putBoolean(primVals, getFieldOffset(name, Boolean.TYPE), val);
1602 }
1603
1604 public void put(String name, byte val) {
1605 primVals[getFieldOffset(name, Byte.TYPE)] = val;
1606 }
1607
1608 public void put(String name, char val) {
1609 Bits.putChar(primVals, getFieldOffset(name, Character.TYPE), val);
1610 }
1611
1612 public void put(String name, short val) {
1613 Bits.putShort(primVals, getFieldOffset(name, Short.TYPE), val);
1614 }
1615
1616 public void put(String name, int val) {
1617 Bits.putInt(primVals, getFieldOffset(name, Integer.TYPE), val);
1618 }
1619
1620 public void put(String name, float val) {
1621 Bits.putFloat(primVals, getFieldOffset(name, Float.TYPE), val);
1622 }
1623
1624 public void put(String name, long val) {
1625 Bits.putLong(primVals, getFieldOffset(name, Long.TYPE), val);
1626 }
1627
1628 public void put(String name, double val) {
1629 Bits.putDouble(primVals, getFieldOffset(name, Double.TYPE), val);
1630 }
1631
1632 public void put(String name, Object val) {
1633 objVals[getFieldOffset(name, Object.class)] = val;
1634 }
1635
1636 // deprecated in ObjectOutputStream.PutField
1637 public void write(ObjectOutput out) throws IOException {
1638 /*
1639 * Applications should *not* use this method to write PutField
1640 * data, as it will lead to stream corruption if the PutField
1641 * object writes any primitive data (since block data mode is not
1642 * unset/set properly, as is done in OOS.writeFields()). This
1643 * broken implementation is being retained solely for behavioral
1644 * compatibility, in order to support applications which use
1645 * OOS.PutField.write() for writing only non-primitive data.
1646 *
1647 * Serialization of unshared objects is not implemented here since
1648 * it is not necessary for backwards compatibility; also, unshared
1649 * semantics may not be supported by the given ObjectOutput
1650 * instance. Applications which write unshared objects using the
1651 * PutField API must use OOS.writeFields().
1652 */
1653 if (ObjectOutputStream.this != out) {
1654 throw new IllegalArgumentException("wrong stream");
1655 }
1656 out.write(primVals, 0, primVals.length);
1657
1658 ObjectStreamField[] fields = desc.getFields(false);
1659 int numPrimFields = fields.length - objVals.length;
1660 // REMIND: warn if numPrimFields > 0?
1661 for (int i = 0; i < objVals.length; i++) {
1662 if (fields[numPrimFields + i].isUnshared()) {
1663 throw new IOException("cannot write unshared object");
1664 }
1665 out.writeObject(objVals[i]);
1666 }
1667 }
1668
1669 /**
1670 * Writes buffered primitive data and object fields to stream.
1671 */
1672 void writeFields() throws IOException {
1673 bout.write(primVals, 0, primVals.length, false);
1674
1675 ObjectStreamField[] fields = desc.getFields(false);
1676 int numPrimFields = fields.length - objVals.length;
1677 for (int i = 0; i < objVals.length; i++) {
1678 if (extendedDebugInfo) {
1679 debugInfoStack.push(
1680 "field (class \"" + desc.getName() + "\", name: \"" +
1681 fields[numPrimFields + i].getName() + "\", type: \"" +
1682 fields[numPrimFields + i].getType() + "\")");
1683 }
1684 try {
1685 writeObject0(objVals[i],
1686 fields[numPrimFields + i].isUnshared());
1687 } finally {
1688 if (extendedDebugInfo) {
1689 debugInfoStack.pop();
1690 }
1691 }
1692 }
1693 }
1694
1695 /**
1696 * Returns offset of field with given name and type. A specified type
1697 * of null matches all types, Object.class matches all non-primitive
1698 * types, and any other non-null type matches assignable types only.
1699 * Throws IllegalArgumentException if no matching field found.
1700 */
1701 private int getFieldOffset(String name, Class type) {
1702 ObjectStreamField field = desc.getField(name, type);
1703 if (field == null) {
1704 throw new IllegalArgumentException("no such field " + name +
1705 " with type " + type);
1706 }
1707 return field.getOffset();
1708 }
1709 }
1710
1711 /**
1712 * Buffered output stream with two modes: in default mode, outputs data in
1713 * same format as DataOutputStream; in "block data" mode, outputs data
1714 * bracketed by block data markers (see object serialization specification
1715 * for details).
1716 */
1717 private static class BlockDataOutputStream
1718 extends OutputStream implements DataOutput
1719 {
1720 /** maximum data block length */
1721 private static final int MAX_BLOCK_SIZE = 1024;
1722 /** maximum data block header length */
1723 private static final int MAX_HEADER_SIZE = 5;
1724 /** (tunable) length of char buffer (for writing strings) */
1725 private static final int CHAR_BUF_SIZE = 256;
1726
1727 /** buffer for writing general/block data */
1728 private final byte[] buf = new byte[MAX_BLOCK_SIZE];
1729 /** buffer for writing block data headers */
1730 private final byte[] hbuf = new byte[MAX_HEADER_SIZE];
1731 /** char buffer for fast string writes */
1732 private final char[] cbuf = new char[CHAR_BUF_SIZE];
1733
1734 /** block data mode */
1735 private boolean blkmode = false;
1736 /** current offset into buf */
1737 private int pos = 0;
1738
1739 /** underlying output stream */
1740 private final OutputStream out;
1741 /** loopback stream (for data writes that span data blocks) */
1742 private final DataOutputStream dout;
1743
1744 /**
1745 * Creates new BlockDataOutputStream on top of given underlying stream.
1746 * Block data mode is turned off by default.
1747 */
1748 BlockDataOutputStream(OutputStream out) {
1749 this.out = out;
1750 dout = new DataOutputStream(this);
1751 }
1752
1753 /**
1754 * Sets block data mode to the given mode (true == on, false == off)
1755 * and returns the previous mode value. If the new mode is the same as
1756 * the old mode, no action is taken. If the new mode differs from the
1757 * old mode, any buffered data is flushed before switching to the new
1758 * mode.
1759 */
1760 boolean setBlockDataMode(boolean mode) throws IOException {
1761 if (blkmode == mode) {
1762 return blkmode;
1763 }
1764 drain();
1765 blkmode = mode;
1766 return !blkmode;
1767 }
1768
1769 /**
1770 * Returns true if the stream is currently in block data mode, false
1771 * otherwise.
1772 */
1773 boolean getBlockDataMode() {
1774 return blkmode;
1775 }
1776
1777 /* ----------------- generic output stream methods ----------------- */
1778 /*
1779 * The following methods are equivalent to their counterparts in
1780 * OutputStream, except that they partition written data into data
1781 * blocks when in block data mode.
1782 */
1783
1784 public void write(int b) throws IOException {
1785 if (pos >= MAX_BLOCK_SIZE) {
1786 drain();
1787 }
1788 buf[pos++] = (byte) b;
1789 }
1790
1791 public void write(byte[] b) throws IOException {
1792 write(b, 0, b.length, false);
1793 }
1794
1795 public void write(byte[] b, int off, int len) throws IOException {
1796 write(b, off, len, false);
1797 }
1798
1799 public void flush() throws IOException {
1800 drain();
1801 out.flush();
1802 }
1803
1804 public void close() throws IOException {
1805 flush();
1806 out.close();
1807 }
1808
1809 /**
1810 * Writes specified span of byte values from given array. If copy is
1811 * true, copies the values to an intermediate buffer before writing
1812 * them to underlying stream (to avoid exposing a reference to the
1813 * original byte array).
1814 */
1815 void write(byte[] b, int off, int len, boolean copy)
1816 throws IOException
1817 {
1818 if (!(copy || blkmode)) { // write directly
1819 drain();
1820 out.write(b, off, len);
1821 return;
1822 }
1823
1824 while (len > 0) {
1825 if (pos >= MAX_BLOCK_SIZE) {
1826 drain();
1827 }
1828 if (len >= MAX_BLOCK_SIZE && !copy && pos == 0) {
1829 // avoid unnecessary copy
1830 writeBlockHeader(MAX_BLOCK_SIZE);
1831 out.write(b, off, MAX_BLOCK_SIZE);
1832 off += MAX_BLOCK_SIZE;
1833 len -= MAX_BLOCK_SIZE;
1834 } else {
1835 int wlen = Math.min(len, MAX_BLOCK_SIZE - pos);
1836 System.arraycopy(b, off, buf, pos, wlen);
1837 pos += wlen;
1838 off += wlen;
1839 len -= wlen;
1840 }
1841 }
1842 }
1843
1844 /**
1845 * Writes all buffered data from this stream to the underlying stream,
1846 * but does not flush underlying stream.
1847 */
1848 void drain() throws IOException {
1849 if (pos == 0) {
1850 return;
1851 }
1852 if (blkmode) {
1853 writeBlockHeader(pos);
1854 }
1855 out.write(buf, 0, pos);
1856 pos = 0;
1857 }
1858
1859 /**
1860 * Writes block data header. Data blocks shorter than 256 bytes are
1861 * prefixed with a 2-byte header; all others start with a 5-byte
1862 * header.
1863 */
1864 private void writeBlockHeader(int len) throws IOException {
1865 if (len <= 0xFF) {
1866 hbuf[0] = TC_BLOCKDATA;
1867 hbuf[1] = (byte) len;
1868 out.write(hbuf, 0, 2);
1869 } else {
1870 hbuf[0] = TC_BLOCKDATALONG;
1871 Bits.putInt(hbuf, 1, len);
1872 out.write(hbuf, 0, 5);
1873 }
1874 }
1875
1876
1877 /* ----------------- primitive data output methods ----------------- */
1878 /*
1879 * The following methods are equivalent to their counterparts in
1880 * DataOutputStream, except that they partition written data into data
1881 * blocks when in block data mode.
1882 */
1883
1884 public void writeBoolean(boolean v) throws IOException {
1885 if (pos >= MAX_BLOCK_SIZE) {
1886 drain();
1887 }
1888 Bits.putBoolean(buf, pos++, v);
1889 }
1890
1891 public void writeByte(int v) throws IOException {
1892 if (pos >= MAX_BLOCK_SIZE) {
1893 drain();
1894 }
1895 buf[pos++] = (byte) v;
1896 }
1897
1898 public void writeChar(int v) throws IOException {
1899 if (pos + 2 <= MAX_BLOCK_SIZE) {
1900 Bits.putChar(buf, pos, (char) v);
1901 pos += 2;
1902 } else {
1903 dout.writeChar(v);
1904 }
1905 }
1906
1907 public void writeShort(int v) throws IOException {
1908 if (pos + 2 <= MAX_BLOCK_SIZE) {
1909 Bits.putShort(buf, pos, (short) v);
1910 pos += 2;
1911 } else {
1912 dout.writeShort(v);
1913 }
1914 }
1915
1916 public void writeInt(int v) throws IOException {
1917 if (pos + 4 <= MAX_BLOCK_SIZE) {
1918 Bits.putInt(buf, pos, v);
1919 pos += 4;
1920 } else {
1921 dout.writeInt(v);
1922 }
1923 }
1924
1925 public void writeFloat(float v) throws IOException {
1926 if (pos + 4 <= MAX_BLOCK_SIZE) {
1927 Bits.putFloat(buf, pos, v);
1928 pos += 4;
1929 } else {
1930 dout.writeFloat(v);
1931 }
1932 }
1933
1934 public void writeLong(long v) throws IOException {
1935 if (pos + 8 <= MAX_BLOCK_SIZE) {
1936 Bits.putLong(buf, pos, v);
1937 pos += 8;
1938 } else {
1939 dout.writeLong(v);
1940 }
1941 }
1942
1943 public void writeDouble(double v) throws IOException {
1944 if (pos + 8 <= MAX_BLOCK_SIZE) {
1945 Bits.putDouble(buf, pos, v);
1946 pos += 8;
1947 } else {
1948 dout.writeDouble(v);
1949 }
1950 }
1951
1952 public void writeBytes(String s) throws IOException {
1953 int endoff = s.length();
1954 int cpos = 0;
1955 int csize = 0;
1956 for (int off = 0; off < endoff; ) {
1957 if (cpos >= csize) {
1958 cpos = 0;
1959 csize = Math.min(endoff - off, CHAR_BUF_SIZE);
1960 s.getChars(off, off + csize, cbuf, 0);
1961 }
1962 if (pos >= MAX_BLOCK_SIZE) {
1963 drain();
1964 }
1965 int n = Math.min(csize - cpos, MAX_BLOCK_SIZE - pos);
1966 int stop = pos + n;
1967 while (pos < stop) {
1968 buf[pos++] = (byte) cbuf[cpos++];
1969 }
1970 off += n;
1971 }
1972 }
1973
1974 public void writeChars(String s) throws IOException {
1975 int endoff = s.length();
1976 for (int off = 0; off < endoff; ) {
1977 int csize = Math.min(endoff - off, CHAR_BUF_SIZE);
1978 s.getChars(off, off + csize, cbuf, 0);
1979 writeChars(cbuf, 0, csize);
1980 off += csize;
1981 }
1982 }
1983
1984 public void writeUTF(String s) throws IOException {
1985 writeUTF(s, getUTFLength(s));
1986 }
1987
1988
1989 /* -------------- primitive data array output methods -------------- */
1990 /*
1991 * The following methods write out spans of primitive data values.
1992 * Though equivalent to calling the corresponding primitive write
1993 * methods repeatedly, these methods are optimized for writing groups
1994 * of primitive data values more efficiently.
1995 */
1996
1997 void writeBooleans(boolean[] v, int off, int len) throws IOException {
1998 int endoff = off + len;
1999 while (off < endoff) {
2000 if (pos >= MAX_BLOCK_SIZE) {
2001 drain();
2002 }
2003 int stop = Math.min(endoff, off + (MAX_BLOCK_SIZE - pos));
2004 while (off < stop) {
2005 Bits.putBoolean(buf, pos++, v[off++]);
2006 }
2007 }
2008 }
2009
2010 void writeChars(char[] v, int off, int len) throws IOException {
2011 int limit = MAX_BLOCK_SIZE - 2;
2012 int endoff = off + len;
2013 while (off < endoff) {
2014 if (pos <= limit) {
2015 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2016 int stop = Math.min(endoff, off + avail);
2017 while (off < stop) {
2018 Bits.putChar(buf, pos, v[off++]);
2019 pos += 2;
2020 }
2021 } else {
2022 dout.writeChar(v[off++]);
2023 }
2024 }
2025 }
2026
2027 void writeShorts(short[] v, int off, int len) throws IOException {
2028 int limit = MAX_BLOCK_SIZE - 2;
2029 int endoff = off + len;
2030 while (off < endoff) {
2031 if (pos <= limit) {
2032 int avail = (MAX_BLOCK_SIZE - pos) >> 1;
2033 int stop = Math.min(endoff, off + avail);
2034 while (off < stop) {
2035 Bits.putShort(buf, pos, v[off++]);
2036 pos += 2;
2037 }
2038 } else {
2039 dout.writeShort(v[off++]);
2040 }
2041 }
2042 }
2043
2044 void writeInts(int[] v, int off, int len) throws IOException {
2045 int limit = MAX_BLOCK_SIZE - 4;
2046 int endoff = off + len;
2047 while (off < endoff) {
2048 if (pos <= limit) {
2049 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2050 int stop = Math.min(endoff, off + avail);
2051 while (off < stop) {
2052 Bits.putInt(buf, pos, v[off++]);
2053 pos += 4;
2054 }
2055 } else {
2056 dout.writeInt(v[off++]);
2057 }
2058 }
2059 }
2060
2061 void writeFloats(float[] v, int off, int len) throws IOException {
2062 int limit = MAX_BLOCK_SIZE - 4;
2063 int endoff = off + len;
2064 while (off < endoff) {
2065 if (pos <= limit) {
2066 int avail = (MAX_BLOCK_SIZE - pos) >> 2;
2067 int chunklen = Math.min(endoff - off, avail);
2068 floatsToBytes(v, off, buf, pos, chunklen);
2069 off += chunklen;
2070 pos += chunklen << 2;
2071 } else {
2072 dout.writeFloat(v[off++]);
2073 }
2074 }
2075 }
2076
2077 void writeLongs(long[] v, int off, int len) throws IOException {
2078 int limit = MAX_BLOCK_SIZE - 8;
2079 int endoff = off + len;
2080 while (off < endoff) {
2081 if (pos <= limit) {
2082 int avail = (MAX_BLOCK_SIZE - pos) >> 3;
2083 int stop = Math.min(endoff, off + avail);
2084 while (off < stop) {
2085 Bits.putLong(buf, pos, v[off++]);
2086 pos += 8;
2087 }
2088 } else {
2089 dout.writeLong(v[off++]);
2090 }
2091 }
2092 }
2093
2094 void writeDoubles(double[] 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 chunklen = Math.min(endoff - off, avail);
2101 doublesToBytes(v, off, buf, pos, chunklen);
2102 off += chunklen;
2103 pos += chunklen << 3;
2104 } else {
2105 dout.writeDouble(v[off++]);
2106 }
2107 }
2108 }
2109
2110 /**
2111 * Returns the length in bytes of the UTF encoding of the given string.
2112 */
2113 long getUTFLength(String s) {
2114 int len = s.length();
2115 long utflen = 0;
2116 for (int off = 0; off < len; ) {
2117 int csize = Math.min(len - off, CHAR_BUF_SIZE);
2118 s.getChars(off, off + csize, cbuf, 0);
2119 for (int cpos = 0; cpos < csize; cpos++) {
2120 char c = cbuf[cpos];
2121 if (c >= 0x0001 && c <= 0x007F) {
2122 utflen++;
2123 } else if (c > 0x07FF) {
2124 utflen += 3;
2125 } else {
2126 utflen += 2;
2127 }
2128 }
2129 off += csize;
2130 }
2131 return utflen;
2132 }
2133
2134 /**
2135 * Writes the given string in UTF format. This method is used in
2136 * situations where the UTF encoding length of the string is already
2137 * known; specifying it explicitly avoids a prescan of the string to
2138 * determine its UTF length.
2139 */
2140 void writeUTF(String s, long utflen) throws IOException {
2141 if (utflen > 0xFFFFL) {
2142 throw new UTFDataFormatException();
2143 }
2144 writeShort((int) utflen);
2145 if (utflen == (long) s.length()) {
2146 writeBytes(s);
2147 } else {
2148 writeUTFBody(s);
2149 }
2150 }
2151
2152 /**
2153 * Writes given string in "long" UTF format. "Long" UTF format is
2154 * identical to standard UTF, except that it uses an 8 byte header
2155 * (instead of the standard 2 bytes) to convey the UTF encoding length.
2156 */
2157 void writeLongUTF(String s) throws IOException {
2158 writeLongUTF(s, getUTFLength(s));
2159 }
2160
2161 /**
2162 * Writes given string in "long" UTF format, where the UTF encoding
2163 * length of the string is already known.
2164 */
2165 void writeLongUTF(String s, long utflen) throws IOException {
2166 writeLong(utflen);
2167 if (utflen == (long) s.length()) {
2168 writeBytes(s);
2169 } else {
2170 writeUTFBody(s);
2171 }
2172 }
2173
2174 /**
2175 * Writes the "body" (i.e., the UTF representation minus the 2-byte or
2176 * 8-byte length header) of the UTF encoding for the given string.
2177 */
2178 private void writeUTFBody(String s) throws IOException {
2179 int limit = MAX_BLOCK_SIZE - 3;
2180 int len = s.length();
2181 for (int off = 0; off < len; ) {
2182 int csize = Math.min(len - off, CHAR_BUF_SIZE);
2183 s.getChars(off, off + csize, cbuf, 0);
2184 for (int cpos = 0; cpos < csize; cpos++) {
2185 char c = cbuf[cpos];
2186 if (pos <= limit) {
2187 if (c <= 0x007F && c != 0) {
2188 buf[pos++] = (byte) c;
2189 } else if (c > 0x07FF) {
2190 buf[pos + 2] = (byte) (0x80 | ((c >> 0) & 0x3F));
2191 buf[pos + 1] = (byte) (0x80 | ((c >> 6) & 0x3F));
2192 buf[pos + 0] = (byte) (0xE0 | ((c >> 12) & 0x0F));
2193 pos += 3;
2194 } else {
2195 buf[pos + 1] = (byte) (0x80 | ((c >> 0) & 0x3F));
2196 buf[pos + 0] = (byte) (0xC0 | ((c >> 6) & 0x1F));
2197 pos += 2;
2198 }
2199 } else { // write one byte at a time to normalize block
2200 if (c <= 0x007F && c != 0) {
2201 write(c);
2202 } else if (c > 0x07FF) {
2203 write(0xE0 | ((c >> 12) & 0x0F));
2204 write(0x80 | ((c >> 6) & 0x3F));
2205 write(0x80 | ((c >> 0) & 0x3F));
2206 } else {
2207 write(0xC0 | ((c >> 6) & 0x1F));
2208 write(0x80 | ((c >> 0) & 0x3F));
2209 }
2210 }
2211 }
2212 off += csize;
2213 }
2214 }
2215 }
2216
2217 /**
2218 * Lightweight identity hash table which maps objects to integer handles,
2219 * assigned in ascending order.
2220 */
2221 private static class HandleTable {
2222
2223 /* number of mappings in table/next available handle */
2224 private int size;
2225 /* size threshold determining when to expand hash spine */
2226 private int threshold;
2227 /* factor for computing size threshold */
2228 private final float loadFactor;
2229 /* maps hash value -> candidate handle value */
2230 private int[] spine;
2231 /* maps handle value -> next candidate handle value */
2232 private int[] next;
2233 /* maps handle value -> associated object */
2234 private Object[] objs;
2235
2236 /**
2237 * Creates new HandleTable with given capacity and load factor.
2238 */
2239 HandleTable(int initialCapacity, float loadFactor) {
2240 this.loadFactor = loadFactor;
2241 spine = new int[initialCapacity];
2242 next = new int[initialCapacity];
2243 objs = new Object[initialCapacity];
2244 threshold = (int) (initialCapacity * loadFactor);
2245 clear();
2246 }
2247
2248 /**
2249 * Assigns next available handle to given object, and returns handle
2250 * value. Handles are assigned in ascending order starting at 0.
2251 */
2252 int assign(Object obj) {
2253 if (size >= next.length) {
2254 growEntries();
2255 }
2256 if (size >= threshold) {
2257 growSpine();
2258 }
2259 insert(obj, size);
2260 return size++;
2261 }
2262
2263 /**
2264 * Looks up and returns handle associated with given object, or -1 if
2265 * no mapping found.
2266 */
2267 int lookup(Object obj) {
2268 if (size == 0) {
2269 return -1;
2270 }
2271 int index = hash(obj) % spine.length;
2272 for (int i = spine[index]; i >= 0; i = next[i]) {
2273 if (objs[i] == obj) {
2274 return i;
2275 }
2276 }
2277 return -1;
2278 }
2279
2280 /**
2281 * Resets table to its initial (empty) state.
2282 */
2283 void clear() {
2284 Arrays.fill(spine, -1);
2285 Arrays.fill(objs, 0, size, null);
2286 size = 0;
2287 }
2288
2289 /**
2290 * Returns the number of mappings currently in table.
2291 */
2292 int size() {
2293 return size;
2294 }
2295
2296 /**
2297 * Inserts mapping object -> handle mapping into table. Assumes table
2298 * is large enough to accommodate new mapping.
2299 */
2300 private void insert(Object obj, int handle) {
2301 int index = hash(obj) % spine.length;
2302 objs[handle] = obj;
2303 next[handle] = spine[index];
2304 spine[index] = handle;
2305 }
2306
2307 /**
2308 * Expands the hash "spine" -- equivalent to increasing the number of
2309 * buckets in a conventional hash table.
2310 */
2311 private void growSpine() {
2312 spine = new int[(spine.length << 1) + 1];
2313 threshold = (int) (spine.length * loadFactor);
2314 Arrays.fill(spine, -1);
2315 for (int i = 0; i < size; i++) {
2316 insert(objs[i], i);
2317 }
2318 }
2319
2320 /**
2321 * Increases hash table capacity by lengthening entry arrays.
2322 */
2323 private void growEntries() {
2324 int newLength = (next.length << 1) + 1;
2325 int[] newNext = new int[newLength];
2326 System.arraycopy(next, 0, newNext, 0, size);
2327 next = newNext;
2328
2329 Object[] newObjs = new Object[newLength];
2330 System.arraycopy(objs, 0, newObjs, 0, size);
2331 objs = newObjs;
2332 }
2333
2334 /**
2335 * Returns hash value for given object.
2336 */
2337 private int hash(Object obj) {
2338 return System.identityHashCode(obj) & 0x7FFFFFFF;
2339 }
2340 }
2341
2342 /**
2343 * Lightweight identity hash table which maps objects to replacement
2344 * objects.
2345 */
2346 private static class ReplaceTable {
2347
2348 /* maps object -> index */
2349 private final HandleTable htab;
2350 /* maps index -> replacement object */
2351 private Object[] reps;
2352
2353 /**
2354 * Creates new ReplaceTable with given capacity and load factor.
2355 */
2356 ReplaceTable(int initialCapacity, float loadFactor) {
2357 htab = new HandleTable(initialCapacity, loadFactor);
2358 reps = new Object[initialCapacity];
2359 }
2360
2361 /**
2362 * Enters mapping from object to replacement object.
2363 */
2364 void assign(Object obj, Object rep) {
2365 int index = htab.assign(obj);
2366 while (index >= reps.length) {
2367 grow();
2368 }
2369 reps[index] = rep;
2370 }
2371
2372 /**
2373 * Looks up and returns replacement for given object. If no
2374 * replacement is found, returns the lookup object itself.
2375 */
2376 Object lookup(Object obj) {
2377 int index = htab.lookup(obj);
2378 return (index >= 0) ? reps[index] : obj;
2379 }
2380
2381 /**
2382 * Resets table to its initial (empty) state.
2383 */
2384 void clear() {
2385 Arrays.fill(reps, 0, htab.size(), null);
2386 htab.clear();
2387 }
2388
2389 /**
2390 * Returns the number of mappings currently in table.
2391 */
2392 int size() {
2393 return htab.size();
2394 }
2395
2396 /**
2397 * Increases table capacity.
2398 */
2399 private void grow() {
2400 Object[] newReps = new Object[(reps.length << 1) + 1]
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