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 */
25 package java.util.jar;
26
27 import java.util.SortedMap;
28 import java.io.InputStream;
29 import java.io.OutputStream;
30 import java.io.File;
31 import java.io.IOException;
32 import 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 * @deprecated This class has been deprecated
105 */
106 @Deprecated(since="11", forRemoval=true)
107 public abstract class Pack200 {
108 private Pack200() {} //prevent instantiation
109
110 // Static methods of the Pack200 class.
111 /**
112 * Obtain new instance of a class that implements Packer.
113 * <ul>
114 * <li><p>If the system property {@code java.util.jar.Pack200.Packer}
115 * is defined, then the value is taken to be the fully-qualified name
116 * of a concrete implementation class, which must implement Packer.
117 * This class is loaded and instantiated. If this process fails
118 * then an unspecified error is thrown.</p></li>
119 *
120 * <li><p>If an implementation has not been specified with the system
121 * property, then the system-default implementation class is instantiated,
122 * and the result is returned.</p></li>
123 * </ul>
124 *
125 * <p>Note: The returned object is not guaranteed to operate
126 * correctly if multiple threads use it at the same time.
127 * A multi-threaded application should either allocate multiple
128 * packer engines, or else serialize use of one engine with a lock.
129 *
130 * @return A newly allocated Packer engine.
131 */
132 public static synchronized Packer newPacker() {
133 return (Packer) newInstance(PACK_PROVIDER);
134 }
135
136
137 /**
138 * Obtain new instance of a class that implements Unpacker.
139 * <ul>
140 * <li><p>If the system property {@code java.util.jar.Pack200.Unpacker}
141 * is defined, then the value is taken to be the fully-qualified
142 * name of a concrete implementation class, which must implement Unpacker.
143 * The class is loaded and instantiated. If this process fails
144 * then an unspecified error is thrown.</p></li>
145 *
146 * <li><p>If an implementation has not been specified with the
147 * system property, then the system-default implementation class
148 * is instantiated, and the result is returned.</p></li>
149 * </ul>
150 *
151 * <p>Note: The returned object is not guaranteed to operate
152 * correctly if multiple threads use it at the same time.
153 * A multi-threaded application should either allocate multiple
154 * unpacker engines, or else serialize use of one engine with a lock.
155 *
156 * @return A newly allocated Unpacker engine.
157 */
158
159 public static Unpacker newUnpacker() {
160 return (Unpacker) newInstance(UNPACK_PROVIDER);
161 }
162
163 // Interfaces
164 /**
165 * The packer engine applies various transformations to the input JAR file,
166 * making the pack stream highly compressible by a compressor such as
167 * gzip or zip. An instance of the engine can be obtained
168 * using {@link #newPacker}.
169
170 * The high degree of compression is achieved
171 * by using a number of techniques described in the JSR 200 specification.
172 * Some of the techniques are sorting, re-ordering and co-location of the
173 * constant pool.
174 * <p>
175 * The pack engine is initialized to an initial state as described
176 * by their properties below.
177 * The initial state can be manipulated by getting the
178 * engine properties (using {@link #properties}) and storing
179 * the modified properties on the map.
180 * The resource files will be passed through with no changes at all.
181 * The class files will not contain identical bytes, since the unpacker
182 * is free to change minor class file features such as constant pool order.
183 * However, the class files will be semantically identical,
184 * as specified in
185 * <cite>The Java™ Virtual Machine Specification</cite>.
186 * <p>
187 * By default, the packer does not change the order of JAR elements.
188 * Also, the modification time and deflation hint of each
189 * JAR element is passed unchanged.
190 * (Any other ZIP-archive information, such as extra attributes
191 * giving Unix file permissions, are lost.)
192 * <p>
193 * Note that packing and unpacking a JAR will in general alter the
194 * bytewise contents of classfiles in the JAR. This means that packing
195 * and unpacking will in general invalidate any digital signatures
196 * which rely on bytewise images of JAR elements. In order both to sign
197 * and to pack a JAR, you must first pack and unpack the JAR to
198 * "normalize" it, then compute signatures on the unpacked JAR elements,
199 * and finally repack the signed JAR.
200 * Both packing steps should
201 * use precisely the same options, and the segment limit may also
202 * need to be set to "-1", to prevent accidental variation of segment
203 * boundaries as class file sizes change slightly.
204 * <p>
205 * (Here's why this works: Any reordering the packer does
206 * of any classfile structures is idempotent, so the second packing
207 * does not change the orderings produced by the first packing.
208 * Also, the unpacker is guaranteed by the JSR 200 specification
209 * to produce a specific bytewise image for any given transmission
210 * ordering of archive elements.)
211 * <p>
212 * In order to maintain backward compatibility, the pack file's version is
213 * set to accommodate the class files present in the input JAR file. In
214 * other words, the pack file version will be the latest, if the class files
215 * are the latest and conversely the pack file version will be the oldest
216 * if the class file versions are also the oldest. For intermediate class
217 * file versions the corresponding pack file version will be used.
218 * For example:
219 * If the input JAR-files are solely comprised of 1.5 (or lesser)
220 * class files, a 1.5 compatible pack file is produced. This will also be
221 * the case for archives that have no class files.
222 * If the input JAR-files contains a 1.6 class file, then the pack file
223 * version will be set to 1.6.
224 * <p>
225 * Note: Unless otherwise noted, passing a {@code null} argument to a
226 * constructor or method in this class will cause a {@link NullPointerException}
227 * to be thrown.
228 *
229 * @since 1.5
230 */
231 @Deprecated(since="11", forRemoval=true)
232 public interface Packer {
233 /**
234 * This property is a numeral giving the estimated target size N
235 * (in bytes) of each archive segment.
236 * If a single input file requires more than N bytes,
237 * it will be given its own archive segment.
238 * <p>
239 * As a special case, a value of -1 will produce a single large
240 * segment with all input files, while a value of 0 will
241 * produce one segment for each class.
242 * Larger archive segments result in less fragmentation and
243 * better compression, but processing them requires more memory.
244 * <p>
245 * The size of each segment is estimated by counting the size of each
246 * input file to be transmitted in the segment, along with the size
247 * of its name and other transmitted properties.
248 * <p>
249 * The default is -1, which means the packer will always create a single
250 * segment output file. In cases where extremely large output files are
251 * generated, users are strongly encouraged to use segmenting or break
252 * up the input file into smaller JARs.
253 * <p>
254 * A 10Mb JAR packed without this limit will
255 * typically pack about 10% smaller, but the packer may require
256 * a larger Java heap (about ten times the segment limit).
257 */
258 String SEGMENT_LIMIT = "pack.segment.limit";
259
260 /**
261 * If this property is set to {@link #TRUE}, the packer will transmit
262 * all elements in their original order within the source archive.
263 * <p>
264 * If it is set to {@link #FALSE}, the packer may reorder elements,
265 * and also remove JAR directory entries, which carry no useful
266 * information for Java applications.
267 * (Typically this enables better compression.)
268 * <p>
269 * The default is {@link #TRUE}, which preserves the input information,
270 * but may cause the transmitted archive to be larger than necessary.
271 */
272 String KEEP_FILE_ORDER = "pack.keep.file.order";
273
274
275 /**
276 * If this property is set to a single decimal digit, the packer will
277 * use the indicated amount of effort in compressing the archive.
278 * Level 1 may produce somewhat larger size and faster compression speed,
279 * while level 9 will take much longer but may produce better compression.
280 * <p>
281 * The special value 0 instructs the packer to copy through the
282 * original JAR file directly, with no compression. The JSR 200
283 * standard requires any unpacker to understand this special case
284 * as a pass-through of the entire archive.
285 * <p>
286 * The default is 5, investing a modest amount of time to
287 * produce reasonable compression.
288 */
289 String EFFORT = "pack.effort";
290
291 /**
292 * If this property is set to {@link #TRUE} or {@link #FALSE}, the packer
293 * will set the deflation hint accordingly in the output archive, and
294 * will not transmit the individual deflation hints of archive elements.
295 * <p>
296 * If this property is set to the special string {@link #KEEP}, the packer
297 * will attempt to determine an independent deflation hint for each
298 * available element of the input archive, and transmit this hint separately.
299 * <p>
300 * The default is {@link #KEEP}, which preserves the input information,
301 * but may cause the transmitted archive to be larger than necessary.
302 * <p>
303 * It is up to the unpacker implementation
304 * to take action upon the hint to suitably compress the elements of
305 * the resulting unpacked jar.
306 * <p>
307 * The deflation hint of a ZIP or JAR element indicates
308 * whether the element was deflated or stored directly.
309 */
310 String DEFLATE_HINT = "pack.deflate.hint";
311
312 /**
313 * If this property is set to the special string {@link #LATEST},
314 * the packer will attempt to determine the latest modification time,
315 * among all the available entries in the original archive or the latest
316 * modification time of all the available entries in each segment.
317 * This single value will be transmitted as part of the segment and applied
318 * to all the entries in each segment, {@link #SEGMENT_LIMIT}.
319 * <p>
320 * This can marginally decrease the transmitted size of the
321 * archive, at the expense of setting all installed files to a single
322 * date.
323 * <p>
324 * If this property is set to the special string {@link #KEEP},
325 * the packer transmits a separate modification time for each input
326 * element.
327 * <p>
328 * The default is {@link #KEEP}, which preserves the input information,
329 * but may cause the transmitted archive to be larger than necessary.
330 * <p>
331 * It is up to the unpacker implementation to take action to suitably
332 * set the modification time of each element of its output file.
333 * @see #SEGMENT_LIMIT
334 */
335 String MODIFICATION_TIME = "pack.modification.time";
336
337 /**
338 * Indicates that a file should be passed through bytewise, with no
339 * compression. Multiple files may be specified by specifying
340 * additional properties with distinct strings appended, to
341 * make a family of properties with the common prefix.
342 * <p>
343 * There is no pathname transformation, except
344 * that the system file separator is replaced by the JAR file
345 * separator '/'.
346 * <p>
347 * The resulting file names must match exactly as strings with their
348 * occurrences in the JAR file.
349 * <p>
350 * If a property value is a directory name, all files under that
351 * directory will be passed also.
352 * <p>
353 * Examples:
354 * <pre>{@code
355 * Map p = packer.properties();
356 * p.put(PASS_FILE_PFX+0, "mutants/Rogue.class");
357 * p.put(PASS_FILE_PFX+1, "mutants/Wolverine.class");
358 * p.put(PASS_FILE_PFX+2, "mutants/Storm.class");
359 * # Pass all files in an entire directory hierarchy:
360 * p.put(PASS_FILE_PFX+3, "police/");
361 * }</pre>
362 */
363 String PASS_FILE_PFX = "pack.pass.file.";
364
365 /// Attribute control.
366
367 /**
368 * Indicates the action to take when a class-file containing an unknown
369 * attribute is encountered. Possible values are the strings {@link #ERROR},
370 * {@link #STRIP}, and {@link #PASS}.
371 * <p>
372 * The string {@link #ERROR} means that the pack operation
373 * as a whole will fail, with an exception of type {@code IOException}.
374 * The string
375 * {@link #STRIP} means that the attribute will be dropped.
376 * The string
377 * {@link #PASS} means that the whole class-file will be passed through
378 * (as if it were a resource file) without compression, with a suitable warning.
379 * This is the default value for this property.
380 * <p>
381 * Examples:
382 * <pre>{@code
383 * Map p = pack200.getProperties();
384 * p.put(UNKNOWN_ATTRIBUTE, ERROR);
385 * p.put(UNKNOWN_ATTRIBUTE, STRIP);
386 * p.put(UNKNOWN_ATTRIBUTE, PASS);
387 * }</pre>
388 */
389 String UNKNOWN_ATTRIBUTE = "pack.unknown.attribute";
390
391 /**
392 * When concatenated with a class attribute name,
393 * indicates the format of that attribute,
394 * using the layout language specified in the JSR 200 specification.
395 * <p>
396 * For example, the effect of this option is built in:
397 * {@code pack.class.attribute.SourceFile=RUH}.
398 * <p>
399 * The special strings {@link #ERROR}, {@link #STRIP}, and {@link #PASS} are
400 * also allowed, with the same meaning as {@link #UNKNOWN_ATTRIBUTE}.
401 * This provides a way for users to request that specific attributes be
402 * refused, stripped, or passed bitwise (with no class compression).
403 * <p>
404 * Code like this might be used to support attributes for JCOV:
405 * <pre>{@code
406 * Map p = packer.properties();
407 * p.put(CODE_ATTRIBUTE_PFX+"CoverageTable", "NH[PHHII]");
408 * p.put(CODE_ATTRIBUTE_PFX+"CharacterRangeTable", "NH[PHPOHIIH]");
409 * p.put(CLASS_ATTRIBUTE_PFX+"SourceID", "RUH");
410 * p.put(CLASS_ATTRIBUTE_PFX+"CompilationID", "RUH");
411 * }</pre>
412 * <p>
413 * Code like this might be used to strip debugging attributes:
414 * <pre>{@code
415 * Map p = packer.properties();
416 * p.put(CODE_ATTRIBUTE_PFX+"LineNumberTable", STRIP);
417 * p.put(CODE_ATTRIBUTE_PFX+"LocalVariableTable", STRIP);
418 * p.put(CLASS_ATTRIBUTE_PFX+"SourceFile", STRIP);
419 * }</pre>
420 */
421 String CLASS_ATTRIBUTE_PFX = "pack.class.attribute.";
422
423 /**
424 * When concatenated with a field attribute name,
425 * indicates the format of that attribute.
426 * For example, the effect of this option is built in:
427 * {@code pack.field.attribute.Deprecated=}.
428 * The special strings {@link #ERROR}, {@link #STRIP}, and
429 * {@link #PASS} are also allowed.
430 * @see #CLASS_ATTRIBUTE_PFX
431 */
432 String FIELD_ATTRIBUTE_PFX = "pack.field.attribute.";
433
434 /**
435 * When concatenated with a method attribute name,
436 * indicates the format of that attribute.
437 * For example, the effect of this option is built in:
438 * {@code pack.method.attribute.Exceptions=NH[RCH]}.
439 * The special strings {@link #ERROR}, {@link #STRIP}, and {@link #PASS}
440 * are also allowed.
441 * @see #CLASS_ATTRIBUTE_PFX
442 */
443 String METHOD_ATTRIBUTE_PFX = "pack.method.attribute.";
444
445 /**
446 * When concatenated with a code attribute name,
447 * indicates the format of that attribute.
448 * For example, the effect of this option is built in:
449 * {@code pack.code.attribute.LocalVariableTable=NH[PHOHRUHRSHH]}.
450 * The special strings {@link #ERROR}, {@link #STRIP}, and {@link #PASS}
451 * are also allowed.
452 * @see #CLASS_ATTRIBUTE_PFX
453 */
454 String CODE_ATTRIBUTE_PFX = "pack.code.attribute.";
455
456 /**
457 * The packer's progress as a percentage, as periodically
458 * updated by the packer.
459 * Values of 0 - 100 are normal, and -1 indicates a stall.
460 * Progress can be monitored by polling the value of this
461 * property.
462 * <p>
463 * At a minimum, the packer must set progress to 0
464 * at the beginning of a packing operation, and to 100
465 * at the end.
466 */
467 String PROGRESS = "pack.progress";
468
469 /** The string "keep", a possible value for certain properties.
470 * @see #DEFLATE_HINT
471 * @see #MODIFICATION_TIME
472 */
473 String KEEP = "keep";
474
475 /** The string "pass", a possible value for certain properties.
476 * @see #UNKNOWN_ATTRIBUTE
477 * @see #CLASS_ATTRIBUTE_PFX
478 * @see #FIELD_ATTRIBUTE_PFX
479 * @see #METHOD_ATTRIBUTE_PFX
480 * @see #CODE_ATTRIBUTE_PFX
481 */
482 String PASS = "pass";
483
484 /** The string "strip", a possible value for certain properties.
485 * @see #UNKNOWN_ATTRIBUTE
486 * @see #CLASS_ATTRIBUTE_PFX
487 * @see #FIELD_ATTRIBUTE_PFX
488 * @see #METHOD_ATTRIBUTE_PFX
489 * @see #CODE_ATTRIBUTE_PFX
490 */
491 String STRIP = "strip";
492
493 /** The string "error", a possible value for certain properties.
494 * @see #UNKNOWN_ATTRIBUTE
495 * @see #CLASS_ATTRIBUTE_PFX
496 * @see #FIELD_ATTRIBUTE_PFX
497 * @see #METHOD_ATTRIBUTE_PFX
498 * @see #CODE_ATTRIBUTE_PFX
499 */
500 String ERROR = "error";
501
502 /** The string "true", a possible value for certain properties.
503 * @see #KEEP_FILE_ORDER
504 * @see #DEFLATE_HINT
505 */
506 String TRUE = "true";
507
508 /** The string "false", a possible value for certain properties.
509 * @see #KEEP_FILE_ORDER
510 * @see #DEFLATE_HINT
511 */
512 String FALSE = "false";
513
514 /** The string "latest", a possible value for certain properties.
515 * @see #MODIFICATION_TIME
516 */
517 String LATEST = "latest";
518
519 /**
520 * Get the set of this engine's properties.
521 * This set is a "live view", so that changing its
522 * contents immediately affects the Packer engine, and
523 * changes from the engine (such as progress indications)
524 * are immediately visible in the map.
525 *
526 * <p>The property map may contain pre-defined implementation
527 * specific and default properties. Users are encouraged to
528 * read the information and fully understand the implications,
529 * before modifying pre-existing properties.
530 * <p>
531 * Implementation specific properties are prefixed with a
532 * package name associated with the implementor, beginning
533 * with {@code com.} or a similar prefix.
534 * All property names beginning with {@code pack.} and
535 * {@code unpack.} are reserved for use by this API.
536 * <p>
537 * Unknown properties may be ignored or rejected with an
538 * unspecified error, and invalid entries may cause an
539 * unspecified error to be thrown.
540 *
541 * <p>
542 * The returned map implements all optional {@link SortedMap} operations
543 * @return A sorted association of property key strings to property
544 * values.
545 */
546 SortedMap<String,String> properties();
547
548 /**
549 * Takes a JarFile and converts it into a Pack200 archive.
550 * <p>
551 * Closes its input but not its output. (Pack200 archives are appendable.)
552 * @param in a JarFile
553 * @param out an OutputStream
554 * @exception IOException if an error is encountered.
555 */
556 void pack(JarFile in, OutputStream out) throws IOException ;
557
558 /**
559 * Takes a JarInputStream and converts it into a Pack200 archive.
560 * <p>
561 * Closes its input but not its output. (Pack200 archives are appendable.)
562 * <p>
563 * The modification time and deflation hint attributes are not available,
564 * for the JAR manifest file and its containing directory.
565 *
566 * @see #MODIFICATION_TIME
567 * @see #DEFLATE_HINT
568 * @param in a JarInputStream
569 * @param out an OutputStream
570 * @exception IOException if an error is encountered.
571 */
572 void pack(JarInputStream in, OutputStream out) throws IOException ;
573 }
574
575 /**
576 * The unpacker engine converts the packed stream to a JAR file.
577 * An instance of the engine can be obtained
578 * using {@link #newUnpacker}.
579 * <p>
580 * Every JAR file produced by this engine will include the string
581 * "{@code PACK200}" as a zip file comment.
582 * This allows a deployer to detect if a JAR archive was packed and unpacked.
583 * <p>
584 * Note: Unless otherwise noted, passing a {@code null} argument to a
585 * constructor or method in this class will cause a {@link NullPointerException}
586 * to be thrown.
587 * <p>
588 * This version of the unpacker is compatible with all previous versions.
589 * @since 1.5
590 */
591 @Deprecated(since="11", forRemoval=true)
592 public interface Unpacker {
593
594 /** The string "keep", a possible value for certain properties.
595 * @see #DEFLATE_HINT
596 */
597 String KEEP = "keep";
598
599 /** The string "true", a possible value for certain properties.
600 * @see #DEFLATE_HINT
601 */
602 String TRUE = "true";
603
604 /** The string "false", a possible value for certain properties.
605 * @see #DEFLATE_HINT
606 */
607 String FALSE = "false";
608
609 /**
610 * Property indicating that the unpacker should
611 * ignore all transmitted values for DEFLATE_HINT,
612 * replacing them by the given value, {@link #TRUE} or {@link #FALSE}.
613 * The default value is the special string {@link #KEEP},
614 * which asks the unpacker to preserve all transmitted
615 * deflation hints.
616 */
617 String DEFLATE_HINT = "unpack.deflate.hint";
618
619
620
621 /**
622 * The unpacker's progress as a percentage, as periodically
623 * updated by the unpacker.
624 * Values of 0 - 100 are normal, and -1 indicates a stall.
625 * Progress can be monitored by polling the value of this
626 * property.
627 * <p>
628 * At a minimum, the unpacker must set progress to 0
629 * at the beginning of an unpacking operation, and to 100
630 * at the end.
631 */
632 String PROGRESS = "unpack.progress";
633
634 /**
635 * Get the set of this engine's properties. This set is
636 * a "live view", so that changing its
637 * contents immediately affects the Unpacker engine, and
638 * changes from the engine (such as progress indications)
639 * are immediately visible in the map.
640 *
641 * <p>The property map may contain pre-defined implementation
642 * specific and default properties. Users are encouraged to
643 * read the information and fully understand the implications,
644 * before modifying pre-existing properties.
645 * <p>
646 * Implementation specific properties are prefixed with a
647 * package name associated with the implementor, beginning
648 * with {@code com.} or a similar prefix.
649 * All property names beginning with {@code pack.} and
650 * {@code unpack.} are reserved for use by this API.
651 * <p>
652 * Unknown properties may be ignored or rejected with an
653 * unspecified error, and invalid entries may cause an
654 * unspecified error to be thrown.
655 *
656 * @return A sorted association of option key strings to option values.
657 */
658 SortedMap<String,String> properties();
659
660 /**
661 * Read a Pack200 archive, and write the encoded JAR to
662 * a JarOutputStream.
663 * The entire contents of the input stream will be read.
664 * It may be more efficient to read the Pack200 archive
665 * to a file and pass the File object, using the alternate
666 * method described below.
667 * <p>
668 * Closes its input but not its output. (The output can accumulate more elements.)
669 * @param in an InputStream.
670 * @param out a JarOutputStream.
671 * @exception IOException if an error is encountered.
672 */
673 void unpack(InputStream in, JarOutputStream out) throws IOException;
674
675 /**
676 * Read a Pack200 archive, and write the encoded JAR to
677 * a JarOutputStream.
678 * <p>
679 * Does not close its output. (The output can accumulate more elements.)
680 * @param in a File.
681 * @param out a JarOutputStream.
682 * @exception IOException if an error is encountered.
683 */
684 void unpack(File in, JarOutputStream out) throws IOException;
685 }
686
687 // Private stuff....
688
689 private static final String PACK_PROVIDER = "java.util.jar.Pack200.Packer";
690 private static final String UNPACK_PROVIDER = "java.util.jar.Pack200.Unpacker";
691
692 private static Class<?> packerImpl;
693 private static Class<?> unpackerImpl;
694
695 private static synchronized Object newInstance(String prop) {
696 String implName = "(unknown)";
697 try {
698 Class<?> impl = (PACK_PROVIDER.equals(prop))? packerImpl: unpackerImpl;
699 if (impl == null) {
700 // The first time, we must decide which class to use.
701 implName = GetPropertyAction.privilegedGetProperty(prop,"");
702 if (implName != null && !implName.equals(""))
703 impl = Class.forName(implName);
704 else if (PACK_PROVIDER.equals(prop))
705 impl = com.sun.java.util.jar.pack.PackerImpl.class;
706 else
707 impl = com.sun.java.util.jar.pack.UnpackerImpl.class;
708 }
709 // We have a class. Now instantiate it.
710 @SuppressWarnings("deprecation")
711 Object result = impl.newInstance();
712 return result;
713 } catch (ClassNotFoundException e) {
714 throw new Error("Class not found: " + implName +
715 ":\ncheck property " + prop +
716 " in your properties file.", e);
717 } catch (InstantiationException e) {
718 throw new Error("Could not instantiate: " + implName +
719 ":\ncheck property " + prop +
720 " in your properties file.", e);
721 } catch (IllegalAccessException e) {
722 throw new Error("Cannot access class: " + implName +
723 ":\ncheck property " + prop +
724 " in your properties file.", e);
725 }
726 }
727
728 }