1 /*
2 * Copyright (c) 2014, 2016, 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.lang.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.ModuleDescriptor.Requires;
36 import java.net.URI;
37 import java.nio.file.DirectoryStream;
38 import java.nio.file.Files;
39 import java.nio.file.NoSuchFileException;
40 import java.nio.file.Path;
41 import java.nio.file.Paths;
42 import java.nio.file.attribute.BasicFileAttributes;
43 import java.util.ArrayList;
44 import java.util.Collections;
45 import java.util.HashMap;
46 import java.util.List;
47 import java.util.Map;
48 import java.util.Objects;
49 import java.util.Optional;
50 import java.util.Set;
51 import java.util.jar.Attributes;
52 import java.util.jar.JarEntry;
53 import java.util.jar.JarFile;
54 import java.util.jar.Manifest;
55 import java.util.regex.Matcher;
56 import java.util.regex.Pattern;
57 import java.util.stream.Collectors;
58 import java.util.zip.ZipFile;
59
60 import jdk.internal.jmod.JmodFile;
61 import jdk.internal.jmod.JmodFile.Section;
62 import jdk.internal.module.Checks;
63 import jdk.internal.perf.PerfCounter;
64 import jdk.internal.util.jar.VersionedStream;
65
66
67 /**
68 * A {@code ModuleFinder} that locates modules on the file system by searching
69 * a sequence of directories or packaged modules.
70 *
71 * The {@code ModuleFinder} can be created to work in either the run-time
72 * or link-time phases. In both cases it locates modular JAR and exploded
73 * modules. When created for link-time then it additionally locates
74 * modules in JMOD files.
75 */
76
77 class ModulePath implements ModuleFinder {
78 private static final String MODULE_INFO = "module-info.class";
79
80 // the version to use for multi-release modular JARs
81 private final Runtime.Version releaseVersion;
82
83 // true for the link phase (supports modules packaged in JMOD format)
84 private final boolean isLinkPhase;
85
86 // the entries on this module path
87 private final Path[] entries;
88 private int next;
89
90 // map of module name to module reference map for modules already located
91 private final Map<String, ModuleReference> cachedModules = new HashMap<>();
92
93 ModulePath(Runtime.Version version, boolean isLinkPhase, Path... entries) {
94 this.releaseVersion = version;
95 this.isLinkPhase = isLinkPhase;
96 this.entries = entries.clone();
97 for (Path entry : this.entries) {
98 Objects.requireNonNull(entry);
99 }
100 }
101
102 ModulePath(Path... entries) {
103 this(JarFile.runtimeVersion(), false, entries);
104 }
105
106 @Override
107 public Optional<ModuleReference> find(String name) {
108 Objects.requireNonNull(name);
109
110 // try cached modules
111 ModuleReference m = cachedModules.get(name);
112 if (m != null)
113 return Optional.of(m);
114
115 // the module may not have been encountered yet
116 while (hasNextEntry()) {
117 scanNextEntry();
118 m = cachedModules.get(name);
119 if (m != null)
120 return Optional.of(m);
121 }
122 return Optional.empty();
123 }
124
125 @Override
126 public Set<ModuleReference> findAll() {
127 // need to ensure that all entries have been scanned
128 while (hasNextEntry()) {
129 scanNextEntry();
130 }
131 return cachedModules.values().stream().collect(Collectors.toSet());
132 }
133
134 /**
135 * Returns {@code true} if there are additional entries to scan
136 */
137 private boolean hasNextEntry() {
138 return next < entries.length;
139 }
140
141 /**
142 * Scans the next entry on the module path. A no-op if all entries have
143 * already been scanned.
144 *
145 * @throws FindException if an error occurs scanning the next entry
146 */
147 private void scanNextEntry() {
148 if (hasNextEntry()) {
149
150 long t0 = System.nanoTime();
151
152 Path entry = entries[next];
153 Map<String, ModuleReference> modules = scan(entry);
154 next++;
155
156 // update cache, ignoring duplicates
157 int initialSize = cachedModules.size();
158 for (Map.Entry<String, ModuleReference> e : modules.entrySet()) {
159 cachedModules.putIfAbsent(e.getKey(), e.getValue());
160 }
161
162 // update counters
163 int added = cachedModules.size() - initialSize;
164 moduleCount.add(added);
165
166 scanTime.addElapsedTimeFrom(t0);
167 }
168 }
169
170
171 /**
172 * Scan the given module path entry. If the entry is a directory then it is
173 * a directory of modules or an exploded module. If the entry is a regular
174 * file then it is assumed to be a packaged module.
175 *
176 * @throws FindException if an error occurs scanning the entry
177 */
178 private Map<String, ModuleReference> scan(Path entry) {
179
180 BasicFileAttributes attrs;
181 try {
182 attrs = Files.readAttributes(entry, BasicFileAttributes.class);
183 } catch (NoSuchFileException e) {
184 return Collections.emptyMap();
185 } catch (IOException ioe) {
186 throw new FindException(ioe);
187 }
188
189 try {
190
191 if (attrs.isDirectory()) {
192 Path mi = entry.resolve(MODULE_INFO);
193 if (!Files.exists(mi)) {
194 // does not exist or unable to determine so assume a
195 // directory of modules
196 return scanDirectory(entry);
197 }
198 }
199
200 // packaged or exploded module
201 ModuleReference mref = readModule(entry, attrs);
202 if (mref != null) {
203 String name = mref.descriptor().name();
204 return Collections.singletonMap(name, mref);
205 } else {
206 // skipped
207 return Collections.emptyMap();
208 }
209
210 } catch (IOException ioe) {
211 throw new FindException(ioe);
212 }
213 }
214
215
216 /**
217 * Scans the given directory for packaged or exploded modules.
218 *
219 * @return a map of module name to ModuleReference for the modules found
220 * in the directory
221 *
222 * @throws IOException if an I/O error occurs
223 * @throws FindException if an error occurs scanning the entry or the
224 * directory contains two or more modules with the same name
225 */
226 private Map<String, ModuleReference> scanDirectory(Path dir)
227 throws IOException
228 {
229 // The map of name -> mref of modules found in this directory.
230 Map<String, ModuleReference> nameToReference = new HashMap<>();
231
232 try (DirectoryStream<Path> stream = Files.newDirectoryStream(dir)) {
233 for (Path entry : stream) {
234 BasicFileAttributes attrs;
235 try {
236 attrs = Files.readAttributes(entry, BasicFileAttributes.class);
237 } catch (NoSuchFileException ignore) {
238 // file has been removed or moved, ignore for now
239 continue;
240 }
241
242 ModuleReference mref = readModule(entry, attrs);
243
244 // module found
245 if (mref != null) {
246 // can have at most one version of a module in the directory
247 String name = mref.descriptor().name();
248 ModuleReference previous = nameToReference.put(name, mref);
249 if (previous != null) {
250 String fn1 = fileName(mref);
251 String fn2 = fileName(previous);
252 throw new FindException("Two versions of module "
253 + name + " found in " + dir
254 + " (" + fn1 + " and " + fn2 + ")");
255 }
256 }
257 }
258 }
259
260 return nameToReference;
261 }
262
263
264 /**
265 * Locates a packaged or exploded module, returning a {@code ModuleReference}
266 * to the module. Returns {@code null} if the entry is skipped because it is
267 * to a directory that does not contain a module-info.class or it's a hidden
268 * file.
269 *
270 * @throws IOException if an I/O error occurs
271 * @throws FindException if the file is not recognized as a module or an
272 * error occurs parsing its module descriptor
273 */
274 private ModuleReference readModule(Path entry, BasicFileAttributes attrs)
275 throws IOException
276 {
277 try {
278
279 if (attrs.isDirectory()) {
280 return readExplodedModule(entry); // may return null
281 }
282
283 String fn = entry.getFileName().toString();
284 if (attrs.isRegularFile()) {
285 if (fn.endsWith(".jar")) {
286 return readJar(entry);
287 } else if (fn.endsWith(".jmod")) {
288 if (isLinkPhase)
289 return readJMod(entry);
290 throw new FindException("JMOD files not supported: " + entry);
291 }
292 }
293
294 // skip hidden files
295 if (fn.startsWith(".") || Files.isHidden(entry)) {
296 return null;
297 } else {
298 throw new FindException("Unrecognized module: " + entry);
299 }
300
301 } catch (InvalidModuleDescriptorException e) {
302 throw new FindException("Error reading module: " + entry, e);
303 }
304 }
305
306
307 /**
308 * Returns a string with the file name of the module if possible.
309 * If the module location is not a file URI then return the URI
310 * as a string.
311 */
312 private String fileName(ModuleReference mref) {
313 URI uri = mref.location().orElse(null);
314 if (uri != null) {
315 if (uri.getScheme().equalsIgnoreCase("file")) {
316 Path file = Paths.get(uri);
317 return file.getFileName().toString();
318 } else {
319 return uri.toString();
320 }
321 } else {
322 return "<unknown>";
323 }
324 }
325
326 // -- jmod files --
327
328 private Set<String> jmodPackages(JmodFile jf) {
329 return jf.stream()
330 .filter(e -> e.section() == Section.CLASSES)
331 .map(JmodFile.Entry::name)
332 .map(this::toPackageName)
333 .flatMap(Optional::stream)
334 .collect(Collectors.toSet());
335 }
336
337 /**
338 * Returns a {@code ModuleReference} to a module in jmod file on the
339 * file system.
340 *
341 * @throws IOException
342 * @throws InvalidModuleDescriptorException
343 */
344 private ModuleReference readJMod(Path file) throws IOException {
345 try (JmodFile jf = new JmodFile(file)) {
346 ModuleDescriptor md;
347 try (InputStream in = jf.getInputStream(Section.CLASSES, MODULE_INFO)) {
348 md = ModuleDescriptor.read(in, () -> jmodPackages(jf));
349 }
350 return ModuleReferences.newJModModule(md, file);
351 }
352 }
353
354
355 // -- JAR files --
356
357 private static final String SERVICES_PREFIX = "META-INF/services/";
358
359 /**
360 * Returns the service type corresponding to the name of a services
361 * configuration file if it is a valid Java identifier.
362 *
363 * For example, if called with "META-INF/services/p.S" then this method
364 * returns a container with the value "p.S".
365 */
366 private Optional<String> toServiceName(String cf) {
367 assert cf.startsWith(SERVICES_PREFIX);
368 int index = cf.lastIndexOf("/") + 1;
369 if (index < cf.length()) {
370 String prefix = cf.substring(0, index);
371 if (prefix.equals(SERVICES_PREFIX)) {
372 String sn = cf.substring(index);
373 if (Checks.isJavaIdentifier(sn))
374 return Optional.of(sn);
375 }
376 }
377 return Optional.empty();
378 }
379
380 /**
381 * Reads the next line from the given reader and trims it of comments and
382 * leading/trailing white space.
383 *
384 * Returns null if the reader is at EOF.
385 */
386 private String nextLine(BufferedReader reader) throws IOException {
387 String ln = reader.readLine();
388 if (ln != null) {
389 int ci = ln.indexOf('#');
390 if (ci >= 0)
391 ln = ln.substring(0, ci);
392 ln = ln.trim();
393 }
394 return ln;
395 }
396
397 /**
398 * Treat the given JAR file as a module as follows:
399 *
400 * 1. The module name (and optionally the version) is derived from the file
401 * name of the JAR file
402 * 2. All packages are exported and open
403 * 3. It has no non-exported/non-open packages
404 * 4. The contents of any META-INF/services configuration files are mapped
405 * to "provides" declarations
406 * 5. The Main-Class attribute in the main attributes of the JAR manifest
407 * is mapped to the module descriptor mainClass
408 */
409 private ModuleDescriptor deriveModuleDescriptor(JarFile jf)
410 throws IOException
411 {
412 // Derive module name and version from JAR file name
413
414 String fn = jf.getName();
415 int i = fn.lastIndexOf(File.separator);
416 if (i != -1)
417 fn = fn.substring(i+1);
418
419 // drop .jar
420 String mn = fn.substring(0, fn.length()-4);
421 String vs = null;
422
423 // find first occurrence of -${NUMBER}. or -${NUMBER}$
424 Matcher matcher = Patterns.DASH_VERSION.matcher(mn);
425 if (matcher.find()) {
426 int start = matcher.start();
427
428 // attempt to parse the tail as a version string
429 try {
430 String tail = mn.substring(start+1);
431 ModuleDescriptor.Version.parse(tail);
432 vs = tail;
433 } catch (IllegalArgumentException ignore) { }
434
435 mn = mn.substring(0, start);
436 }
437
438 // finally clean up the module name
439 mn = cleanModuleName(mn);
440
441 // Builder throws IAE if module name is empty or invalid
442 ModuleDescriptor.Builder builder
443 = ModuleDescriptor.automaticModule(mn)
444 .requires(Set.of(Requires.Modifier.MANDATED), "java.base");
445 if (vs != null)
446 builder.version(vs);
447
448 // scan the names of the entries in the JAR file
449 Map<Boolean, Set<String>> map = VersionedStream.stream(jf)
450 .filter(e -> !e.isDirectory())
451 .map(JarEntry::getName)
452 .collect(Collectors.partitioningBy(e -> e.startsWith(SERVICES_PREFIX),
453 Collectors.toSet()));
454
455 Set<String> resources = map.get(Boolean.FALSE);
456 Set<String> configFiles = map.get(Boolean.TRUE);
457 // all packages are exported and open
458 resources.stream()
459 .map(this::toPackageName)
460 .flatMap(Optional::stream)
461 .distinct()
462 .forEach(pn -> builder.exports(pn).opens(pn));
463
464 // map names of service configuration files to service names
465 Set<String> serviceNames = configFiles.stream()
466 .map(this::toServiceName)
467 .flatMap(Optional::stream)
468 .collect(Collectors.toSet());
469
470 // parse each service configuration file
471 for (String sn : serviceNames) {
472 JarEntry entry = jf.getJarEntry(SERVICES_PREFIX + sn);
473 List<String> providerClasses = new ArrayList<>();
474 try (InputStream in = jf.getInputStream(entry)) {
475 BufferedReader reader
476 = new BufferedReader(new InputStreamReader(in, "UTF-8"));
477 String cn;
478 while ((cn = nextLine(reader)) != null) {
479 if (cn.length() > 0) {
480 providerClasses.add(cn);
481 }
482 }
483 }
484 if (!providerClasses.isEmpty())
485 builder.provides(sn, providerClasses);
486 }
487
488 // Main-Class attribute if it exists
489 Manifest man = jf.getManifest();
490 if (man != null) {
491 Attributes attrs = man.getMainAttributes();
492 String mainClass = attrs.getValue(Attributes.Name.MAIN_CLASS);
493 if (mainClass != null)
494 builder.mainClass(mainClass.replace("/", "."));
495 }
496
497 return builder.build();
498 }
499
500 /**
501 * Patterns used to derive the module name from a JAR file name.
502 */
503 private static class Patterns {
504 static final Pattern DASH_VERSION = Pattern.compile("-(\\d+(\\.|$))");
505 static final Pattern TRAILING_VERSION = Pattern.compile("(\\.|\\d)*$");
506 static final Pattern NON_ALPHANUM = Pattern.compile("[^A-Za-z0-9]");
507 static final Pattern REPEATING_DOTS = Pattern.compile("(\\.)(\\1)+");
508 static final Pattern LEADING_DOTS = Pattern.compile("^\\.");
509 static final Pattern TRAILING_DOTS = Pattern.compile("\\.$");
510 }
511
512 /**
513 * Clean up candidate module name derived from a JAR file name.
514 */
515 private static String cleanModuleName(String mn) {
516 // drop trailing version from name
517 mn = Patterns.TRAILING_VERSION.matcher(mn).replaceAll("");
518
519 // replace non-alphanumeric
520 mn = Patterns.NON_ALPHANUM.matcher(mn).replaceAll(".");
521
522 // collapse repeating dots
523 mn = Patterns.REPEATING_DOTS.matcher(mn).replaceAll(".");
524
525 // drop leading dots
526 if (mn.length() > 0 && mn.charAt(0) == '.')
527 mn = Patterns.LEADING_DOTS.matcher(mn).replaceAll("");
528
529 // drop trailing dots
530 int len = mn.length();
531 if (len > 0 && mn.charAt(len-1) == '.')
532 mn = Patterns.TRAILING_DOTS.matcher(mn).replaceAll("");
533
534 return mn;
535 }
536
537 private Set<String> jarPackages(JarFile jf) {
538 return VersionedStream.stream(jf)
539 .filter(e -> !e.isDirectory())
540 .map(JarEntry::getName)
541 .map(this::toPackageName)
542 .flatMap(Optional::stream)
543 .collect(Collectors.toSet());
544 }
545
546 /**
547 * Returns a {@code ModuleReference} to a module in modular JAR file on
548 * the file system.
549 *
550 * @throws IOException
551 * @throws FindException
552 * @throws InvalidModuleDescriptorException
553 */
554 private ModuleReference readJar(Path file) throws IOException {
555 try (JarFile jf = new JarFile(file.toFile(),
556 true, // verify
557 ZipFile.OPEN_READ,
558 releaseVersion))
559 {
560 ModuleDescriptor md;
561 JarEntry entry = jf.getJarEntry(MODULE_INFO);
562 if (entry == null) {
563
564 // no module-info.class so treat it as automatic module
565 try {
566 md = deriveModuleDescriptor(jf);
567 } catch (IllegalArgumentException iae) {
568 throw new FindException(
569 "Unable to derive module descriptor for: "
570 + jf.getName(), iae);
571 }
572
573 } else {
574 md = ModuleDescriptor.read(jf.getInputStream(entry),
575 () -> jarPackages(jf));
576 }
577
578 return ModuleReferences.newJarModule(md, file);
579 }
580 }
581
582
583 // -- exploded directories --
584
585 private Set<String> explodedPackages(Path dir) {
586 try {
587 return Files.find(dir, Integer.MAX_VALUE,
588 ((path, attrs) -> attrs.isRegularFile()))
589 .map(path -> dir.relativize(path))
590 .map(this::toPackageName)
591 .flatMap(Optional::stream)
592 .collect(Collectors.toSet());
593 } catch (IOException x) {
594 throw new UncheckedIOException(x);
595 }
596 }
597
598 /**
599 * Returns a {@code ModuleReference} to an exploded module on the file
600 * system or {@code null} if {@code module-info.class} not found.
601 *
602 * @throws IOException
603 * @throws InvalidModuleDescriptorException
604 */
605 private ModuleReference readExplodedModule(Path dir) throws IOException {
606 Path mi = dir.resolve(MODULE_INFO);
607 ModuleDescriptor md;
608 try (InputStream in = Files.newInputStream(mi)) {
609 md = ModuleDescriptor.read(new BufferedInputStream(in),
610 () -> explodedPackages(dir));
611 } catch (NoSuchFileException e) {
612 // for now
613 return null;
614 }
615 return ModuleReferences.newExplodedModule(md, dir);
616 }
617
618 /**
619 * Maps the name of an entry in a JAR or ZIP file to a package name.
620 *
621 * @throws IllegalArgumentException if the name is a class file in
622 * the top-level directory of the JAR/ZIP file (and it's
623 * not module-info.class)
624 */
625 private Optional<String> toPackageName(String name) {
626 assert !name.endsWith("/");
627
628 int index = name.lastIndexOf("/");
629 if (index == -1) {
630 if (name.endsWith(".class") && !name.equals(MODULE_INFO)) {
631 throw new IllegalArgumentException(name
632 + " found in top-level directory:"
633 + " (unnamed package not allowed in module)");
634 }
635 return Optional.empty();
636 }
637
638 String pn = name.substring(0, index).replace('/', '.');
639 if (Checks.isJavaIdentifier(pn)) {
640 return Optional.of(pn);
641 } else {
642 // not a valid package name
643 return Optional.empty();
644 }
645 }
646
647 /**
648 * Maps the relative path of an entry in an exploded module to a package
649 * name.
650 *
651 * @throws IllegalArgumentException if the name is a class file in
652 * the top-level directory (and it's not module-info.class)
653 */
654 private Optional<String> toPackageName(Path file) {
655 assert file.getRoot() == null;
656
657 Path parent = file.getParent();
658 if (parent == null) {
659 String name = file.toString();
660 if (name.endsWith(".class") && !name.equals(MODULE_INFO)) {
661 throw new IllegalArgumentException(name
662 + " found in in top-level directory"
663 + " (unnamed package not allowed in module)");
664 }
665 return Optional.empty();
666 }
667
668 String pn = parent.toString().replace(File.separatorChar, '.');
669 if (Checks.isJavaIdentifier(pn)) {
670 return Optional.of(pn);
671 } else {
672 // not a valid package name
673 return Optional.empty();
674 }
675 }
676
677 private static final PerfCounter scanTime
678 = PerfCounter.newPerfCounter("jdk.module.finder.modulepath.scanTime");
679 private static final PerfCounter moduleCount
680 = PerfCounter.newPerfCounter("jdk.module.finder.modulepath.modules");
681 }