1 /*
2 * Copyright (c) 2014, 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 jdk.internal.module;
27
28 import java.io.BufferedInputStream;
29 import java.io.BufferedReader;
30 import java.io.File;
31 import java.io.IOException;
32 import java.io.InputStream;
33 import java.io.InputStreamReader;
34 import java.io.UncheckedIOException;
35 import java.lang.module.FindException;
36 import java.lang.module.InvalidModuleDescriptorException;
37 import java.lang.module.ModuleDescriptor;
38 import java.lang.module.ModuleDescriptor.Builder;
39 import java.lang.module.ModuleFinder;
40 import java.lang.module.ModuleReference;
41 import java.net.URI;
42 import java.nio.file.DirectoryStream;
43 import java.nio.file.Files;
44 import java.nio.file.NoSuchFileException;
45 import java.nio.file.Path;
46 import java.nio.file.Paths;
47 import java.nio.file.attribute.BasicFileAttributes;
48 import java.util.ArrayList;
49 import java.util.Collections;
50 import java.util.HashMap;
51 import java.util.List;
52 import java.util.Map;
53 import java.util.Objects;
54 import java.util.Optional;
55 import java.util.Set;
56 import java.util.jar.Attributes;
57 import java.util.jar.JarEntry;
58 import java.util.jar.JarFile;
59 import java.util.jar.Manifest;
60 import java.util.regex.Matcher;
61 import java.util.regex.Pattern;
62 import java.util.stream.Collectors;
63 import java.util.zip.ZipException;
64 import java.util.zip.ZipFile;
65
66 import jdk.internal.jmod.JmodFile;
67 import jdk.internal.jmod.JmodFile.Section;
68 import jdk.internal.perf.PerfCounter;
69 import jdk.internal.util.jar.VersionedStream;
70
71
72 /**
73 * A {@code ModuleFinder} that locates modules on the file system by searching
74 * a sequence of directories or packaged modules. The ModuleFinder can be
75 * created to work in either the run-time or link-time phases. In both cases it
76 * locates modular JAR and exploded modules. When created for link-time then it
77 * additionally locates modules in JMOD files. The ModuleFinder can also
78 * optionally patch any modules that it locates with a ModulePatcher.
79 */
80
81 public class ModulePath implements ModuleFinder {
82 private static final String MODULE_INFO = "module-info.class";
83
84 // the version to use for multi-release modular JARs
85 private final Runtime.Version releaseVersion;
86
87 // true for the link phase (supports modules packaged in JMOD format)
88 private final boolean isLinkPhase;
89
90 // for patching modules, can be null
91 private final ModulePatcher patcher;
92
93 // the entries on this module path
94 private final Path[] entries;
95 private int next;
96
97 // map of module name to module reference map for modules already located
98 private final Map<String, ModuleReference> cachedModules = new HashMap<>();
99
100
101 private ModulePath(Runtime.Version version,
102 boolean isLinkPhase,
103 ModulePatcher patcher,
104 Path... entries) {
105 this.releaseVersion = version;
106 this.isLinkPhase = isLinkPhase;
107 this.patcher = patcher;
108 this.entries = entries.clone();
109 for (Path entry : this.entries) {
110 Objects.requireNonNull(entry);
111 }
112 }
113
114 /**
115 * Returns a ModuleFinder that locates modules on the file system by
116 * searching a sequence of directories and/or packaged modules. The modules
117 * may be patched by the given ModulePatcher.
118 */
119 public static ModuleFinder of(ModulePatcher patcher, Path... entries) {
120 return new ModulePath(JarFile.runtimeVersion(), false, patcher, entries);
121 }
122
123 /**
124 * Returns a ModuleFinder that locates modules on the file system by
125 * searching a sequence of directories and/or packaged modules.
126 */
127 public static ModuleFinder of(Path... entries) {
128 return of((ModulePatcher)null, entries);
129 }
130
131 /**
132 * Returns a ModuleFinder that locates modules on the file system by
133 * searching a sequence of directories and/or packaged modules.
134 *
135 * @param version The release version to use for multi-release JAR files
136 * @param isLinkPhase {@code true} if the link phase to locate JMOD files
137 */
138 public static ModuleFinder of(Runtime.Version version,
139 boolean isLinkPhase,
140 Path... entries) {
141 return new ModulePath(version, isLinkPhase, null, entries);
142 }
143
144
145 @Override
146 public Optional<ModuleReference> find(String name) {
147 Objects.requireNonNull(name);
148
149 // try cached modules
150 ModuleReference m = cachedModules.get(name);
151 if (m != null)
152 return Optional.of(m);
153
154 // the module may not have been encountered yet
155 while (hasNextEntry()) {
156 scanNextEntry();
157 m = cachedModules.get(name);
158 if (m != null)
159 return Optional.of(m);
160 }
161 return Optional.empty();
162 }
163
164 @Override
165 public Set<ModuleReference> findAll() {
166 // need to ensure that all entries have been scanned
167 while (hasNextEntry()) {
168 scanNextEntry();
169 }
170 return cachedModules.values().stream().collect(Collectors.toSet());
171 }
172
173 /**
174 * Returns {@code true} if there are additional entries to scan
175 */
176 private boolean hasNextEntry() {
177 return next < entries.length;
178 }
179
180 /**
181 * Scans the next entry on the module path. A no-op if all entries have
182 * already been scanned.
183 *
184 * @throws FindException if an error occurs scanning the next entry
185 */
186 private void scanNextEntry() {
187 if (hasNextEntry()) {
188
189 long t0 = System.nanoTime();
190
191 Path entry = entries[next];
192 Map<String, ModuleReference> modules = scan(entry);
193 next++;
194
195 // update cache, ignoring duplicates
196 int initialSize = cachedModules.size();
197 for (Map.Entry<String, ModuleReference> e : modules.entrySet()) {
198 cachedModules.putIfAbsent(e.getKey(), e.getValue());
199 }
200
201 // update counters
202 int added = cachedModules.size() - initialSize;
203 moduleCount.add(added);
204
205 scanTime.addElapsedTimeFrom(t0);
206 }
207 }
208
209
210 /**
211 * Scan the given module path entry. If the entry is a directory then it is
212 * a directory of modules or an exploded module. If the entry is a regular
213 * file then it is assumed to be a packaged module.
214 *
215 * @throws FindException if an error occurs scanning the entry
216 */
217 private Map<String, ModuleReference> scan(Path entry) {
218
219 BasicFileAttributes attrs;
220 try {
221 attrs = Files.readAttributes(entry, BasicFileAttributes.class);
222 } catch (NoSuchFileException e) {
223 return Collections.emptyMap();
224 } catch (IOException ioe) {
225 throw new FindException(ioe);
226 }
227
228 try {
229
230 if (attrs.isDirectory()) {
231 Path mi = entry.resolve(MODULE_INFO);
232 if (!Files.exists(mi)) {
233 // assume a directory of modules
234 return scanDirectory(entry);
235 }
236 }
237
238 // packaged or exploded module
239 ModuleReference mref = readModule(entry, attrs);
240 if (mref != null) {
241 String name = mref.descriptor().name();
242 return Collections.singletonMap(name, mref);
243 }
244
245 // not recognized
246 String msg;
247 if (!isLinkPhase && entry.toString().endsWith(".jmod")) {
248 msg = "JMOD format not supported at execution time";
249 } else {
250 msg = "Module format not recognized";
251 }
252 throw new FindException(msg + ": " + entry);
253
254 } catch (IOException ioe) {
255 throw new FindException(ioe);
256 }
257 }
258
259
260 /**
261 * Scans the given directory for packaged or exploded modules.
262 *
263 * @return a map of module name to ModuleReference for the modules found
264 * in the directory
265 *
266 * @throws IOException if an I/O error occurs
267 * @throws FindException if an error occurs scanning the entry or the
268 * directory contains two or more modules with the same name
269 */
270 private Map<String, ModuleReference> scanDirectory(Path dir)
271 throws IOException
272 {
273 // The map of name -> mref of modules found in this directory.
274 Map<String, ModuleReference> nameToReference = new HashMap<>();
275
276 try (DirectoryStream<Path> stream = Files.newDirectoryStream(dir)) {
277 for (Path entry : stream) {
278 BasicFileAttributes attrs;
279 try {
280 attrs = Files.readAttributes(entry, BasicFileAttributes.class);
281 } catch (NoSuchFileException ignore) {
282 // file has been removed or moved, ignore for now
283 continue;
284 }
285
286 ModuleReference mref = readModule(entry, attrs);
287
288 // module found
289 if (mref != null) {
290 // can have at most one version of a module in the directory
291 String name = mref.descriptor().name();
292 ModuleReference previous = nameToReference.put(name, mref);
293 if (previous != null) {
294 String fn1 = fileName(mref);
295 String fn2 = fileName(previous);
296 throw new FindException("Two versions of module "
297 + name + " found in " + dir
298 + " (" + fn1 + " and " + fn2 + ")");
299 }
300 }
301 }
302 }
303
304 return nameToReference;
305 }
306
307
308 /**
309 * Reads a packaged or exploded module, returning a {@code ModuleReference}
310 * to the module. Returns {@code null} if the entry is not recognized.
311 *
312 * @throws IOException if an I/O error occurs
313 * @throws FindException if an error occurs parsing its module descriptor
314 */
315 private ModuleReference readModule(Path entry, BasicFileAttributes attrs)
316 throws IOException
317 {
318 try {
319
320 // exploded module
321 if (attrs.isDirectory()) {
322 return readExplodedModule(entry); // may return null
323 }
324
325 // JAR or JMOD file
326 if (attrs.isRegularFile()) {
327 String fn = entry.getFileName().toString();
328 boolean isDefaultFileSystem = isDefaultFileSystem(entry);
329
330 // JAR file
331 if (fn.endsWith(".jar")) {
332 if (isDefaultFileSystem) {
333 return readJar(entry);
334 } else {
335 // the JAR file is in a custom file system so
336 // need to copy it to the local file system
337 Path tmpdir = Files.createTempDirectory("mlib");
338 Path target = Files.copy(entry, tmpdir.resolve(fn));
339 return readJar(target);
340 }
341 }
342
343 // JMOD file
344 if (isDefaultFileSystem && isLinkPhase && fn.endsWith(".jmod")) {
345 return readJMod(entry);
346 }
347 }
348
349 return null;
350
351 } catch (InvalidModuleDescriptorException e) {
352 throw new FindException("Error reading module: " + entry, e);
353 }
354 }
355
356 /**
357 * Returns a string with the file name of the module if possible.
358 * If the module location is not a file URI then return the URI
359 * as a string.
360 */
361 private String fileName(ModuleReference mref) {
362 URI uri = mref.location().orElse(null);
363 if (uri != null) {
364 if (uri.getScheme().equalsIgnoreCase("file")) {
365 Path file = Paths.get(uri);
366 return file.getFileName().toString();
367 } else {
368 return uri.toString();
369 }
370 } else {
371 return "<unknown>";
372 }
373 }
374
375 // -- JMOD files --
376
377 private Set<String> jmodPackages(JmodFile jf) {
378 return jf.stream()
379 .filter(e -> e.section() == Section.CLASSES)
380 .map(JmodFile.Entry::name)
381 .map(this::toPackageName)
382 .flatMap(Optional::stream)
383 .collect(Collectors.toSet());
384 }
385
386 /**
387 * Returns a {@code ModuleReference} to a module in JMOD file on the
388 * file system.
389 *
390 * @throws IOException
391 * @throws InvalidModuleDescriptorException
392 */
393 private ModuleReference readJMod(Path file) throws IOException {
394 try (JmodFile jf = new JmodFile(file)) {
395 ModuleInfo.Attributes attrs;
396 try (InputStream in = jf.getInputStream(Section.CLASSES, MODULE_INFO)) {
397 attrs = ModuleInfo.read(in, () -> jmodPackages(jf));
398 }
399 return ModuleReferences.newJModModule(attrs, file);
400 }
401 }
402
403
404 // -- JAR files --
405
406 private static final String SERVICES_PREFIX = "META-INF/services/";
407
408 private static final Attributes.Name AUTOMATIC_MODULE_NAME
409 = new Attributes.Name("Automatic-Module-Name");
410
411 /**
412 * Returns the service type corresponding to the name of a services
413 * configuration file if it is a legal type name.
414 *
415 * For example, if called with "META-INF/services/p.S" then this method
416 * returns a container with the value "p.S".
417 */
418 private Optional<String> toServiceName(String cf) {
419 assert cf.startsWith(SERVICES_PREFIX);
420 int index = cf.lastIndexOf("/") + 1;
421 if (index < cf.length()) {
422 String prefix = cf.substring(0, index);
423 if (prefix.equals(SERVICES_PREFIX)) {
424 String sn = cf.substring(index);
425 if (Checks.isClassName(sn))
426 return Optional.of(sn);
427 }
428 }
429 return Optional.empty();
430 }
431
432 /**
433 * Reads the next line from the given reader and trims it of comments and
434 * leading/trailing white space.
435 *
436 * Returns null if the reader is at EOF.
437 */
438 private String nextLine(BufferedReader reader) throws IOException {
439 String ln = reader.readLine();
440 if (ln != null) {
441 int ci = ln.indexOf('#');
442 if (ci >= 0)
443 ln = ln.substring(0, ci);
444 ln = ln.trim();
445 }
446 return ln;
447 }
448
449 /**
450 * Treat the given JAR file as a module as follows:
451 *
452 * 1. The value of the Automatic-Module-Name attribute is the module name
453 * 2. The version, and the module name when the Automatic-Module-Name
454 * attribute is not present, is derived from the file ame of the JAR file
455 * 3. All packages are derived from the .class files in the JAR file
456 * 4. The contents of any META-INF/services configuration files are mapped
457 * to "provides" declarations
458 * 5. The Main-Class attribute in the main attributes of the JAR manifest
459 * is mapped to the module descriptor mainClass if possible
460 */
461 private ModuleDescriptor deriveModuleDescriptor(JarFile jf)
462 throws IOException
463 {
464 // Read Automatic-Module-Name attribute if present
465 Manifest man = jf.getManifest();
466 Attributes attrs = null;
467 String moduleName = null;
468 if (man != null) {
469 attrs = man.getMainAttributes();
470 if (attrs != null) {
471 moduleName = attrs.getValue(AUTOMATIC_MODULE_NAME);
472 }
473 }
474
475 // Derive the version, and the module name if needed, from JAR file name
476 String fn = jf.getName();
477 int i = fn.lastIndexOf(File.separator);
478 if (i != -1)
479 fn = fn.substring(i + 1);
480
481 // drop ".jar"
482 String name = fn.substring(0, fn.length() - 4);
483 String vs = null;
484
485 // find first occurrence of -${NUMBER}. or -${NUMBER}$
486 Matcher matcher = Patterns.DASH_VERSION.matcher(name);
487 if (matcher.find()) {
488 int start = matcher.start();
489
490 // attempt to parse the tail as a version string
491 try {
492 String tail = name.substring(start + 1);
493 ModuleDescriptor.Version.parse(tail);
494 vs = tail;
495 } catch (IllegalArgumentException ignore) { }
496
497 name = name.substring(0, start);
498 }
499
500 // Create builder, using the name derived from file name when
501 // Automatic-Module-Name not present
502 Builder builder;
503 if (moduleName != null) {
504 try {
505 builder = ModuleDescriptor.newAutomaticModule(moduleName);
506 } catch (IllegalArgumentException e) {
507 throw new FindException(AUTOMATIC_MODULE_NAME + ": " + e.getMessage());
508 }
509 } else {
510 builder = ModuleDescriptor.newAutomaticModule(cleanModuleName(name));
511 }
512
513 // module version if present
514 if (vs != null)
515 builder.version(vs);
516
517 // scan the names of the entries in the JAR file
518 Map<Boolean, Set<String>> map = VersionedStream.stream(jf)
519 .filter(e -> !e.isDirectory())
520 .map(JarEntry::getName)
521 .filter(e -> (e.endsWith(".class") ^ e.startsWith(SERVICES_PREFIX)))
522 .collect(Collectors.partitioningBy(e -> e.startsWith(SERVICES_PREFIX),
523 Collectors.toSet()));
524
525 Set<String> classFiles = map.get(Boolean.FALSE);
526 Set<String> configFiles = map.get(Boolean.TRUE);
527
528 // the packages containing class files
529 Set<String> packages = classFiles.stream()
530 .map(this::toPackageName)
531 .flatMap(Optional::stream)
532 .distinct()
533 .collect(Collectors.toSet());
534
535 // all packages are exported and open
536 builder.packages(packages);
537
538 // map names of service configuration files to service names
539 Set<String> serviceNames = configFiles.stream()
540 .map(this::toServiceName)
541 .flatMap(Optional::stream)
542 .collect(Collectors.toSet());
543
544 // parse each service configuration file
545 for (String sn : serviceNames) {
546 JarEntry entry = jf.getJarEntry(SERVICES_PREFIX + sn);
547 List<String> providerClasses = new ArrayList<>();
548 try (InputStream in = jf.getInputStream(entry)) {
549 BufferedReader reader
550 = new BufferedReader(new InputStreamReader(in, "UTF-8"));
551 String cn;
552 while ((cn = nextLine(reader)) != null) {
553 if (cn.length() > 0) {
554 String pn = packageName(cn);
555 if (!packages.contains(pn)) {
556 String msg = "Provider class " + cn + " not in module";
557 throw new InvalidModuleDescriptorException(msg);
558 }
559 providerClasses.add(cn);
560 }
561 }
562 }
563 if (!providerClasses.isEmpty())
564 builder.provides(sn, providerClasses);
565 }
566
567 // Main-Class attribute if it exists
568 if (attrs != null) {
569 String mainClass = attrs.getValue(Attributes.Name.MAIN_CLASS);
570 if (mainClass != null) {
571 mainClass = mainClass.replace("/", ".");
572 if (Checks.isClassName(mainClass)) {
573 String pn = packageName(mainClass);
574 if (packages.contains(pn)) {
575 builder.mainClass(mainClass);
576 }
577 }
578 }
579 }
580
581 return builder.build();
582 }
583
584 /**
585 * Patterns used to derive the module name from a JAR file name.
586 */
587 private static class Patterns {
588 static final Pattern DASH_VERSION = Pattern.compile("-(\\d+(\\.|$))");
589 static final Pattern NON_ALPHANUM = Pattern.compile("[^A-Za-z0-9]");
590 static final Pattern REPEATING_DOTS = Pattern.compile("(\\.)(\\1)+");
591 static final Pattern LEADING_DOTS = Pattern.compile("^\\.");
592 static final Pattern TRAILING_DOTS = Pattern.compile("\\.$");
593 }
594
595 /**
596 * Clean up candidate module name derived from a JAR file name.
597 */
598 private static String cleanModuleName(String mn) {
599 // replace non-alphanumeric
600 mn = Patterns.NON_ALPHANUM.matcher(mn).replaceAll(".");
601
602 // collapse repeating dots
603 mn = Patterns.REPEATING_DOTS.matcher(mn).replaceAll(".");
604
605 // drop leading dots
606 if (mn.length() > 0 && mn.charAt(0) == '.')
607 mn = Patterns.LEADING_DOTS.matcher(mn).replaceAll("");
608
609 // drop trailing dots
610 int len = mn.length();
611 if (len > 0 && mn.charAt(len-1) == '.')
612 mn = Patterns.TRAILING_DOTS.matcher(mn).replaceAll("");
613
614 return mn;
615 }
616
617 private Set<String> jarPackages(JarFile jf) {
618 return VersionedStream.stream(jf)
619 .filter(e -> !e.isDirectory())
620 .map(JarEntry::getName)
621 .map(this::toPackageName)
622 .flatMap(Optional::stream)
623 .collect(Collectors.toSet());
624 }
625
626 /**
627 * Returns a {@code ModuleReference} to a module in modular JAR file on
628 * the file system.
629 *
630 * @throws IOException
631 * @throws FindException
632 * @throws InvalidModuleDescriptorException
633 */
634 private ModuleReference readJar(Path file) throws IOException {
635 try (JarFile jf = new JarFile(file.toFile(),
636 true, // verify
637 ZipFile.OPEN_READ,
638 releaseVersion))
639 {
640 ModuleInfo.Attributes attrs;
641 JarEntry entry = jf.getJarEntry(MODULE_INFO);
642 if (entry == null) {
643
644 // no module-info.class so treat it as automatic module
645 try {
646 ModuleDescriptor md = deriveModuleDescriptor(jf);
647 attrs = new ModuleInfo.Attributes(md, null, null, null);
648 } catch (RuntimeException e) {
649 throw new FindException("Unable to derive module descriptor for "
650 + jf.getName(), e);
651 }
652
653 } else {
654 attrs = ModuleInfo.read(jf.getInputStream(entry),
655 () -> jarPackages(jf));
656 }
657
658 return ModuleReferences.newJarModule(attrs, patcher, file);
659 } catch (ZipException e) {
660 throw new FindException("Error reading " + file, e);
661 }
662 }
663
664
665 // -- exploded directories --
666
667 private Set<String> explodedPackages(Path dir) {
668 try {
669 return Files.find(dir, Integer.MAX_VALUE,
670 ((path, attrs) -> attrs.isRegularFile() && !isHidden(path)))
671 .map(path -> dir.relativize(path))
672 .map(this::toPackageName)
673 .flatMap(Optional::stream)
674 .collect(Collectors.toSet());
675 } catch (IOException x) {
676 throw new UncheckedIOException(x);
677 }
678 }
679
680 /**
681 * Returns a {@code ModuleReference} to an exploded module on the file
682 * system or {@code null} if {@code module-info.class} not found.
683 *
684 * @throws IOException
685 * @throws InvalidModuleDescriptorException
686 */
687 private ModuleReference readExplodedModule(Path dir) throws IOException {
688 Path mi = dir.resolve(MODULE_INFO);
689 ModuleInfo.Attributes attrs;
690 try (InputStream in = Files.newInputStream(mi)) {
691 attrs = ModuleInfo.read(new BufferedInputStream(in),
692 () -> explodedPackages(dir));
693 } catch (NoSuchFileException e) {
694 // for now
695 return null;
696 }
697 return ModuleReferences.newExplodedModule(attrs, patcher, dir);
698 }
699
700 /**
701 * Maps a type name to its package name.
702 */
703 private static String packageName(String cn) {
704 int index = cn.lastIndexOf('.');
705 return (index == -1) ? "" : cn.substring(0, index);
706 }
707
708 /**
709 * Maps the name of an entry in a JAR or ZIP file to a package name.
710 *
711 * @throws InvalidModuleDescriptorException if the name is a class file in
712 * the top-level directory of the JAR/ZIP file (and it's not
713 * module-info.class)
714 */
715 private Optional<String> toPackageName(String name) {
716 assert !name.endsWith("/");
717 int index = name.lastIndexOf("/");
718 if (index == -1) {
719 if (name.endsWith(".class") && !name.equals(MODULE_INFO)) {
720 String msg = name + " found in top-level directory"
721 + " (unnamed package not allowed in module)";
722 throw new InvalidModuleDescriptorException(msg);
723 }
724 return Optional.empty();
725 }
726
727 String pn = name.substring(0, index).replace('/', '.');
728 if (Checks.isPackageName(pn)) {
729 return Optional.of(pn);
730 } else {
731 // not a valid package name
732 return Optional.empty();
733 }
734 }
735
736 /**
737 * Maps the relative path of an entry in an exploded module to a package
738 * name.
739 *
740 * @throws InvalidModuleDescriptorException if the name is a class file in
741 * the top-level directory (and it's not module-info.class)
742 */
743 private Optional<String> toPackageName(Path file) {
744 assert file.getRoot() == null;
745
746 Path parent = file.getParent();
747 if (parent == null) {
748 String name = file.toString();
749 if (name.endsWith(".class") && !name.equals(MODULE_INFO)) {
750 String msg = name + " found in top-level directory"
751 + " (unnamed package not allowed in module)";
752 throw new InvalidModuleDescriptorException(msg);
753 }
754 return Optional.empty();
755 }
756
757 String pn = parent.toString().replace(File.separatorChar, '.');
758 if (Checks.isPackageName(pn)) {
759 return Optional.of(pn);
760 } else {
761 // not a valid package name
762 return Optional.empty();
763 }
764 }
765
766 /**
767 * Returns true if the given file exists and is a hidden file
768 */
769 private boolean isHidden(Path file) {
770 try {
771 return Files.isHidden(file);
772 } catch (IOException ioe) {
773 return false;
774 }
775 }
776
777
778 /**
779 * Return true if a path locates a path in the default file system
780 */
781 private boolean isDefaultFileSystem(Path path) {
782 return path.getFileSystem().provider()
783 .getScheme().equalsIgnoreCase("file");
784 }
785
786
787 private static final PerfCounter scanTime
788 = PerfCounter.newPerfCounter("jdk.module.finder.modulepath.scanTime");
789 private static final PerfCounter moduleCount
790 = PerfCounter.newPerfCounter("jdk.module.finder.modulepath.modules");
791 }