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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 java.beans.PropertyChangeListener;
33 
34 
35 
36 
37 /**
38  * Transforms a JAR file to or from a packed stream in Pack200 format.
39  * Please refer to Network Transfer Format JSR 200 Specification at
40  * <a href=http://jcp.org/aboutJava/communityprocess/review/jsr200/index.html>http://jcp.org/aboutJava/communityprocess/review/jsr200/index.html</a>
41  * <p>
42  * Typically the packer engine is used by application developers
43  * to deploy or host JAR files on a website.
44  * The unpacker  engine is used by deployment applications to
45  * transform the byte-stream back to JAR format.
46  * <p>
47  * Here is an example using  packer and unpacker:
48  * <pre>{@code
49  *    import java.util.jar.Pack200;
50  *    import java.util.jar.Pack200.*;
51  *    ...
52  *    // Create the Packer object
53  *    Packer packer = Pack200.newPacker();
54  *
55  *    // Initialize the state by setting the desired properties
56  *    Map p = packer.properties();
57  *    // take more time choosing codings for better compression
58  *    p.put(Packer.EFFORT, "7");  // default is "5"
59  *    // use largest-possible archive segments (>10% better compression).
60  *    p.put(Packer.SEGMENT_LIMIT, "-1");
61  *    // reorder files for better compression.
62  *    p.put(Packer.KEEP_FILE_ORDER, Packer.FALSE);
63  *    // smear modification times to a single value.
64  *    p.put(Packer.MODIFICATION_TIME, Packer.LATEST);
65  *    // ignore all JAR deflation requests,
66  *    // transmitting a single request to use "store" mode.
67  *    p.put(Packer.DEFLATE_HINT, Packer.FALSE);
68  *    // discard debug attributes
69  *    p.put(Packer.CODE_ATTRIBUTE_PFX+"LineNumberTable", Packer.STRIP);
70  *    // throw an error if an attribute is unrecognized
71  *    p.put(Packer.UNKNOWN_ATTRIBUTE, Packer.ERROR);
72  *    // pass one class file uncompressed:
73  *    p.put(Packer.PASS_FILE_PFX+0, "mutants/Rogue.class");
74  *    try {
75  *        JarFile jarFile = new JarFile("/tmp/testref.jar");
76  *        FileOutputStream fos = new FileOutputStream("/tmp/test.pack");
77  *        // Call the packer
78  *        packer.pack(jarFile, fos);
79  *        jarFile.close();
80  *        fos.close();
81  *
82  *        File f = new File("/tmp/test.pack");
83  *        FileOutputStream fostream = new FileOutputStream("/tmp/test.jar");
84  *        JarOutputStream jostream = new JarOutputStream(fostream);
85  *        Unpacker unpacker = Pack200.newUnpacker();
86  *        // Call the unpacker
87  *        unpacker.unpack(f, jostream);
88  *        // Must explicitly close the output.
89  *        jostream.close();
90  *    } catch (IOException ioe) {
91  *        ioe.printStackTrace();
92  *    }
93  * }</pre>
94  * <p>
95  * A Pack200 file compressed with gzip can be hosted on HTTP/1.1 web servers.
96  * The deployment applications can use "Accept-Encoding=pack200-gzip". This
97  * indicates to the server that the client application desires a version of
98  * the file encoded with Pack200 and further compressed with gzip. Please
99  * refer to  <a href="{@docRoot}openjdk-redirect.html?v=8&path=/technotes/guides/deployment/deployment-guide/pack200.html">Java Deployment Guide</a> for more details and
100  * techniques.
101  * <p>
102  * Unless otherwise noted, passing a <tt>null</tt> argument to a constructor or
103  * method in this class will cause a {@link NullPointerException} to be thrown.
104  *
105  * @author John Rose
106  * @author Kumar Srinivasan
107  * @since 1.5
108  */
109 public abstract class Pack200 {
Pack200()110     private Pack200() {} //prevent instantiation
111 
112     // Static methods of the Pack200 class.
113     /**
114      * Obtain new instance of a class that implements Packer.
115      * <ul>
116      * <li><p>If the system property <tt>java.util.jar.Pack200.Packer</tt>
117      * is defined, then the value is taken to be the fully-qualified name
118      * of a concrete implementation class, which must implement Packer.
119      * This class is loaded and instantiated.  If this process fails
120      * then an unspecified error is thrown.</p></li>
121      *
122      * <li><p>If an implementation has not been specified with the system
123      * property, then the system-default implementation class is instantiated,
124      * and the result is returned.</p></li>
125      * </ul>
126      *
127      * <p>Note:  The returned object is not guaranteed to operate
128      * correctly if multiple threads use it at the same time.
129      * A multi-threaded application should either allocate multiple
130      * packer engines, or else serialize use of one engine with a lock.
131      *
132      * @return  A newly allocated Packer engine.
133      */
newPacker()134     public synchronized static Packer newPacker() {
135         return (Packer) newInstance(PACK_PROVIDER);
136     }
137 
138 
139     /**
140      * Obtain new instance of a class that implements Unpacker.
141      * <ul>
142      * <li><p>If the system property <tt>java.util.jar.Pack200.Unpacker</tt>
143      * is defined, then the value is taken to be the fully-qualified
144      * name of a concrete implementation class, which must implement Unpacker.
145      * The class is loaded and instantiated.  If this process fails
146      * then an unspecified error is thrown.</p></li>
147      *
148      * <li><p>If an implementation has not been specified with the
149      * system property, then the system-default implementation class
150      * is instantiated, and the result is returned.</p></li>
151      * </ul>
152      *
153      * <p>Note:  The returned object is not guaranteed to operate
154      * correctly if multiple threads use it at the same time.
155      * A multi-threaded application should either allocate multiple
156      * unpacker engines, or else serialize use of one engine with a lock.
157      *
158      * @return  A newly allocated Unpacker engine.
159      */
160 
newUnpacker()161     public static Unpacker newUnpacker() {
162         return (Unpacker) newInstance(UNPACK_PROVIDER);
163     }
164 
165     // Interfaces
166     /**
167      * The packer engine applies various transformations to the input JAR file,
168      * making the pack stream highly compressible by a compressor such as
169      * gzip or zip. An instance of the engine can be obtained
170      * using {@link #newPacker}.
171 
172      * The high degree of compression is achieved
173      * by using a number of techniques described in the JSR 200 specification.
174      * Some of the techniques are sorting, re-ordering and co-location of the
175      * constant pool.
176      * <p>
177      * The pack engine is initialized to an initial state as described
178      * by their properties below.
179      * The initial state can be manipulated by getting the
180      * engine properties (using {@link #properties}) and storing
181      * the modified properties on the map.
182      * The resource files will be passed through with no changes at all.
183      * The class files will not contain identical bytes, since the unpacker
184      * is free to change minor class file features such as constant pool order.
185      * However, the class files will be semantically identical,
186      * as specified in
187      * <cite>The Java&trade; Virtual Machine Specification</cite>.
188      * <p>
189      * By default, the packer does not change the order of JAR elements.
190      * Also, the modification time and deflation hint of each
191      * JAR element is passed unchanged.
192      * (Any other ZIP-archive information, such as extra attributes
193      * giving Unix file permissions, are lost.)
194      * <p>
195      * Note that packing and unpacking a JAR will in general alter the
196      * bytewise contents of classfiles in the JAR.  This means that packing
197      * and unpacking will in general invalidate any digital signatures
198      * which rely on bytewise images of JAR elements.  In order both to sign
199      * and to pack a JAR, you must first pack and unpack the JAR to
200      * "normalize" it, then compute signatures on the unpacked JAR elements,
201      * and finally repack the signed JAR.
202      * Both packing steps should
203      * use precisely the same options, and the segment limit may also
204      * need to be set to "-1", to prevent accidental variation of segment
205      * boundaries as class file sizes change slightly.
206      * <p>
207      * (Here's why this works:  Any reordering the packer does
208      * of any classfile structures is idempotent, so the second packing
209      * does not change the orderings produced by the first packing.
210      * Also, the unpacker is guaranteed by the JSR 200 specification
211      * to produce a specific bytewise image for any given transmission
212      * ordering of archive elements.)
213      * <p>
214      * In order to maintain backward compatibility, the pack file's version is
215      * set to accommodate the class files present in the input JAR file. In
216      * other words, the pack file version will be the latest, if the class files
217      * are the latest and conversely the pack file version will be the oldest
218      * if the class file versions are also the oldest. For intermediate class
219      * file versions the corresponding pack file version will be used.
220      * For example:
221      *    If the input JAR-files are solely comprised of 1.5  (or  lesser)
222      * class files, a 1.5 compatible pack file is  produced. This will also be
223      * the case for archives that have no class files.
224      *    If the input JAR-files contains a 1.6 class file, then the pack file
225      * version will be set to 1.6.
226      * <p>
227      * Note: Unless otherwise noted, passing a <tt>null</tt> argument to a
228      * constructor or method in this class will cause a {@link NullPointerException}
229      * to be thrown.
230      * <p>
231      * @since 1.5
232      */
233     public interface Packer {
234         /**
235          * This property is a numeral giving the estimated target size N
236          * (in bytes) of each archive segment.
237          * If a single input file requires more than N bytes,
238          * it will be given its own archive segment.
239          * <p>
240          * As a special case, a value of -1 will produce a single large
241          * segment with all input files, while a value of 0 will
242          * produce one segment for each class.
243          * Larger archive segments result in less fragmentation and
244          * better compression, but processing them requires more memory.
245          * <p>
246          * The size of each segment is estimated by counting the size of each
247          * input file to be transmitted in the segment, along with the size
248          * of its name and other transmitted properties.
249          * <p>
250          * The default is -1, which means the packer will always create a single
251          * segment output file. In cases where extremely large output files are
252          * generated, users are strongly encouraged to use segmenting or break
253          * up the input file into smaller JARs.
254          * <p>
255          * A 10Mb JAR packed without this limit will
256          * typically pack about 10% smaller, but the packer may require
257          * a larger Java heap (about ten times the segment limit).
258          */
259         String SEGMENT_LIMIT    = "pack.segment.limit";
260 
261         /**
262          * If this property is set to {@link #TRUE}, the packer will transmit
263          * all elements in their original order within the source archive.
264          * <p>
265          * If it is set to {@link #FALSE}, the packer may reorder elements,
266          * and also remove JAR directory entries, which carry no useful
267          * information for Java applications.
268          * (Typically this enables better compression.)
269          * <p>
270          * The default is {@link #TRUE}, which preserves the input information,
271          * but may cause the transmitted archive to be larger than necessary.
272          */
273         String KEEP_FILE_ORDER = "pack.keep.file.order";
274 
275 
276         /**
277          * If this property is set to a single decimal digit, the packer will
278          * use the indicated amount of effort in compressing the archive.
279          * Level 1 may produce somewhat larger size and faster compression speed,
280          * while level 9 will take much longer but may produce better compression.
281          * <p>
282          * The special value 0 instructs the packer to copy through the
283          * original JAR file directly, with no compression.  The JSR 200
284          * standard requires any unpacker to understand this special case
285          * as a pass-through of the entire archive.
286          * <p>
287          * The default is 5, investing a modest amount of time to
288          * produce reasonable compression.
289          */
290         String EFFORT           = "pack.effort";
291 
292         /**
293          * If this property is set to {@link #TRUE} or {@link #FALSE}, the packer
294          * will set the deflation hint accordingly in the output archive, and
295          * will not transmit the individual deflation hints of archive elements.
296          * <p>
297          * If this property is set to the special string {@link #KEEP}, the packer
298          * will attempt to determine an independent deflation hint for each
299          * available element of the input archive, and transmit this hint separately.
300          * <p>
301          * The default is {@link #KEEP}, which preserves the input information,
302          * but may cause the transmitted archive to be larger than necessary.
303          * <p>
304          * It is up to the unpacker implementation
305          * to take action upon the hint to suitably compress the elements of
306          * the resulting unpacked jar.
307          * <p>
308          * The deflation hint of a ZIP or JAR element indicates
309          * whether the element was deflated or stored directly.
310          */
311         String DEFLATE_HINT     = "pack.deflate.hint";
312 
313         /**
314          * If this property is set to the special string {@link #LATEST},
315          * the packer will attempt to determine the latest modification time,
316          * among all the available entries in the original archive or the latest
317          * modification time of all the available entries in each segment.
318          * This single value will be transmitted as part of the segment and applied
319          * to all the entries in each segment, {@link #SEGMENT_LIMIT}.
320          * <p>
321          * This can marginally decrease the transmitted size of the
322          * archive, at the expense of setting all installed files to a single
323          * date.
324          * <p>
325          * If this property is set to the special string {@link #KEEP},
326          * the packer transmits a separate modification time for each input
327          * element.
328          * <p>
329          * The default is {@link #KEEP}, which preserves the input information,
330          * but may cause the transmitted archive to be larger than necessary.
331          * <p>
332          * It is up to the unpacker implementation to take action to suitably
333          * set the modification time of each element of its output file.
334          * @see #SEGMENT_LIMIT
335          */
336         String MODIFICATION_TIME        = "pack.modification.time";
337 
338         /**
339          * Indicates that a file should be passed through bytewise, with no
340          * compression.  Multiple files may be specified by specifying
341          * additional properties with distinct strings appended, to
342          * make a family of properties with the common prefix.
343          * <p>
344          * There is no pathname transformation, except
345          * that the system file separator is replaced by the JAR file
346          * separator '/'.
347          * <p>
348          * The resulting file names must match exactly as strings with their
349          * occurrences in the JAR file.
350          * <p>
351          * If a property value is a directory name, all files under that
352          * directory will be passed also.
353          * <p>
354          * Examples:
355          * <pre>{@code
356          *     Map p = packer.properties();
357          *     p.put(PASS_FILE_PFX+0, "mutants/Rogue.class");
358          *     p.put(PASS_FILE_PFX+1, "mutants/Wolverine.class");
359          *     p.put(PASS_FILE_PFX+2, "mutants/Storm.class");
360          *     # Pass all files in an entire directory hierarchy:
361          *     p.put(PASS_FILE_PFX+3, "police/");
362          * }</pre>
363          */
364         String PASS_FILE_PFX            = "pack.pass.file.";
365 
366         /// Attribute control.
367 
368         /**
369          * Indicates the action to take when a class-file containing an unknown
370          * attribute is encountered.  Possible values are the strings {@link #ERROR},
371          * {@link #STRIP}, and {@link #PASS}.
372          * <p>
373          * The string {@link #ERROR} means that the pack operation
374          * as a whole will fail, with an exception of type <code>IOException</code>.
375          * The string
376          * {@link #STRIP} means that the attribute will be dropped.
377          * The string
378          * {@link #PASS} means that the whole class-file will be passed through
379          * (as if it were a resource file) without compression, with  a suitable warning.
380          * This is the default value for this property.
381          * <p>
382          * Examples:
383          * <pre>{@code
384          *     Map p = pack200.getProperties();
385          *     p.put(UNKNOWN_ATTRIBUTE, ERROR);
386          *     p.put(UNKNOWN_ATTRIBUTE, STRIP);
387          *     p.put(UNKNOWN_ATTRIBUTE, PASS);
388          * }</pre>
389          */
390         String UNKNOWN_ATTRIBUTE        = "pack.unknown.attribute";
391 
392         /**
393          * When concatenated with a class attribute name,
394          * indicates the format of that attribute,
395          * using the layout language specified in the JSR 200 specification.
396          * <p>
397          * For example, the effect of this option is built in:
398          * <code>pack.class.attribute.SourceFile=RUH</code>.
399          * <p>
400          * The special strings {@link #ERROR}, {@link #STRIP}, and {@link #PASS} are
401          * also allowed, with the same meaning as {@link #UNKNOWN_ATTRIBUTE}.
402          * This provides a way for users to request that specific attributes be
403          * refused, stripped, or passed bitwise (with no class compression).
404          * <p>
405          * Code like this might be used to support attributes for JCOV:
406          * <pre><code>
407          *     Map p = packer.properties();
408          *     p.put(CODE_ATTRIBUTE_PFX+"CoverageTable",       "NH[PHHII]");
409          *     p.put(CODE_ATTRIBUTE_PFX+"CharacterRangeTable", "NH[PHPOHIIH]");
410          *     p.put(CLASS_ATTRIBUTE_PFX+"SourceID",           "RUH");
411          *     p.put(CLASS_ATTRIBUTE_PFX+"CompilationID",      "RUH");
412          * </code></pre>
413          * <p>
414          * Code like this might be used to strip debugging attributes:
415          * <pre><code>
416          *     Map p = packer.properties();
417          *     p.put(CODE_ATTRIBUTE_PFX+"LineNumberTable",    STRIP);
418          *     p.put(CODE_ATTRIBUTE_PFX+"LocalVariableTable", STRIP);
419          *     p.put(CLASS_ATTRIBUTE_PFX+"SourceFile",        STRIP);
420          * </code></pre>
421          */
422         String CLASS_ATTRIBUTE_PFX      = "pack.class.attribute.";
423 
424         /**
425          * When concatenated with a field attribute name,
426          * indicates the format of that attribute.
427          * For example, the effect of this option is built in:
428          * <code>pack.field.attribute.Deprecated=</code>.
429          * The special strings {@link #ERROR}, {@link #STRIP}, and
430          * {@link #PASS} are also allowed.
431          * @see #CLASS_ATTRIBUTE_PFX
432          */
433         String FIELD_ATTRIBUTE_PFX      = "pack.field.attribute.";
434 
435         /**
436          * When concatenated with a method attribute name,
437          * indicates the format of that attribute.
438          * For example, the effect of this option is built in:
439          * <code>pack.method.attribute.Exceptions=NH[RCH]</code>.
440          * The special strings {@link #ERROR}, {@link #STRIP}, and {@link #PASS}
441          * are also allowed.
442          * @see #CLASS_ATTRIBUTE_PFX
443          */
444         String METHOD_ATTRIBUTE_PFX     = "pack.method.attribute.";
445 
446         /**
447          * When concatenated with a code attribute name,
448          * indicates the format of that attribute.
449          * For example, the effect of this option is built in:
450          * <code>pack.code.attribute.LocalVariableTable=NH[PHOHRUHRSHH]</code>.
451          * The special strings {@link #ERROR}, {@link #STRIP}, and {@link #PASS}
452          * are also allowed.
453          * @see #CLASS_ATTRIBUTE_PFX
454          */
455         String CODE_ATTRIBUTE_PFX       = "pack.code.attribute.";
456 
457         /**
458          * The unpacker's progress as a percentage, as periodically
459          * updated by the unpacker.
460          * Values of 0 - 100 are normal, and -1 indicates a stall.
461          * Progress can be monitored by polling the value of this
462          * property.
463          * <p>
464          * At a minimum, the unpacker must set progress to 0
465          * at the beginning of a packing operation, and to 100
466          * at the end.
467          */
468         String PROGRESS                 = "pack.progress";
469 
470         /** The string "keep", a possible value for certain properties.
471          * @see #DEFLATE_HINT
472          * @see #MODIFICATION_TIME
473          */
474         String KEEP  = "keep";
475 
476         /** The string "pass", a possible value for certain properties.
477          * @see #UNKNOWN_ATTRIBUTE
478          * @see #CLASS_ATTRIBUTE_PFX
479          * @see #FIELD_ATTRIBUTE_PFX
480          * @see #METHOD_ATTRIBUTE_PFX
481          * @see #CODE_ATTRIBUTE_PFX
482          */
483         String PASS  = "pass";
484 
485         /** The string "strip", a possible value for certain properties.
486          * @see #UNKNOWN_ATTRIBUTE
487          * @see #CLASS_ATTRIBUTE_PFX
488          * @see #FIELD_ATTRIBUTE_PFX
489          * @see #METHOD_ATTRIBUTE_PFX
490          * @see #CODE_ATTRIBUTE_PFX
491          */
492         String STRIP = "strip";
493 
494         /** The string "error", a possible value for certain properties.
495          * @see #UNKNOWN_ATTRIBUTE
496          * @see #CLASS_ATTRIBUTE_PFX
497          * @see #FIELD_ATTRIBUTE_PFX
498          * @see #METHOD_ATTRIBUTE_PFX
499          * @see #CODE_ATTRIBUTE_PFX
500          */
501         String ERROR = "error";
502 
503         /** The string "true", a possible value for certain properties.
504          * @see #KEEP_FILE_ORDER
505          * @see #DEFLATE_HINT
506          */
507         String TRUE = "true";
508 
509         /** The string "false", a possible value for certain properties.
510          * @see #KEEP_FILE_ORDER
511          * @see #DEFLATE_HINT
512          */
513         String FALSE = "false";
514 
515         /** The string "latest", a possible value for certain properties.
516          * @see #MODIFICATION_TIME
517          */
518         String LATEST = "latest";
519 
520         /**
521          * Get the set of this engine's properties.
522          * This set is a "live view", so that changing its
523          * contents immediately affects the Packer engine, and
524          * changes from the engine (such as progress indications)
525          * are immediately visible in the map.
526          *
527          * <p>The property map may contain pre-defined implementation
528          * specific and default properties.  Users are encouraged to
529          * read the information and fully understand the implications,
530          * before modifying pre-existing properties.
531          * <p>
532          * Implementation specific properties are prefixed with a
533          * package name associated with the implementor, beginning
534          * with <tt>com.</tt> or a similar prefix.
535          * All property names beginning with <tt>pack.</tt> and
536          * <tt>unpack.</tt> are reserved for use by this API.
537          * <p>
538          * Unknown properties may be ignored or rejected with an
539          * unspecified error, and invalid entries may cause an
540          * unspecified error to be thrown.
541          *
542          * <p>
543          * The returned map implements all optional {@link SortedMap} operations
544          * @return A sorted association of property key strings to property
545          * values.
546          */
properties()547         SortedMap<String,String> properties();
548 
549         /**
550          * Takes a JarFile and converts it into a Pack200 archive.
551          * <p>
552          * Closes its input but not its output.  (Pack200 archives are appendable.)
553          * @param in a JarFile
554          * @param out an OutputStream
555          * @exception IOException if an error is encountered.
556          */
pack(JarFile in, OutputStream out)557         void pack(JarFile in, OutputStream out) throws IOException ;
558 
559         /**
560          * Takes a JarInputStream and converts it into a Pack200 archive.
561          * <p>
562          * Closes its input but not its output.  (Pack200 archives are appendable.)
563          * <p>
564          * The modification time and deflation hint attributes are not available,
565          * for the JAR manifest file and its containing directory.
566          *
567          * @see #MODIFICATION_TIME
568          * @see #DEFLATE_HINT
569          * @param in a JarInputStream
570          * @param out an OutputStream
571          * @exception IOException if an error is encountered.
572          */
pack(JarInputStream in, OutputStream out)573         void pack(JarInputStream in, OutputStream out) throws IOException ;
574 
575         /**
576          * Registers a listener for PropertyChange events on the properties map.
577          * This is typically used by applications to update a progress bar.
578          *
579          * <p> The default implementation of this method does nothing and has
580          * no side-effects.</p>
581          *
582          * <p><b>WARNING:</b> This method is omitted from the interface
583          * declaration in all subset Profiles of Java SE that do not include
584          * the {@code java.beans} package. </p>
585 
586          * @see #properties
587          * @see #PROGRESS
588          * @param listener  An object to be invoked when a property is changed.
589          * @deprecated The dependency on {@code PropertyChangeListener} creates
590          *             a significant impediment to future modularization of the
591          *             Java platform. This method will be removed in a future
592          *             release.
593          *             Applications that need to monitor progress of the packer
594          *             can poll the value of the {@link #PROGRESS PROGRESS}
595          *             property instead.
596          */
597         @Deprecated
addPropertyChangeListener(PropertyChangeListener listener)598         default void addPropertyChangeListener(PropertyChangeListener listener) {
599         }
600 
601         /**
602          * Remove a listener for PropertyChange events, added by
603          * the {@link #addPropertyChangeListener}.
604          *
605          * <p> The default implementation of this method does nothing and has
606          * no side-effects.</p>
607          *
608          * <p><b>WARNING:</b> This method is omitted from the interface
609          * declaration in all subset Profiles of Java SE that do not include
610          * the {@code java.beans} package. </p>
611          *
612          * @see #addPropertyChangeListener
613          * @param listener  The PropertyChange listener to be removed.
614          * @deprecated The dependency on {@code PropertyChangeListener} creates
615          *             a significant impediment to future modularization of the
616          *             Java platform. This method will be removed in a future
617          *             release.
618          */
619         @Deprecated
removePropertyChangeListener(PropertyChangeListener listener)620         default void removePropertyChangeListener(PropertyChangeListener listener) {
621         }
622     }
623 
624     /**
625      * The unpacker engine converts the packed stream to a JAR file.
626      * An instance of the engine can be obtained
627      * using {@link #newUnpacker}.
628      * <p>
629      * Every JAR file produced by this engine will include the string
630      * "<tt>PACK200</tt>" as a zip file comment.
631      * This allows a deployer to detect if a JAR archive was packed and unpacked.
632      * <p>
633      * Note: Unless otherwise noted, passing a <tt>null</tt> argument to a
634      * constructor or method in this class will cause a {@link NullPointerException}
635      * to be thrown.
636      * <p>
637      * This version of the unpacker is compatible with all previous versions.
638      * @since 1.5
639      */
640     public interface Unpacker {
641 
642         /** The string "keep", a possible value for certain properties.
643          * @see #DEFLATE_HINT
644          */
645         String KEEP  = "keep";
646 
647         /** The string "true", a possible value for certain properties.
648          * @see #DEFLATE_HINT
649          */
650         String TRUE = "true";
651 
652         /** The string "false", a possible value for certain properties.
653          * @see #DEFLATE_HINT
654          */
655         String FALSE = "false";
656 
657         /**
658          * Property indicating that the unpacker should
659          * ignore all transmitted values for DEFLATE_HINT,
660          * replacing them by the given value, {@link #TRUE} or {@link #FALSE}.
661          * The default value is the special string {@link #KEEP},
662          * which asks the unpacker to preserve all transmitted
663          * deflation hints.
664          */
665         String DEFLATE_HINT      = "unpack.deflate.hint";
666 
667 
668 
669         /**
670          * The unpacker's progress as a percentage, as periodically
671          * updated by the unpacker.
672          * Values of 0 - 100 are normal, and -1 indicates a stall.
673          * Progress can be monitored by polling the value of this
674          * property.
675          * <p>
676          * At a minimum, the unpacker must set progress to 0
677          * at the beginning of a packing operation, and to 100
678          * at the end.
679          */
680         String PROGRESS         = "unpack.progress";
681 
682         /**
683          * Get the set of this engine's properties. This set is
684          * a "live view", so that changing its
685          * contents immediately affects the Packer engine, and
686          * changes from the engine (such as progress indications)
687          * are immediately visible in the map.
688          *
689          * <p>The property map may contain pre-defined implementation
690          * specific and default properties.  Users are encouraged to
691          * read the information and fully understand the implications,
692          * before modifying pre-existing properties.
693          * <p>
694          * Implementation specific properties are prefixed with a
695          * package name associated with the implementor, beginning
696          * with <tt>com.</tt> or a similar prefix.
697          * All property names beginning with <tt>pack.</tt> and
698          * <tt>unpack.</tt> are reserved for use by this API.
699          * <p>
700          * Unknown properties may be ignored or rejected with an
701          * unspecified error, and invalid entries may cause an
702          * unspecified error to be thrown.
703          *
704          * @return A sorted association of option key strings to option values.
705          */
properties()706         SortedMap<String,String> properties();
707 
708         /**
709          * Read a Pack200 archive, and write the encoded JAR to
710          * a JarOutputStream.
711          * The entire contents of the input stream will be read.
712          * It may be more efficient to read the Pack200 archive
713          * to a file and pass the File object, using the alternate
714          * method described below.
715          * <p>
716          * Closes its input but not its output.  (The output can accumulate more elements.)
717          * @param in an InputStream.
718          * @param out a JarOutputStream.
719          * @exception IOException if an error is encountered.
720          */
unpack(InputStream in, JarOutputStream out)721         void unpack(InputStream in, JarOutputStream out) throws IOException;
722 
723         /**
724          * Read a Pack200 archive, and write the encoded JAR to
725          * a JarOutputStream.
726          * <p>
727          * Does not close its output.  (The output can accumulate more elements.)
728          * @param in a File.
729          * @param out a JarOutputStream.
730          * @exception IOException if an error is encountered.
731          */
unpack(File in, JarOutputStream out)732         void unpack(File in, JarOutputStream out) throws IOException;
733 
734         /**
735          * Registers a listener for PropertyChange events on the properties map.
736          * This is typically used by applications to update a progress bar.
737          *
738          * <p> The default implementation of this method does nothing and has
739          * no side-effects.</p>
740          *
741          * <p><b>WARNING:</b> This method is omitted from the interface
742          * declaration in all subset Profiles of Java SE that do not include
743          * the {@code java.beans} package. </p>
744          *
745          * @see #properties
746          * @see #PROGRESS
747          * @param listener  An object to be invoked when a property is changed.
748          * @deprecated The dependency on {@code PropertyChangeListener} creates
749          *             a significant impediment to future modularization of the
750          *             Java platform. This method will be removed in a future
751          *             release.
752          *             Applications that need to monitor progress of the
753          *             unpacker can poll the value of the {@link #PROGRESS
754          *             PROGRESS} property instead.
755          */
756         @Deprecated
addPropertyChangeListener(PropertyChangeListener listener)757         default void addPropertyChangeListener(PropertyChangeListener listener) {
758         }
759 
760         /**
761          * Remove a listener for PropertyChange events, added by
762          * the {@link #addPropertyChangeListener}.
763          *
764          * <p> The default implementation of this method does nothing and has
765          * no side-effects.</p>
766          *
767          * <p><b>WARNING:</b> This method is omitted from the interface
768          * declaration in all subset Profiles of Java SE that do not include
769          * the {@code java.beans} package. </p>
770          *
771          * @see #addPropertyChangeListener
772          * @param listener  The PropertyChange listener to be removed.
773          * @deprecated The dependency on {@code PropertyChangeListener} creates
774          *             a significant impediment to future modularization of the
775          *             Java platform. This method will be removed in a future
776          *             release.
777          */
778         @Deprecated
removePropertyChangeListener(PropertyChangeListener listener)779         default void removePropertyChangeListener(PropertyChangeListener listener) {
780         }
781     }
782 
783     // Private stuff....
784 
785     private static final String PACK_PROVIDER = "java.util.jar.Pack200.Packer";
786     private static final String UNPACK_PROVIDER = "java.util.jar.Pack200.Unpacker";
787 
788     private static Class<?> packerImpl;
789     private static Class<?> unpackerImpl;
790 
newInstance(String prop)791     private synchronized static Object newInstance(String prop) {
792         String implName = "(unknown)";
793         try {
794             Class<?> impl = (PACK_PROVIDER.equals(prop))? packerImpl: unpackerImpl;
795             if (impl == null) {
796                 // The first time, we must decide which class to use.
797                 implName = java.security.AccessController.doPrivileged(
798                     new sun.security.action.GetPropertyAction(prop,""));
799                 if (implName != null && !implName.equals(""))
800                     impl = Class.forName(implName);
801                 // Android-changed: Remove default Packer Impl.
802                 //
803                 // else if (PACK_PROVIDER.equals(prop))
804                 //     impl = com.sun.java.util.jar.pack.PackerImpl.class;
805                 // else
806                 //    impl = com.sun.java.util.jar.pack.UnpackerImpl.class;
807             }
808             // We have a class.  Now instantiate it.
809             return impl.newInstance();
810         } catch (ClassNotFoundException e) {
811             throw new Error("Class not found: " + implName +
812                                 ":\ncheck property " + prop +
813                                 " in your properties file.", e);
814         } catch (InstantiationException e) {
815             throw new Error("Could not instantiate: " + implName +
816                                 ":\ncheck property " + prop +
817                                 " in your properties file.", e);
818         } catch (IllegalAccessException e) {
819             throw new Error("Cannot access class: " + implName +
820                                 ":\ncheck property " + prop +
821                                 " in your properties file.", e);
822         }
823     }
824 
825 }
826