ObjectOutputStream.java revision 51b1b6997fd3f980076b8081f7f1165ccc2a4008
1/* 2 * Copyright (c) 1996, 2010, 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 26package java.io; 27 28import java.io.ObjectStreamClass.WeakClassKey; 29import java.lang.ref.ReferenceQueue; 30import java.security.AccessController; 31import java.security.PrivilegedAction; 32import java.util.ArrayList; 33import java.util.Arrays; 34import java.util.List; 35import java.util.concurrent.ConcurrentHashMap; 36import java.util.concurrent.ConcurrentMap; 37import static java.io.ObjectStreamClass.processQueue; 38import java.io.SerialCallbackContext; 39import 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="../../../platform/serialization/spec/output.html">Object Serialization Specification, Section 2, Object Output Classes</a> 160 * @since JDK1.1 161 */ 162public class ObjectOutputStream 163 extends OutputStream implements ObjectOutput, ObjectStreamConstants 164{ 165 166 private static class Caches { 167 /** cache of subclass security audit results */ 168 static final ConcurrentMap<WeakClassKey,Boolean> subclassAudits = 169 new ConcurrentHashMap<>(); 170 171 /** queue for WeakReferences to audited subclasses */ 172 static final ReferenceQueue<Class<?>> subclassAuditsQueue = 173 new ReferenceQueue<>(); 174 } 175 176 /** filter stream for handling block data conversion */ 177 private final BlockDataOutputStream bout; 178 /** obj -> wire handle map */ 179 private final HandleTable handles; 180 /** obj -> replacement obj map */ 181 private final ReplaceTable subs; 182 /** stream protocol version */ 183 private int protocol = PROTOCOL_VERSION_2; 184 /** recursion depth */ 185 private int depth; 186 187 /** buffer for writing primitive field values */ 188 private byte[] primVals; 189 190 /** if true, invoke writeObjectOverride() instead of writeObject() */ 191 private final boolean enableOverride; 192 /** if true, invoke replaceObject() */ 193 private boolean enableReplace; 194 195 // values below valid only during upcalls to writeObject()/writeExternal() 196 /** 197 * Context during upcalls to class-defined writeObject methods; holds 198 * object currently being serialized and descriptor for current class. 199 * Null when not during writeObject upcall. 200 */ 201 private SerialCallbackContext curContext; 202 /** current PutField object */ 203 private PutFieldImpl curPut; 204 205 /** custom storage for debug trace info */ 206 private final DebugTraceInfoStack debugInfoStack; 207 208 /** 209 * value of "sun.io.serialization.extendedDebugInfo" property, 210 * as true or false for extended information about exception's place 211 */ 212 private static final boolean extendedDebugInfo = 213 java.security.AccessController.doPrivileged( 214 new sun.security.action.GetBooleanAction( 215 "sun.io.serialization.extendedDebugInfo")).booleanValue(); 216 217 /** 218 * Creates an ObjectOutputStream that writes to the specified OutputStream. 219 * This constructor writes the serialization stream header to the 220 * underlying stream; callers may wish to flush the stream immediately to 221 * ensure that constructors for receiving ObjectInputStreams will not block 222 * when reading the header. 223 * 224 * <p>If a security manager is installed, this constructor will check for 225 * the "enableSubclassImplementation" SerializablePermission when invoked 226 * directly or indirectly by the constructor of a subclass which overrides 227 * the ObjectOutputStream.putFields or ObjectOutputStream.writeUnshared 228 * methods. 229 * 230 * @param out output stream to write to 231 * @throws IOException if an I/O error occurs while writing stream header 232 * @throws SecurityException if untrusted subclass illegally overrides 233 * security-sensitive methods 234 * @throws NullPointerException if <code>out</code> is <code>null</code> 235 * @since 1.4 236 * @see ObjectOutputStream#ObjectOutputStream() 237 * @see ObjectOutputStream#putFields() 238 * @see ObjectInputStream#ObjectInputStream(InputStream) 239 */ 240 public ObjectOutputStream(OutputStream out) throws IOException { 241 verifySubclass(); 242 bout = new BlockDataOutputStream(out); 243 handles = new HandleTable(10, (float) 3.00); 244 subs = new ReplaceTable(10, (float) 3.00); 245 enableOverride = false; 246 writeStreamHeader(); 247 bout.setBlockDataMode(true); 248 if (extendedDebugInfo) { 249 debugInfoStack = new DebugTraceInfoStack(); 250 } else { 251 debugInfoStack = null; 252 } 253 } 254 255 /** 256 * Provide a way for subclasses that are completely reimplementing 257 * ObjectOutputStream to not have to allocate private data just used by 258 * this implementation of ObjectOutputStream. 259 * 260 * <p>If there is a security manager installed, this method first calls the 261 * security manager's <code>checkPermission</code> method with a 262 * <code>SerializablePermission("enableSubclassImplementation")</code> 263 * permission to ensure it's ok to enable subclassing. 264 * 265 * @throws SecurityException if a security manager exists and its 266 * <code>checkPermission</code> method denies enabling 267 * subclassing. 268 * @see SecurityManager#checkPermission 269 * @see java.io.SerializablePermission 270 */ 271 protected ObjectOutputStream() throws IOException, SecurityException { 272 SecurityManager sm = System.getSecurityManager(); 273 if (sm != null) { 274 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION); 275 } 276 bout = null; 277 handles = null; 278 subs = null; 279 enableOverride = true; 280 debugInfoStack = null; 281 } 282 283 /** 284 * Specify stream protocol version to use when writing the stream. 285 * 286 * <p>This routine provides a hook to enable the current version of 287 * Serialization to write in a format that is backwards compatible to a 288 * previous version of the stream format. 289 * 290 * <p>Every effort will be made to avoid introducing additional 291 * backwards incompatibilities; however, sometimes there is no 292 * other alternative. 293 * 294 * @param version use ProtocolVersion from java.io.ObjectStreamConstants. 295 * @throws IllegalStateException if called after any objects 296 * have been serialized. 297 * @throws IllegalArgumentException if invalid version is passed in. 298 * @throws IOException if I/O errors occur 299 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1 300 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_2 301 * @since 1.2 302 */ 303 public void useProtocolVersion(int version) throws IOException { 304 if (handles.size() != 0) { 305 // REMIND: implement better check for pristine stream? 306 throw new IllegalStateException("stream non-empty"); 307 } 308 switch (version) { 309 case PROTOCOL_VERSION_1: 310 case PROTOCOL_VERSION_2: 311 protocol = version; 312 break; 313 314 default: 315 throw new IllegalArgumentException( 316 "unknown version: " + version); 317 } 318 } 319 320 /** 321 * Write the specified object to the ObjectOutputStream. The class of the 322 * object, the signature of the class, and the values of the non-transient 323 * and non-static fields of the class and all of its supertypes are 324 * written. Default serialization for a class can be overridden using the 325 * writeObject and the readObject methods. Objects referenced by this 326 * object are written transitively so that a complete equivalent graph of 327 * objects can be reconstructed by an ObjectInputStream. 328 * 329 * <p>Exceptions are thrown for problems with the OutputStream and for 330 * classes that should not be serialized. All exceptions are fatal to the 331 * OutputStream, which is left in an indeterminate state, and it is up to 332 * the caller to ignore or recover the stream state. 333 * 334 * @throws InvalidClassException Something is wrong with a class used by 335 * serialization. 336 * @throws NotSerializableException Some object to be serialized does not 337 * implement the java.io.Serializable interface. 338 * @throws IOException Any exception thrown by the underlying 339 * OutputStream. 340 */ 341 public final void writeObject(Object obj) throws IOException { 342 if (enableOverride) { 343 writeObjectOverride(obj); 344 return; 345 } 346 try { 347 writeObject0(obj, false); 348 } catch (IOException ex) { 349 if (depth == 0) { 350 writeFatalException(ex); 351 } 352 throw ex; 353 } 354 } 355 356 /** 357 * Method used by subclasses to override the default writeObject method. 358 * This method is called by trusted subclasses of ObjectInputStream that 359 * constructed ObjectInputStream using the protected no-arg constructor. 360 * The subclass is expected to provide an override method with the modifier 361 * "final". 362 * 363 * @param obj object to be written to the underlying stream 364 * @throws IOException if there are I/O errors while writing to the 365 * underlying stream 366 * @see #ObjectOutputStream() 367 * @see #writeObject(Object) 368 * @since 1.2 369 */ 370 protected void writeObjectOverride(Object obj) throws IOException { 371 } 372 373 /** 374 * Writes an "unshared" object to the ObjectOutputStream. This method is 375 * identical to writeObject, except that it always writes the given object 376 * as a new, unique object in the stream (as opposed to a back-reference 377 * pointing to a previously serialized instance). Specifically: 378 * <ul> 379 * <li>An object written via writeUnshared is always serialized in the 380 * same manner as a newly appearing object (an object that has not 381 * been written to the stream yet), regardless of whether or not the 382 * object has been written previously. 383 * 384 * <li>If writeObject is used to write an object that has been previously 385 * written with writeUnshared, the previous writeUnshared operation 386 * is treated as if it were a write of a separate object. In other 387 * words, ObjectOutputStream will never generate back-references to 388 * object data written by calls to writeUnshared. 389 * </ul> 390 * While writing an object via writeUnshared does not in itself guarantee a 391 * unique reference to the object when it is deserialized, it allows a 392 * single object to be defined multiple times in a stream, so that multiple 393 * calls to readUnshared by the receiver will not conflict. Note that the 394 * rules described above only apply to the base-level object written with 395 * writeUnshared, and not to any transitively referenced sub-objects in the 396 * object graph to be serialized. 397 * 398 * <p>ObjectOutputStream subclasses which override this method can only be 399 * constructed in security contexts possessing the 400 * "enableSubclassImplementation" SerializablePermission; any attempt to 401 * instantiate such a subclass without this permission will cause a 402 * SecurityException to be thrown. 403 * 404 * @param obj object to write to stream 405 * @throws NotSerializableException if an object in the graph to be 406 * serialized does not implement the Serializable interface 407 * @throws InvalidClassException if a problem exists with the class of an 408 * object to be serialized 409 * @throws IOException if an I/O error occurs during serialization 410 * @since 1.4 411 */ 412 public void writeUnshared(Object obj) throws IOException { 413 try { 414 writeObject0(obj, true); 415 } catch (IOException ex) { 416 if (depth == 0) { 417 writeFatalException(ex); 418 } 419 throw ex; 420 } 421 } 422 423 /** 424 * Write the non-static and non-transient fields of the current class to 425 * this stream. This may only be called from the writeObject method of the 426 * class being serialized. It will throw the NotActiveException if it is 427 * called otherwise. 428 * 429 * @throws IOException if I/O errors occur while writing to the underlying 430 * <code>OutputStream</code> 431 */ 432 public void defaultWriteObject() throws IOException { 433 if ( curContext == null ) { 434 throw new NotActiveException("not in call to writeObject"); 435 } 436 Object curObj = curContext.getObj(); 437 ObjectStreamClass curDesc = curContext.getDesc(); 438 bout.setBlockDataMode(false); 439 defaultWriteFields(curObj, curDesc); 440 bout.setBlockDataMode(true); 441 } 442 443 /** 444 * Retrieve the object used to buffer persistent fields to be written to 445 * the stream. The fields will be written to the stream when writeFields 446 * method is called. 447 * 448 * @return an instance of the class Putfield that holds the serializable 449 * fields 450 * @throws IOException if I/O errors occur 451 * @since 1.2 452 */ 453 public ObjectOutputStream.PutField putFields() throws IOException { 454 if (curPut == null) { 455 if (curContext == null) { 456 throw new NotActiveException("not in call to writeObject"); 457 } 458 Object curObj = curContext.getObj(); 459 ObjectStreamClass curDesc = curContext.getDesc(); 460 curPut = new PutFieldImpl(curDesc); 461 } 462 return curPut; 463 } 464 465 /** 466 * Write the buffered fields to the stream. 467 * 468 * @throws IOException if I/O errors occur while writing to the underlying 469 * stream 470 * @throws NotActiveException Called when a classes writeObject method was 471 * not called to write the state of the object. 472 * @since 1.2 473 */ 474 public void writeFields() throws IOException { 475 if (curPut == null) { 476 throw new NotActiveException("no current PutField object"); 477 } 478 bout.setBlockDataMode(false); 479 curPut.writeFields(); 480 bout.setBlockDataMode(true); 481 } 482 483 /** 484 * Reset will disregard the state of any objects already written to the 485 * stream. The state is reset to be the same as a new ObjectOutputStream. 486 * The current point in the stream is marked as reset so the corresponding 487 * ObjectInputStream will be reset at the same point. Objects previously 488 * written to the stream will not be refered to as already being in the 489 * stream. They will be written to the stream again. 490 * 491 * @throws IOException if reset() is invoked while serializing an object. 492 */ 493 public void reset() throws IOException { 494 if (depth != 0) { 495 throw new IOException("stream active"); 496 } 497 bout.setBlockDataMode(false); 498 bout.writeByte(TC_RESET); 499 clear(); 500 bout.setBlockDataMode(true); 501 } 502 503 /** 504 * Subclasses may implement this method to allow class data to be stored in 505 * the stream. By default this method does nothing. The corresponding 506 * method in ObjectInputStream is resolveClass. This method is called 507 * exactly once for each unique class in the stream. The class name and 508 * signature will have already been written to the stream. This method may 509 * make free use of the ObjectOutputStream to save any representation of 510 * the class it deems suitable (for example, the bytes of the class file). 511 * The resolveClass method in the corresponding subclass of 512 * ObjectInputStream must read and use any data or objects written by 513 * annotateClass. 514 * 515 * @param cl the class to annotate custom data for 516 * @throws IOException Any exception thrown by the underlying 517 * OutputStream. 518 */ 519 protected void annotateClass(Class<?> cl) throws IOException { 520 } 521 522 /** 523 * Subclasses may implement this method to store custom data in the stream 524 * along with descriptors for dynamic proxy classes. 525 * 526 * <p>This method is called exactly once for each unique proxy class 527 * descriptor in the stream. The default implementation of this method in 528 * <code>ObjectOutputStream</code> does nothing. 529 * 530 * <p>The corresponding method in <code>ObjectInputStream</code> is 531 * <code>resolveProxyClass</code>. For a given subclass of 532 * <code>ObjectOutputStream</code> that overrides this method, the 533 * <code>resolveProxyClass</code> method in the corresponding subclass of 534 * <code>ObjectInputStream</code> must read any data or objects written by 535 * <code>annotateProxyClass</code>. 536 * 537 * @param cl the proxy class to annotate custom data for 538 * @throws IOException any exception thrown by the underlying 539 * <code>OutputStream</code> 540 * @see ObjectInputStream#resolveProxyClass(String[]) 541 * @since 1.3 542 */ 543 protected void annotateProxyClass(Class<?> cl) throws IOException { 544 } 545 546 /** 547 * This method will allow trusted subclasses of ObjectOutputStream to 548 * substitute one object for another during serialization. Replacing 549 * objects is disabled until enableReplaceObject is called. The 550 * enableReplaceObject method checks that the stream requesting to do 551 * replacement can be trusted. The first occurrence of each object written 552 * into the serialization stream is passed to replaceObject. Subsequent 553 * references to the object are replaced by the object returned by the 554 * original call to replaceObject. To ensure that the private state of 555 * objects is not unintentionally exposed, only trusted streams may use 556 * replaceObject. 557 * 558 * <p>The ObjectOutputStream.writeObject method takes a parameter of type 559 * Object (as opposed to type Serializable) to allow for cases where 560 * non-serializable objects are replaced by serializable ones. 561 * 562 * <p>When a subclass is replacing objects it must insure that either a 563 * complementary substitution must be made during deserialization or that 564 * the substituted object is compatible with every field where the 565 * reference will be stored. Objects whose type is not a subclass of the 566 * type of the field or array element abort the serialization by raising an 567 * exception and the object is not be stored. 568 * 569 * <p>This method is called only once when each object is first 570 * encountered. All subsequent references to the object will be redirected 571 * to the new object. This method should return the object to be 572 * substituted or the original object. 573 * 574 * <p>Null can be returned as the object to be substituted, but may cause 575 * NullReferenceException in classes that contain references to the 576 * original object since they may be expecting an object instead of 577 * null. 578 * 579 * @param obj the object to be replaced 580 * @return the alternate object that replaced the specified one 581 * @throws IOException Any exception thrown by the underlying 582 * OutputStream. 583 */ 584 protected Object replaceObject(Object obj) throws IOException { 585 return obj; 586 } 587 588 /** 589 * Enable the stream to do replacement of objects in the stream. When 590 * enabled, the replaceObject method is called for every object being 591 * serialized. 592 * 593 * <p>If <code>enable</code> is true, and there is a security manager 594 * installed, this method first calls the security manager's 595 * <code>checkPermission</code> method with a 596 * <code>SerializablePermission("enableSubstitution")</code> permission to 597 * ensure it's ok to enable the stream to do replacement of objects in the 598 * stream. 599 * 600 * @param enable boolean parameter to enable replacement of objects 601 * @return the previous setting before this method was invoked 602 * @throws SecurityException if a security manager exists and its 603 * <code>checkPermission</code> method denies enabling the stream 604 * to do replacement of objects in the stream. 605 * @see SecurityManager#checkPermission 606 * @see java.io.SerializablePermission 607 */ 608 protected boolean enableReplaceObject(boolean enable) 609 throws SecurityException 610 { 611 if (enable == enableReplace) { 612 return enable; 613 } 614 if (enable) { 615 SecurityManager sm = System.getSecurityManager(); 616 if (sm != null) { 617 sm.checkPermission(SUBSTITUTION_PERMISSION); 618 } 619 } 620 enableReplace = enable; 621 return !enableReplace; 622 } 623 624 /** 625 * The writeStreamHeader method is provided so subclasses can append or 626 * prepend their own header to the stream. It writes the magic number and 627 * version to the stream. 628 * 629 * @throws IOException if I/O errors occur while writing to the underlying 630 * stream 631 */ 632 protected void writeStreamHeader() throws IOException { 633 bout.writeShort(STREAM_MAGIC); 634 bout.writeShort(STREAM_VERSION); 635 } 636 637 /** 638 * Write the specified class descriptor to the ObjectOutputStream. Class 639 * descriptors are used to identify the classes of objects written to the 640 * stream. Subclasses of ObjectOutputStream may override this method to 641 * customize the way in which class descriptors are written to the 642 * serialization stream. The corresponding method in ObjectInputStream, 643 * <code>readClassDescriptor</code>, should then be overridden to 644 * reconstitute the class descriptor from its custom stream representation. 645 * By default, this method writes class descriptors according to the format 646 * defined in the Object Serialization specification. 647 * 648 * <p>Note that this method will only be called if the ObjectOutputStream 649 * is not using the old serialization stream format (set by calling 650 * ObjectOutputStream's <code>useProtocolVersion</code> method). If this 651 * serialization stream is using the old format 652 * (<code>PROTOCOL_VERSION_1</code>), the class descriptor will be written 653 * internally in a manner that cannot be overridden or customized. 654 * 655 * @param desc class descriptor to write to the stream 656 * @throws IOException If an I/O error has occurred. 657 * @see java.io.ObjectInputStream#readClassDescriptor() 658 * @see #useProtocolVersion(int) 659 * @see java.io.ObjectStreamConstants#PROTOCOL_VERSION_1 660 * @since 1.3 661 */ 662 protected void writeClassDescriptor(ObjectStreamClass desc) 663 throws IOException 664 { 665 desc.writeNonProxy(this); 666 } 667 668 /** 669 * Writes a byte. This method will block until the byte is actually 670 * written. 671 * 672 * @param val the byte to be written to the stream 673 * @throws IOException If an I/O error has occurred. 674 */ 675 public void write(int val) throws IOException { 676 bout.write(val); 677 } 678 679 /** 680 * Writes an array of bytes. This method will block until the bytes are 681 * actually written. 682 * 683 * @param buf the data to be written 684 * @throws IOException If an I/O error has occurred. 685 */ 686 public void write(byte[] buf) throws IOException { 687 bout.write(buf, 0, buf.length, false); 688 } 689 690 /** 691 * Writes a sub array of bytes. 692 * 693 * @param buf the data to be written 694 * @param off the start offset in the data 695 * @param len the number of bytes that are written 696 * @throws IOException If an I/O error has occurred. 697 */ 698 public void write(byte[] buf, int off, int len) throws IOException { 699 if (buf == null) { 700 throw new NullPointerException(); 701 } 702 int endoff = off + len; 703 if (off < 0 || len < 0 || endoff > buf.length || endoff < 0) { 704 throw new IndexOutOfBoundsException(); 705 } 706 bout.write(buf, off, len, false); 707 } 708 709 /** 710 * Flushes the stream. This will write any buffered output bytes and flush 711 * through to the underlying stream. 712 * 713 * @throws IOException If an I/O error has occurred. 714 */ 715 public void flush() throws IOException { 716 bout.flush(); 717 } 718 719 /** 720 * Drain any buffered data in ObjectOutputStream. Similar to flush but 721 * does not propagate the flush to the underlying stream. 722 * 723 * @throws IOException if I/O errors occur while writing to the underlying 724 * stream 725 */ 726 protected void drain() throws IOException { 727 bout.drain(); 728 } 729 730 /** 731 * Closes the stream. This method must be called to release any resources 732 * associated with the stream. 733 * 734 * @throws IOException If an I/O error has occurred. 735 */ 736 public void close() throws IOException { 737 flush(); 738 clear(); 739 bout.close(); 740 } 741 742 /** 743 * Writes a boolean. 744 * 745 * @param val the boolean to be written 746 * @throws IOException if I/O errors occur while writing to the underlying 747 * stream 748 */ 749 public void writeBoolean(boolean val) throws IOException { 750 bout.writeBoolean(val); 751 } 752 753 /** 754 * Writes an 8 bit byte. 755 * 756 * @param val the byte value to be written 757 * @throws IOException if I/O errors occur while writing to the underlying 758 * stream 759 */ 760 public void writeByte(int val) throws IOException { 761 bout.writeByte(val); 762 } 763 764 /** 765 * Writes a 16 bit short. 766 * 767 * @param val the short value to be written 768 * @throws IOException if I/O errors occur while writing to the underlying 769 * stream 770 */ 771 public void writeShort(int val) throws IOException { 772 bout.writeShort(val); 773 } 774 775 /** 776 * Writes a 16 bit char. 777 * 778 * @param val the char value to be written 779 * @throws IOException if I/O errors occur while writing to the underlying 780 * stream 781 */ 782 public void writeChar(int val) throws IOException { 783 bout.writeChar(val); 784 } 785 786 /** 787 * Writes a 32 bit int. 788 * 789 * @param val the integer value to be written 790 * @throws IOException if I/O errors occur while writing to the underlying 791 * stream 792 */ 793 public void writeInt(int val) throws IOException { 794 bout.writeInt(val); 795 } 796 797 /** 798 * Writes a 64 bit long. 799 * 800 * @param val the long value to be written 801 * @throws IOException if I/O errors occur while writing to the underlying 802 * stream 803 */ 804 public void writeLong(long val) throws IOException { 805 bout.writeLong(val); 806 } 807 808 /** 809 * Writes a 32 bit float. 810 * 811 * @param val the float value to be written 812 * @throws IOException if I/O errors occur while writing to the underlying 813 * stream 814 */ 815 public void writeFloat(float val) throws IOException { 816 bout.writeFloat(val); 817 } 818 819 /** 820 * Writes a 64 bit double. 821 * 822 * @param val the double value to be written 823 * @throws IOException if I/O errors occur while writing to the underlying 824 * stream 825 */ 826 public void writeDouble(double val) throws IOException { 827 bout.writeDouble(val); 828 } 829 830 /** 831 * Writes a String as a sequence of bytes. 832 * 833 * @param str the String of bytes to be written 834 * @throws IOException if I/O errors occur while writing to the underlying 835 * stream 836 */ 837 public void writeBytes(String str) throws IOException { 838 bout.writeBytes(str); 839 } 840 841 /** 842 * Writes a String as a sequence of chars. 843 * 844 * @param str the String of chars to be written 845 * @throws IOException if I/O errors occur while writing to the underlying 846 * stream 847 */ 848 public void writeChars(String str) throws IOException { 849 bout.writeChars(str); 850 } 851 852 /** 853 * Primitive data write of this String in 854 * <a href="DataInput.html#modified-utf-8">modified UTF-8</a> 855 * format. Note that there is a 856 * significant difference between writing a String into the stream as 857 * primitive data or as an Object. A String instance written by writeObject 858 * is written into the stream as a String initially. Future writeObject() 859 * calls write references to the string into the stream. 860 * 861 * @param str the String to be written 862 * @throws IOException if I/O errors occur while writing to the underlying 863 * stream 864 */ 865 public void writeUTF(String str) throws IOException { 866 bout.writeUTF(str); 867 } 868 869 /** 870 * Provide programmatic access to the persistent fields to be written 871 * to ObjectOutput. 872 * 873 * @since 1.2 874 */ 875 public static abstract class PutField { 876 877 /** 878 * Put the value of the named boolean field into the persistent field. 879 * 880 * @param name the name of the serializable field 881 * @param val the value to assign to the field 882 * @throws IllegalArgumentException if <code>name</code> does not 883 * match the name of a serializable field for the class whose fields 884 * are being written, or if the type of the named field is not 885 * <code>boolean</code> 886 */ 887 public abstract void put(String name, boolean val); 888 889 /** 890 * Put the value of the named byte field into the persistent field. 891 * 892 * @param name the name of the serializable field 893 * @param val the value to assign to the field 894 * @throws IllegalArgumentException if <code>name</code> does not 895 * match the name of a serializable field for the class whose fields 896 * are being written, or if the type of the named field is not 897 * <code>byte</code> 898 */ 899 public abstract void put(String name, byte val); 900 901 /** 902 * Put the value of the named char field into the persistent field. 903 * 904 * @param name the name of the serializable field 905 * @param val the value to assign to the field 906 * @throws IllegalArgumentException if <code>name</code> does not 907 * match the name of a serializable field for the class whose fields 908 * are being written, or if the type of the named field is not 909 * <code>char</code> 910 */ 911 public abstract void put(String name, char val); 912 913 /** 914 * Put the value of the named short field into the persistent field. 915 * 916 * @param name the name of the serializable field 917 * @param val the value to assign to the field 918 * @throws IllegalArgumentException if <code>name</code> does not 919 * match the name of a serializable field for the class whose fields 920 * are being written, or if the type of the named field is not 921 * <code>short</code> 922 */ 923 public abstract void put(String name, short val); 924 925 /** 926 * Put the value of the named int field into the persistent field. 927 * 928 * @param name the name of the serializable field 929 * @param val the value to assign to the field 930 * @throws IllegalArgumentException if <code>name</code> does not 931 * match the name of a serializable field for the class whose fields 932 * are being written, or if the type of the named field is not 933 * <code>int</code> 934 */ 935 public abstract void put(String name, int val); 936 937 /** 938 * Put the value of the named long field into the persistent field. 939 * 940 * @param name the name of the serializable field 941 * @param val the value to assign to the field 942 * @throws IllegalArgumentException if <code>name</code> does not 943 * match the name of a serializable field for the class whose fields 944 * are being written, or if the type of the named field is not 945 * <code>long</code> 946 */ 947 public abstract void put(String name, long val); 948 949 /** 950 * Put the value of the named float field into the persistent field. 951 * 952 * @param name the name of the serializable field 953 * @param val the value to assign to the field 954 * @throws IllegalArgumentException if <code>name</code> does not 955 * match the name of a serializable field for the class whose fields 956 * are being written, or if the type of the named field is not 957 * <code>float</code> 958 */ 959 public abstract void put(String name, float val); 960 961 /** 962 * Put the value of the named double field into the persistent field. 963 * 964 * @param name the name of the serializable field 965 * @param val the value to assign to the field 966 * @throws IllegalArgumentException if <code>name</code> does not 967 * match the name of a serializable field for the class whose fields 968 * are being written, or if the type of the named field is not 969 * <code>double</code> 970 */ 971 public abstract void put(String name, double val); 972 973 /** 974 * Put the value of the named Object field into the persistent field. 975 * 976 * @param name the name of the serializable field 977 * @param val the value to assign to the field 978 * (which may be <code>null</code>) 979 * @throws IllegalArgumentException if <code>name</code> does not 980 * match the name of a serializable field for the class whose fields 981 * are being written, or if the type of the named field is not a 982 * reference type 983 */ 984 public abstract void put(String name, Object val); 985 986 /** 987 * Write the data and fields to the specified ObjectOutput stream, 988 * which must be the same stream that produced this 989 * <code>PutField</code> object. 990 * 991 * @param out the stream to write the data and fields to 992 * @throws IOException if I/O errors occur while writing to the 993 * underlying stream 994 * @throws IllegalArgumentException if the specified stream is not 995 * the same stream that produced this <code>PutField</code> 996 * object 997 * @deprecated This method does not write the values contained by this 998 * <code>PutField</code> object in a proper format, and may 999 * result in corruption of the serialization stream. The 1000 * correct way to write <code>PutField</code> data is by 1001 * calling the {@link java.io.ObjectOutputStream#writeFields()} 1002 * method. 1003 */ 1004 @Deprecated 1005 public abstract void write(ObjectOutput out) throws IOException; 1006 } 1007 1008 1009 /** 1010 * Returns protocol version in use. 1011 */ 1012 int getProtocolVersion() { 1013 return protocol; 1014 } 1015 1016 /** 1017 * Writes string without allowing it to be replaced in stream. Used by 1018 * ObjectStreamClass to write class descriptor type strings. 1019 */ 1020 void writeTypeString(String str) throws IOException { 1021 int handle; 1022 if (str == null) { 1023 writeNull(); 1024 } else if ((handle = handles.lookup(str)) != -1) { 1025 writeHandle(handle); 1026 } else { 1027 writeString(str, false); 1028 } 1029 } 1030 1031 /** 1032 * Verifies that this (possibly subclass) instance can be constructed 1033 * without violating security constraints: the subclass must not override 1034 * security-sensitive non-final methods, or else the 1035 * "enableSubclassImplementation" SerializablePermission is checked. 1036 */ 1037 private void verifySubclass() { 1038 Class cl = getClass(); 1039 if (cl == ObjectOutputStream.class) { 1040 return; 1041 } 1042 SecurityManager sm = System.getSecurityManager(); 1043 if (sm == null) { 1044 return; 1045 } 1046 processQueue(Caches.subclassAuditsQueue, Caches.subclassAudits); 1047 WeakClassKey key = new WeakClassKey(cl, Caches.subclassAuditsQueue); 1048 Boolean result = Caches.subclassAudits.get(key); 1049 if (result == null) { 1050 result = Boolean.valueOf(auditSubclass(cl)); 1051 Caches.subclassAudits.putIfAbsent(key, result); 1052 } 1053 if (result.booleanValue()) { 1054 return; 1055 } 1056 sm.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION); 1057 } 1058 1059 /** 1060 * Performs reflective checks on given subclass to verify that it doesn't 1061 * override security-sensitive non-final methods. Returns true if subclass 1062 * is "safe", false otherwise. 1063 */ 1064 private static boolean auditSubclass(final Class subcl) { 1065 Boolean result = AccessController.doPrivileged( 1066 new PrivilegedAction<Boolean>() { 1067 public Boolean run() { 1068 for (Class cl = subcl; 1069 cl != ObjectOutputStream.class; 1070 cl = cl.getSuperclass()) 1071 { 1072 try { 1073 cl.getDeclaredMethod( 1074 "writeUnshared", new Class[] { Object.class }); 1075 return Boolean.FALSE; 1076 } catch (NoSuchMethodException ex) { 1077 } 1078 try { 1079 cl.getDeclaredMethod("putFields", (Class[]) null); 1080 return Boolean.FALSE; 1081 } catch (NoSuchMethodException ex) { 1082 } 1083 } 1084 return Boolean.TRUE; 1085 } 1086 } 1087 ); 1088 return result.booleanValue(); 1089 } 1090 1091 /** 1092 * Clears internal data structures. 1093 */ 1094 private void clear() { 1095 subs.clear(); 1096 handles.clear(); 1097 } 1098 1099 /** 1100 * Underlying writeObject/writeUnshared implementation. 1101 */ 1102 private void writeObject0(Object obj, boolean unshared) 1103 throws IOException 1104 { 1105 boolean oldMode = bout.setBlockDataMode(false); 1106 depth++; 1107 try { 1108 // handle previously written and non-replaceable objects 1109 int h; 1110 if ((obj = subs.lookup(obj)) == null) { 1111 writeNull(); 1112 return; 1113 } else if (!unshared && (h = handles.lookup(obj)) != -1) { 1114 writeHandle(h); 1115 return; 1116 } else if (obj instanceof Class) { 1117 writeClass((Class) obj, unshared); 1118 return; 1119 } else if (obj instanceof ObjectStreamClass) { 1120 writeClassDesc((ObjectStreamClass) obj, unshared); 1121 return; 1122 } 1123 1124 // check for replacement object 1125 Object orig = obj; 1126 Class cl = obj.getClass(); 1127 ObjectStreamClass desc; 1128 for (;;) { 1129 // REMIND: skip this check for strings/arrays? 1130 Class repCl; 1131 desc = ObjectStreamClass.lookup(cl, true); 1132 if (!desc.hasWriteReplaceMethod() || 1133 (obj = desc.invokeWriteReplace(obj)) == null || 1134 (repCl = obj.getClass()) == cl) 1135 { 1136 break; 1137 } 1138 cl = repCl; 1139 } 1140 if (enableReplace) { 1141 Object rep = replaceObject(obj); 1142 if (rep != obj && rep != null) { 1143 cl = rep.getClass(); 1144 desc = ObjectStreamClass.lookup(cl, true); 1145 } 1146 obj = rep; 1147 } 1148 1149 // if object replaced, run through original checks a second time 1150 if (obj != orig) { 1151 subs.assign(orig, obj); 1152 if (obj == null) { 1153 writeNull(); 1154 return; 1155 } else if (!unshared && (h = handles.lookup(obj)) != -1) { 1156 writeHandle(h); 1157 return; 1158 } else if (obj instanceof Class) { 1159 writeClass((Class) obj, unshared); 1160 return; 1161 } else if (obj instanceof ObjectStreamClass) { 1162 writeClassDesc((ObjectStreamClass) obj, unshared); 1163 return; 1164 } 1165 } 1166 1167 // remaining cases 1168 if (obj instanceof String) { 1169 writeString((String) obj, unshared); 1170 } else if (cl.isArray()) { 1171 writeArray(obj, desc, unshared); 1172 } else if (obj instanceof Enum) { 1173 writeEnum((Enum) obj, desc, unshared); 1174 } else if (obj instanceof Serializable) { 1175 writeOrdinaryObject(obj, desc, unshared); 1176 } else { 1177 if (extendedDebugInfo) { 1178 throw new NotSerializableException( 1179 cl.getName() + "\n" + debugInfoStack.toString()); 1180 } else { 1181 throw new NotSerializableException(cl.getName()); 1182 } 1183 } 1184 } finally { 1185 depth--; 1186 bout.setBlockDataMode(oldMode); 1187 } 1188 } 1189 1190 /** 1191 * Writes null code to stream. 1192 */ 1193 private void writeNull() throws IOException { 1194 bout.writeByte(TC_NULL); 1195 } 1196 1197 /** 1198 * Writes given object handle to stream. 1199 */ 1200 private void writeHandle(int handle) throws IOException { 1201 bout.writeByte(TC_REFERENCE); 1202 bout.writeInt(baseWireHandle + handle); 1203 } 1204 1205 /** 1206 * Writes representation of given class to stream. 1207 */ 1208 private void writeClass(Class cl, boolean unshared) throws IOException { 1209 bout.writeByte(TC_CLASS); 1210 writeClassDesc(ObjectStreamClass.lookup(cl, true), false); 1211 handles.assign(unshared ? null : cl); 1212 } 1213 1214 /** 1215 * Writes representation of given class descriptor to stream. 1216 */ 1217 private void writeClassDesc(ObjectStreamClass desc, boolean unshared) 1218 throws IOException 1219 { 1220 int handle; 1221 if (desc == null) { 1222 writeNull(); 1223 } else if (!unshared && (handle = handles.lookup(desc)) != -1) { 1224 writeHandle(handle); 1225 } else if (desc.isProxy()) { 1226 writeProxyDesc(desc, unshared); 1227 } else { 1228 writeNonProxyDesc(desc, unshared); 1229 } 1230 } 1231 1232 private boolean isCustomSubclass() { 1233 // Return true if this class is a custom subclass of ObjectOutputStream 1234 return getClass().getClassLoader() 1235 != ObjectOutputStream.class.getClassLoader(); 1236 } 1237 1238 /** 1239 * Writes class descriptor representing a dynamic proxy class to stream. 1240 */ 1241 private void writeProxyDesc(ObjectStreamClass desc, boolean unshared) 1242 throws IOException 1243 { 1244 bout.writeByte(TC_PROXYCLASSDESC); 1245 handles.assign(unshared ? null : desc); 1246 1247 Class cl = desc.forClass(); 1248 Class[] ifaces = cl.getInterfaces(); 1249 bout.writeInt(ifaces.length); 1250 for (int i = 0; i < ifaces.length; i++) { 1251 bout.writeUTF(ifaces[i].getName()); 1252 } 1253 1254 bout.setBlockDataMode(true); 1255 if (isCustomSubclass()) { 1256 ReflectUtil.checkPackageAccess(cl); 1257 } 1258 annotateProxyClass(cl); 1259 bout.setBlockDataMode(false); 1260 bout.writeByte(TC_ENDBLOCKDATA); 1261 1262 writeClassDesc(desc.getSuperDesc(), false); 1263 } 1264 1265 /** 1266 * Writes class descriptor representing a standard (i.e., not a dynamic 1267 * proxy) class to stream. 1268 */ 1269 private void writeNonProxyDesc(ObjectStreamClass desc, boolean unshared) 1270 throws IOException 1271 { 1272 bout.writeByte(TC_CLASSDESC); 1273 handles.assign(unshared ? null : desc); 1274 1275 if (protocol == PROTOCOL_VERSION_1) { 1276 // do not invoke class descriptor write hook with old protocol 1277 desc.writeNonProxy(this); 1278 } else { 1279 writeClassDescriptor(desc); 1280 } 1281 1282 Class cl = desc.forClass(); 1283 bout.setBlockDataMode(true); 1284 if (isCustomSubclass()) { 1285 ReflectUtil.checkPackageAccess(cl); 1286 } 1287 annotateClass(cl); 1288 bout.setBlockDataMode(false); 1289 bout.writeByte(TC_ENDBLOCKDATA); 1290 1291 writeClassDesc(desc.getSuperDesc(), false); 1292 } 1293 1294 /** 1295 * Writes given string to stream, using standard or long UTF format 1296 * depending on string length. 1297 */ 1298 private void writeString(String str, boolean unshared) throws IOException { 1299 handles.assign(unshared ? null : str); 1300 long utflen = bout.getUTFLength(str); 1301 if (utflen <= 0xFFFF) { 1302 bout.writeByte(TC_STRING); 1303 bout.writeUTF(str, utflen); 1304 } else { 1305 bout.writeByte(TC_LONGSTRING); 1306 bout.writeLongUTF(str, utflen); 1307 } 1308 } 1309 1310 /** 1311 * Writes given array object to stream. 1312 */ 1313 private void writeArray(Object array, 1314 ObjectStreamClass desc, 1315 boolean unshared) 1316 throws IOException 1317 { 1318 bout.writeByte(TC_ARRAY); 1319 writeClassDesc(desc, false); 1320 handles.assign(unshared ? null : array); 1321 1322 Class ccl = desc.forClass().getComponentType(); 1323 if (ccl.isPrimitive()) { 1324 if (ccl == Integer.TYPE) { 1325 int[] ia = (int[]) array; 1326 bout.writeInt(ia.length); 1327 bout.writeInts(ia, 0, ia.length); 1328 } else if (ccl == Byte.TYPE) { 1329 byte[] ba = (byte[]) array; 1330 bout.writeInt(ba.length); 1331 bout.write(ba, 0, ba.length, true); 1332 } else if (ccl == Long.TYPE) { 1333 long[] ja = (long[]) array; 1334 bout.writeInt(ja.length); 1335 bout.writeLongs(ja, 0, ja.length); 1336 } else if (ccl == Float.TYPE) { 1337 float[] fa = (float[]) array; 1338 bout.writeInt(fa.length); 1339 bout.writeFloats(fa, 0, fa.length); 1340 } else if (ccl == Double.TYPE) { 1341 double[] da = (double[]) array; 1342 bout.writeInt(da.length); 1343 bout.writeDoubles(da, 0, da.length); 1344 } else if (ccl == Short.TYPE) { 1345 short[] sa = (short[]) array; 1346 bout.writeInt(sa.length); 1347 bout.writeShorts(sa, 0, sa.length); 1348 } else if (ccl == Character.TYPE) { 1349 char[] ca = (char[]) array; 1350 bout.writeInt(ca.length); 1351 bout.writeChars(ca, 0, ca.length); 1352 } else if (ccl == Boolean.TYPE) { 1353 boolean[] za = (boolean[]) array; 1354 bout.writeInt(za.length); 1355 bout.writeBooleans(za, 0, za.length); 1356 } else { 1357 throw new InternalError(); 1358 } 1359 } else { 1360 Object[] objs = (Object[]) array; 1361 int len = objs.length; 1362 bout.writeInt(len); 1363 if (extendedDebugInfo) { 1364 debugInfoStack.push( 1365 "array (class \"" + array.getClass().getName() + 1366 "\", size: " + len + ")"); 1367 } 1368 try { 1369 for (int i = 0; i < len; i++) { 1370 if (extendedDebugInfo) { 1371 debugInfoStack.push( 1372 "element of array (index: " + i + ")"); 1373 } 1374 try { 1375 writeObject0(objs[i], false); 1376 } finally { 1377 if (extendedDebugInfo) { 1378 debugInfoStack.pop(); 1379 } 1380 } 1381 } 1382 } finally { 1383 if (extendedDebugInfo) { 1384 debugInfoStack.pop(); 1385 } 1386 } 1387 } 1388 } 1389 1390 /** 1391 * Writes given enum constant to stream. 1392 */ 1393 private void writeEnum(Enum en, 1394 ObjectStreamClass desc, 1395 boolean unshared) 1396 throws IOException 1397 { 1398 bout.writeByte(TC_ENUM); 1399 ObjectStreamClass sdesc = desc.getSuperDesc(); 1400 writeClassDesc((sdesc.forClass() == Enum.class) ? desc : sdesc, false); 1401 handles.assign(unshared ? null : en); 1402 writeString(en.name(), false); 1403 } 1404 1405 /** 1406 * Writes representation of a "ordinary" (i.e., not a String, Class, 1407 * ObjectStreamClass, array, or enum constant) serializable object to the 1408 * stream. 1409 */ 1410 private void writeOrdinaryObject(Object obj, 1411 ObjectStreamClass desc, 1412 boolean unshared) 1413 throws IOException 1414 { 1415 if (extendedDebugInfo) { 1416 debugInfoStack.push( 1417 (depth == 1 ? "root " : "") + "object (class \"" + 1418 obj.getClass().getName() + "\", " + obj.toString() + ")"); 1419 } 1420 try { 1421 desc.checkSerialize(); 1422 1423 bout.writeByte(TC_OBJECT); 1424 writeClassDesc(desc, false); 1425 handles.assign(unshared ? null : obj); 1426 if (desc.isExternalizable() && !desc.isProxy()) { 1427 writeExternalData((Externalizable) obj); 1428 } else { 1429 writeSerialData(obj, desc); 1430 } 1431 } finally { 1432 if (extendedDebugInfo) { 1433 debugInfoStack.pop(); 1434 } 1435 } 1436 } 1437 1438 /** 1439 * Writes externalizable data of given object by invoking its 1440 * writeExternal() method. 1441 */ 1442 private void writeExternalData(Externalizable obj) throws IOException { 1443 PutFieldImpl oldPut = curPut; 1444 curPut = null; 1445 1446 if (extendedDebugInfo) { 1447 debugInfoStack.push("writeExternal data"); 1448 } 1449 SerialCallbackContext oldContext = curContext; 1450 try { 1451 curContext = null; 1452 if (protocol == PROTOCOL_VERSION_1) { 1453 obj.writeExternal(this); 1454 } else { 1455 bout.setBlockDataMode(true); 1456 obj.writeExternal(this); 1457 bout.setBlockDataMode(false); 1458 bout.writeByte(TC_ENDBLOCKDATA); 1459 } 1460 } finally { 1461 curContext = oldContext; 1462 if (extendedDebugInfo) { 1463 debugInfoStack.pop(); 1464 } 1465 } 1466 1467 curPut = oldPut; 1468 } 1469 1470 /** 1471 * Writes instance data for each serializable class of given object, from 1472 * superclass to subclass. 1473 */ 1474 private void writeSerialData(Object obj, ObjectStreamClass desc) 1475 throws IOException 1476 { 1477 ObjectStreamClass.ClassDataSlot[] slots = desc.getClassDataLayout(); 1478 for (int i = 0; i < slots.length; i++) { 1479 ObjectStreamClass slotDesc = slots[i].desc; 1480 if (slotDesc.hasWriteObjectMethod()) { 1481 PutFieldImpl oldPut = curPut; 1482 curPut = null; 1483 SerialCallbackContext oldContext = curContext; 1484 1485 if (extendedDebugInfo) { 1486 debugInfoStack.push( 1487 "custom writeObject data (class \"" + 1488 slotDesc.getName() + "\")"); 1489 } 1490 try { 1491 curContext = new SerialCallbackContext(obj, slotDesc); 1492 bout.setBlockDataMode(true); 1493 slotDesc.invokeWriteObject(obj, this); 1494 bout.setBlockDataMode(false); 1495 bout.writeByte(TC_ENDBLOCKDATA); 1496 } finally { 1497 curContext.setUsed(); 1498 curContext = oldContext; 1499 if (extendedDebugInfo) { 1500 debugInfoStack.pop(); 1501 } 1502 } 1503 1504 curPut = oldPut; 1505 } else { 1506 defaultWriteFields(obj, slotDesc); 1507 } 1508 } 1509 } 1510 1511 /** 1512 * Fetches and writes values of serializable fields of given object to 1513 * stream. The given class descriptor specifies which field values to 1514 * write, and in which order they should be written. 1515 */ 1516 private void defaultWriteFields(Object obj, ObjectStreamClass desc) 1517 throws IOException 1518 { 1519 // REMIND: perform conservative isInstance check here? 1520 desc.checkDefaultSerialize(); 1521 1522 int primDataSize = desc.getPrimDataSize(); 1523 if (primVals == null || primVals.length < primDataSize) { 1524 primVals = new byte[primDataSize]; 1525 } 1526 desc.getPrimFieldValues(obj, primVals); 1527 bout.write(primVals, 0, primDataSize, false); 1528 1529 ObjectStreamField[] fields = desc.getFields(false); 1530 Object[] objVals = new Object[desc.getNumObjFields()]; 1531 int numPrimFields = fields.length - objVals.length; 1532 desc.getObjFieldValues(obj, objVals); 1533 for (int i = 0; i < objVals.length; i++) { 1534 if (extendedDebugInfo) { 1535 debugInfoStack.push( 1536 "field (class \"" + desc.getName() + "\", name: \"" + 1537 fields[numPrimFields + i].getName() + "\", type: \"" + 1538 fields[numPrimFields + i].getType() + "\")"); 1539 } 1540 try { 1541 writeObject0(objVals[i], 1542 fields[numPrimFields + i].isUnshared()); 1543 } finally { 1544 if (extendedDebugInfo) { 1545 debugInfoStack.pop(); 1546 } 1547 } 1548 } 1549 } 1550 1551 /** 1552 * Attempts to write to stream fatal IOException that has caused 1553 * serialization to abort. 1554 */ 1555 private void writeFatalException(IOException ex) throws IOException { 1556 /* 1557 * Note: the serialization specification states that if a second 1558 * IOException occurs while attempting to serialize the original fatal 1559 * exception to the stream, then a StreamCorruptedException should be 1560 * thrown (section 2.1). However, due to a bug in previous 1561 * implementations of serialization, StreamCorruptedExceptions were 1562 * rarely (if ever) actually thrown--the "root" exceptions from 1563 * underlying streams were thrown instead. This historical behavior is 1564 * followed here for consistency. 1565 */ 1566 clear(); 1567 boolean oldMode = bout.setBlockDataMode(false); 1568 try { 1569 bout.writeByte(TC_EXCEPTION); 1570 writeObject0(ex, false); 1571 clear(); 1572 } finally { 1573 bout.setBlockDataMode(oldMode); 1574 } 1575 } 1576 1577 /** 1578 * Converts specified span of float values into byte values. 1579 */ 1580 // REMIND: remove once hotspot inlines Float.floatToIntBits 1581 private static native void floatsToBytes(float[] src, int srcpos, 1582 byte[] dst, int dstpos, 1583 int nfloats); 1584 1585 /** 1586 * Converts specified span of double values into byte values. 1587 */ 1588 // REMIND: remove once hotspot inlines Double.doubleToLongBits 1589 private static native void doublesToBytes(double[] src, int srcpos, 1590 byte[] dst, int dstpos, 1591 int ndoubles); 1592 1593 /** 1594 * Default PutField implementation. 1595 */ 1596 private class PutFieldImpl extends PutField { 1597 1598 /** class descriptor describing serializable fields */ 1599 private final ObjectStreamClass desc; 1600 /** primitive field values */ 1601 private final byte[] primVals; 1602 /** object field values */ 1603 private final Object[] objVals; 1604 1605 /** 1606 * Creates PutFieldImpl object for writing fields defined in given 1607 * class descriptor. 1608 */ 1609 PutFieldImpl(ObjectStreamClass desc) { 1610 this.desc = desc; 1611 primVals = new byte[desc.getPrimDataSize()]; 1612 objVals = new Object[desc.getNumObjFields()]; 1613 } 1614 1615 public void put(String name, boolean val) { 1616 Bits.putBoolean(primVals, getFieldOffset(name, Boolean.TYPE), val); 1617 } 1618 1619 public void put(String name, byte val) { 1620 primVals[getFieldOffset(name, Byte.TYPE)] = val; 1621 } 1622 1623 public void put(String name, char val) { 1624 Bits.putChar(primVals, getFieldOffset(name, Character.TYPE), val); 1625 } 1626 1627 public void put(String name, short val) { 1628 Bits.putShort(primVals, getFieldOffset(name, Short.TYPE), val); 1629 } 1630 1631 public void put(String name, int val) { 1632 Bits.putInt(primVals, getFieldOffset(name, Integer.TYPE), val); 1633 } 1634 1635 public void put(String name, float val) { 1636 Bits.putFloat(primVals, getFieldOffset(name, Float.TYPE), val); 1637 } 1638 1639 public void put(String name, long val) { 1640 Bits.putLong(primVals, getFieldOffset(name, Long.TYPE), val); 1641 } 1642 1643 public void put(String name, double val) { 1644 Bits.putDouble(primVals, getFieldOffset(name, Double.TYPE), val); 1645 } 1646 1647 public void put(String name, Object val) { 1648 objVals[getFieldOffset(name, Object.class)] = val; 1649 } 1650 1651 // deprecated in ObjectOutputStream.PutField 1652 public void write(ObjectOutput out) throws IOException { 1653 /* 1654 * Applications should *not* use this method to write PutField 1655 * data, as it will lead to stream corruption if the PutField 1656 * object writes any primitive data (since block data mode is not 1657 * unset/set properly, as is done in OOS.writeFields()). This 1658 * broken implementation is being retained solely for behavioral 1659 * compatibility, in order to support applications which use 1660 * OOS.PutField.write() for writing only non-primitive data. 1661 * 1662 * Serialization of unshared objects is not implemented here since 1663 * it is not necessary for backwards compatibility; also, unshared 1664 * semantics may not be supported by the given ObjectOutput 1665 * instance. Applications which write unshared objects using the 1666 * PutField API must use OOS.writeFields(). 1667 */ 1668 if (ObjectOutputStream.this != out) { 1669 throw new IllegalArgumentException("wrong stream"); 1670 } 1671 out.write(primVals, 0, primVals.length); 1672 1673 ObjectStreamField[] fields = desc.getFields(false); 1674 int numPrimFields = fields.length - objVals.length; 1675 // REMIND: warn if numPrimFields > 0? 1676 for (int i = 0; i < objVals.length; i++) { 1677 if (fields[numPrimFields + i].isUnshared()) { 1678 throw new IOException("cannot write unshared object"); 1679 } 1680 out.writeObject(objVals[i]); 1681 } 1682 } 1683 1684 /** 1685 * Writes buffered primitive data and object fields to stream. 1686 */ 1687 void writeFields() throws IOException { 1688 bout.write(primVals, 0, primVals.length, false); 1689 1690 ObjectStreamField[] fields = desc.getFields(false); 1691 int numPrimFields = fields.length - objVals.length; 1692 for (int i = 0; i < objVals.length; i++) { 1693 if (extendedDebugInfo) { 1694 debugInfoStack.push( 1695 "field (class \"" + desc.getName() + "\", name: \"" + 1696 fields[numPrimFields + i].getName() + "\", type: \"" + 1697 fields[numPrimFields + i].getType() + "\")"); 1698 } 1699 try { 1700 writeObject0(objVals[i], 1701 fields[numPrimFields + i].isUnshared()); 1702 } finally { 1703 if (extendedDebugInfo) { 1704 debugInfoStack.pop(); 1705 } 1706 } 1707 } 1708 } 1709 1710 /** 1711 * Returns offset of field with given name and type. A specified type 1712 * of null matches all types, Object.class matches all non-primitive 1713 * types, and any other non-null type matches assignable types only. 1714 * Throws IllegalArgumentException if no matching field found. 1715 */ 1716 private int getFieldOffset(String name, Class type) { 1717 ObjectStreamField field = desc.getField(name, type); 1718 if (field == null) { 1719 throw new IllegalArgumentException("no such field " + name + 1720 " with type " + type); 1721 } 1722 return field.getOffset(); 1723 } 1724 } 1725 1726 /** 1727 * Buffered output stream with two modes: in default mode, outputs data in 1728 * same format as DataOutputStream; in "block data" mode, outputs data 1729 * bracketed by block data markers (see object serialization specification 1730 * for details). 1731 */ 1732 private static class BlockDataOutputStream 1733 extends OutputStream implements DataOutput 1734 { 1735 /** maximum data block length */ 1736 private static final int MAX_BLOCK_SIZE = 1024; 1737 /** maximum data block header length */ 1738 private static final int MAX_HEADER_SIZE = 5; 1739 /** (tunable) length of char buffer (for writing strings) */ 1740 private static final int CHAR_BUF_SIZE = 256; 1741 1742 /** buffer for writing general/block data */ 1743 private final byte[] buf = new byte[MAX_BLOCK_SIZE]; 1744 /** buffer for writing block data headers */ 1745 private final byte[] hbuf = new byte[MAX_HEADER_SIZE]; 1746 /** char buffer for fast string writes */ 1747 private final char[] cbuf = new char[CHAR_BUF_SIZE]; 1748 1749 /** block data mode */ 1750 private boolean blkmode = false; 1751 /** current offset into buf */ 1752 private int pos = 0; 1753 1754 /** underlying output stream */ 1755 private final OutputStream out; 1756 /** loopback stream (for data writes that span data blocks) */ 1757 private final DataOutputStream dout; 1758 1759 /** 1760 * Creates new BlockDataOutputStream on top of given underlying stream. 1761 * Block data mode is turned off by default. 1762 */ 1763 BlockDataOutputStream(OutputStream out) { 1764 this.out = out; 1765 dout = new DataOutputStream(this); 1766 } 1767 1768 /** 1769 * Sets block data mode to the given mode (true == on, false == off) 1770 * and returns the previous mode value. If the new mode is the same as 1771 * the old mode, no action is taken. If the new mode differs from the 1772 * old mode, any buffered data is flushed before switching to the new 1773 * mode. 1774 */ 1775 boolean setBlockDataMode(boolean mode) throws IOException { 1776 if (blkmode == mode) { 1777 return blkmode; 1778 } 1779 drain(); 1780 blkmode = mode; 1781 return !blkmode; 1782 } 1783 1784 /** 1785 * Returns true if the stream is currently in block data mode, false 1786 * otherwise. 1787 */ 1788 boolean getBlockDataMode() { 1789 return blkmode; 1790 } 1791 1792 /* ----------------- generic output stream methods ----------------- */ 1793 /* 1794 * The following methods are equivalent to their counterparts in 1795 * OutputStream, except that they partition written data into data 1796 * blocks when in block data mode. 1797 */ 1798 1799 public void write(int b) throws IOException { 1800 if (pos >= MAX_BLOCK_SIZE) { 1801 drain(); 1802 } 1803 buf[pos++] = (byte) b; 1804 } 1805 1806 public void write(byte[] b) throws IOException { 1807 write(b, 0, b.length, false); 1808 } 1809 1810 public void write(byte[] b, int off, int len) throws IOException { 1811 write(b, off, len, false); 1812 } 1813 1814 public void flush() throws IOException { 1815 drain(); 1816 out.flush(); 1817 } 1818 1819 public void close() throws IOException { 1820 flush(); 1821 out.close(); 1822 } 1823 1824 /** 1825 * Writes specified span of byte values from given array. If copy is 1826 * true, copies the values to an intermediate buffer before writing 1827 * them to underlying stream (to avoid exposing a reference to the 1828 * original byte array). 1829 */ 1830 void write(byte[] b, int off, int len, boolean copy) 1831 throws IOException 1832 { 1833 if (!(copy || blkmode)) { // write directly 1834 drain(); 1835 out.write(b, off, len); 1836 return; 1837 } 1838 1839 while (len > 0) { 1840 if (pos >= MAX_BLOCK_SIZE) { 1841 drain(); 1842 } 1843 if (len >= MAX_BLOCK_SIZE && !copy && pos == 0) { 1844 // avoid unnecessary copy 1845 writeBlockHeader(MAX_BLOCK_SIZE); 1846 out.write(b, off, MAX_BLOCK_SIZE); 1847 off += MAX_BLOCK_SIZE; 1848 len -= MAX_BLOCK_SIZE; 1849 } else { 1850 int wlen = Math.min(len, MAX_BLOCK_SIZE - pos); 1851 System.arraycopy(b, off, buf, pos, wlen); 1852 pos += wlen; 1853 off += wlen; 1854 len -= wlen; 1855 } 1856 } 1857 } 1858 1859 /** 1860 * Writes all buffered data from this stream to the underlying stream, 1861 * but does not flush underlying stream. 1862 */ 1863 void drain() throws IOException { 1864 if (pos == 0) { 1865 return; 1866 } 1867 if (blkmode) { 1868 writeBlockHeader(pos); 1869 } 1870 out.write(buf, 0, pos); 1871 pos = 0; 1872 } 1873 1874 /** 1875 * Writes block data header. Data blocks shorter than 256 bytes are 1876 * prefixed with a 2-byte header; all others start with a 5-byte 1877 * header. 1878 */ 1879 private void writeBlockHeader(int len) throws IOException { 1880 if (len <= 0xFF) { 1881 hbuf[0] = TC_BLOCKDATA; 1882 hbuf[1] = (byte) len; 1883 out.write(hbuf, 0, 2); 1884 } else { 1885 hbuf[0] = TC_BLOCKDATALONG; 1886 Bits.putInt(hbuf, 1, len); 1887 out.write(hbuf, 0, 5); 1888 } 1889 } 1890 1891 1892 /* ----------------- primitive data output methods ----------------- */ 1893 /* 1894 * The following methods are equivalent to their counterparts in 1895 * DataOutputStream, except that they partition written data into data 1896 * blocks when in block data mode. 1897 */ 1898 1899 public void writeBoolean(boolean v) throws IOException { 1900 if (pos >= MAX_BLOCK_SIZE) { 1901 drain(); 1902 } 1903 Bits.putBoolean(buf, pos++, v); 1904 } 1905 1906 public void writeByte(int v) throws IOException { 1907 if (pos >= MAX_BLOCK_SIZE) { 1908 drain(); 1909 } 1910 buf[pos++] = (byte) v; 1911 } 1912 1913 public void writeChar(int v) throws IOException { 1914 if (pos + 2 <= MAX_BLOCK_SIZE) { 1915 Bits.putChar(buf, pos, (char) v); 1916 pos += 2; 1917 } else { 1918 dout.writeChar(v); 1919 } 1920 } 1921 1922 public void writeShort(int v) throws IOException { 1923 if (pos + 2 <= MAX_BLOCK_SIZE) { 1924 Bits.putShort(buf, pos, (short) v); 1925 pos += 2; 1926 } else { 1927 dout.writeShort(v); 1928 } 1929 } 1930 1931 public void writeInt(int v) throws IOException { 1932 if (pos + 4 <= MAX_BLOCK_SIZE) { 1933 Bits.putInt(buf, pos, v); 1934 pos += 4; 1935 } else { 1936 dout.writeInt(v); 1937 } 1938 } 1939 1940 public void writeFloat(float v) throws IOException { 1941 if (pos + 4 <= MAX_BLOCK_SIZE) { 1942 Bits.putFloat(buf, pos, v); 1943 pos += 4; 1944 } else { 1945 dout.writeFloat(v); 1946 } 1947 } 1948 1949 public void writeLong(long v) throws IOException { 1950 if (pos + 8 <= MAX_BLOCK_SIZE) { 1951 Bits.putLong(buf, pos, v); 1952 pos += 8; 1953 } else { 1954 dout.writeLong(v); 1955 } 1956 } 1957 1958 public void writeDouble(double v) throws IOException { 1959 if (pos + 8 <= MAX_BLOCK_SIZE) { 1960 Bits.putDouble(buf, pos, v); 1961 pos += 8; 1962 } else { 1963 dout.writeDouble(v); 1964 } 1965 } 1966 1967 public void writeBytes(String s) throws IOException { 1968 int endoff = s.length(); 1969 int cpos = 0; 1970 int csize = 0; 1971 for (int off = 0; off < endoff; ) { 1972 if (cpos >= csize) { 1973 cpos = 0; 1974 csize = Math.min(endoff - off, CHAR_BUF_SIZE); 1975 s.getChars(off, off + csize, cbuf, 0); 1976 } 1977 if (pos >= MAX_BLOCK_SIZE) { 1978 drain(); 1979 } 1980 int n = Math.min(csize - cpos, MAX_BLOCK_SIZE - pos); 1981 int stop = pos + n; 1982 while (pos < stop) { 1983 buf[pos++] = (byte) cbuf[cpos++]; 1984 } 1985 off += n; 1986 } 1987 } 1988 1989 public void writeChars(String s) throws IOException { 1990 int endoff = s.length(); 1991 for (int off = 0; off < endoff; ) { 1992 int csize = Math.min(endoff - off, CHAR_BUF_SIZE); 1993 s.getChars(off, off + csize, cbuf, 0); 1994 writeChars(cbuf, 0, csize); 1995 off += csize; 1996 } 1997 } 1998 1999 public void writeUTF(String s) throws IOException { 2000 writeUTF(s, getUTFLength(s)); 2001 } 2002 2003 2004 /* -------------- primitive data array output methods -------------- */ 2005 /* 2006 * The following methods write out spans of primitive data values. 2007 * Though equivalent to calling the corresponding primitive write 2008 * methods repeatedly, these methods are optimized for writing groups 2009 * of primitive data values more efficiently. 2010 */ 2011 2012 void writeBooleans(boolean[] v, int off, int len) throws IOException { 2013 int endoff = off + len; 2014 while (off < endoff) { 2015 if (pos >= MAX_BLOCK_SIZE) { 2016 drain(); 2017 } 2018 int stop = Math.min(endoff, off + (MAX_BLOCK_SIZE - pos)); 2019 while (off < stop) { 2020 Bits.putBoolean(buf, pos++, v[off++]); 2021 } 2022 } 2023 } 2024 2025 void writeChars(char[] v, int off, int len) throws IOException { 2026 int limit = MAX_BLOCK_SIZE - 2; 2027 int endoff = off + len; 2028 while (off < endoff) { 2029 if (pos <= limit) { 2030 int avail = (MAX_BLOCK_SIZE - pos) >> 1; 2031 int stop = Math.min(endoff, off + avail); 2032 while (off < stop) { 2033 Bits.putChar(buf, pos, v[off++]); 2034 pos += 2; 2035 } 2036 } else { 2037 dout.writeChar(v[off++]); 2038 } 2039 } 2040 } 2041 2042 void writeShorts(short[] v, int off, int len) throws IOException { 2043 int limit = MAX_BLOCK_SIZE - 2; 2044 int endoff = off + len; 2045 while (off < endoff) { 2046 if (pos <= limit) { 2047 int avail = (MAX_BLOCK_SIZE - pos) >> 1; 2048 int stop = Math.min(endoff, off + avail); 2049 while (off < stop) { 2050 Bits.putShort(buf, pos, v[off++]); 2051 pos += 2; 2052 } 2053 } else { 2054 dout.writeShort(v[off++]); 2055 } 2056 } 2057 } 2058 2059 void writeInts(int[] v, int off, int len) throws IOException { 2060 int limit = MAX_BLOCK_SIZE - 4; 2061 int endoff = off + len; 2062 while (off < endoff) { 2063 if (pos <= limit) { 2064 int avail = (MAX_BLOCK_SIZE - pos) >> 2; 2065 int stop = Math.min(endoff, off + avail); 2066 while (off < stop) { 2067 Bits.putInt(buf, pos, v[off++]); 2068 pos += 4; 2069 } 2070 } else { 2071 dout.writeInt(v[off++]); 2072 } 2073 } 2074 } 2075 2076 void writeFloats(float[] v, int off, int len) throws IOException { 2077 int limit = MAX_BLOCK_SIZE - 4; 2078 int endoff = off + len; 2079 while (off < endoff) { 2080 if (pos <= limit) { 2081 int avail = (MAX_BLOCK_SIZE - pos) >> 2; 2082 int chunklen = Math.min(endoff - off, avail); 2083 floatsToBytes(v, off, buf, pos, chunklen); 2084 off += chunklen; 2085 pos += chunklen << 2; 2086 } else { 2087 dout.writeFloat(v[off++]); 2088 } 2089 } 2090 } 2091 2092 void writeLongs(long[] v, int off, int len) throws IOException { 2093 int limit = MAX_BLOCK_SIZE - 8; 2094 int endoff = off + len; 2095 while (off < endoff) { 2096 if (pos <= limit) { 2097 int avail = (MAX_BLOCK_SIZE - pos) >> 3; 2098 int stop = Math.min(endoff, off + avail); 2099 while (off < stop) { 2100 Bits.putLong(buf, pos, v[off++]); 2101 pos += 8; 2102 } 2103 } else { 2104 dout.writeLong(v[off++]); 2105 } 2106 } 2107 } 2108 2109 void writeDoubles(double[] v, int off, int len) throws IOException { 2110 int limit = MAX_BLOCK_SIZE - 8; 2111 int endoff = off + len; 2112 while (off < endoff) { 2113 if (pos <= limit) { 2114 int avail = (MAX_BLOCK_SIZE - pos) >> 3; 2115 int chunklen = Math.min(endoff - off, avail); 2116 doublesToBytes(v, off, buf, pos, chunklen); 2117 off += chunklen; 2118 pos += chunklen << 3; 2119 } else { 2120 dout.writeDouble(v[off++]); 2121 } 2122 } 2123 } 2124 2125 /** 2126 * Returns the length in bytes of the UTF encoding of the given string. 2127 */ 2128 long getUTFLength(String s) { 2129 int len = s.length(); 2130 long utflen = 0; 2131 for (int off = 0; off < len; ) { 2132 int csize = Math.min(len - off, CHAR_BUF_SIZE); 2133 s.getChars(off, off + csize, cbuf, 0); 2134 for (int cpos = 0; cpos < csize; cpos++) { 2135 char c = cbuf[cpos]; 2136 if (c >= 0x0001 && c <= 0x007F) { 2137 utflen++; 2138 } else if (c > 0x07FF) { 2139 utflen += 3; 2140 } else { 2141 utflen += 2; 2142 } 2143 } 2144 off += csize; 2145 } 2146 return utflen; 2147 } 2148 2149 /** 2150 * Writes the given string in UTF format. This method is used in 2151 * situations where the UTF encoding length of the string is already 2152 * known; specifying it explicitly avoids a prescan of the string to 2153 * determine its UTF length. 2154 */ 2155 void writeUTF(String s, long utflen) throws IOException { 2156 if (utflen > 0xFFFFL) { 2157 throw new UTFDataFormatException(); 2158 } 2159 writeShort((int) utflen); 2160 if (utflen == (long) s.length()) { 2161 writeBytes(s); 2162 } else { 2163 writeUTFBody(s); 2164 } 2165 } 2166 2167 /** 2168 * Writes given string in "long" UTF format. "Long" UTF format is 2169 * identical to standard UTF, except that it uses an 8 byte header 2170 * (instead of the standard 2 bytes) to convey the UTF encoding length. 2171 */ 2172 void writeLongUTF(String s) throws IOException { 2173 writeLongUTF(s, getUTFLength(s)); 2174 } 2175 2176 /** 2177 * Writes given string in "long" UTF format, where the UTF encoding 2178 * length of the string is already known. 2179 */ 2180 void writeLongUTF(String s, long utflen) throws IOException { 2181 writeLong(utflen); 2182 if (utflen == (long) s.length()) { 2183 writeBytes(s); 2184 } else { 2185 writeUTFBody(s); 2186 } 2187 } 2188 2189 /** 2190 * Writes the "body" (i.e., the UTF representation minus the 2-byte or 2191 * 8-byte length header) of the UTF encoding for the given string. 2192 */ 2193 private void writeUTFBody(String s) throws IOException { 2194 int limit = MAX_BLOCK_SIZE - 3; 2195 int len = s.length(); 2196 for (int off = 0; off < len; ) { 2197 int csize = Math.min(len - off, CHAR_BUF_SIZE); 2198 s.getChars(off, off + csize, cbuf, 0); 2199 for (int cpos = 0; cpos < csize; cpos++) { 2200 char c = cbuf[cpos]; 2201 if (pos <= limit) { 2202 if (c <= 0x007F && c != 0) { 2203 buf[pos++] = (byte) c; 2204 } else if (c > 0x07FF) { 2205 buf[pos + 2] = (byte) (0x80 | ((c >> 0) & 0x3F)); 2206 buf[pos + 1] = (byte) (0x80 | ((c >> 6) & 0x3F)); 2207 buf[pos + 0] = (byte) (0xE0 | ((c >> 12) & 0x0F)); 2208 pos += 3; 2209 } else { 2210 buf[pos + 1] = (byte) (0x80 | ((c >> 0) & 0x3F)); 2211 buf[pos + 0] = (byte) (0xC0 | ((c >> 6) & 0x1F)); 2212 pos += 2; 2213 } 2214 } else { // write one byte at a time to normalize block 2215 if (c <= 0x007F && c != 0) { 2216 write(c); 2217 } else if (c > 0x07FF) { 2218 write(0xE0 | ((c >> 12) & 0x0F)); 2219 write(0x80 | ((c >> 6) & 0x3F)); 2220 write(0x80 | ((c >> 0) & 0x3F)); 2221 } else { 2222 write(0xC0 | ((c >> 6) & 0x1F)); 2223 write(0x80 | ((c >> 0) & 0x3F)); 2224 } 2225 } 2226 } 2227 off += csize; 2228 } 2229 } 2230 } 2231 2232 /** 2233 * Lightweight identity hash table which maps objects to integer handles, 2234 * assigned in ascending order. 2235 */ 2236 private static class HandleTable { 2237 2238 /* number of mappings in table/next available handle */ 2239 private int size; 2240 /* size threshold determining when to expand hash spine */ 2241 private int threshold; 2242 /* factor for computing size threshold */ 2243 private final float loadFactor; 2244 /* maps hash value -> candidate handle value */ 2245 private int[] spine; 2246 /* maps handle value -> next candidate handle value */ 2247 private int[] next; 2248 /* maps handle value -> associated object */ 2249 private Object[] objs; 2250 2251 /** 2252 * Creates new HandleTable with given capacity and load factor. 2253 */ 2254 HandleTable(int initialCapacity, float loadFactor) { 2255 this.loadFactor = loadFactor; 2256 spine = new int[initialCapacity]; 2257 next = new int[initialCapacity]; 2258 objs = new Object[initialCapacity]; 2259 threshold = (int) (initialCapacity * loadFactor); 2260 clear(); 2261 } 2262 2263 /** 2264 * Assigns next available handle to given object, and returns handle 2265 * value. Handles are assigned in ascending order starting at 0. 2266 */ 2267 int assign(Object obj) { 2268 if (size >= next.length) { 2269 growEntries(); 2270 } 2271 if (size >= threshold) { 2272 growSpine(); 2273 } 2274 insert(obj, size); 2275 return size++; 2276 } 2277 2278 /** 2279 * Looks up and returns handle associated with given object, or -1 if 2280 * no mapping found. 2281 */ 2282 int lookup(Object obj) { 2283 if (size == 0) { 2284 return -1; 2285 } 2286 int index = hash(obj) % spine.length; 2287 for (int i = spine[index]; i >= 0; i = next[i]) { 2288 if (objs[i] == obj) { 2289 return i; 2290 } 2291 } 2292 return -1; 2293 } 2294 2295 /** 2296 * Resets table to its initial (empty) state. 2297 */ 2298 void clear() { 2299 Arrays.fill(spine, -1); 2300 Arrays.fill(objs, 0, size, null); 2301 size = 0; 2302 } 2303 2304 /** 2305 * Returns the number of mappings currently in table. 2306 */ 2307 int size() { 2308 return size; 2309 } 2310 2311 /** 2312 * Inserts mapping object -> handle mapping into table. Assumes table 2313 * is large enough to accommodate new mapping. 2314 */ 2315 private void insert(Object obj, int handle) { 2316 int index = hash(obj) % spine.length; 2317 objs[handle] = obj; 2318 next[handle] = spine[index]; 2319 spine[index] = handle; 2320 } 2321 2322 /** 2323 * Expands the hash "spine" -- equivalent to increasing the number of 2324 * buckets in a conventional hash table. 2325 */ 2326 private void growSpine() { 2327 spine = new int[(spine.length << 1) + 1]; 2328 threshold = (int) (spine.length * loadFactor); 2329 Arrays.fill(spine, -1); 2330 for (int i = 0; i < size; i++) { 2331 insert(objs[i], i); 2332 } 2333 } 2334 2335 /** 2336 * Increases hash table capacity by lengthening entry arrays. 2337 */ 2338 private void growEntries() { 2339 int newLength = (next.length << 1) + 1; 2340 int[] newNext = new int[newLength]; 2341 System.arraycopy(next, 0, newNext, 0, size); 2342 next = newNext; 2343 2344 Object[] newObjs = new Object[newLength]; 2345 System.arraycopy(objs, 0, newObjs, 0, size); 2346 objs = newObjs; 2347 } 2348 2349 /** 2350 * Returns hash value for given object. 2351 */ 2352 private int hash(Object obj) { 2353 return System.identityHashCode(obj) & 0x7FFFFFFF; 2354 } 2355 } 2356 2357 /** 2358 * Lightweight identity hash table which maps objects to replacement 2359 * objects. 2360 */ 2361 private static class ReplaceTable { 2362 2363 /* maps object -> index */ 2364 private final HandleTable htab; 2365 /* maps index -> replacement object */ 2366 private Object[] reps; 2367 2368 /** 2369 * Creates new ReplaceTable with given capacity and load factor. 2370 */ 2371 ReplaceTable(int initialCapacity, float loadFactor) { 2372 htab = new HandleTable(initialCapacity, loadFactor); 2373 reps = new Object[initialCapacity]; 2374 } 2375 2376 /** 2377 * Enters mapping from object to replacement object. 2378 */ 2379 void assign(Object obj, Object rep) { 2380 int index = htab.assign(obj); 2381 while (index >= reps.length) { 2382 grow(); 2383 } 2384 reps[index] = rep; 2385 } 2386 2387 /** 2388 * Looks up and returns replacement for given object. If no 2389 * replacement is found, returns the lookup object itself. 2390 */ 2391 Object lookup(Object obj) { 2392 int index = htab.lookup(obj); 2393 return (index >= 0) ? reps[index] : obj; 2394 } 2395 2396 /** 2397 * Resets table to its initial (empty) state. 2398 */ 2399 void clear() { 2400 Arrays.fill(reps, 0, htab.size(), null); 2401 htab.clear(); 2402 } 2403 2404 /** 2405 * Returns the number of mappings currently in table. 2406 */ 2407 int size() { 2408 return htab.size(); 2409 } 2410 2411 /** 2412 * Increases table capacity. 2413 */ 2414 private void grow() { 2415 Object[] newReps = new Object[(reps.length << 1) + 1]; 2416 System.arraycopy(reps, 0, newReps, 0, reps.length); 2417 reps = newReps; 2418 } 2419 } 2420 2421 /** 2422 * Stack to keep debug information about the state of the 2423 * serialization process, for embedding in exception messages. 2424 */ 2425 private static class DebugTraceInfoStack { 2426 private final List<String> stack; 2427 2428 DebugTraceInfoStack() { 2429 stack = new ArrayList<>(); 2430 } 2431 2432 /** 2433 * Removes all of the elements from enclosed list. 2434 */ 2435 void clear() { 2436 stack.clear(); 2437 } 2438 2439 /** 2440 * Removes the object at the top of enclosed list. 2441 */ 2442 void pop() { 2443 stack.remove(stack.size()-1); 2444 } 2445 2446 /** 2447 * Pushes a String onto the top of enclosed list. 2448 */ 2449 void push(String entry) { 2450 stack.add("\t- " + entry); 2451 } 2452 2453 /** 2454 * Returns a string representation of this object 2455 */ 2456 public String toString() { 2457 StringBuilder buffer = new StringBuilder(); 2458 if (!stack.isEmpty()) { 2459 for(int i = stack.size(); i > 0; i-- ) { 2460 buffer.append(stack.get(i-1) + ((i != 1) ? "\n" : "")); 2461 } 2462 } 2463 return buffer.toString(); 2464 } 2465 } 2466 2467} 2468