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 java.lang; 27 28 import java.io.IOException; 29 import java.io.InputStream; 30 import java.lang.annotation.Annotation; 31 import java.lang.module.Configuration; 32 import java.lang.module.ModuleReference; 33 import java.lang.module.ModuleDescriptor; 34 import java.lang.module.ModuleDescriptor.Exports; 35 import java.lang.module.ModuleDescriptor.Opens; 36 import java.lang.module.ModuleDescriptor.Version; 37 import java.lang.module.ResolvedModule; 38 import java.lang.reflect.AnnotatedElement; 39 import java.net.URI; 40 import java.net.URL; 41 import java.security.AccessController; 42 import java.security.PrivilegedAction; 43 import java.util.Collections; 44 import java.util.HashMap; 45 import java.util.HashSet; 46 import java.util.Iterator; 47 import java.util.List; 48 import java.util.Map; 49 import java.util.Objects; 50 import java.util.Optional; 51 import java.util.Set; 52 import java.util.concurrent.ConcurrentHashMap; 53 import java.util.function.Function; 54 import java.util.stream.Collectors; 55 import java.util.stream.Stream; 56 57 import jdk.internal.loader.BuiltinClassLoader; 58 import jdk.internal.loader.BootLoader; 59 import jdk.internal.loader.ClassLoaders; 60 import jdk.internal.misc.JavaLangAccess; 61 import jdk.internal.misc.SharedSecrets; 62 import jdk.internal.module.IllegalAccessLogger; 63 import jdk.internal.module.ModuleLoaderMap; 64 import jdk.internal.module.ServicesCatalog; 65 import jdk.internal.module.Resources; 66 import jdk.internal.org.objectweb.asm.AnnotationVisitor; 67 import jdk.internal.org.objectweb.asm.Attribute; 68 import jdk.internal.org.objectweb.asm.ClassReader; 69 import jdk.internal.org.objectweb.asm.ClassVisitor; 70 import jdk.internal.org.objectweb.asm.ClassWriter; 71 import jdk.internal.org.objectweb.asm.Opcodes; 72 import jdk.internal.reflect.CallerSensitive; 73 import jdk.internal.reflect.Reflection; 74 import sun.security.util.SecurityConstants; 75 76 /** 77 * Represents a run-time module, either {@link #isNamed() named} or unnamed. 78 * 79 * <p> Named modules have a {@link #getName() name} and are constructed by the 80 * Java Virtual Machine when a graph of modules is defined to the Java virtual 81 * machine to create a {@linkplain ModuleLayer module layer}. </p> 82 * 83 * <p> An unnamed module does not have a name. There is an unnamed module for 84 * each {@link ClassLoader ClassLoader}, obtained by invoking its {@link 85 * ClassLoader#getUnnamedModule() getUnnamedModule} method. All types that are 86 * not in a named module are members of their defining class loader's unnamed 87 * module. </p> 88 * 89 * <p> The package names that are parameters or returned by methods defined in 90 * this class are the fully-qualified names of the packages as defined in 91 * section 6.5.3 of <cite>The Java™ Language Specification</cite>, for 92 * example, {@code "java.lang"}. </p> 93 * 94 * <p> Unless otherwise specified, passing a {@code null} argument to a method 95 * in this class causes a {@link NullPointerException NullPointerException} to 96 * be thrown. </p> 97 * 98 * @since 9 99 * @spec JPMS 100 * @see Class#getModule() 101 */ 102 103 public final class Module implements AnnotatedElement { 104 105 // the layer that contains this module, can be null 106 private final ModuleLayer layer; 107 108 // module name and loader, these fields are read by VM 109 private final String name; 110 private final ClassLoader loader; 111 112 // the module descriptor 113 private final ModuleDescriptor descriptor; 114 115 116 /** 117 * Creates a new named Module. The resulting Module will be defined to the 118 * VM but will not read any other modules, will not have any exports setup 119 * and will not be registered in the service catalog. 120 */ 121 Module(ModuleLayer layer, 122 ClassLoader loader, 123 ModuleDescriptor descriptor, 124 URI uri) 125 { 126 this.layer = layer; 127 this.name = descriptor.name(); 128 this.loader = loader; 129 this.descriptor = descriptor; 130 131 // define module to VM 132 133 boolean isOpen = descriptor.isOpen() || descriptor.isAutomatic(); 134 Version version = descriptor.version().orElse(null); 135 String vs = Objects.toString(version, null); 136 String loc = Objects.toString(uri, null); 137 String[] packages = descriptor.packages().toArray(new String[0]); 138 defineModule0(this, isOpen, vs, loc, packages); 139 } 140 141 142 /** 143 * Create the unnamed Module for the given ClassLoader. 144 * 145 * @see ClassLoader#getUnnamedModule 146 */ 147 Module(ClassLoader loader) { 148 this.layer = null; 149 this.name = null; 150 this.loader = loader; 151 this.descriptor = null; 152 } 153 154 155 /** 156 * Creates a named module but without defining the module to the VM. 157 * 158 * @apiNote This constructor is for VM white-box testing. 159 */ 160 Module(ClassLoader loader, ModuleDescriptor descriptor) { 161 this.layer = null; 162 this.name = descriptor.name(); 163 this.loader = loader; 164 this.descriptor = descriptor; 165 } 166 167 168 /** 169 * Returns {@code true} if this module is a named module. 170 * 171 * @return {@code true} if this is a named module 172 * 173 * @see ClassLoader#getUnnamedModule() 174 */ 175 public boolean isNamed() { 176 return name != null; 177 } 178 179 /** 180 * Returns the module name or {@code null} if this module is an unnamed 181 * module. 182 * 183 * @return The module name 184 */ 185 public String getName() { 186 return name; 187 } 188 189 /** 190 * Returns the {@code ClassLoader} for this module. 191 * 192 * <p> If there is a security manager then its {@code checkPermission} 193 * method if first called with a {@code RuntimePermission("getClassLoader")} 194 * permission to check that the caller is allowed to get access to the 195 * class loader. </p> 196 * 197 * @return The class loader for this module 198 * 199 * @throws SecurityException 200 * If denied by the security manager 201 */ 202 public ClassLoader getClassLoader() { 203 SecurityManager sm = System.getSecurityManager(); 204 if (sm != null) { 205 sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION); 206 } 207 return loader; 208 } 209 210 /** 211 * Returns the module descriptor for this module or {@code null} if this 212 * module is an unnamed module. 213 * 214 * @return The module descriptor for this module 215 */ 216 public ModuleDescriptor getDescriptor() { 217 return descriptor; 218 } 219 220 /** 221 * Returns the module layer that contains this module or {@code null} if 222 * this module is not in a module layer. 223 * 224 * A module layer contains named modules and therefore this method always 225 * returns {@code null} when invoked on an unnamed module. 226 * 227 * <p> <a href="reflect/Proxy.html#dynamicmodule">Dynamic modules</a> are 228 * named modules that are generated at runtime. A dynamic module may or may 229 * not be in a module layer. </p> 230 * 231 * @return The module layer that contains this module 232 * 233 * @see java.lang.reflect.Proxy 234 */ 235 public ModuleLayer getLayer() { 236 if (isNamed()) { 237 ModuleLayer layer = this.layer; 238 if (layer != null) 239 return layer; 240 241 // special-case java.base as it is created before the boot layer 242 if (loader == null && name.equals("java.base")) { 243 return ModuleLayer.boot(); 244 } 245 } 246 return null; 247 } 248 249 // -- 250 251 // special Module to mean "all unnamed modules" 252 private static final Module ALL_UNNAMED_MODULE = new Module(null); 253 private static final Set<Module> ALL_UNNAMED_MODULE_SET = Set.of(ALL_UNNAMED_MODULE); 254 255 // special Module to mean "everyone" 256 private static final Module EVERYONE_MODULE = new Module(null); 257 private static final Set<Module> EVERYONE_SET = Set.of(EVERYONE_MODULE); 258 259 /** 260 * The holder of data structures to support readability, exports, and 261 * service use added at runtime with the reflective APIs. 262 */ 263 private static class ReflectionData { 264 /** 265 * A module (1st key) reads another module (2nd key) 266 */ 267 static final WeakPairMap<Module, Module, Boolean> reads = 268 new WeakPairMap<>(); 269 270 /** 271 * A module (1st key) exports or opens a package to another module 272 * (2nd key). The map value is a map of package name to a boolean 273 * that indicates if the package is opened. 274 */ 275 static final WeakPairMap<Module, Module, Map<String, Boolean>> exports = 276 new WeakPairMap<>(); 277 278 /** 279 * A module (1st key) uses a service (2nd key) 280 */ 281 static final WeakPairMap<Module, Class<?>, Boolean> uses = 282 new WeakPairMap<>(); 283 } 284 285 286 // -- readability -- 287 288 // the modules that this module reads 289 private volatile Set<Module> reads; 290 291 /** 292 * Indicates if this module reads the given module. This method returns 293 * {@code true} if invoked to test if this module reads itself. It also 294 * returns {@code true} if invoked on an unnamed module (as unnamed 295 * modules read all modules). 296 * 297 * @param other 298 * The other module 299 * 300 * @return {@code true} if this module reads {@code other} 301 * 302 * @see #addReads(Module) 303 */ 304 public boolean canRead(Module other) { 305 Objects.requireNonNull(other); 306 307 // an unnamed module reads all modules 308 if (!this.isNamed()) 309 return true; 310 311 // all modules read themselves 312 if (other == this) 313 return true; 314 315 // check if this module reads other 316 if (other.isNamed()) { 317 Set<Module> reads = this.reads; // volatile read 318 if (reads != null && reads.contains(other)) 319 return true; 320 } 321 322 // check if this module reads the other module reflectively 323 if (ReflectionData.reads.containsKeyPair(this, other)) 324 return true; 325 326 // if other is an unnamed module then check if this module reads 327 // all unnamed modules 328 if (!other.isNamed() 329 && ReflectionData.reads.containsKeyPair(this, ALL_UNNAMED_MODULE)) 330 return true; 331 332 return false; 333 } 334 335 /** 336 * If the caller's module is this module then update this module to read 337 * the given module. 338 * 339 * This method is a no-op if {@code other} is this module (all modules read 340 * themselves), this module is an unnamed module (as unnamed modules read 341 * all modules), or this module already reads {@code other}. 342 * 343 * @implNote <em>Read edges</em> added by this method are <em>weak</em> and 344 * do not prevent {@code other} from being GC'ed when this module is 345 * strongly reachable. 346 * 347 * @param other 348 * The other module 349 * 350 * @return this module 351 * 352 * @throws IllegalCallerException 353 * If this is a named module and the caller's module is not this 354 * module 355 * 356 * @see #canRead 357 */ 358 @CallerSensitive 359 public Module addReads(Module other) { 360 Objects.requireNonNull(other); 361 if (this.isNamed()) { 362 Module caller = getCallerModule(Reflection.getCallerClass()); 363 if (caller != this) { 364 throw new IllegalCallerException(caller + " != " + this); 365 } 366 implAddReads(other, true); 367 } 368 return this; 369 } 370 371 /** 372 * Updates this module to read another module. 373 * 374 * @apiNote Used by the --add-reads command line option. 375 */ 376 void implAddReads(Module other) { 377 implAddReads(other, true); 378 } 379 380 /** 381 * Updates this module to read all unnamed modules. 382 * 383 * @apiNote Used by the --add-reads command line option. 384 */ 385 void implAddReadsAllUnnamed() { 386 implAddReads(Module.ALL_UNNAMED_MODULE, true); 387 } 388 389 /** 390 * Updates this module to read another module without notifying the VM. 391 * 392 * @apiNote This method is for VM white-box testing. 393 */ 394 void implAddReadsNoSync(Module other) { 395 implAddReads(other, false); 396 } 397 398 /** 399 * Makes the given {@code Module} readable to this module. 400 * 401 * If {@code syncVM} is {@code true} then the VM is notified. 402 */ 403 private void implAddReads(Module other, boolean syncVM) { 404 Objects.requireNonNull(other); 405 if (!canRead(other)) { 406 // update VM first, just in case it fails 407 if (syncVM) { 408 if (other == ALL_UNNAMED_MODULE) { 409 addReads0(this, null); 410 } else { 411 addReads0(this, other); 412 } 413 } 414 415 // add reflective read 416 ReflectionData.reads.putIfAbsent(this, other, Boolean.TRUE); 417 } 418 } 419 420 421 // -- exported and open packages -- 422 423 // the packages are open to other modules, can be null 424 // if the value contains EVERYONE_MODULE then the package is open to all 425 private volatile Map<String, Set<Module>> openPackages; 426 427 // the packages that are exported, can be null 428 // if the value contains EVERYONE_MODULE then the package is exported to all 429 private volatile Map<String, Set<Module>> exportedPackages; 430 431 /** 432 * Returns {@code true} if this module exports the given package to at 433 * least the given module. 434 * 435 * <p> This method returns {@code true} if invoked to test if a package in 436 * this module is exported to itself. It always returns {@code true} when 437 * invoked on an unnamed module. A package that is {@link #isOpen open} to 438 * the given module is considered exported to that module at run-time and 439 * so this method returns {@code true} if the package is open to the given 440 * module. </p> 441 * 442 * <p> This method does not check if the given module reads this module. </p> 443 * 444 * @param pn 445 * The package name 446 * @param other 447 * The other module 448 * 449 * @return {@code true} if this module exports the package to at least the 450 * given module 451 * 452 * @see ModuleDescriptor#exports() 453 * @see #addExports(String,Module) 454 */ 455 public boolean isExported(String pn, Module other) { 456 Objects.requireNonNull(pn); 457 Objects.requireNonNull(other); 458 return implIsExportedOrOpen(pn, other, /*open*/false); 459 } 460 461 /** 462 * Returns {@code true} if this module has <em>opened</em> a package to at 463 * least the given module. 464 * 465 * <p> This method returns {@code true} if invoked to test if a package in 466 * this module is open to itself. It returns {@code true} when invoked on an 467 * {@link ModuleDescriptor#isOpen open} module with a package in the module. 468 * It always returns {@code true} when invoked on an unnamed module. </p> 469 * 470 * <p> This method does not check if the given module reads this module. </p> 471 * 472 * @param pn 473 * The package name 474 * @param other 475 * The other module 476 * 477 * @return {@code true} if this module has <em>opened</em> the package 478 * to at least the given module 479 * 480 * @see ModuleDescriptor#opens() 481 * @see #addOpens(String,Module) 482 * @see AccessibleObject#setAccessible(boolean) 483 * @see java.lang.invoke.MethodHandles#privateLookupIn 484 */ 485 public boolean isOpen(String pn, Module other) { 486 Objects.requireNonNull(pn); 487 Objects.requireNonNull(other); 488 return implIsExportedOrOpen(pn, other, /*open*/true); 489 } 490 491 /** 492 * Returns {@code true} if this module exports the given package 493 * unconditionally. 494 * 495 * <p> This method always returns {@code true} when invoked on an unnamed 496 * module. A package that is {@link #isOpen(String) opened} unconditionally 497 * is considered exported unconditionally at run-time and so this method 498 * returns {@code true} if the package is opened unconditionally. </p> 499 * 500 * <p> This method does not check if the given module reads this module. </p> 501 * 502 * @param pn 503 * The package name 504 * 505 * @return {@code true} if this module exports the package unconditionally 506 * 507 * @see ModuleDescriptor#exports() 508 */ 509 public boolean isExported(String pn) { 510 Objects.requireNonNull(pn); 511 return implIsExportedOrOpen(pn, EVERYONE_MODULE, /*open*/false); 512 } 513 514 /** 515 * Returns {@code true} if this module has <em>opened</em> a package 516 * unconditionally. 517 * 518 * <p> This method always returns {@code true} when invoked on an unnamed 519 * module. Additionally, it always returns {@code true} when invoked on an 520 * {@link ModuleDescriptor#isOpen open} module with a package in the 521 * module. </p> 522 * 523 * <p> This method does not check if the given module reads this module. </p> 524 * 525 * @param pn 526 * The package name 527 * 528 * @return {@code true} if this module has <em>opened</em> the package 529 * unconditionally 530 * 531 * @see ModuleDescriptor#opens() 532 */ 533 public boolean isOpen(String pn) { 534 Objects.requireNonNull(pn); 535 return implIsExportedOrOpen(pn, EVERYONE_MODULE, /*open*/true); 536 } 537 538 539 /** 540 * Returns {@code true} if this module exports or opens the given package 541 * to the given module. If the other module is {@code EVERYONE_MODULE} then 542 * this method tests if the package is exported or opened unconditionally. 543 */ 544 private boolean implIsExportedOrOpen(String pn, Module other, boolean open) { 545 // all packages in unnamed modules are open 546 if (!isNamed()) 547 return true; 548 549 // all packages are exported/open to self 550 if (other == this && descriptor.packages().contains(pn)) 551 return true; 552 553 // all packages in open and automatic modules are open 554 if (descriptor.isOpen() || descriptor.isAutomatic()) 555 return descriptor.packages().contains(pn); 556 557 // exported/opened via module declaration/descriptor 558 if (isStaticallyExportedOrOpen(pn, other, open)) 559 return true; 560 561 // exported via addExports/addOpens 562 if (isReflectivelyExportedOrOpen(pn, other, open)) 563 return true; 564 565 // not exported or open to other 566 return false; 567 } 568 569 /** 570 * Returns {@code true} if this module exports or opens a package to 571 * the given module via its module declaration or CLI options. 572 */ 573 private boolean isStaticallyExportedOrOpen(String pn, Module other, boolean open) { 574 // test if package is open to everyone or <other> 575 Map<String, Set<Module>> openPackages = this.openPackages; 576 if (openPackages != null && allows(openPackages.get(pn), other)) { 577 return true; 578 } 579 580 if (!open) { 581 // test package is exported to everyone or <other> 582 Map<String, Set<Module>> exportedPackages = this.exportedPackages; 583 if (exportedPackages != null && allows(exportedPackages.get(pn), other)) { 584 return true; 585 } 586 } 587 588 return false; 589 } 590 591 /** 592 * Returns {@code true} if targets is non-null and contains EVERYONE_MODULE 593 * or the given module. Also returns true if the given module is an unnamed 594 * module and targets contains ALL_UNNAMED_MODULE. 595 */ 596 private boolean allows(Set<Module> targets, Module module) { 597 if (targets != null) { 598 if (targets.contains(EVERYONE_MODULE)) 599 return true; 600 if (module != EVERYONE_MODULE) { 601 if (targets.contains(module)) 602 return true; 603 if (!module.isNamed() && targets.contains(ALL_UNNAMED_MODULE)) 604 return true; 605 } 606 } 607 return false; 608 } 609 610 /** 611 * Returns {@code true} if this module reflectively exports or opens the 612 * given package to the given module. 613 */ 614 private boolean isReflectivelyExportedOrOpen(String pn, Module other, boolean open) { 615 // exported or open to all modules 616 Map<String, Boolean> exports = ReflectionData.exports.get(this, EVERYONE_MODULE); 617 if (exports != null) { 618 Boolean b = exports.get(pn); 619 if (b != null) { 620 boolean isOpen = b.booleanValue(); 621 if (!open || isOpen) return true; 622 } 623 } 624 625 if (other != EVERYONE_MODULE) { 626 627 // exported or open to other 628 exports = ReflectionData.exports.get(this, other); 629 if (exports != null) { 630 Boolean b = exports.get(pn); 631 if (b != null) { 632 boolean isOpen = b.booleanValue(); 633 if (!open || isOpen) return true; 634 } 635 } 636 637 // other is an unnamed module && exported or open to all unnamed 638 if (!other.isNamed()) { 639 exports = ReflectionData.exports.get(this, ALL_UNNAMED_MODULE); 640 if (exports != null) { 641 Boolean b = exports.get(pn); 642 if (b != null) { 643 boolean isOpen = b.booleanValue(); 644 if (!open || isOpen) return true; 645 } 646 } 647 } 648 649 } 650 651 return false; 652 } 653 654 /** 655 * Returns {@code true} if this module reflectively exports the 656 * given package to the given module. 657 */ 658 boolean isReflectivelyExported(String pn, Module other) { 659 return isReflectivelyExportedOrOpen(pn, other, false); 660 } 661 662 /** 663 * Returns {@code true} if this module reflectively opens the 664 * given package to the given module. 665 */ 666 boolean isReflectivelyOpened(String pn, Module other) { 667 return isReflectivelyExportedOrOpen(pn, other, true); 668 } 669 670 671 /** 672 * If the caller's module is this module then update this module to export 673 * the given package to the given module. 674 * 675 * <p> This method has no effect if the package is already exported (or 676 * <em>open</em>) to the given module. </p> 677 * 678 * @apiNote As specified in section 5.4.3 of the <cite>The Java™ 679 * Virtual Machine Specification </cite>, if an attempt to resolve a 680 * symbolic reference fails because of a linkage error, then subsequent 681 * attempts to resolve the reference always fail with the same error that 682 * was thrown as a result of the initial resolution attempt. 683 * 684 * @param pn 685 * The package name 686 * @param other 687 * The module 688 * 689 * @return this module 690 * 691 * @throws IllegalArgumentException 692 * If {@code pn} is {@code null}, or this is a named module and the 693 * package {@code pn} is not a package in this module 694 * @throws IllegalCallerException 695 * If this is a named module and the caller's module is not this 696 * module 697 * 698 * @jvms 5.4.3 Resolution 699 * @see #isExported(String,Module) 700 */ 701 @CallerSensitive 702 public Module addExports(String pn, Module other) { 703 if (pn == null) 704 throw new IllegalArgumentException("package is null"); 705 Objects.requireNonNull(other); 706 707 if (isNamed()) { 708 Module caller = getCallerModule(Reflection.getCallerClass()); 709 if (caller != this) { 710 throw new IllegalCallerException(caller + " != " + this); 711 } 712 implAddExportsOrOpens(pn, other, /*open*/false, /*syncVM*/true); 713 } 714 715 return this; 716 } 717 718 /** 719 * If this module has <em>opened</em> a package to at least the caller 720 * module then update this module to open the package to the given module. 721 * Opening a package with this method allows all types in the package, 722 * and all their members, not just public types and their public members, 723 * to be reflected on by the given module when using APIs that support 724 * private access or a way to bypass or suppress default Java language 725 * access control checks. 726 * 727 * <p> This method has no effect if the package is already <em>open</em> 728 * to the given module. </p> 729 * 730 * @apiNote This method can be used for cases where a <em>consumer 731 * module</em> uses a qualified opens to open a package to an <em>API 732 * module</em> but where the reflective access to the members of classes in 733 * the consumer module is delegated to code in another module. Code in the 734 * API module can use this method to open the package in the consumer module 735 * to the other module. 736 * 737 * @param pn 738 * The package name 739 * @param other 740 * The module 741 * 742 * @return this module 743 * 744 * @throws IllegalArgumentException 745 * If {@code pn} is {@code null}, or this is a named module and the 746 * package {@code pn} is not a package in this module 747 * @throws IllegalCallerException 748 * If this is a named module and this module has not opened the 749 * package to at least the caller's module 750 * 751 * @see #isOpen(String,Module) 752 * @see AccessibleObject#setAccessible(boolean) 753 * @see java.lang.invoke.MethodHandles#privateLookupIn 754 */ 755 @CallerSensitive 756 public Module addOpens(String pn, Module other) { 757 if (pn == null) 758 throw new IllegalArgumentException("package is null"); 759 Objects.requireNonNull(other); 760 761 if (isNamed()) { 762 Module caller = getCallerModule(Reflection.getCallerClass()); 763 if (caller != this && (caller == null || !isOpen(pn, caller))) 764 throw new IllegalCallerException(pn + " is not open to " + caller); 765 implAddExportsOrOpens(pn, other, /*open*/true, /*syncVM*/true); 766 } 767 768 return this; 769 } 770 771 772 /** 773 * Updates this module to export a package unconditionally. 774 * 775 * @apiNote This method is for JDK tests only. 776 */ 777 void implAddExports(String pn) { 778 implAddExportsOrOpens(pn, Module.EVERYONE_MODULE, false, true); 779 } 780 781 /** 782 * Updates this module to export a package to another module. 783 * 784 * @apiNote Used by Instrumentation::redefineModule and --add-exports 785 */ 786 void implAddExports(String pn, Module other) { 787 implAddExportsOrOpens(pn, other, false, true); 788 } 789 790 /** 791 * Updates this module to export a package to all unnamed modules. 792 * 793 * @apiNote Used by the --add-exports command line option. 794 */ 795 void implAddExportsToAllUnnamed(String pn) { 796 implAddExportsOrOpens(pn, Module.ALL_UNNAMED_MODULE, false, true); 797 } 798 799 /** 800 * Updates this export to export a package unconditionally without 801 * notifying the VM. 802 * 803 * @apiNote This method is for VM white-box testing. 804 */ 805 void implAddExportsNoSync(String pn) { 806 implAddExportsOrOpens(pn.replace('/', '.'), Module.EVERYONE_MODULE, false, false); 807 } 808 809 /** 810 * Updates a module to export a package to another module without 811 * notifying the VM. 812 * 813 * @apiNote This method is for VM white-box testing. 814 */ 815 void implAddExportsNoSync(String pn, Module other) { 816 implAddExportsOrOpens(pn.replace('/', '.'), other, false, false); 817 } 818 819 /** 820 * Updates this module to open a package unconditionally. 821 * 822 * @apiNote This method is for JDK tests only. 823 */ 824 void implAddOpens(String pn) { 825 implAddExportsOrOpens(pn, Module.EVERYONE_MODULE, true, true); 826 } 827 828 /** 829 * Updates this module to open a package to another module. 830 * 831 * @apiNote Used by Instrumentation::redefineModule and --add-opens 832 */ 833 void implAddOpens(String pn, Module other) { 834 implAddExportsOrOpens(pn, other, true, true); 835 } 836 837 /** 838 * Updates this module to open a package to all unnamed modules. 839 * 840 * @apiNote Used by the --add-opens command line option. 841 */ 842 void implAddOpensToAllUnnamed(String pn) { 843 implAddExportsOrOpens(pn, Module.ALL_UNNAMED_MODULE, true, true); 844 } 845 846 /** 847 * Updates a module to export or open a module to another module. 848 * 849 * If {@code syncVM} is {@code true} then the VM is notified. 850 */ 851 private void implAddExportsOrOpens(String pn, 852 Module other, 853 boolean open, 854 boolean syncVM) { 855 Objects.requireNonNull(other); 856 Objects.requireNonNull(pn); 857 858 // all packages are open in unnamed, open, and automatic modules 859 if (!isNamed() || descriptor.isOpen() || descriptor.isAutomatic()) 860 return; 861 862 // check if the package is already exported/open to other 863 if (implIsExportedOrOpen(pn, other, open)) { 864 865 // if the package is exported/open for illegal access then we need 866 // to record that it has also been exported/opened reflectively so 867 // that the IllegalAccessLogger doesn't emit a warning. 868 boolean needToAdd = false; 869 if (!other.isNamed()) { 870 IllegalAccessLogger l = IllegalAccessLogger.illegalAccessLogger(); 871 if (l != null) { 872 if (open) { 873 needToAdd = l.isOpenForIllegalAccess(this, pn); 874 } else { 875 needToAdd = l.isExportedForIllegalAccess(this, pn); 876 } 877 } 878 } 879 if (!needToAdd) { 880 // nothing to do 881 return; 882 } 883 } 884 885 // can only export a package in the module 886 if (!descriptor.packages().contains(pn)) { 887 throw new IllegalArgumentException("package " + pn 888 + " not in contents"); 889 } 890 891 // update VM first, just in case it fails 892 if (syncVM) { 893 if (other == EVERYONE_MODULE) { 894 addExportsToAll0(this, pn); 895 } else if (other == ALL_UNNAMED_MODULE) { 896 addExportsToAllUnnamed0(this, pn); 897 } else { 898 addExports0(this, pn, other); 899 } 900 } 901 902 // add package name to exports if absent 903 Map<String, Boolean> map = ReflectionData.exports 904 .computeIfAbsent(this, other, 905 (m1, m2) -> new ConcurrentHashMap<>()); 906 if (open) { 907 map.put(pn, Boolean.TRUE); // may need to promote from FALSE to TRUE 908 } else { 909 map.putIfAbsent(pn, Boolean.FALSE); 910 } 911 } 912 913 /** 914 * Updates a module to open all packages returned by the given iterator to 915 * all unnamed modules. 916 * 917 * @apiNote Used during startup to open packages for illegal access. 918 */ 919 void implAddOpensToAllUnnamed(Iterator<String> iterator) { 920 if (jdk.internal.misc.VM.isModuleSystemInited()) { 921 throw new IllegalStateException("Module system already initialized"); 922 } 923 924 // replace this module's openPackages map with a new map that opens 925 // the packages to all unnamed modules. 926 Map<String, Set<Module>> openPackages = this.openPackages; 927 if (openPackages == null) { 928 openPackages = new HashMap<>(); 929 } else { 930 openPackages = new HashMap<>(openPackages); 931 } 932 while (iterator.hasNext()) { 933 String pn = iterator.next(); 934 Set<Module> prev = openPackages.putIfAbsent(pn, ALL_UNNAMED_MODULE_SET); 935 if (prev != null) { 936 prev.add(ALL_UNNAMED_MODULE); 937 } 938 939 // update VM to export the package 940 addExportsToAllUnnamed0(this, pn); 941 } 942 this.openPackages = openPackages; 943 } 944 945 946 // -- services -- 947 948 /** 949 * If the caller's module is this module then update this module to add a 950 * service dependence on the given service type. This method is intended 951 * for use by frameworks that invoke {@link java.util.ServiceLoader 952 * ServiceLoader} on behalf of other modules or where the framework is 953 * passed a reference to the service type by other code. This method is 954 * a no-op when invoked on an unnamed module or an automatic module. 955 * 956 * <p> This method does not cause {@link Configuration#resolveAndBind 957 * resolveAndBind} to be re-run. </p> 958 * 959 * @param service 960 * The service type 961 * 962 * @return this module 963 * 964 * @throws IllegalCallerException 965 * If this is a named module and the caller's module is not this 966 * module 967 * 968 * @see #canUse(Class) 969 * @see ModuleDescriptor#uses() 970 */ 971 @CallerSensitive 972 public Module addUses(Class<?> service) { 973 Objects.requireNonNull(service); 974 975 if (isNamed() && !descriptor.isAutomatic()) { 976 Module caller = getCallerModule(Reflection.getCallerClass()); 977 if (caller != this) { 978 throw new IllegalCallerException(caller + " != " + this); 979 } 980 implAddUses(service); 981 } 982 983 return this; 984 } 985 986 /** 987 * Update this module to add a service dependence on the given service 988 * type. 989 */ 990 void implAddUses(Class<?> service) { 991 if (!canUse(service)) { 992 ReflectionData.uses.putIfAbsent(this, service, Boolean.TRUE); 993 } 994 } 995 996 997 /** 998 * Indicates if this module has a service dependence on the given service 999 * type. This method always returns {@code true} when invoked on an unnamed 1000 * module or an automatic module. 1001 * 1002 * @param service 1003 * The service type 1004 * 1005 * @return {@code true} if this module uses service type {@code st} 1006 * 1007 * @see #addUses(Class) 1008 */ 1009 public boolean canUse(Class<?> service) { 1010 Objects.requireNonNull(service); 1011 1012 if (!isNamed()) 1013 return true; 1014 1015 if (descriptor.isAutomatic()) 1016 return true; 1017 1018 // uses was declared 1019 if (descriptor.uses().contains(service.getName())) 1020 return true; 1021 1022 // uses added via addUses 1023 return ReflectionData.uses.containsKeyPair(this, service); 1024 } 1025 1026 1027 1028 // -- packages -- 1029 1030 /** 1031 * Returns the set of package names for the packages in this module. 1032 * 1033 * <p> For named modules, the returned set contains an element for each 1034 * package in the module. </p> 1035 * 1036 * <p> For unnamed modules, this method is the equivalent to invoking the 1037 * {@link ClassLoader#getDefinedPackages() getDefinedPackages} method of 1038 * this module's class loader and returning the set of package names. </p> 1039 * 1040 * @return the set of the package names of the packages in this module 1041 */ 1042 public Set<String> getPackages() { 1043 if (isNamed()) { 1044 return descriptor.packages(); 1045 } else { 1046 // unnamed module 1047 Stream<Package> packages; 1048 if (loader == null) { 1049 packages = BootLoader.packages(); 1050 } else { 1051 packages = loader.packages(); 1052 } 1053 return packages.map(Package::getName).collect(Collectors.toSet()); 1054 } 1055 } 1056 1057 1058 // -- creating Module objects -- 1059 1060 /** 1061 * Defines all module in a configuration to the runtime. 1062 * 1063 * @return a map of module name to runtime {@code Module} 1064 * 1065 * @throws IllegalArgumentException 1066 * If defining any of the modules to the VM fails 1067 */ 1068 static Map<String, Module> defineModules(Configuration cf, 1069 Function<String, ClassLoader> clf, 1070 ModuleLayer layer) 1071 { 1072 boolean isBootLayer = (ModuleLayer.boot() == null); 1073 1074 int cap = (int)(cf.modules().size() / 0.75f + 1.0f); 1075 Map<String, Module> nameToModule = new HashMap<>(cap); 1076 Map<String, ClassLoader> nameToLoader = new HashMap<>(cap); 1077 1078 Set<ClassLoader> loaders = new HashSet<>(); 1079 boolean hasPlatformModules = false; 1080 1081 // map each module to a class loader 1082 for (ResolvedModule resolvedModule : cf.modules()) { 1083 String name = resolvedModule.name(); 1084 ClassLoader loader = clf.apply(name); 1085 nameToLoader.put(name, loader); 1086 if (loader == null || loader == ClassLoaders.platformClassLoader()) { 1087 if (!(clf instanceof ModuleLoaderMap.Mapper)) { 1088 throw new IllegalArgumentException("loader can't be 'null'" 1089 + " or the platform class loader"); 1090 } 1091 hasPlatformModules = true; 1092 } else { 1093 loaders.add(loader); 1094 } 1095 } 1096 1097 // define each module in the configuration to the VM 1098 for (ResolvedModule resolvedModule : cf.modules()) { 1099 ModuleReference mref = resolvedModule.reference(); 1100 ModuleDescriptor descriptor = mref.descriptor(); 1101 String name = descriptor.name(); 1102 ClassLoader loader = nameToLoader.get(name); 1103 Module m; 1104 if (loader == null && name.equals("java.base")) { 1105 // java.base is already defined to the VM 1106 m = Object.class.getModule(); 1107 } else { 1108 URI uri = mref.location().orElse(null); 1109 m = new Module(layer, loader, descriptor, uri); 1110 } 1111 nameToModule.put(name, m); 1112 } 1113 1114 // setup readability and exports/opens 1115 for (ResolvedModule resolvedModule : cf.modules()) { 1116 ModuleReference mref = resolvedModule.reference(); 1117 ModuleDescriptor descriptor = mref.descriptor(); 1118 1119 String mn = descriptor.name(); 1120 Module m = nameToModule.get(mn); 1121 assert m != null; 1122 1123 // reads 1124 Set<Module> reads = new HashSet<>(); 1125 1126 // name -> source Module when in parent layer 1127 Map<String, Module> nameToSource = Collections.emptyMap(); 1128 1129 for (ResolvedModule other : resolvedModule.reads()) { 1130 Module m2 = null; 1131 if (other.configuration() == cf) { 1132 // this configuration 1133 m2 = nameToModule.get(other.name()); 1134 assert m2 != null; 1135 } else { 1136 // parent layer 1137 for (ModuleLayer parent: layer.parents()) { 1138 m2 = findModule(parent, other); 1139 if (m2 != null) 1140 break; 1141 } 1142 assert m2 != null; 1143 if (nameToSource.isEmpty()) 1144 nameToSource = new HashMap<>(); 1145 nameToSource.put(other.name(), m2); 1146 } 1147 reads.add(m2); 1148 1149 // update VM view 1150 addReads0(m, m2); 1151 } 1152 m.reads = reads; 1153 1154 // automatic modules read all unnamed modules 1155 if (descriptor.isAutomatic()) { 1156 m.implAddReads(ALL_UNNAMED_MODULE, true); 1157 } 1158 1159 // exports and opens, skipped for open and automatic 1160 if (!descriptor.isOpen() && !descriptor.isAutomatic()) { 1161 if (isBootLayer && descriptor.opens().isEmpty()) { 1162 // no open packages, no qualified exports to modules in parent layers 1163 initExports(m, nameToModule); 1164 } else { 1165 initExportsAndOpens(m, nameToSource, nameToModule, layer.parents()); 1166 } 1167 } 1168 } 1169 1170 // if there are modules defined to the boot or platform class loaders 1171 // then register the modules in the class loader's services catalog 1172 if (hasPlatformModules) { 1173 ClassLoader pcl = ClassLoaders.platformClassLoader(); 1174 ServicesCatalog bootCatalog = BootLoader.getServicesCatalog(); 1175 ServicesCatalog pclCatalog = ServicesCatalog.getServicesCatalog(pcl); 1176 for (ResolvedModule resolvedModule : cf.modules()) { 1177 ModuleReference mref = resolvedModule.reference(); 1178 ModuleDescriptor descriptor = mref.descriptor(); 1179 if (!descriptor.provides().isEmpty()) { 1180 String name = descriptor.name(); 1181 Module m = nameToModule.get(name); 1182 ClassLoader loader = nameToLoader.get(name); 1183 if (loader == null) { 1184 bootCatalog.register(m); 1185 } else if (loader == pcl) { 1186 pclCatalog.register(m); 1187 } 1188 } 1189 } 1190 } 1191 1192 // record that there is a layer with modules defined to the class loader 1193 for (ClassLoader loader : loaders) { 1194 layer.bindToLoader(loader); 1195 } 1196 1197 return nameToModule; 1198 } 1199 1200 /** 1201 * Find the runtime Module corresponding to the given ResolvedModule 1202 * in the given parent layer (or its parents). 1203 */ 1204 private static Module findModule(ModuleLayer parent, 1205 ResolvedModule resolvedModule) { 1206 Configuration cf = resolvedModule.configuration(); 1207 String dn = resolvedModule.name(); 1208 return parent.layers() 1209 .filter(l -> l.configuration() == cf) 1210 .findAny() 1211 .map(layer -> { 1212 Optional<Module> om = layer.findModule(dn); 1213 assert om.isPresent() : dn + " not found in layer"; 1214 Module m = om.get(); 1215 assert m.getLayer() == layer : m + " not in expected layer"; 1216 return m; 1217 }) 1218 .orElse(null); 1219 } 1220 1221 /** 1222 * Initialize/setup a module's exports. 1223 * 1224 * @param m the module 1225 * @param nameToModule map of module name to Module (for qualified exports) 1226 */ 1227 private static void initExports(Module m, Map<String, Module> nameToModule) { 1228 Map<String, Set<Module>> exportedPackages = new HashMap<>(); 1229 1230 for (Exports exports : m.getDescriptor().exports()) { 1231 String source = exports.source(); 1232 if (exports.isQualified()) { 1233 // qualified exports 1234 Set<Module> targets = new HashSet<>(); 1235 for (String target : exports.targets()) { 1236 Module m2 = nameToModule.get(target); 1237 if (m2 != null) { 1238 addExports0(m, source, m2); 1239 targets.add(m2); 1240 } 1241 } 1242 if (!targets.isEmpty()) { 1243 exportedPackages.put(source, targets); 1244 } 1245 } else { 1246 // unqualified exports 1247 addExportsToAll0(m, source); 1248 exportedPackages.put(source, EVERYONE_SET); 1249 } 1250 } 1251 1252 if (!exportedPackages.isEmpty()) 1253 m.exportedPackages = exportedPackages; 1254 } 1255 1256 /** 1257 * Initialize/setup a module's exports. 1258 * 1259 * @param m the module 1260 * @param nameToSource map of module name to Module for modules that m reads 1261 * @param nameToModule map of module name to Module for modules in the layer 1262 * under construction 1263 * @param parents the parent layers 1264 */ 1265 private static void initExportsAndOpens(Module m, 1266 Map<String, Module> nameToSource, 1267 Map<String, Module> nameToModule, 1268 List<ModuleLayer> parents) { 1269 ModuleDescriptor descriptor = m.getDescriptor(); 1270 Map<String, Set<Module>> openPackages = new HashMap<>(); 1271 Map<String, Set<Module>> exportedPackages = new HashMap<>(); 1272 1273 // process the open packages first 1274 for (Opens opens : descriptor.opens()) { 1275 String source = opens.source(); 1276 1277 if (opens.isQualified()) { 1278 // qualified opens 1279 Set<Module> targets = new HashSet<>(); 1280 for (String target : opens.targets()) { 1281 Module m2 = findModule(target, nameToSource, nameToModule, parents); 1282 if (m2 != null) { 1283 addExports0(m, source, m2); 1284 targets.add(m2); 1285 } 1286 } 1287 if (!targets.isEmpty()) { 1288 openPackages.put(source, targets); 1289 } 1290 } else { 1291 // unqualified opens 1292 addExportsToAll0(m, source); 1293 openPackages.put(source, EVERYONE_SET); 1294 } 1295 } 1296 1297 // next the exports, skipping exports when the package is open 1298 for (Exports exports : descriptor.exports()) { 1299 String source = exports.source(); 1300 1301 // skip export if package is already open to everyone 1302 Set<Module> openToTargets = openPackages.get(source); 1303 if (openToTargets != null && openToTargets.contains(EVERYONE_MODULE)) 1304 continue; 1305 1306 if (exports.isQualified()) { 1307 // qualified exports 1308 Set<Module> targets = new HashSet<>(); 1309 for (String target : exports.targets()) { 1310 Module m2 = findModule(target, nameToSource, nameToModule, parents); 1311 if (m2 != null) { 1312 // skip qualified export if already open to m2 1313 if (openToTargets == null || !openToTargets.contains(m2)) { 1314 addExports0(m, source, m2); 1315 targets.add(m2); 1316 } 1317 } 1318 } 1319 if (!targets.isEmpty()) { 1320 exportedPackages.put(source, targets); 1321 } 1322 } else { 1323 // unqualified exports 1324 addExportsToAll0(m, source); 1325 exportedPackages.put(source, EVERYONE_SET); 1326 } 1327 } 1328 1329 if (!openPackages.isEmpty()) 1330 m.openPackages = openPackages; 1331 if (!exportedPackages.isEmpty()) 1332 m.exportedPackages = exportedPackages; 1333 } 1334 1335 /** 1336 * Find the runtime Module with the given name. The module name is the 1337 * name of a target module in a qualified exports or opens directive. 1338 * 1339 * @param target The target module to find 1340 * @param nameToSource The modules in parent layers that are read 1341 * @param nameToModule The modules in the layer under construction 1342 * @param parents The parent layers 1343 */ 1344 private static Module findModule(String target, 1345 Map<String, Module> nameToSource, 1346 Map<String, Module> nameToModule, 1347 List<ModuleLayer> parents) { 1348 Module m = nameToSource.get(target); 1349 if (m == null) { 1350 m = nameToModule.get(target); 1351 if (m == null) { 1352 for (ModuleLayer parent : parents) { 1353 m = parent.findModule(target).orElse(null); 1354 if (m != null) break; 1355 } 1356 } 1357 } 1358 return m; 1359 } 1360 1361 1362 // -- annotations -- 1363 1364 /** 1365 * {@inheritDoc} 1366 * This method returns {@code null} when invoked on an unnamed module. 1367 */ 1368 @Override 1369 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) { 1370 return moduleInfoClass().getDeclaredAnnotation(annotationClass); 1371 } 1372 1373 /** 1374 * {@inheritDoc} 1375 * This method returns an empty array when invoked on an unnamed module. 1376 */ 1377 @Override 1378 public Annotation[] getAnnotations() { 1379 return moduleInfoClass().getAnnotations(); 1380 } 1381 1382 /** 1383 * {@inheritDoc} 1384 * This method returns an empty array when invoked on an unnamed module. 1385 */ 1386 @Override 1387 public Annotation[] getDeclaredAnnotations() { 1388 return moduleInfoClass().getDeclaredAnnotations(); 1389 } 1390 1391 // cached class file with annotations 1392 private volatile Class<?> moduleInfoClass; 1393 1394 private Class<?> moduleInfoClass() { 1395 Class<?> clazz = this.moduleInfoClass; 1396 if (clazz != null) 1397 return clazz; 1398 1399 synchronized (this) { 1400 clazz = this.moduleInfoClass; 1401 if (clazz == null) { 1402 if (isNamed()) { 1403 PrivilegedAction<Class<?>> pa = this::loadModuleInfoClass; 1404 clazz = AccessController.doPrivileged(pa); 1405 } 1406 if (clazz == null) { 1407 class DummyModuleInfo { } 1408 clazz = DummyModuleInfo.class; 1409 } 1410 this.moduleInfoClass = clazz; 1411 } 1412 return clazz; 1413 } 1414 } 1415 1416 private Class<?> loadModuleInfoClass() { 1417 Class<?> clazz = null; 1418 try (InputStream in = getResourceAsStream("module-info.class")) { 1419 if (in != null) 1420 clazz = loadModuleInfoClass(in); 1421 } catch (Exception ignore) { } 1422 return clazz; 1423 } 1424 1425 /** 1426 * Loads module-info.class as a package-private interface in a class loader 1427 * that is a child of this module's class loader. 1428 */ 1429 private Class<?> loadModuleInfoClass(InputStream in) throws IOException { 1430 final String MODULE_INFO = "module-info"; 1431 1432 ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS 1433 + ClassWriter.COMPUTE_FRAMES); 1434 1435 ClassVisitor cv = new ClassVisitor(Opcodes.ASM5, cw) { 1436 @Override 1437 public void visit(int version, 1438 int access, 1439 String name, 1440 String signature, 1441 String superName, 1442 String[] interfaces) { 1443 cw.visit(version, 1444 Opcodes.ACC_INTERFACE 1445 + Opcodes.ACC_ABSTRACT 1446 + Opcodes.ACC_SYNTHETIC, 1447 MODULE_INFO, 1448 null, 1449 "java/lang/Object", 1450 null); 1451 } 1452 @Override 1453 public AnnotationVisitor visitAnnotation(String desc, boolean visible) { 1454 // keep annotations 1455 return super.visitAnnotation(desc, visible); 1456 } 1457 @Override 1458 public void visitAttribute(Attribute attr) { 1459 // drop non-annotation attributes 1460 } 1461 }; 1462 1463 ClassReader cr = new ClassReader(in); 1464 cr.accept(cv, 0); 1465 byte[] bytes = cw.toByteArray(); 1466 1467 ClassLoader cl = new ClassLoader(loader) { 1468 @Override 1469 protected Class<?> findClass(String cn)throws ClassNotFoundException { 1470 if (cn.equals(MODULE_INFO)) { 1471 return super.defineClass(cn, bytes, 0, bytes.length); 1472 } else { 1473 throw new ClassNotFoundException(cn); 1474 } 1475 } 1476 }; 1477 1478 try { 1479 return cl.loadClass(MODULE_INFO); 1480 } catch (ClassNotFoundException e) { 1481 throw new InternalError(e); 1482 } 1483 } 1484 1485 1486 // -- misc -- 1487 1488 1489 /** 1490 * Returns an input stream for reading a resource in this module. 1491 * The {@code name} parameter is a {@code '/'}-separated path name that 1492 * identifies the resource. As with {@link Class#getResourceAsStream 1493 * Class.getResourceAsStream}, this method delegates to the module's class 1494 * loader {@link ClassLoader#findResource(String,String) 1495 * findResource(String,String)} method, invoking it with the module name 1496 * (or {@code null} when the module is unnamed) and the name of the 1497 * resource. If the resource name has a leading slash then it is dropped 1498 * before delegation. 1499 * 1500 * <p> A resource in a named module may be <em>encapsulated</em> so that 1501 * it cannot be located by code in other modules. Whether a resource can be 1502 * located or not is determined as follows: </p> 1503 * 1504 * <ul> 1505 * <li> If the resource name ends with "{@code .class}" then it is not 1506 * encapsulated. </li> 1507 * 1508 * <li> A <em>package name</em> is derived from the resource name. If 1509 * the package name is a {@linkplain #getPackages() package} in the 1510 * module then the resource can only be located by the caller of this 1511 * method when the package is {@linkplain #isOpen(String,Module) open} 1512 * to at least the caller's module. If the resource is not in a 1513 * package in the module then the resource is not encapsulated. </li> 1514 * </ul> 1515 * 1516 * <p> In the above, the <em>package name</em> for a resource is derived 1517 * from the subsequence of characters that precedes the last {@code '/'} in 1518 * the name and then replacing each {@code '/'} character in the subsequence 1519 * with {@code '.'}. A leading slash is ignored when deriving the package 1520 * name. As an example, the package name derived for a resource named 1521 * "{@code a/b/c/foo.properties}" is "{@code a.b.c}". A resource name 1522 * with the name "{@code META-INF/MANIFEST.MF}" is never encapsulated 1523 * because "{@code META-INF}" is not a legal package name. </p> 1524 * 1525 * <p> This method returns {@code null} if the resource is not in this 1526 * module, the resource is encapsulated and cannot be located by the caller, 1527 * or access to the resource is denied by the security manager. </p> 1528 * 1529 * @param name 1530 * The resource name 1531 * 1532 * @return An input stream for reading the resource or {@code null} 1533 * 1534 * @throws IOException 1535 * If an I/O error occurs 1536 * 1537 * @see Class#getResourceAsStream(String) 1538 */ 1539 @CallerSensitive 1540 public InputStream getResourceAsStream(String name) throws IOException { 1541 if (name.startsWith("/")) { 1542 name = name.substring(1); 1543 } 1544 1545 if (isNamed() && Resources.canEncapsulate(name)) { 1546 Module caller = getCallerModule(Reflection.getCallerClass()); 1547 if (caller != this && caller != Object.class.getModule()) { 1548 String pn = Resources.toPackageName(name); 1549 if (getPackages().contains(pn)) { 1550 if (caller == null && !isOpen(pn)) { 1551 // no caller, package not open 1552 return null; 1553 } 1554 if (!isOpen(pn, caller)) { 1555 // package not open to caller 1556 return null; 1557 } 1558 } 1559 } 1560 } 1561 1562 String mn = this.name; 1563 1564 // special-case built-in class loaders to avoid URL connection 1565 if (loader == null) { 1566 return BootLoader.findResourceAsStream(mn, name); 1567 } else if (loader instanceof BuiltinClassLoader) { 1568 return ((BuiltinClassLoader) loader).findResourceAsStream(mn, name); 1569 } 1570 1571 // locate resource in module 1572 URL url = loader.findResource(mn, name); 1573 if (url != null) { 1574 try { 1575 return url.openStream(); 1576 } catch (SecurityException e) { } 1577 } 1578 1579 return null; 1580 } 1581 1582 /** 1583 * Returns the string representation of this module. For a named module, 1584 * the representation is the string {@code "module"}, followed by a space, 1585 * and then the module name. For an unnamed module, the representation is 1586 * the string {@code "unnamed module"}, followed by a space, and then an 1587 * implementation specific string that identifies the unnamed module. 1588 * 1589 * @return The string representation of this module 1590 */ 1591 @Override 1592 public String toString() { 1593 if (isNamed()) { 1594 return "module " + name; 1595 } else { 1596 String id = Integer.toHexString(System.identityHashCode(this)); 1597 return "unnamed module @" + id; 1598 } 1599 } 1600 1601 /** 1602 * Returns the module that a given caller class is a member of. Returns 1603 * {@code null} if the caller is {@code null}. 1604 */ 1605 private Module getCallerModule(Class<?> caller) { 1606 return (caller != null) ? caller.getModule() : null; 1607 } 1608 1609 1610 // -- native methods -- 1611 1612 // JVM_DefineModule 1613 private static native void defineModule0(Module module, 1614 boolean isOpen, 1615 String version, 1616 String location, 1617 String[] pns); 1618 1619 // JVM_AddReadsModule 1620 private static native void addReads0(Module from, Module to); 1621 1622 // JVM_AddModuleExports 1623 private static native void addExports0(Module from, String pn, Module to); 1624 1625 // JVM_AddModuleExportsToAll 1626 private static native void addExportsToAll0(Module from, String pn); 1627 1628 // JVM_AddModuleExportsToAllUnnamed 1629 private static native void addExportsToAllUnnamed0(Module from, String pn); 1630 }