1/* 2 * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25package java.util.jar; 26 27import java.util.SortedMap; 28import java.io.InputStream; 29import java.io.OutputStream; 30import java.io.File; 31import java.io.IOException; 32import sun.security.action.GetPropertyAction; 33 34 35/** 36 * Transforms a JAR file to or from a packed stream in Pack200 format. 37 * Please refer to <a href="{@docRoot}/../specs/pack-spec.html">Network Transfer Format JSR 200 Specification</a> 38 * <p> 39 * Typically the packer engine is used by application developers 40 * to deploy or host JAR files on a website. 41 * The unpacker engine is used by deployment applications to 42 * transform the byte-stream back to JAR format. 43 * <p> 44 * Here is an example using packer and unpacker: 45 * <pre>{@code 46 * import java.util.jar.Pack200; 47 * import java.util.jar.Pack200.*; 48 * ... 49 * // Create the Packer object 50 * Packer packer = Pack200.newPacker(); 51 * 52 * // Initialize the state by setting the desired properties 53 * Map p = packer.properties(); 54 * // take more time choosing codings for better compression 55 * p.put(Packer.EFFORT, "7"); // default is "5" 56 * // use largest-possible archive segments (>10% better compression). 57 * p.put(Packer.SEGMENT_LIMIT, "-1"); 58 * // reorder files for better compression. 59 * p.put(Packer.KEEP_FILE_ORDER, Packer.FALSE); 60 * // smear modification times to a single value. 61 * p.put(Packer.MODIFICATION_TIME, Packer.LATEST); 62 * // ignore all JAR deflation requests, 63 * // transmitting a single request to use "store" mode. 64 * p.put(Packer.DEFLATE_HINT, Packer.FALSE); 65 * // discard debug attributes 66 * p.put(Packer.CODE_ATTRIBUTE_PFX+"LineNumberTable", Packer.STRIP); 67 * // throw an error if an attribute is unrecognized 68 * p.put(Packer.UNKNOWN_ATTRIBUTE, Packer.ERROR); 69 * // pass one class file uncompressed: 70 * p.put(Packer.PASS_FILE_PFX+0, "mutants/Rogue.class"); 71 * try { 72 * JarFile jarFile = new JarFile("/tmp/testref.jar"); 73 * FileOutputStream fos = new FileOutputStream("/tmp/test.pack"); 74 * // Call the packer 75 * packer.pack(jarFile, fos); 76 * jarFile.close(); 77 * fos.close(); 78 * 79 * File f = new File("/tmp/test.pack"); 80 * FileOutputStream fostream = new FileOutputStream("/tmp/test.jar"); 81 * JarOutputStream jostream = new JarOutputStream(fostream); 82 * Unpacker unpacker = Pack200.newUnpacker(); 83 * // Call the unpacker 84 * unpacker.unpack(f, jostream); 85 * // Must explicitly close the output. 86 * jostream.close(); 87 * } catch (IOException ioe) { 88 * ioe.printStackTrace(); 89 * } 90 * }</pre> 91 * <p> 92 * A Pack200 file compressed with gzip can be hosted on HTTP/1.1 web servers. 93 * The deployment applications can use "Accept-Encoding=pack200-gzip". This 94 * indicates to the server that the client application desires a version of 95 * the file encoded with Pack200 and further compressed with gzip. Please 96 * refer to the Java Deployment Guide for techniques and details. 97 * <p> 98 * Unless otherwise noted, passing a {@code null} argument to a constructor or 99 * method in this class will cause a {@link NullPointerException} to be thrown. 100 * 101 * @author John Rose 102 * @author Kumar Srinivasan 103 * @since 1.5 104 */ 105public abstract class Pack200 { 106 private Pack200() {} //prevent instantiation 107 108 // Static methods of the Pack200 class. 109 /** 110 * Obtain new instance of a class that implements Packer. 111 * <ul> 112 * <li><p>If the system property {@code java.util.jar.Pack200.Packer} 113 * is defined, then the value is taken to be the fully-qualified name 114 * of a concrete implementation class, which must implement Packer. 115 * This class is loaded and instantiated. If this process fails 116 * then an unspecified error is thrown.</p></li> 117 * 118 * <li><p>If an implementation has not been specified with the system 119 * property, then the system-default implementation class is instantiated, 120 * and the result is returned.</p></li> 121 * </ul> 122 * 123 * <p>Note: The returned object is not guaranteed to operate 124 * correctly if multiple threads use it at the same time. 125 * A multi-threaded application should either allocate multiple 126 * packer engines, or else serialize use of one engine with a lock. 127 * 128 * @return A newly allocated Packer engine. 129 */ 130 public static synchronized Packer newPacker() { 131 return (Packer) newInstance(PACK_PROVIDER); 132 } 133 134 135 /** 136 * Obtain new instance of a class that implements Unpacker. 137 * <ul> 138 * <li><p>If the system property {@code java.util.jar.Pack200.Unpacker} 139 * is defined, then the value is taken to be the fully-qualified 140 * name of a concrete implementation class, which must implement Unpacker. 141 * The class is loaded and instantiated. If this process fails 142 * then an unspecified error is thrown.</p></li> 143 * 144 * <li><p>If an implementation has not been specified with the 145 * system property, then the system-default implementation class 146 * is instantiated, and the result is returned.</p></li> 147 * </ul> 148 * 149 * <p>Note: The returned object is not guaranteed to operate 150 * correctly if multiple threads use it at the same time. 151 * A multi-threaded application should either allocate multiple 152 * unpacker engines, or else serialize use of one engine with a lock. 153 * 154 * @return A newly allocated Unpacker engine. 155 */ 156 157 public static Unpacker newUnpacker() { 158 return (Unpacker) newInstance(UNPACK_PROVIDER); 159 } 160 161 // Interfaces 162 /** 163 * The packer engine applies various transformations to the input JAR file, 164 * making the pack stream highly compressible by a compressor such as 165 * gzip or zip. An instance of the engine can be obtained 166 * using {@link #newPacker}. 167 168 * The high degree of compression is achieved 169 * by using a number of techniques described in the JSR 200 specification. 170 * Some of the techniques are sorting, re-ordering and co-location of the 171 * constant pool. 172 * <p> 173 * The pack engine is initialized to an initial state as described 174 * by their properties below. 175 * The initial state can be manipulated by getting the 176 * engine properties (using {@link #properties}) and storing 177 * the modified properties on the map. 178 * The resource files will be passed through with no changes at all. 179 * The class files will not contain identical bytes, since the unpacker 180 * is free to change minor class file features such as constant pool order. 181 * However, the class files will be semantically identical, 182 * as specified in 183 * <cite>The Java™ Virtual Machine Specification</cite>. 184 * <p> 185 * By default, the packer does not change the order of JAR elements. 186 * Also, the modification time and deflation hint of each 187 * JAR element is passed unchanged. 188 * (Any other ZIP-archive information, such as extra attributes 189 * giving Unix file permissions, are lost.) 190 * <p> 191 * Note that packing and unpacking a JAR will in general alter the 192 * bytewise contents of classfiles in the JAR. This means that packing 193 * and unpacking will in general invalidate any digital signatures 194 * which rely on bytewise images of JAR elements. In order both to sign 195 * and to pack a JAR, you must first pack and unpack the JAR to 196 * "normalize" it, then compute signatures on the unpacked JAR elements, 197 * and finally repack the signed JAR. 198 * Both packing steps should 199 * use precisely the same options, and the segment limit may also 200 * need to be set to "-1", to prevent accidental variation of segment 201 * boundaries as class file sizes change slightly. 202 * <p> 203 * (Here's why this works: Any reordering the packer does 204 * of any classfile structures is idempotent, so the second packing 205 * does not change the orderings produced by the first packing. 206 * Also, the unpacker is guaranteed by the JSR 200 specification 207 * to produce a specific bytewise image for any given transmission 208 * ordering of archive elements.) 209 * <p> 210 * In order to maintain backward compatibility, the pack file's version is 211 * set to accommodate the class files present in the input JAR file. In 212 * other words, the pack file version will be the latest, if the class files 213 * are the latest and conversely the pack file version will be the oldest 214 * if the class file versions are also the oldest. For intermediate class 215 * file versions the corresponding pack file version will be used. 216 * For example: 217 * If the input JAR-files are solely comprised of 1.5 (or lesser) 218 * class files, a 1.5 compatible pack file is produced. This will also be 219 * the case for archives that have no class files. 220 * If the input JAR-files contains a 1.6 class file, then the pack file 221 * version will be set to 1.6. 222 * <p> 223 * Note: Unless otherwise noted, passing a {@code null} argument to a 224 * constructor or method in this class will cause a {@link NullPointerException} 225 * to be thrown. 226 * 227 * @since 1.5 228 */ 229 public interface Packer { 230 /** 231 * This property is a numeral giving the estimated target size N 232 * (in bytes) of each archive segment. 233 * If a single input file requires more than N bytes, 234 * it will be given its own archive segment. 235 * <p> 236 * As a special case, a value of -1 will produce a single large 237 * segment with all input files, while a value of 0 will 238 * produce one segment for each class. 239 * Larger archive segments result in less fragmentation and 240 * better compression, but processing them requires more memory. 241 * <p> 242 * The size of each segment is estimated by counting the size of each 243 * input file to be transmitted in the segment, along with the size 244 * of its name and other transmitted properties. 245 * <p> 246 * The default is -1, which means the packer will always create a single 247 * segment output file. In cases where extremely large output files are 248 * generated, users are strongly encouraged to use segmenting or break 249 * up the input file into smaller JARs. 250 * <p> 251 * A 10Mb JAR packed without this limit will 252 * typically pack about 10% smaller, but the packer may require 253 * a larger Java heap (about ten times the segment limit). 254 */ 255 String SEGMENT_LIMIT = "pack.segment.limit"; 256 257 /** 258 * If this property is set to {@link #TRUE}, the packer will transmit 259 * all elements in their original order within the source archive. 260 * <p> 261 * If it is set to {@link #FALSE}, the packer may reorder elements, 262 * and also remove JAR directory entries, which carry no useful 263 * information for Java applications. 264 * (Typically this enables better compression.) 265 * <p> 266 * The default is {@link #TRUE}, which preserves the input information, 267 * but may cause the transmitted archive to be larger than necessary. 268 */ 269 String KEEP_FILE_ORDER = "pack.keep.file.order"; 270 271 272 /** 273 * If this property is set to a single decimal digit, the packer will 274 * use the indicated amount of effort in compressing the archive. 275 * Level 1 may produce somewhat larger size and faster compression speed, 276 * while level 9 will take much longer but may produce better compression. 277 * <p> 278 * The special value 0 instructs the packer to copy through the 279 * original JAR file directly, with no compression. The JSR 200 280 * standard requires any unpacker to understand this special case 281 * as a pass-through of the entire archive. 282 * <p> 283 * The default is 5, investing a modest amount of time to 284 * produce reasonable compression. 285 */ 286 String EFFORT = "pack.effort"; 287 288 /** 289 * If this property is set to {@link #TRUE} or {@link #FALSE}, the packer 290 * will set the deflation hint accordingly in the output archive, and 291 * will not transmit the individual deflation hints of archive elements. 292 * <p> 293 * If this property is set to the special string {@link #KEEP}, the packer 294 * will attempt to determine an independent deflation hint for each 295 * available element of the input archive, and transmit this hint separately. 296 * <p> 297 * The default is {@link #KEEP}, which preserves the input information, 298 * but may cause the transmitted archive to be larger than necessary. 299 * <p> 300 * It is up to the unpacker implementation 301 * to take action upon the hint to suitably compress the elements of 302 * the resulting unpacked jar. 303 * <p> 304 * The deflation hint of a ZIP or JAR element indicates 305 * whether the element was deflated or stored directly. 306 */ 307 String DEFLATE_HINT = "pack.deflate.hint"; 308 309 /** 310 * If this property is set to the special string {@link #LATEST}, 311 * the packer will attempt to determine the latest modification time, 312 * among all the available entries in the original archive or the latest 313 * modification time of all the available entries in each segment. 314 * This single value will be transmitted as part of the segment and applied 315 * to all the entries in each segment, {@link #SEGMENT_LIMIT}. 316 * <p> 317 * This can marginally decrease the transmitted size of the 318 * archive, at the expense of setting all installed files to a single 319 * date. 320 * <p> 321 * If this property is set to the special string {@link #KEEP}, 322 * the packer transmits a separate modification time for each input 323 * element. 324 * <p> 325 * The default is {@link #KEEP}, which preserves the input information, 326 * but may cause the transmitted archive to be larger than necessary. 327 * <p> 328 * It is up to the unpacker implementation to take action to suitably 329 * set the modification time of each element of its output file. 330 * @see #SEGMENT_LIMIT 331 */ 332 String MODIFICATION_TIME = "pack.modification.time"; 333 334 /** 335 * Indicates that a file should be passed through bytewise, with no 336 * compression. Multiple files may be specified by specifying 337 * additional properties with distinct strings appended, to 338 * make a family of properties with the common prefix. 339 * <p> 340 * There is no pathname transformation, except 341 * that the system file separator is replaced by the JAR file 342 * separator '/'. 343 * <p> 344 * The resulting file names must match exactly as strings with their 345 * occurrences in the JAR file. 346 * <p> 347 * If a property value is a directory name, all files under that 348 * directory will be passed also. 349 * <p> 350 * Examples: 351 * <pre>{@code 352 * Map p = packer.properties(); 353 * p.put(PASS_FILE_PFX+0, "mutants/Rogue.class"); 354 * p.put(PASS_FILE_PFX+1, "mutants/Wolverine.class"); 355 * p.put(PASS_FILE_PFX+2, "mutants/Storm.class"); 356 * # Pass all files in an entire directory hierarchy: 357 * p.put(PASS_FILE_PFX+3, "police/"); 358 * }</pre> 359 */ 360 String PASS_FILE_PFX = "pack.pass.file."; 361 362 /// Attribute control. 363 364 /** 365 * Indicates the action to take when a class-file containing an unknown 366 * attribute is encountered. Possible values are the strings {@link #ERROR}, 367 * {@link #STRIP}, and {@link #PASS}. 368 * <p> 369 * The string {@link #ERROR} means that the pack operation 370 * as a whole will fail, with an exception of type {@code IOException}. 371 * The string 372 * {@link #STRIP} means that the attribute will be dropped. 373 * The string 374 * {@link #PASS} means that the whole class-file will be passed through 375 * (as if it were a resource file) without compression, with a suitable warning. 376 * This is the default value for this property. 377 * <p> 378 * Examples: 379 * <pre>{@code 380 * Map p = pack200.getProperties(); 381 * p.put(UNKNOWN_ATTRIBUTE, ERROR); 382 * p.put(UNKNOWN_ATTRIBUTE, STRIP); 383 * p.put(UNKNOWN_ATTRIBUTE, PASS); 384 * }</pre> 385 */ 386 String UNKNOWN_ATTRIBUTE = "pack.unknown.attribute"; 387 388 /** 389 * When concatenated with a class attribute name, 390 * indicates the format of that attribute, 391 * using the layout language specified in the JSR 200 specification. 392 * <p> 393 * For example, the effect of this option is built in: 394 * {@code pack.class.attribute.SourceFile=RUH}. 395 * <p> 396 * The special strings {@link #ERROR}, {@link #STRIP}, and {@link #PASS} are 397 * also allowed, with the same meaning as {@link #UNKNOWN_ATTRIBUTE}. 398 * This provides a way for users to request that specific attributes be 399 * refused, stripped, or passed bitwise (with no class compression). 400 * <p> 401 * Code like this might be used to support attributes for JCOV: 402 * <pre>{@code 403 * Map p = packer.properties(); 404 * p.put(CODE_ATTRIBUTE_PFX+"CoverageTable", "NH[PHHII]"); 405 * p.put(CODE_ATTRIBUTE_PFX+"CharacterRangeTable", "NH[PHPOHIIH]"); 406 * p.put(CLASS_ATTRIBUTE_PFX+"SourceID", "RUH"); 407 * p.put(CLASS_ATTRIBUTE_PFX+"CompilationID", "RUH"); 408 * }</pre> 409 * <p> 410 * Code like this might be used to strip debugging attributes: 411 * <pre>{@code 412 * Map p = packer.properties(); 413 * p.put(CODE_ATTRIBUTE_PFX+"LineNumberTable", STRIP); 414 * p.put(CODE_ATTRIBUTE_PFX+"LocalVariableTable", STRIP); 415 * p.put(CLASS_ATTRIBUTE_PFX+"SourceFile", STRIP); 416 * }</pre> 417 */ 418 String CLASS_ATTRIBUTE_PFX = "pack.class.attribute."; 419 420 /** 421 * When concatenated with a field attribute name, 422 * indicates the format of that attribute. 423 * For example, the effect of this option is built in: 424 * {@code pack.field.attribute.Deprecated=}. 425 * The special strings {@link #ERROR}, {@link #STRIP}, and 426 * {@link #PASS} are also allowed. 427 * @see #CLASS_ATTRIBUTE_PFX 428 */ 429 String FIELD_ATTRIBUTE_PFX = "pack.field.attribute."; 430 431 /** 432 * When concatenated with a method attribute name, 433 * indicates the format of that attribute. 434 * For example, the effect of this option is built in: 435 * {@code pack.method.attribute.Exceptions=NH[RCH]}. 436 * The special strings {@link #ERROR}, {@link #STRIP}, and {@link #PASS} 437 * are also allowed. 438 * @see #CLASS_ATTRIBUTE_PFX 439 */ 440 String METHOD_ATTRIBUTE_PFX = "pack.method.attribute."; 441 442 /** 443 * When concatenated with a code attribute name, 444 * indicates the format of that attribute. 445 * For example, the effect of this option is built in: 446 * {@code pack.code.attribute.LocalVariableTable=NH[PHOHRUHRSHH]}. 447 * The special strings {@link #ERROR}, {@link #STRIP}, and {@link #PASS} 448 * are also allowed. 449 * @see #CLASS_ATTRIBUTE_PFX 450 */ 451 String CODE_ATTRIBUTE_PFX = "pack.code.attribute."; 452 453 /** 454 * The packer's progress as a percentage, as periodically 455 * updated by the packer. 456 * Values of 0 - 100 are normal, and -1 indicates a stall. 457 * Progress can be monitored by polling the value of this 458 * property. 459 * <p> 460 * At a minimum, the packer must set progress to 0 461 * at the beginning of a packing operation, and to 100 462 * at the end. 463 */ 464 String PROGRESS = "pack.progress"; 465 466 /** The string "keep", a possible value for certain properties. 467 * @see #DEFLATE_HINT 468 * @see #MODIFICATION_TIME 469 */ 470 String KEEP = "keep"; 471 472 /** The string "pass", a possible value for certain properties. 473 * @see #UNKNOWN_ATTRIBUTE 474 * @see #CLASS_ATTRIBUTE_PFX 475 * @see #FIELD_ATTRIBUTE_PFX 476 * @see #METHOD_ATTRIBUTE_PFX 477 * @see #CODE_ATTRIBUTE_PFX 478 */ 479 String PASS = "pass"; 480 481 /** The string "strip", a possible value for certain properties. 482 * @see #UNKNOWN_ATTRIBUTE 483 * @see #CLASS_ATTRIBUTE_PFX 484 * @see #FIELD_ATTRIBUTE_PFX 485 * @see #METHOD_ATTRIBUTE_PFX 486 * @see #CODE_ATTRIBUTE_PFX 487 */ 488 String STRIP = "strip"; 489 490 /** The string "error", a possible value for certain properties. 491 * @see #UNKNOWN_ATTRIBUTE 492 * @see #CLASS_ATTRIBUTE_PFX 493 * @see #FIELD_ATTRIBUTE_PFX 494 * @see #METHOD_ATTRIBUTE_PFX 495 * @see #CODE_ATTRIBUTE_PFX 496 */ 497 String ERROR = "error"; 498 499 /** The string "true", a possible value for certain properties. 500 * @see #KEEP_FILE_ORDER 501 * @see #DEFLATE_HINT 502 */ 503 String TRUE = "true"; 504 505 /** The string "false", a possible value for certain properties. 506 * @see #KEEP_FILE_ORDER 507 * @see #DEFLATE_HINT 508 */ 509 String FALSE = "false"; 510 511 /** The string "latest", a possible value for certain properties. 512 * @see #MODIFICATION_TIME 513 */ 514 String LATEST = "latest"; 515 516 /** 517 * Get the set of this engine's properties. 518 * This set is a "live view", so that changing its 519 * contents immediately affects the Packer engine, and 520 * changes from the engine (such as progress indications) 521 * are immediately visible in the map. 522 * 523 * <p>The property map may contain pre-defined implementation 524 * specific and default properties. Users are encouraged to 525 * read the information and fully understand the implications, 526 * before modifying pre-existing properties. 527 * <p> 528 * Implementation specific properties are prefixed with a 529 * package name associated with the implementor, beginning 530 * with {@code com.} or a similar prefix. 531 * All property names beginning with {@code pack.} and 532 * {@code unpack.} are reserved for use by this API. 533 * <p> 534 * Unknown properties may be ignored or rejected with an 535 * unspecified error, and invalid entries may cause an 536 * unspecified error to be thrown. 537 * 538 * <p> 539 * The returned map implements all optional {@link SortedMap} operations 540 * @return A sorted association of property key strings to property 541 * values. 542 */ 543 SortedMap<String,String> properties(); 544 545 /** 546 * Takes a JarFile and converts it into a Pack200 archive. 547 * <p> 548 * Closes its input but not its output. (Pack200 archives are appendable.) 549 * @param in a JarFile 550 * @param out an OutputStream 551 * @exception IOException if an error is encountered. 552 */ 553 void pack(JarFile in, OutputStream out) throws IOException ; 554 555 /** 556 * Takes a JarInputStream and converts it into a Pack200 archive. 557 * <p> 558 * Closes its input but not its output. (Pack200 archives are appendable.) 559 * <p> 560 * The modification time and deflation hint attributes are not available, 561 * for the JAR manifest file and its containing directory. 562 * 563 * @see #MODIFICATION_TIME 564 * @see #DEFLATE_HINT 565 * @param in a JarInputStream 566 * @param out an OutputStream 567 * @exception IOException if an error is encountered. 568 */ 569 void pack(JarInputStream in, OutputStream out) throws IOException ; 570 } 571 572 /** 573 * The unpacker engine converts the packed stream to a JAR file. 574 * An instance of the engine can be obtained 575 * using {@link #newUnpacker}. 576 * <p> 577 * Every JAR file produced by this engine will include the string 578 * "{@code PACK200}" as a zip file comment. 579 * This allows a deployer to detect if a JAR archive was packed and unpacked. 580 * <p> 581 * Note: Unless otherwise noted, passing a {@code null} argument to a 582 * constructor or method in this class will cause a {@link NullPointerException} 583 * to be thrown. 584 * <p> 585 * This version of the unpacker is compatible with all previous versions. 586 * @since 1.5 587 */ 588 public interface Unpacker { 589 590 /** The string "keep", a possible value for certain properties. 591 * @see #DEFLATE_HINT 592 */ 593 String KEEP = "keep"; 594 595 /** The string "true", a possible value for certain properties. 596 * @see #DEFLATE_HINT 597 */ 598 String TRUE = "true"; 599 600 /** The string "false", a possible value for certain properties. 601 * @see #DEFLATE_HINT 602 */ 603 String FALSE = "false"; 604 605 /** 606 * Property indicating that the unpacker should 607 * ignore all transmitted values for DEFLATE_HINT, 608 * replacing them by the given value, {@link #TRUE} or {@link #FALSE}. 609 * The default value is the special string {@link #KEEP}, 610 * which asks the unpacker to preserve all transmitted 611 * deflation hints. 612 */ 613 String DEFLATE_HINT = "unpack.deflate.hint"; 614 615 616 617 /** 618 * The unpacker's progress as a percentage, as periodically 619 * updated by the unpacker. 620 * Values of 0 - 100 are normal, and -1 indicates a stall. 621 * Progress can be monitored by polling the value of this 622 * property. 623 * <p> 624 * At a minimum, the unpacker must set progress to 0 625 * at the beginning of an unpacking operation, and to 100 626 * at the end. 627 */ 628 String PROGRESS = "unpack.progress"; 629 630 /** 631 * Get the set of this engine's properties. This set is 632 * a "live view", so that changing its 633 * contents immediately affects the Unpacker engine, and 634 * changes from the engine (such as progress indications) 635 * are immediately visible in the map. 636 * 637 * <p>The property map may contain pre-defined implementation 638 * specific and default properties. Users are encouraged to 639 * read the information and fully understand the implications, 640 * before modifying pre-existing properties. 641 * <p> 642 * Implementation specific properties are prefixed with a 643 * package name associated with the implementor, beginning 644 * with {@code com.} or a similar prefix. 645 * All property names beginning with {@code pack.} and 646 * {@code unpack.} are reserved for use by this API. 647 * <p> 648 * Unknown properties may be ignored or rejected with an 649 * unspecified error, and invalid entries may cause an 650 * unspecified error to be thrown. 651 * 652 * @return A sorted association of option key strings to option values. 653 */ 654 SortedMap<String,String> properties(); 655 656 /** 657 * Read a Pack200 archive, and write the encoded JAR to 658 * a JarOutputStream. 659 * The entire contents of the input stream will be read. 660 * It may be more efficient to read the Pack200 archive 661 * to a file and pass the File object, using the alternate 662 * method described below. 663 * <p> 664 * Closes its input but not its output. (The output can accumulate more elements.) 665 * @param in an InputStream. 666 * @param out a JarOutputStream. 667 * @exception IOException if an error is encountered. 668 */ 669 void unpack(InputStream in, JarOutputStream out) throws IOException; 670 671 /** 672 * Read a Pack200 archive, and write the encoded JAR to 673 * a JarOutputStream. 674 * <p> 675 * Does not close its output. (The output can accumulate more elements.) 676 * @param in a File. 677 * @param out a JarOutputStream. 678 * @exception IOException if an error is encountered. 679 */ 680 void unpack(File in, JarOutputStream out) throws IOException; 681 } 682 683 // Private stuff.... 684 685 private static final String PACK_PROVIDER = "java.util.jar.Pack200.Packer"; 686 private static final String UNPACK_PROVIDER = "java.util.jar.Pack200.Unpacker"; 687 688 private static Class<?> packerImpl; 689 private static Class<?> unpackerImpl; 690 691 private static synchronized Object newInstance(String prop) { 692 String implName = "(unknown)"; 693 try { 694 Class<?> impl = (PACK_PROVIDER.equals(prop))? packerImpl: unpackerImpl; 695 if (impl == null) { 696 // The first time, we must decide which class to use. 697 implName = GetPropertyAction.privilegedGetProperty(prop,""); 698 if (implName != null && !implName.equals("")) 699 impl = Class.forName(implName); 700 else if (PACK_PROVIDER.equals(prop)) 701 impl = com.sun.java.util.jar.pack.PackerImpl.class; 702 else 703 impl = com.sun.java.util.jar.pack.UnpackerImpl.class; 704 } 705 // We have a class. Now instantiate it. 706 @SuppressWarnings("deprecation") 707 Object result = impl.newInstance(); 708 return result; 709 } catch (ClassNotFoundException e) { 710 throw new Error("Class not found: " + implName + 711 ":\ncheck property " + prop + 712 " in your properties file.", e); 713 } catch (InstantiationException e) { 714 throw new Error("Could not instantiate: " + implName + 715 ":\ncheck property " + prop + 716 " in your properties file.", e); 717 } catch (IllegalAccessException e) { 718 throw new Error("Cannot access class: " + implName + 719 ":\ncheck property " + prop + 720 " in your properties file.", e); 721 } 722 } 723 724} 725