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