1 /*
2 * Copyright (c) 1995, 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
26 package java.util.zip;
27
28 import java.io.Closeable;
29 import java.io.InputStream;
30 import java.io.IOException;
31 import java.io.EOFException;
32 import java.io.File;
33 import java.io.RandomAccessFile;
34 import java.io.UncheckedIOException;
35 import java.lang.ref.Cleaner.Cleanable;
36 import java.nio.charset.Charset;
37 import java.nio.charset.StandardCharsets;
38 import java.nio.file.attribute.BasicFileAttributes;
39 import java.nio.file.Files;
40
41 import java.util.ArrayDeque;
42 import java.util.ArrayList;
43 import java.util.Arrays;
44 import java.util.Collections;
45 import java.util.Deque;
46 import java.util.Enumeration;
47 import java.util.HashMap;
48 import java.util.Iterator;
49 import java.util.Objects;
50 import java.util.NoSuchElementException;
51 import java.util.Set;
52 import java.util.Spliterator;
53 import java.util.Spliterators;
54 import java.util.WeakHashMap;
55
56 import java.util.function.Consumer;
57 import java.util.function.Function;
58 import java.util.function.IntFunction;
59 import java.util.jar.JarEntry;
60 import java.util.stream.Stream;
61 import java.util.stream.StreamSupport;
62 import jdk.internal.misc.JavaUtilZipFileAccess;
63 import jdk.internal.misc.SharedSecrets;
64 import jdk.internal.misc.VM;
65 import jdk.internal.perf.PerfCounter;
66 import jdk.internal.ref.CleanerFactory;
67
68 import static java.util.zip.ZipConstants64.*;
69 import static java.util.zip.ZipUtils.*;
70
71 /**
72 * This class is used to read entries from a zip file.
73 *
74 * <p> Unless otherwise noted, passing a {@code null} argument to a constructor
75 * or method in this class will cause a {@link NullPointerException} to be
76 * thrown.
77 *
78 * @apiNote
79 * To release resources used by this {@code ZipFile}, the {@link #close()} method
80 * should be called explicitly or by try-with-resources. Subclasses are responsible
81 * for the cleanup of resources acquired by the subclass. Subclasses that override
82 * {@link #finalize()} in order to perform cleanup should be modified to use alternative
83 * cleanup mechanisms such as {@link java.lang.ref.Cleaner} and remove the overriding
84 * {@code finalize} method.
85 *
86 * @implSpec
87 * If this {@code ZipFile} has been subclassed and the {@code close} method has
88 * been overridden, the {@code close} method will be called by the finalization
89 * when {@code ZipFile} is unreachable. But the subclasses should not depend on
90 * this specific implementation; the finalization is not reliable and the
91 * {@code finalize} method is deprecated to be removed.
92 *
93 * @author David Connelly
94 * @since 1.1
95 */
96 public
97 class ZipFile implements ZipConstants, Closeable {
98
99 private final String name; // zip file name
100 private volatile boolean closeRequested;
101 private ZipCoder zc;
102
103 // The "resource" used by this zip file that needs to be
104 // cleaned after use.
105 // a) the input streams that need to be closed
106 // b) the list of cached Inflater objects
107 // c) the "native" source of this zip file.
108 private final CleanableResource res;
109
110 private static final int STORED = ZipEntry.STORED;
111 private static final int DEFLATED = ZipEntry.DEFLATED;
112
113 /**
114 * Mode flag to open a zip file for reading.
115 */
116 public static final int OPEN_READ = 0x1;
117
118 /**
119 * Mode flag to open a zip file and mark it for deletion. The file will be
120 * deleted some time between the moment that it is opened and the moment
121 * that it is closed, but its contents will remain accessible via the
122 * {@code ZipFile} object until either the close method is invoked or the
123 * virtual machine exits.
124 */
125 public static final int OPEN_DELETE = 0x4;
126
127 /**
128 * Opens a zip file for reading.
129 *
130 * <p>First, if there is a security manager, its {@code checkRead}
131 * method is called with the {@code name} argument as its argument
132 * to ensure the read is allowed.
133 *
134 * <p>The UTF-8 {@link java.nio.charset.Charset charset} is used to
135 * decode the entry names and comments.
136 *
137 * @param name the name of the zip file
138 * @throws ZipException if a ZIP format error has occurred
139 * @throws IOException if an I/O error has occurred
140 * @throws SecurityException if a security manager exists and its
141 * {@code checkRead} method doesn't allow read access to the file.
142 *
143 * @see SecurityManager#checkRead(java.lang.String)
144 */
145 public ZipFile(String name) throws IOException {
146 this(new File(name), OPEN_READ);
147 }
148
149 /**
150 * Opens a new {@code ZipFile} to read from the specified
151 * {@code File} object in the specified mode. The mode argument
152 * must be either {@code OPEN_READ} or {@code OPEN_READ | OPEN_DELETE}.
153 *
154 * <p>First, if there is a security manager, its {@code checkRead}
155 * method is called with the {@code name} argument as its argument to
156 * ensure the read is allowed.
157 *
158 * <p>The UTF-8 {@link java.nio.charset.Charset charset} is used to
159 * decode the entry names and comments
160 *
161 * @param file the ZIP file to be opened for reading
162 * @param mode the mode in which the file is to be opened
163 * @throws ZipException if a ZIP format error has occurred
164 * @throws IOException if an I/O error has occurred
165 * @throws SecurityException if a security manager exists and
166 * its {@code checkRead} method
167 * doesn't allow read access to the file,
168 * or its {@code checkDelete} method doesn't allow deleting
169 * the file when the {@code OPEN_DELETE} flag is set.
170 * @throws IllegalArgumentException if the {@code mode} argument is invalid
171 * @see SecurityManager#checkRead(java.lang.String)
172 * @since 1.3
173 */
174 public ZipFile(File file, int mode) throws IOException {
175 this(file, mode, StandardCharsets.UTF_8);
176 }
177
178 /**
179 * Opens a ZIP file for reading given the specified File object.
180 *
181 * <p>The UTF-8 {@link java.nio.charset.Charset charset} is used to
182 * decode the entry names and comments.
183 *
184 * @param file the ZIP file to be opened for reading
185 * @throws ZipException if a ZIP format error has occurred
186 * @throws IOException if an I/O error has occurred
187 */
188 public ZipFile(File file) throws ZipException, IOException {
189 this(file, OPEN_READ);
190 }
191
192 /**
193 * Opens a new {@code ZipFile} to read from the specified
194 * {@code File} object in the specified mode. The mode argument
195 * must be either {@code OPEN_READ} or {@code OPEN_READ | OPEN_DELETE}.
196 *
197 * <p>First, if there is a security manager, its {@code checkRead}
198 * method is called with the {@code name} argument as its argument to
199 * ensure the read is allowed.
200 *
201 * @param file the ZIP file to be opened for reading
202 * @param mode the mode in which the file is to be opened
203 * @param charset
204 * the {@linkplain java.nio.charset.Charset charset} to
205 * be used to decode the ZIP entry name and comment that are not
206 * encoded by using UTF-8 encoding (indicated by entry's general
207 * purpose flag).
208 *
209 * @throws ZipException if a ZIP format error has occurred
210 * @throws IOException if an I/O error has occurred
211 *
212 * @throws SecurityException
213 * if a security manager exists and its {@code checkRead}
214 * method doesn't allow read access to the file,or its
215 * {@code checkDelete} method doesn't allow deleting the
216 * file when the {@code OPEN_DELETE} flag is set
217 *
218 * @throws IllegalArgumentException if the {@code mode} argument is invalid
219 *
220 * @see SecurityManager#checkRead(java.lang.String)
221 *
222 * @since 1.7
223 */
224 public ZipFile(File file, int mode, Charset charset) throws IOException
225 {
226 if (((mode & OPEN_READ) == 0) ||
227 ((mode & ~(OPEN_READ | OPEN_DELETE)) != 0)) {
228 throw new IllegalArgumentException("Illegal mode: 0x"+
229 Integer.toHexString(mode));
230 }
231 String name = file.getPath();
232 SecurityManager sm = System.getSecurityManager();
233 if (sm != null) {
234 sm.checkRead(name);
235 if ((mode & OPEN_DELETE) != 0) {
236 sm.checkDelete(name);
237 }
238 }
239 Objects.requireNonNull(charset, "charset");
240
241 this.zc = ZipCoder.get(charset);
242 this.name = name;
243 long t0 = System.nanoTime();
244
245 this.res = CleanableResource.get(this, file, mode);
246
247 PerfCounter.getZipFileOpenTime().addElapsedTimeFrom(t0);
248 PerfCounter.getZipFileCount().increment();
249 }
250
251 /**
252 * Opens a zip file for reading.
253 *
254 * <p>First, if there is a security manager, its {@code checkRead}
255 * method is called with the {@code name} argument as its argument
256 * to ensure the read is allowed.
257 *
258 * @param name the name of the zip file
259 * @param charset
260 * the {@linkplain java.nio.charset.Charset charset} to
261 * be used to decode the ZIP entry name and comment that are not
262 * encoded by using UTF-8 encoding (indicated by entry's general
263 * purpose flag).
264 *
265 * @throws ZipException if a ZIP format error has occurred
266 * @throws IOException if an I/O error has occurred
267 * @throws SecurityException
268 * if a security manager exists and its {@code checkRead}
269 * method doesn't allow read access to the file
270 *
271 * @see SecurityManager#checkRead(java.lang.String)
272 *
273 * @since 1.7
274 */
275 public ZipFile(String name, Charset charset) throws IOException
276 {
277 this(new File(name), OPEN_READ, charset);
278 }
279
280 /**
281 * Opens a ZIP file for reading given the specified File object.
282 *
283 * @param file the ZIP file to be opened for reading
284 * @param charset
285 * The {@linkplain java.nio.charset.Charset charset} to be
286 * used to decode the ZIP entry name and comment (ignored if
287 * the <a href="package-summary.html#lang_encoding"> language
288 * encoding bit</a> of the ZIP entry's general purpose bit
289 * flag is set).
290 *
291 * @throws ZipException if a ZIP format error has occurred
292 * @throws IOException if an I/O error has occurred
293 *
294 * @since 1.7
295 */
296 public ZipFile(File file, Charset charset) throws IOException
297 {
298 this(file, OPEN_READ, charset);
299 }
300
301 /**
302 * Returns the zip file comment, or null if none.
303 *
304 * @return the comment string for the zip file, or null if none
305 *
306 * @throws IllegalStateException if the zip file has been closed
307 *
308 * @since 1.7
309 */
310 public String getComment() {
311 synchronized (this) {
312 ensureOpen();
313 if (res.zsrc.comment == null) {
314 return null;
315 }
316 return zc.toString(res.zsrc.comment);
317 }
318 }
319
320 /**
321 * Returns the zip file entry for the specified name, or null
322 * if not found.
323 *
324 * @param name the name of the entry
325 * @return the zip file entry, or null if not found
326 * @throws IllegalStateException if the zip file has been closed
327 */
328 public ZipEntry getEntry(String name) {
329 return getEntry(name, ZipEntry::new);
330 }
331
332 /*
333 * Returns the zip file entry for the specified name, or null
334 * if not found.
335 *
336 * @param name the name of the entry
337 * @param func the function that creates the returned entry
338 *
339 * @return the zip file entry, or null if not found
340 * @throws IllegalStateException if the zip file has been closed
341 */
342 private ZipEntry getEntry(String name, Function<String, ? extends ZipEntry> func) {
343 Objects.requireNonNull(name, "name");
344 synchronized (this) {
345 ensureOpen();
346 byte[] bname = zc.getBytes(name);
347 int pos = res.zsrc.getEntryPos(bname, true);
348 if (pos != -1) {
349 return getZipEntry(name, bname, pos, func);
350 }
351 }
352 return null;
353 }
354
355 /**
356 * Returns an input stream for reading the contents of the specified
357 * zip file entry.
358 * <p>
359 * Closing this ZIP file will, in turn, close all input streams that
360 * have been returned by invocations of this method.
361 *
362 * @param entry the zip file entry
363 * @return the input stream for reading the contents of the specified
364 * zip file entry.
365 * @throws ZipException if a ZIP format error has occurred
366 * @throws IOException if an I/O error has occurred
367 * @throws IllegalStateException if the zip file has been closed
368 */
369 public InputStream getInputStream(ZipEntry entry) throws IOException {
370 Objects.requireNonNull(entry, "entry");
371 int pos = -1;
372 ZipFileInputStream in = null;
373 Source zsrc = res.zsrc;
374 Set<InputStream> istreams = res.istreams;
375 synchronized (this) {
376 ensureOpen();
377 if (Objects.equals(lastEntryName, entry.name)) {
378 pos = lastEntryPos;
379 } else if (!zc.isUTF8() && (entry.flag & EFS) != 0) {
380 pos = zsrc.getEntryPos(zc.getBytesUTF8(entry.name), false);
381 } else {
382 pos = zsrc.getEntryPos(zc.getBytes(entry.name), false);
383 }
384 if (pos == -1) {
385 return null;
386 }
387 in = new ZipFileInputStream(zsrc.cen, pos);
388 switch (CENHOW(zsrc.cen, pos)) {
389 case STORED:
390 synchronized (istreams) {
391 istreams.add(in);
392 }
393 return in;
394 case DEFLATED:
395 // Inflater likes a bit of slack
396 // MORE: Compute good size for inflater stream:
397 long size = CENLEN(zsrc.cen, pos) + 2;
398 if (size > 65536) {
399 size = 8192;
400 }
401 if (size <= 0) {
402 size = 4096;
403 }
404 InputStream is = new ZipFileInflaterInputStream(in, res, (int)size);
405 synchronized (istreams) {
406 istreams.add(is);
407 }
408 return is;
409 default:
410 throw new ZipException("invalid compression method");
411 }
412 }
413 }
414
415 private class ZipFileInflaterInputStream extends InflaterInputStream {
416 private volatile boolean closeRequested;
417 private boolean eof = false;
418 private final Cleanable cleanable;
419
420 ZipFileInflaterInputStream(ZipFileInputStream zfin,
421 CleanableResource res, int size) {
422 this(zfin, res, res.getInflater(), size);
423 }
424
425 private ZipFileInflaterInputStream(ZipFileInputStream zfin,
426 CleanableResource res,
427 Inflater inf, int size) {
428 super(zfin, inf, size);
429 this.cleanable = CleanerFactory.cleaner().register(this,
430 () -> res.releaseInflater(inf));
431 }
432
433 public void close() throws IOException {
434 if (closeRequested)
435 return;
436 closeRequested = true;
437 super.close();
438 synchronized (res.istreams) {
439 res.istreams.remove(this);
440 }
441 cleanable.clean();
442 }
443
444 // Override fill() method to provide an extra "dummy" byte
445 // at the end of the input stream. This is required when
446 // using the "nowrap" Inflater option.
447 protected void fill() throws IOException {
448 if (eof) {
449 throw new EOFException("Unexpected end of ZLIB input stream");
450 }
451 len = in.read(buf, 0, buf.length);
452 if (len == -1) {
453 buf[0] = 0;
454 len = 1;
455 eof = true;
456 }
457 inf.setInput(buf, 0, len);
458 }
459
460 public int available() throws IOException {
461 if (closeRequested)
462 return 0;
463 long avail = ((ZipFileInputStream)in).size() - inf.getBytesWritten();
464 return (avail > (long) Integer.MAX_VALUE ?
465 Integer.MAX_VALUE : (int) avail);
466 }
467 }
468
469 /**
470 * Returns the path name of the ZIP file.
471 * @return the path name of the ZIP file
472 */
473 public String getName() {
474 return name;
475 }
476
477 private class ZipEntryIterator<T extends ZipEntry>
478 implements Enumeration<T>, Iterator<T> {
479
480 private int i = 0;
481 private final int entryCount;
482 private final Function<String, T> gen;
483
484 public ZipEntryIterator(int entryCount, Function<String, T> gen) {
485 this.entryCount = entryCount;
486 this.gen = gen;
487 }
488
489 @Override
490 public boolean hasMoreElements() {
491 return hasNext();
492 }
493
494 @Override
495 public boolean hasNext() {
496 return i < entryCount;
497 }
498
499 @Override
500 public T nextElement() {
501 return next();
502 }
503
504 @Override
505 @SuppressWarnings("unchecked")
506 public T next() {
507 synchronized (ZipFile.this) {
508 ensureOpen();
509 if (!hasNext()) {
510 throw new NoSuchElementException();
511 }
512 // each "entry" has 3 ints in table entries
513 return (T)getZipEntry(null, null, res.zsrc.getEntryPos(i++ * 3), gen);
514 }
515 }
516
517 @Override
518 public Iterator<T> asIterator() {
519 return this;
520 }
521 }
522
523 /**
524 * Returns an enumeration of the ZIP file entries.
525 * @return an enumeration of the ZIP file entries
526 * @throws IllegalStateException if the zip file has been closed
527 */
528 public Enumeration<? extends ZipEntry> entries() {
529 synchronized (this) {
530 ensureOpen();
531 return new ZipEntryIterator<ZipEntry>(res.zsrc.total, ZipEntry::new);
532 }
533 }
534
535 private Enumeration<JarEntry> entries(Function<String, JarEntry> func) {
536 synchronized (this) {
537 ensureOpen();
538 return new ZipEntryIterator<JarEntry>(res.zsrc.total, func);
539 }
540 }
541
542 private class EntrySpliterator<T> extends Spliterators.AbstractSpliterator<T> {
543 private int index;
544 private final int fence;
545 private final IntFunction<T> gen;
546
547 EntrySpliterator(int index, int fence, IntFunction<T> gen) {
548 super((long)fence,
549 Spliterator.ORDERED | Spliterator.DISTINCT | Spliterator.IMMUTABLE |
550 Spliterator.NONNULL);
551 this.index = index;
552 this.fence = fence;
553 this.gen = gen;
554 }
555
556 @Override
557 public boolean tryAdvance(Consumer<? super T> action) {
558 if (action == null)
559 throw new NullPointerException();
560 if (index >= 0 && index < fence) {
561 synchronized (ZipFile.this) {
562 ensureOpen();
563 action.accept(gen.apply(res.zsrc.getEntryPos(index++ * 3)));
564 }
565 return true;
566 }
567 return false;
568 }
569 }
570
571 /**
572 * Returns an ordered {@code Stream} over the ZIP file entries.
573 *
574 * Entries appear in the {@code Stream} in the order they appear in
575 * the central directory of the ZIP file.
576 *
577 * @return an ordered {@code Stream} of entries in this ZIP file
578 * @throws IllegalStateException if the zip file has been closed
579 * @since 1.8
580 */
581 public Stream<? extends ZipEntry> stream() {
582 synchronized (this) {
583 ensureOpen();
584 return StreamSupport.stream(new EntrySpliterator<>(0, res.zsrc.total,
585 pos -> getZipEntry(null, null, pos, ZipEntry::new)), false);
586 }
587 }
588
589 private String getEntryName(int pos) {
590 byte[] cen = res.zsrc.cen;
591 int nlen = CENNAM(cen, pos);
592 int clen = CENCOM(cen, pos);
593 int flag = CENFLG(cen, pos);
594 if (!zc.isUTF8() && (flag & EFS) != 0) {
595 return zc.toStringUTF8(cen, pos + CENHDR, nlen);
596 } else {
597 return zc.toString(cen, pos + CENHDR, nlen);
598 }
599 }
600
601 /*
602 * Returns an ordered {@code Stream} over the zip file entry names.
603 *
604 * Entry names appear in the {@code Stream} in the order they appear in
605 * the central directory of the ZIP file.
606 *
607 * @return an ordered {@code Stream} of entry names in this zip file
608 * @throws IllegalStateException if the zip file has been closed
609 * @since 10
610 */
611 private Stream<String> entryNameStream() {
612 synchronized (this) {
613 ensureOpen();
614 return StreamSupport.stream(
615 new EntrySpliterator<>(0, res.zsrc.total, this::getEntryName), false);
616 }
617 }
618
619 /*
620 * Returns an ordered {@code Stream} over the zip file entries.
621 *
622 * Entries appear in the {@code Stream} in the order they appear in
623 * the central directory of the jar file.
624 *
625 * @param func the function that creates the returned entry
626 * @return an ordered {@code Stream} of entries in this zip file
627 * @throws IllegalStateException if the zip file has been closed
628 * @since 10
629 */
630 private Stream<JarEntry> stream(Function<String, JarEntry> func) {
631 synchronized (this) {
632 ensureOpen();
633 return StreamSupport.stream(new EntrySpliterator<>(0, res.zsrc.total,
634 pos -> (JarEntry)getZipEntry(null, null, pos, func)), false);
635 }
636 }
637
638 private String lastEntryName;
639 private int lastEntryPos;
640
641 /* Checks ensureOpen() before invoke this method */
642 private ZipEntry getZipEntry(String name, byte[] bname, int pos,
643 Function<String, ? extends ZipEntry> func) {
644 byte[] cen = res.zsrc.cen;
645 int nlen = CENNAM(cen, pos);
646 int elen = CENEXT(cen, pos);
647 int clen = CENCOM(cen, pos);
648 int flag = CENFLG(cen, pos);
649 if (name == null || bname.length != nlen) {
650 // to use the entry name stored in cen, if the passed in name is
651 // (1) null, invoked from iterator, or
652 // (2) not equal to the name stored, a slash is appended during
653 // getEntryPos() search.
654 if (!zc.isUTF8() && (flag & EFS) != 0) {
655 name = zc.toStringUTF8(cen, pos + CENHDR, nlen);
656 } else {
657 name = zc.toString(cen, pos + CENHDR, nlen);
658 }
659 }
660 ZipEntry e = func.apply(name); //ZipEntry e = new ZipEntry(name);
661 e.flag = flag;
662 e.xdostime = CENTIM(cen, pos);
663 e.crc = CENCRC(cen, pos);
664 e.size = CENLEN(cen, pos);
665 e.csize = CENSIZ(cen, pos);
666 e.method = CENHOW(cen, pos);
667 if (elen != 0) {
668 int start = pos + CENHDR + nlen;
669 e.setExtra0(Arrays.copyOfRange(cen, start, start + elen), true);
670 }
671 if (clen != 0) {
672 int start = pos + CENHDR + nlen + elen;
673 if (!zc.isUTF8() && (flag & EFS) != 0) {
674 e.comment = zc.toStringUTF8(cen, start, clen);
675 } else {
676 e.comment = zc.toString(cen, start, clen);
677 }
678 }
679 lastEntryName = e.name;
680 lastEntryPos = pos;
681 return e;
682 }
683
684 /**
685 * Returns the number of entries in the ZIP file.
686 *
687 * @return the number of entries in the ZIP file
688 * @throws IllegalStateException if the zip file has been closed
689 */
690 public int size() {
691 synchronized (this) {
692 ensureOpen();
693 return res.zsrc.total;
694 }
695 }
696
697 private static class CleanableResource implements Runnable {
698 // The outstanding inputstreams that need to be closed
699 final Set<InputStream> istreams;
700
701 // List of cached Inflater objects for decompression
702 Deque<Inflater> inflaterCache;
703
704 final Cleanable cleanable;
705
706 Source zsrc;
707
708 CleanableResource(ZipFile zf, File file, int mode) throws IOException {
709 this.cleanable = CleanerFactory.cleaner().register(zf, this);
710 this.istreams = Collections.newSetFromMap(new WeakHashMap<>());
711 this.inflaterCache = new ArrayDeque<>();
712 this.zsrc = Source.get(file, (mode & OPEN_DELETE) != 0);
713 }
714
715 void clean() {
716 cleanable.clean();
717 }
718
719 /*
720 * Gets an inflater from the list of available inflaters or allocates
721 * a new one.
722 */
723 Inflater getInflater() {
724 Inflater inf;
725 synchronized (inflaterCache) {
726 if ((inf = inflaterCache.poll()) != null) {
727 return inf;
728 }
729 }
730 return new Inflater(true);
731 }
732
733 /*
734 * Releases the specified inflater to the list of available inflaters.
735 */
736 void releaseInflater(Inflater inf) {
737 Deque<Inflater> inflaters = this.inflaterCache;
738 if (inflaters != null) {
739 synchronized (inflaters) {
740 // double checked!
741 if (inflaters == this.inflaterCache) {
742 inf.reset();
743 inflaters.add(inf);
744 return;
745 }
746 }
747 }
748 // inflaters cache already closed - just end it.
749 inf.end();
750 }
751
752 public void run() {
753 IOException ioe = null;
754
755 // Release cached inflaters and close the cache first
756 Deque<Inflater> inflaters = this.inflaterCache;
757 if (inflaters != null) {
758 synchronized (inflaters) {
759 // no need to double-check as only one thread gets a
760 // chance to execute run() (Cleaner guarantee)...
761 Inflater inf;
762 while ((inf = inflaters.poll()) != null) {
763 inf.end();
764 }
765 // close inflaters cache
766 this.inflaterCache = null;
767 }
768 }
769
770 // Close streams, release their inflaters
771 if (istreams != null) {
772 synchronized (istreams) {
773 if (!istreams.isEmpty()) {
774 InputStream[] copy = istreams.toArray(new InputStream[0]);
775 istreams.clear();
776 for (InputStream is : copy) {
777 try {
778 is.close();
779 } catch (IOException e) {
780 if (ioe == null) ioe = e;
781 else ioe.addSuppressed(e);
782 }
783 }
784 }
785 }
786 }
787
788 // Release zip src
789 if (zsrc != null) {
790 synchronized (zsrc) {
791 try {
792 Source.release(zsrc);
793 zsrc = null;
794 } catch (IOException e) {
795 if (ioe == null) ioe = e;
796 else ioe.addSuppressed(e);
797 }
798 }
799 }
800 if (ioe != null) {
801 throw new UncheckedIOException(ioe);
802 }
803 }
804
805 CleanableResource(File file, int mode)
806 throws IOException {
807 this.cleanable = null;
808 this.istreams = Collections.newSetFromMap(new WeakHashMap<>());
809 this.inflaterCache = new ArrayDeque<>();
810 this.zsrc = Source.get(file, (mode & OPEN_DELETE) != 0);
811 }
812
813 /*
814 * If {@code ZipFile} has been subclassed and the {@code close} method is
815 * overridden, uses the {@code finalizer} mechanism for resource cleanup.
816 * So {@code close} method can be called when the the {@code ZipFile} is
817 * unreachable. This mechanism will be removed when {@code finalize} method
818 * is removed from {@code ZipFile}.
819 */
820 static CleanableResource get(ZipFile zf, File file, int mode)
821 throws IOException {
822 Class<?> clz = zf.getClass();
823 while (clz != ZipFile.class) {
824 try {
825 clz.getDeclaredMethod("close");
826 return new FinalizableResource(zf, file, mode);
827 } catch (NoSuchMethodException nsme) {}
828 clz = clz.getSuperclass();
829 }
830 return new CleanableResource(zf, file, mode);
831 }
832
833 static class FinalizableResource extends CleanableResource {
834 ZipFile zf;
835 FinalizableResource(ZipFile zf, File file, int mode)
836 throws IOException {
837 super(file, mode);
838 this.zf = zf;
839 }
840
841 @Override
842 void clean() {
843 run();
844 }
845
846 @Override
847 @SuppressWarnings("deprecation")
848 protected void finalize() throws IOException {
849 zf.close();
850 }
851 }
852 }
853
854 /**
855 * Closes the ZIP file.
856 *
857 * <p> Closing this ZIP file will close all of the input streams
858 * previously returned by invocations of the {@link #getInputStream
859 * getInputStream} method.
860 *
861 * @throws IOException if an I/O error has occurred
862 */
863 public void close() throws IOException {
864 if (closeRequested) {
865 return;
866 }
867 closeRequested = true;
868
869 synchronized (this) {
870 // Close streams, release their inflaters, release cached inflaters
871 // and release zip source
872 try {
873 res.clean();
874 } catch (UncheckedIOException ioe) {
875 throw ioe.getCause();
876 }
877 }
878 }
879
880 /**
881 * Ensures that the system resources held by this ZipFile object are
882 * released when there are no more references to it.
883 *
884 * @deprecated The {@code finalize} method has been deprecated and will be
885 * removed. It is implemented as a no-op. Subclasses that override
886 * {@code finalize} in order to perform cleanup should be modified to
887 * use alternative cleanup mechanisms and to remove the overriding
888 * {@code finalize} method. The recommended cleanup for ZipFile object
889 * is to explicitly invoke {@code close} method when it is no longer in
890 * use, or use try-with-resources. If the {@code close} is not invoked
891 * explicitly the resources held by this object will be released when
892 * the instance becomes unreachable.
893 *
894 * @throws IOException if an I/O error has occurred
895 */
896 @Deprecated(since="9", forRemoval=true)
897 protected void finalize() throws IOException {}
898
899 private void ensureOpen() {
900 if (closeRequested) {
901 throw new IllegalStateException("zip file closed");
902 }
903 if (res.zsrc == null) {
904 throw new IllegalStateException("The object is not initialized.");
905 }
906 }
907
908 private void ensureOpenOrZipException() throws IOException {
909 if (closeRequested) {
910 throw new ZipException("ZipFile closed");
911 }
912 }
913
914 /*
915 * Inner class implementing the input stream used to read a
916 * (possibly compressed) zip file entry.
917 */
918 private class ZipFileInputStream extends InputStream {
919 private volatile boolean closeRequested;
920 private long pos; // current position within entry data
921 protected long rem; // number of remaining bytes within entry
922 protected long size; // uncompressed size of this entry
923
924 ZipFileInputStream(byte[] cen, int cenpos) {
925 rem = CENSIZ(cen, cenpos);
926 size = CENLEN(cen, cenpos);
927 pos = CENOFF(cen, cenpos);
928 // zip64
929 if (rem == ZIP64_MAGICVAL || size == ZIP64_MAGICVAL ||
930 pos == ZIP64_MAGICVAL) {
931 checkZIP64(cen, cenpos);
932 }
933 // negative for lazy initialization, see getDataOffset();
934 pos = - (pos + ZipFile.this.res.zsrc.locpos);
935 }
936
937 private void checkZIP64(byte[] cen, int cenpos) {
938 int off = cenpos + CENHDR + CENNAM(cen, cenpos);
939 int end = off + CENEXT(cen, cenpos);
940 while (off + 4 < end) {
941 int tag = get16(cen, off);
942 int sz = get16(cen, off + 2);
943 off += 4;
944 if (off + sz > end) // invalid data
945 break;
946 if (tag == EXTID_ZIP64) {
947 if (size == ZIP64_MAGICVAL) {
948 if (sz < 8 || (off + 8) > end)
949 break;
950 size = get64(cen, off);
951 sz -= 8;
952 off += 8;
953 }
954 if (rem == ZIP64_MAGICVAL) {
955 if (sz < 8 || (off + 8) > end)
956 break;
957 rem = get64(cen, off);
958 sz -= 8;
959 off += 8;
960 }
961 if (pos == ZIP64_MAGICVAL) {
962 if (sz < 8 || (off + 8) > end)
963 break;
964 pos = get64(cen, off);
965 sz -= 8;
966 off += 8;
967 }
968 break;
969 }
970 off += sz;
971 }
972 }
973
974 /* The Zip file spec explicitly allows the LOC extra data size to
975 * be different from the CEN extra data size. Since we cannot trust
976 * the CEN extra data size, we need to read the LOC to determine
977 * the entry data offset.
978 */
979 private long initDataOffset() throws IOException {
980 if (pos <= 0) {
981 byte[] loc = new byte[LOCHDR];
982 pos = -pos;
983 int len = ZipFile.this.res.zsrc.readFullyAt(loc, 0, loc.length, pos);
984 if (len != LOCHDR) {
985 throw new ZipException("ZipFile error reading zip file");
986 }
987 if (LOCSIG(loc) != LOCSIG) {
988 throw new ZipException("ZipFile invalid LOC header (bad signature)");
989 }
990 pos += LOCHDR + LOCNAM(loc) + LOCEXT(loc);
991 }
992 return pos;
993 }
994
995 public int read(byte b[], int off, int len) throws IOException {
996 synchronized (ZipFile.this) {
997 ensureOpenOrZipException();
998 initDataOffset();
999 if (rem == 0) {
1000 return -1;
1001 }
1002 if (len > rem) {
1003 len = (int) rem;
1004 }
1005 if (len <= 0) {
1006 return 0;
1007 }
1008 len = ZipFile.this.res.zsrc.readAt(b, off, len, pos);
1009 if (len > 0) {
1010 pos += len;
1011 rem -= len;
1012 }
1013 }
1014 if (rem == 0) {
1015 close();
1016 }
1017 return len;
1018 }
1019
1020 public int read() throws IOException {
1021 byte[] b = new byte[1];
1022 if (read(b, 0, 1) == 1) {
1023 return b[0] & 0xff;
1024 } else {
1025 return -1;
1026 }
1027 }
1028
1029 public long skip(long n) throws IOException {
1030 synchronized (ZipFile.this) {
1031 initDataOffset();
1032 if (n > rem) {
1033 n = rem;
1034 }
1035 pos += n;
1036 rem -= n;
1037 }
1038 if (rem == 0) {
1039 close();
1040 }
1041 return n;
1042 }
1043
1044 public int available() {
1045 return rem > Integer.MAX_VALUE ? Integer.MAX_VALUE : (int) rem;
1046 }
1047
1048 public long size() {
1049 return size;
1050 }
1051
1052 public void close() {
1053 if (closeRequested) {
1054 return;
1055 }
1056 closeRequested = true;
1057 rem = 0;
1058 synchronized (res.istreams) {
1059 res.istreams.remove(this);
1060 }
1061 }
1062
1063 }
1064
1065 /**
1066 * Returns the names of all non-directory entries that begin with
1067 * "META-INF/" (case ignored). This method is used in JarFile, via
1068 * SharedSecrets, as an optimization when looking up manifest and
1069 * signature file entries. Returns null if no entries were found.
1070 */
1071 private String[] getMetaInfEntryNames() {
1072 synchronized (this) {
1073 ensureOpen();
1074 Source zsrc = res.zsrc;
1075 if (zsrc.metanames == null) {
1076 return null;
1077 }
1078 String[] names = new String[zsrc.metanames.length];
1079 byte[] cen = zsrc.cen;
1080 for (int i = 0; i < names.length; i++) {
1081 int pos = zsrc.metanames[i];
1082 names[i] = new String(cen, pos + CENHDR, CENNAM(cen, pos),
1083 StandardCharsets.UTF_8);
1084 }
1085 return names;
1086 }
1087 }
1088
1089 private static boolean isWindows;
1090 static {
1091 SharedSecrets.setJavaUtilZipFileAccess(
1092 new JavaUtilZipFileAccess() {
1093 @Override
1094 public boolean startsWithLocHeader(ZipFile zip) {
1095 return zip.res.zsrc.startsWithLoc;
1096 }
1097 @Override
1098 public String[] getMetaInfEntryNames(ZipFile zip) {
1099 return zip.getMetaInfEntryNames();
1100 }
1101 @Override
1102 public JarEntry getEntry(ZipFile zip, String name,
1103 Function<String, JarEntry> func) {
1104 return (JarEntry)zip.getEntry(name, func);
1105 }
1106 @Override
1107 public Enumeration<JarEntry> entries(ZipFile zip,
1108 Function<String, JarEntry> func) {
1109 return zip.entries(func);
1110 }
1111 @Override
1112 public Stream<JarEntry> stream(ZipFile zip,
1113 Function<String, JarEntry> func) {
1114 return zip.stream(func);
1115 }
1116 @Override
1117 public Stream<String> entryNameStream(ZipFile zip) {
1118 return zip.entryNameStream();
1119 }
1120 }
1121 );
1122 isWindows = VM.getSavedProperty("os.name").contains("Windows");
1123 }
1124
1125 private static class Source {
1126 private final Key key; // the key in files
1127 private int refs = 1;
1128
1129 private RandomAccessFile zfile; // zfile of the underlying zip file
1130 private byte[] cen; // CEN & ENDHDR
1131 private long locpos; // position of first LOC header (usually 0)
1132 private byte[] comment; // zip file comment
1133 // list of meta entries in META-INF dir
1134 private int[] metanames;
1135 private final boolean startsWithLoc; // true, if zip file starts with LOCSIG (usually true)
1136
1137 // A Hashmap for all entries.
1138 //
1139 // A cen entry of Zip/JAR file. As we have one for every entry in every active Zip/JAR,
1140 // We might have a lot of these in a typical system. In order to save space we don't
1141 // keep the name in memory, but merely remember a 32 bit {@code hash} value of the
1142 // entry name and its offset {@code pos} in the central directory hdeader.
1143 //
1144 // private static class Entry {
1145 // int hash; // 32 bit hashcode on name
1146 // int next; // hash chain: index into entries
1147 // int pos; // Offset of central directory file header
1148 // }
1149 // private Entry[] entries; // array of hashed cen entry
1150 //
1151 // To reduce the total size of entries further, we use a int[] here to store 3 "int"
1152 // {@code hash}, {@code next and {@code "pos for each entry. The entry can then be
1153 // referred by their index of their positions in the {@code entries}.
1154 //
1155 private int[] entries; // array of hashed cen entry
1156 private int addEntry(int index, int hash, int next, int pos) {
1157 entries[index++] = hash;
1158 entries[index++] = next;
1159 entries[index++] = pos;
1160 return index;
1161 }
1162 private int getEntryHash(int index) { return entries[index]; }
1163 private int getEntryNext(int index) { return entries[index + 1]; }
1164 private int getEntryPos(int index) { return entries[index + 2]; }
1165 private static final int ZIP_ENDCHAIN = -1;
1166 private int total; // total number of entries
1167 private int[] table; // Hash chain heads: indexes into entries
1168 private int tablelen; // number of hash heads
1169
1170 private static class Key {
1171 BasicFileAttributes attrs;
1172 File file;
1173
1174 public Key(File file, BasicFileAttributes attrs) {
1175 this.attrs = attrs;
1176 this.file = file;
1177 }
1178
1179 public int hashCode() {
1180 long t = attrs.lastModifiedTime().toMillis();
1181 return ((int)(t ^ (t >>> 32))) + file.hashCode();
1182 }
1183
1184 public boolean equals(Object obj) {
1185 if (obj instanceof Key) {
1186 Key key = (Key)obj;
1187 if (!attrs.lastModifiedTime().equals(key.attrs.lastModifiedTime())) {
1188 return false;
1189 }
1190 Object fk = attrs.fileKey();
1191 if (fk != null) {
1192 return fk.equals(key.attrs.fileKey());
1193 } else {
1194 return file.equals(key.file);
1195 }
1196 }
1197 return false;
1198 }
1199 }
1200 private static final HashMap<Key, Source> files = new HashMap<>();
1201
1202
1203 static Source get(File file, boolean toDelete) throws IOException {
1204 Key key = new Key(file,
1205 Files.readAttributes(file.toPath(), BasicFileAttributes.class));
1206 Source src = null;
1207 synchronized (files) {
1208 src = files.get(key);
1209 if (src != null) {
1210 src.refs++;
1211 return src;
1212 }
1213 }
1214 src = new Source(key, toDelete);
1215
1216 synchronized (files) {
1217 if (files.containsKey(key)) { // someone else put in first
1218 src.close(); // close the newly created one
1219 src = files.get(key);
1220 src.refs++;
1221 return src;
1222 }
1223 files.put(key, src);
1224 return src;
1225 }
1226 }
1227
1228 static void release(Source src) throws IOException {
1229 synchronized (files) {
1230 if (src != null && --src.refs == 0) {
1231 files.remove(src.key);
1232 src.close();
1233 }
1234 }
1235 }
1236
1237 private Source(Key key, boolean toDelete) throws IOException {
1238 this.key = key;
1239 if (toDelete) {
1240 if (isWindows) {
1241 this.zfile = SharedSecrets.getJavaIORandomAccessFileAccess()
1242 .openAndDelete(key.file, "r");
1243 } else {
1244 this.zfile = new RandomAccessFile(key.file, "r");
1245 key.file.delete();
1246 }
1247 } else {
1248 this.zfile = new RandomAccessFile(key.file, "r");
1249 }
1250 try {
1251 initCEN(-1);
1252 byte[] buf = new byte[4];
1253 readFullyAt(buf, 0, 4, 0);
1254 this.startsWithLoc = (LOCSIG(buf) == LOCSIG);
1255 } catch (IOException x) {
1256 try {
1257 this.zfile.close();
1258 } catch (IOException xx) {}
1259 throw x;
1260 }
1261 }
1262
1263 private void close() throws IOException {
1264 zfile.close();
1265 zfile = null;
1266 cen = null;
1267 entries = null;
1268 table = null;
1269 metanames = null;
1270 }
1271
1272 private static final int BUF_SIZE = 8192;
1273 private final int readFullyAt(byte[] buf, int off, int len, long pos)
1274 throws IOException
1275 {
1276 synchronized(zfile) {
1277 zfile.seek(pos);
1278 int N = len;
1279 while (N > 0) {
1280 int n = Math.min(BUF_SIZE, N);
1281 zfile.readFully(buf, off, n);
1282 off += n;
1283 N -= n;
1284 }
1285 return len;
1286 }
1287 }
1288
1289 private final int readAt(byte[] buf, int off, int len, long pos)
1290 throws IOException
1291 {
1292 synchronized(zfile) {
1293 zfile.seek(pos);
1294 return zfile.read(buf, off, len);
1295 }
1296 }
1297
1298 private static final int hashN(byte[] a, int off, int len) {
1299 int h = 1;
1300 while (len-- > 0) {
1301 h = 31 * h + a[off++];
1302 }
1303 return h;
1304 }
1305
1306 private static final int hash_append(int hash, byte b) {
1307 return hash * 31 + b;
1308 }
1309
1310 private static class End {
1311 int centot; // 4 bytes
1312 long cenlen; // 4 bytes
1313 long cenoff; // 4 bytes
1314 long endpos; // 4 bytes
1315 }
1316
1317 /*
1318 * Searches for end of central directory (END) header. The contents of
1319 * the END header will be read and placed in endbuf. Returns the file
1320 * position of the END header, otherwise returns -1 if the END header
1321 * was not found or an error occurred.
1322 */
1323 private End findEND() throws IOException {
1324 long ziplen = zfile.length();
1325 if (ziplen <= 0)
1326 zerror("zip file is empty");
1327 End end = new End();
1328 byte[] buf = new byte[READBLOCKSZ];
1329 long minHDR = (ziplen - END_MAXLEN) > 0 ? ziplen - END_MAXLEN : 0;
1330 long minPos = minHDR - (buf.length - ENDHDR);
1331 for (long pos = ziplen - buf.length; pos >= minPos; pos -= (buf.length - ENDHDR)) {
1332 int off = 0;
1333 if (pos < 0) {
1334 // Pretend there are some NUL bytes before start of file
1335 off = (int)-pos;
1336 Arrays.fill(buf, 0, off, (byte)0);
1337 }
1338 int len = buf.length - off;
1339 if (readFullyAt(buf, off, len, pos + off) != len ) {
1340 zerror("zip END header not found");
1341 }
1342 // Now scan the block backwards for END header signature
1343 for (int i = buf.length - ENDHDR; i >= 0; i--) {
1344 if (buf[i+0] == (byte)'P' &&
1345 buf[i+1] == (byte)'K' &&
1346 buf[i+2] == (byte)'\005' &&
1347 buf[i+3] == (byte)'\006') {
1348 // Found ENDSIG header
1349 byte[] endbuf = Arrays.copyOfRange(buf, i, i + ENDHDR);
1350 end.centot = ENDTOT(endbuf);
1351 end.cenlen = ENDSIZ(endbuf);
1352 end.cenoff = ENDOFF(endbuf);
1353 end.endpos = pos + i;
1354 int comlen = ENDCOM(endbuf);
1355 if (end.endpos + ENDHDR + comlen != ziplen) {
1356 // ENDSIG matched, however the size of file comment in it does
1357 // not match the real size. One "common" cause for this problem
1358 // is some "extra" bytes are padded at the end of the zipfile.
1359 // Let's do some extra verification, we don't care about the
1360 // performance in this situation.
1361 byte[] sbuf = new byte[4];
1362 long cenpos = end.endpos - end.cenlen;
1363 long locpos = cenpos - end.cenoff;
1364 if (cenpos < 0 ||
1365 locpos < 0 ||
1366 readFullyAt(sbuf, 0, sbuf.length, cenpos) != 4 ||
1367 GETSIG(sbuf) != CENSIG ||
1368 readFullyAt(sbuf, 0, sbuf.length, locpos) != 4 ||
1369 GETSIG(sbuf) != LOCSIG) {
1370 continue;
1371 }
1372 }
1373 if (comlen > 0) { // this zip file has comlen
1374 comment = new byte[comlen];
1375 if (readFullyAt(comment, 0, comlen, end.endpos + ENDHDR) != comlen) {
1376 zerror("zip comment read failed");
1377 }
1378 }
1379 // must check for a zip64 end record; it is always permitted to be present
1380 try {
1381 byte[] loc64 = new byte[ZIP64_LOCHDR];
1382 if (end.endpos < ZIP64_LOCHDR ||
1383 readFullyAt(loc64, 0, loc64.length, end.endpos - ZIP64_LOCHDR)
1384 != loc64.length || GETSIG(loc64) != ZIP64_LOCSIG) {
1385 return end;
1386 }
1387 long end64pos = ZIP64_LOCOFF(loc64);
1388 byte[] end64buf = new byte[ZIP64_ENDHDR];
1389 if (readFullyAt(end64buf, 0, end64buf.length, end64pos)
1390 != end64buf.length || GETSIG(end64buf) != ZIP64_ENDSIG) {
1391 return end;
1392 }
1393 // end64 candidate found,
1394 long cenlen64 = ZIP64_ENDSIZ(end64buf);
1395 long cenoff64 = ZIP64_ENDOFF(end64buf);
1396 long centot64 = ZIP64_ENDTOT(end64buf);
1397 // double-check
1398 if (cenlen64 != end.cenlen && end.cenlen != ZIP64_MAGICVAL ||
1399 cenoff64 != end.cenoff && end.cenoff != ZIP64_MAGICVAL ||
1400 centot64 != end.centot && end.centot != ZIP64_MAGICCOUNT) {
1401 return end;
1402 }
1403 // to use the end64 values
1404 end.cenlen = cenlen64;
1405 end.cenoff = cenoff64;
1406 end.centot = (int)centot64; // assume total < 2g
1407 end.endpos = end64pos;
1408 } catch (IOException x) {} // no zip64 loc/end
1409 return end;
1410 }
1411 }
1412 }
1413 zerror("zip END header not found");
1414 return null; //make compiler happy
1415 }
1416
1417 // Reads zip file central directory.
1418 private void initCEN(int knownTotal) throws IOException {
1419 if (knownTotal == -1) {
1420 End end = findEND();
1421 if (end.endpos == 0) {
1422 locpos = 0;
1423 total = 0;
1424 entries = new int[0];
1425 cen = null;
1426 return; // only END header present
1427 }
1428 if (end.cenlen > end.endpos)
1429 zerror("invalid END header (bad central directory size)");
1430 long cenpos = end.endpos - end.cenlen; // position of CEN table
1431 // Get position of first local file (LOC) header, taking into
1432 // account that there may be a stub prefixed to the zip file.
1433 locpos = cenpos - end.cenoff;
1434 if (locpos < 0) {
1435 zerror("invalid END header (bad central directory offset)");
1436 }
1437 // read in the CEN and END
1438 cen = new byte[(int)(end.cenlen + ENDHDR)];
1439 if (readFullyAt(cen, 0, cen.length, cenpos) != end.cenlen + ENDHDR) {
1440 zerror("read CEN tables failed");
1441 }
1442 total = end.centot;
1443 } else {
1444 total = knownTotal;
1445 }
1446 // hash table for entries
1447 entries = new int[total * 3];
1448 tablelen = ((total/2) | 1); // Odd -> fewer collisions
1449 table = new int[tablelen];
1450 Arrays.fill(table, ZIP_ENDCHAIN);
1451 int idx = 0;
1452 int hash = 0;
1453 int next = -1;
1454
1455 // list for all meta entries
1456 ArrayList<Integer> metanamesList = null;
1457
1458 // Iterate through the entries in the central directory
1459 int i = 0;
1460 int hsh = 0;
1461 int pos = 0;
1462 int limit = cen.length - ENDHDR;
1463 while (pos + CENHDR <= limit) {
1464 if (i >= total) {
1465 // This will only happen if the zip file has an incorrect
1466 // ENDTOT field, which usually means it contains more than
1467 // 65535 entries.
1468 initCEN(countCENHeaders(cen, limit));
1469 return;
1470 }
1471 if (CENSIG(cen, pos) != CENSIG)
1472 zerror("invalid CEN header (bad signature)");
1473 int method = CENHOW(cen, pos);
1474 int nlen = CENNAM(cen, pos);
1475 int elen = CENEXT(cen, pos);
1476 int clen = CENCOM(cen, pos);
1477 if ((CENFLG(cen, pos) & 1) != 0)
1478 zerror("invalid CEN header (encrypted entry)");
1479 if (method != STORED && method != DEFLATED)
1480 zerror("invalid CEN header (bad compression method: " + method + ")");
1481 if (pos + CENHDR + nlen > limit)
1482 zerror("invalid CEN header (bad header size)");
1483 // Record the CEN offset and the name hash in our hash cell.
1484 hash = hashN(cen, pos + CENHDR, nlen);
1485 hsh = (hash & 0x7fffffff) % tablelen;
1486 next = table[hsh];
1487 table[hsh] = idx;
1488 idx = addEntry(idx, hash, next, pos);
1489 // Adds name to metanames.
1490 if (isMetaName(cen, pos + CENHDR, nlen)) {
1491 if (metanamesList == null)
1492 metanamesList = new ArrayList<>(4);
1493 metanamesList.add(pos);
1494 }
1495 // skip ext and comment
1496 pos += (CENHDR + nlen + elen + clen);
1497 i++;
1498 }
1499 total = i;
1500 if (metanamesList != null) {
1501 metanames = new int[metanamesList.size()];
1502 for (int j = 0, len = metanames.length; j < len; j++) {
1503 metanames[j] = metanamesList.get(j);
1504 }
1505 }
1506 if (pos + ENDHDR != cen.length) {
1507 zerror("invalid CEN header (bad header size)");
1508 }
1509 }
1510
1511 private static void zerror(String msg) throws ZipException {
1512 throw new ZipException(msg);
1513 }
1514
1515 /*
1516 * Returns the {@code pos} of the zip cen entry corresponding to the
1517 * specified entry name, or -1 if not found.
1518 */
1519 private int getEntryPos(byte[] name, boolean addSlash) {
1520 if (total == 0) {
1521 return -1;
1522 }
1523 int hsh = hashN(name, 0, name.length);
1524 int idx = table[(hsh & 0x7fffffff) % tablelen];
1525 /*
1526 * This while loop is an optimization where a double lookup
1527 * for name and name+/ is being performed. The name char
1528 * array has enough room at the end to try again with a
1529 * slash appended if the first table lookup does not succeed.
1530 */
1531 while(true) {
1532 /*
1533 * Search down the target hash chain for a entry whose
1534 * 32 bit hash matches the hashed name.
1535 */
1536 while (idx != ZIP_ENDCHAIN) {
1537 if (getEntryHash(idx) == hsh) {
1538 // The CEN name must match the specfied one
1539 int pos = getEntryPos(idx);
1540 if (name.length == CENNAM(cen, pos)) {
1541 boolean matched = true;
1542 int nameoff = pos + CENHDR;
1543 for (int i = 0; i < name.length; i++) {
1544 if (name[i] != cen[nameoff++]) {
1545 matched = false;
1546 break;
1547 }
1548 }
1549 if (matched) {
1550 return pos;
1551 }
1552 }
1553 }
1554 idx = getEntryNext(idx);
1555 }
1556 /* If not addSlash, or slash is already there, we are done */
1557 if (!addSlash || name.length == 0 || name[name.length - 1] == '/') {
1558 return -1;
1559 }
1560 /* Add slash and try once more */
1561 name = Arrays.copyOf(name, name.length + 1);
1562 name[name.length - 1] = '/';
1563 hsh = hash_append(hsh, (byte)'/');
1564 //idx = table[hsh % tablelen];
1565 idx = table[(hsh & 0x7fffffff) % tablelen];
1566 addSlash = false;
1567 }
1568 }
1569
1570 /**
1571 * Returns true if the bytes represent a non-directory name
1572 * beginning with "META-INF/", disregarding ASCII case.
1573 */
1574 private static boolean isMetaName(byte[] name, int off, int len) {
1575 // Use the "oldest ASCII trick in the book"
1576 return len > 9 // "META-INF/".length()
1577 && name[off + len - 1] != '/' // non-directory
1578 && (name[off++] | 0x20) == 'm'
1579 && (name[off++] | 0x20) == 'e'
1580 && (name[off++] | 0x20) == 't'
1581 && (name[off++] | 0x20) == 'a'
1582 && (name[off++] ) == '-'
1583 && (name[off++] | 0x20) == 'i'
1584 && (name[off++] | 0x20) == 'n'
1585 && (name[off++] | 0x20) == 'f'
1586 && (name[off] ) == '/';
1587 }
1588
1589 /**
1590 * Returns the number of CEN headers in a central directory.
1591 * Will not throw, even if the zip file is corrupt.
1592 *
1593 * @param cen copy of the bytes in a zip file's central directory
1594 * @param size number of bytes in central directory
1595 */
1596 private static int countCENHeaders(byte[] cen, int size) {
1597 int count = 0;
1598 for (int p = 0;
1599 p + CENHDR <= size;
1600 p += CENHDR + CENNAM(cen, p) + CENEXT(cen, p) + CENCOM(cen, p))
1601 count++;
1602 return count;
1603 }
1604 }
1605 }