1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. Oracle designates this 9 * particular file as subject to the "Classpath" exception as provided 10 * by Oracle in the LICENSE file that accompanied this code. 11 * 12 * This code is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 * version 2 for more details (a copy is included in the LICENSE file that 16 * accompanied this code). 17 * 18 * You should have received a copy of the GNU General Public License version 19 * 2 along with this work; if not, write to the Free Software Foundation, 20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 21 * 22 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 23 * or visit www.oracle.com if you need additional information or have any 24 * questions. 25 */ 26 27 package java.lang.reflect; 28 29 30 import dalvik.annotation.optimization.FastNative; 31 import java.lang.ref.Reference; 32 import java.lang.ref.WeakReference; 33 import java.security.Permission; 34 import java.security.PrivilegedAction; 35 import java.util.ArrayList; 36 import java.util.Arrays; 37 import java.util.Arrays; 38 import java.util.Collections; 39 import java.util.Comparator; 40 import java.util.HashMap; 41 import java.util.HashSet; 42 import java.util.IdentityHashMap; 43 import java.util.List; 44 import java.util.Map; 45 import java.util.Objects; 46 import java.util.Set; 47 import java.util.WeakHashMap; 48 import java.util.concurrent.atomic.AtomicLong; 49 import java.util.function.BiFunction; 50 import libcore.util.EmptyArray; 51 import sun.reflect.CallerSensitive; 52 import sun.reflect.misc.ReflectUtil; 53 import sun.security.util.SecurityConstants; 54 55 /** 56 * {@code Proxy} provides static methods for creating dynamic proxy 57 * classes and instances, and it is also the superclass of all 58 * dynamic proxy classes created by those methods. 59 * 60 * <p>To create a proxy for some interface {@code Foo}: 61 * <pre> 62 * InvocationHandler handler = new MyInvocationHandler(...); 63 * Class<?> proxyClass = Proxy.getProxyClass(Foo.class.getClassLoader(), Foo.class); 64 * Foo f = (Foo) proxyClass.getConstructor(InvocationHandler.class). 65 * newInstance(handler); 66 * </pre> 67 * or more simply: 68 * <pre> 69 * Foo f = (Foo) Proxy.newProxyInstance(Foo.class.getClassLoader(), 70 * new Class<?>[] { Foo.class }, 71 * handler); 72 * </pre> 73 * 74 * <p>A <i>dynamic proxy class</i> (simply referred to as a <i>proxy 75 * class</i> below) is a class that implements a list of interfaces 76 * specified at runtime when the class is created, with behavior as 77 * described below. 78 * 79 * A <i>proxy interface</i> is such an interface that is implemented 80 * by a proxy class. 81 * 82 * A <i>proxy instance</i> is an instance of a proxy class. 83 * 84 * Each proxy instance has an associated <i>invocation handler</i> 85 * object, which implements the interface {@link InvocationHandler}. 86 * A method invocation on a proxy instance through one of its proxy 87 * interfaces will be dispatched to the {@link InvocationHandler#invoke 88 * invoke} method of the instance's invocation handler, passing the proxy 89 * instance, a {@code java.lang.reflect.Method} object identifying 90 * the method that was invoked, and an array of type {@code Object} 91 * containing the arguments. The invocation handler processes the 92 * encoded method invocation as appropriate and the result that it 93 * returns will be returned as the result of the method invocation on 94 * the proxy instance. 95 * 96 * <p>A proxy class has the following properties: 97 * 98 * <ul> 99 * <li>Proxy classes are <em>public, final, and not abstract</em> if 100 * all proxy interfaces are public.</li> 101 * 102 * <li>Proxy classes are <em>non-public, final, and not abstract</em> if 103 * any of the proxy interfaces is non-public.</li> 104 * 105 * <li>The unqualified name of a proxy class is unspecified. The space 106 * of class names that begin with the string {@code "$Proxy"} 107 * should be, however, reserved for proxy classes. 108 * 109 * <li>A proxy class extends {@code java.lang.reflect.Proxy}. 110 * 111 * <li>A proxy class implements exactly the interfaces specified at its 112 * creation, in the same order. 113 * 114 * <li>If a proxy class implements a non-public interface, then it will 115 * be defined in the same package as that interface. Otherwise, the 116 * package of a proxy class is also unspecified. Note that package 117 * sealing will not prevent a proxy class from being successfully defined 118 * in a particular package at runtime, and neither will classes already 119 * defined by the same class loader and the same package with particular 120 * signers. 121 * 122 * <li>Since a proxy class implements all of the interfaces specified at 123 * its creation, invoking {@code getInterfaces} on its 124 * {@code Class} object will return an array containing the same 125 * list of interfaces (in the order specified at its creation), invoking 126 * {@code getMethods} on its {@code Class} object will return 127 * an array of {@code Method} objects that include all of the 128 * methods in those interfaces, and invoking {@code getMethod} will 129 * find methods in the proxy interfaces as would be expected. 130 * 131 * <li>The {@link Proxy#isProxyClass Proxy.isProxyClass} method will 132 * return true if it is passed a proxy class-- a class returned by 133 * {@code Proxy.getProxyClass} or the class of an object returned by 134 * {@code Proxy.newProxyInstance}-- and false otherwise. 135 * 136 * <li>The {@code java.security.ProtectionDomain} of a proxy class 137 * is the same as that of system classes loaded by the bootstrap class 138 * loader, such as {@code java.lang.Object}, because the code for a 139 * proxy class is generated by trusted system code. This protection 140 * domain will typically be granted 141 * {@code java.security.AllPermission}. 142 * 143 * <li>Each proxy class has one public constructor that takes one argument, 144 * an implementation of the interface {@link InvocationHandler}, to set 145 * the invocation handler for a proxy instance. Rather than having to use 146 * the reflection API to access the public constructor, a proxy instance 147 * can be also be created by calling the {@link Proxy#newProxyInstance 148 * Proxy.newProxyInstance} method, which combines the actions of calling 149 * {@link Proxy#getProxyClass Proxy.getProxyClass} with invoking the 150 * constructor with an invocation handler. 151 * </ul> 152 * 153 * <p>A proxy instance has the following properties: 154 * 155 * <ul> 156 * <li>Given a proxy instance {@code proxy} and one of the 157 * interfaces implemented by its proxy class {@code Foo}, the 158 * following expression will return true: 159 * <pre> 160 * {@code proxy instanceof Foo} 161 * </pre> 162 * and the following cast operation will succeed (rather than throwing 163 * a {@code ClassCastException}): 164 * <pre> 165 * {@code (Foo) proxy} 166 * </pre> 167 * 168 * <li>Each proxy instance has an associated invocation handler, the one 169 * that was passed to its constructor. The static 170 * {@link Proxy#getInvocationHandler Proxy.getInvocationHandler} method 171 * will return the invocation handler associated with the proxy instance 172 * passed as its argument. 173 * 174 * <li>An interface method invocation on a proxy instance will be 175 * encoded and dispatched to the invocation handler's {@link 176 * InvocationHandler#invoke invoke} method as described in the 177 * documentation for that method. 178 * 179 * <li>An invocation of the {@code hashCode}, 180 * {@code equals}, or {@code toString} methods declared in 181 * {@code java.lang.Object} on a proxy instance will be encoded and 182 * dispatched to the invocation handler's {@code invoke} method in 183 * the same manner as interface method invocations are encoded and 184 * dispatched, as described above. The declaring class of the 185 * {@code Method} object passed to {@code invoke} will be 186 * {@code java.lang.Object}. Other public methods of a proxy 187 * instance inherited from {@code java.lang.Object} are not 188 * overridden by a proxy class, so invocations of those methods behave 189 * like they do for instances of {@code java.lang.Object}. 190 * </ul> 191 * 192 * <h3>Methods Duplicated in Multiple Proxy Interfaces</h3> 193 * 194 * <p>When two or more interfaces of a proxy class contain a method with 195 * the same name and parameter signature, the order of the proxy class's 196 * interfaces becomes significant. When such a <i>duplicate method</i> 197 * is invoked on a proxy instance, the {@code Method} object passed 198 * to the invocation handler will not necessarily be the one whose 199 * declaring class is assignable from the reference type of the interface 200 * that the proxy's method was invoked through. This limitation exists 201 * because the corresponding method implementation in the generated proxy 202 * class cannot determine which interface it was invoked through. 203 * Therefore, when a duplicate method is invoked on a proxy instance, 204 * the {@code Method} object for the method in the foremost interface 205 * that contains the method (either directly or inherited through a 206 * superinterface) in the proxy class's list of interfaces is passed to 207 * the invocation handler's {@code invoke} method, regardless of the 208 * reference type through which the method invocation occurred. 209 * 210 * <p>If a proxy interface contains a method with the same name and 211 * parameter signature as the {@code hashCode}, {@code equals}, 212 * or {@code toString} methods of {@code java.lang.Object}, 213 * when such a method is invoked on a proxy instance, the 214 * {@code Method} object passed to the invocation handler will have 215 * {@code java.lang.Object} as its declaring class. In other words, 216 * the public, non-final methods of {@code java.lang.Object} 217 * logically precede all of the proxy interfaces for the determination of 218 * which {@code Method} object to pass to the invocation handler. 219 * 220 * <p>Note also that when a duplicate method is dispatched to an 221 * invocation handler, the {@code invoke} method may only throw 222 * checked exception types that are assignable to one of the exception 223 * types in the {@code throws} clause of the method in <i>all</i> of 224 * the proxy interfaces that it can be invoked through. If the 225 * {@code invoke} method throws a checked exception that is not 226 * assignable to any of the exception types declared by the method in one 227 * of the proxy interfaces that it can be invoked through, then an 228 * unchecked {@code UndeclaredThrowableException} will be thrown by 229 * the invocation on the proxy instance. This restriction means that not 230 * all of the exception types returned by invoking 231 * {@code getExceptionTypes} on the {@code Method} object 232 * passed to the {@code invoke} method can necessarily be thrown 233 * successfully by the {@code invoke} method. 234 * 235 * @author Peter Jones 236 * @see InvocationHandler 237 * @since 1.3 238 */ 239 public class Proxy implements java.io.Serializable { 240 241 private static final long serialVersionUID = -2222568056686623797L; 242 243 /** prefix for all proxy class names */ 244 private final static String proxyClassNamePrefix = "$Proxy"; 245 246 /** parameter types of a proxy class constructor */ 247 private static final Class<?>[] constructorParams = 248 { InvocationHandler.class }; 249 250 /** 251 * a cache of proxy classes 252 */ 253 private static final WeakCache<ClassLoader, Class<?>[], Class<?>> 254 proxyClassCache = new WeakCache<>(new KeyFactory(), new ProxyClassFactory()); 255 256 /** 257 * the invocation handler for this proxy instance. 258 * @serial 259 */ 260 protected InvocationHandler h; 261 262 /** 263 * Orders methods by their name, parameters, return type and inheritance relationship. 264 * 265 * @hide 266 */ 267 private static final Comparator<Method> ORDER_BY_SIGNATURE_AND_SUBTYPE = new Comparator<Method>() { 268 @Override public int compare(Method a, Method b) { 269 int comparison = Method.ORDER_BY_SIGNATURE.compare(a, b); 270 if (comparison != 0) { 271 return comparison; 272 } 273 Class<?> aClass = a.getDeclaringClass(); 274 Class<?> bClass = b.getDeclaringClass(); 275 if (aClass == bClass) { 276 return 0; 277 } else if (aClass.isAssignableFrom(bClass)) { 278 return 1; 279 } else if (bClass.isAssignableFrom(aClass)) { 280 return -1; 281 } else { 282 return 0; 283 } 284 } 285 }; 286 287 /** 288 * Prohibits instantiation. 289 */ Proxy()290 private Proxy() { 291 } 292 293 /** 294 * Constructs a new {@code Proxy} instance from a subclass 295 * (typically, a dynamic proxy class) with the specified value 296 * for its invocation handler. 297 * 298 * @param h the invocation handler for this proxy instance 299 * 300 * @throws NullPointerException if the given invocation handler, {@code h}, 301 * is {@code null}. 302 */ Proxy(InvocationHandler h)303 protected Proxy(InvocationHandler h) { 304 Objects.requireNonNull(h); 305 this.h = h; 306 } 307 308 /** 309 * Returns the {@code java.lang.Class} object for a proxy class 310 * given a class loader and an array of interfaces. The proxy class 311 * will be defined by the specified class loader and will implement 312 * all of the supplied interfaces. If any of the given interfaces 313 * is non-public, the proxy class will be non-public. If a proxy class 314 * for the same permutation of interfaces has already been defined by the 315 * class loader, then the existing proxy class will be returned; otherwise, 316 * a proxy class for those interfaces will be generated dynamically 317 * and defined by the class loader. 318 * 319 * <p>There are several restrictions on the parameters that may be 320 * passed to {@code Proxy.getProxyClass}: 321 * 322 * <ul> 323 * <li>All of the {@code Class} objects in the 324 * {@code interfaces} array must represent interfaces, not 325 * classes or primitive types. 326 * 327 * <li>No two elements in the {@code interfaces} array may 328 * refer to identical {@code Class} objects. 329 * 330 * <li>All of the interface types must be visible by name through the 331 * specified class loader. In other words, for class loader 332 * {@code cl} and every interface {@code i}, the following 333 * expression must be true: 334 * <pre> 335 * Class.forName(i.getName(), false, cl) == i 336 * </pre> 337 * 338 * <li>All non-public interfaces must be in the same package; 339 * otherwise, it would not be possible for the proxy class to 340 * implement all of the interfaces, regardless of what package it is 341 * defined in. 342 * 343 * <li>For any set of member methods of the specified interfaces 344 * that have the same signature: 345 * <ul> 346 * <li>If the return type of any of the methods is a primitive 347 * type or void, then all of the methods must have that same 348 * return type. 349 * <li>Otherwise, one of the methods must have a return type that 350 * is assignable to all of the return types of the rest of the 351 * methods. 352 * </ul> 353 * 354 * <li>The resulting proxy class must not exceed any limits imposed 355 * on classes by the virtual machine. For example, the VM may limit 356 * the number of interfaces that a class may implement to 65535; in 357 * that case, the size of the {@code interfaces} array must not 358 * exceed 65535. 359 * </ul> 360 * 361 * <p>If any of these restrictions are violated, 362 * {@code Proxy.getProxyClass} will throw an 363 * {@code IllegalArgumentException}. If the {@code interfaces} 364 * array argument or any of its elements are {@code null}, a 365 * {@code NullPointerException} will be thrown. 366 * 367 * <p>Note that the order of the specified proxy interfaces is 368 * significant: two requests for a proxy class with the same combination 369 * of interfaces but in a different order will result in two distinct 370 * proxy classes. 371 * 372 * @param loader the class loader to define the proxy class 373 * @param interfaces the list of interfaces for the proxy class 374 * to implement 375 * @return a proxy class that is defined in the specified class loader 376 * and that implements the specified interfaces 377 * @throws IllegalArgumentException if any of the restrictions on the 378 * parameters that may be passed to {@code getProxyClass} 379 * are violated 380 * @throws SecurityException if a security manager, <em>s</em>, is present 381 * and any of the following conditions is met: 382 * <ul> 383 * <li> the given {@code loader} is {@code null} and 384 * the caller's class loader is not {@code null} and the 385 * invocation of {@link SecurityManager#checkPermission 386 * s.checkPermission} with 387 * {@code RuntimePermission("getClassLoader")} permission 388 * denies access.</li> 389 * <li> for each proxy interface, {@code intf}, 390 * the caller's class loader is not the same as or an 391 * ancestor of the class loader for {@code intf} and 392 * invocation of {@link SecurityManager#checkPackageAccess 393 * s.checkPackageAccess()} denies access to {@code intf}.</li> 394 * </ul> 395 * @throws NullPointerException if the {@code interfaces} array 396 * argument or any of its elements are {@code null} 397 */ 398 @CallerSensitive getProxyClass(ClassLoader loader, Class<?>... interfaces)399 public static Class<?> getProxyClass(ClassLoader loader, 400 Class<?>... interfaces) 401 throws IllegalArgumentException 402 { 403 return getProxyClass0(loader, interfaces); 404 } 405 406 /** 407 * Generate a proxy class. Must call the checkProxyAccess method 408 * to perform permission checks before calling this. 409 */ getProxyClass0(ClassLoader loader, Class<?>... interfaces)410 private static Class<?> getProxyClass0(ClassLoader loader, 411 Class<?>... interfaces) { 412 if (interfaces.length > 65535) { 413 throw new IllegalArgumentException("interface limit exceeded"); 414 } 415 416 // If the proxy class defined by the given loader implementing 417 // the given interfaces exists, this will simply return the cached copy; 418 // otherwise, it will create the proxy class via the ProxyClassFactory 419 return proxyClassCache.get(loader, interfaces); 420 } 421 422 /* 423 * a key used for proxy class with 0 implemented interfaces 424 */ 425 private static final Object key0 = new Object(); 426 427 /* 428 * Key1 and Key2 are optimized for the common use of dynamic proxies 429 * that implement 1 or 2 interfaces. 430 */ 431 432 /* 433 * a key used for proxy class with 1 implemented interface 434 */ 435 private static final class Key1 extends WeakReference<Class<?>> { 436 private final int hash; 437 Key1(Class<?> intf)438 Key1(Class<?> intf) { 439 super(intf); 440 this.hash = intf.hashCode(); 441 } 442 443 @Override hashCode()444 public int hashCode() { 445 return hash; 446 } 447 448 @Override equals(Object obj)449 public boolean equals(Object obj) { 450 Class<?> intf; 451 return this == obj || 452 obj != null && 453 obj.getClass() == Key1.class && 454 (intf = get()) != null && 455 intf == ((Key1) obj).get(); 456 } 457 } 458 459 /* 460 * a key used for proxy class with 2 implemented interfaces 461 */ 462 private static final class Key2 extends WeakReference<Class<?>> { 463 private final int hash; 464 private final WeakReference<Class<?>> ref2; 465 Key2(Class<?> intf1, Class<?> intf2)466 Key2(Class<?> intf1, Class<?> intf2) { 467 super(intf1); 468 hash = 31 * intf1.hashCode() + intf2.hashCode(); 469 ref2 = new WeakReference<Class<?>>(intf2); 470 } 471 472 @Override hashCode()473 public int hashCode() { 474 return hash; 475 } 476 477 @Override equals(Object obj)478 public boolean equals(Object obj) { 479 Class<?> intf1, intf2; 480 return this == obj || 481 obj != null && 482 obj.getClass() == Key2.class && 483 (intf1 = get()) != null && 484 intf1 == ((Key2) obj).get() && 485 (intf2 = ref2.get()) != null && 486 intf2 == ((Key2) obj).ref2.get(); 487 } 488 } 489 490 /* 491 * a key used for proxy class with any number of implemented interfaces 492 * (used here for 3 or more only) 493 */ 494 private static final class KeyX { 495 private final int hash; 496 private final WeakReference<Class<?>>[] refs; 497 498 @SuppressWarnings("unchecked") KeyX(Class<?>[] interfaces)499 KeyX(Class<?>[] interfaces) { 500 hash = Arrays.hashCode(interfaces); 501 refs = (WeakReference<Class<?>>[])new WeakReference<?>[interfaces.length]; 502 for (int i = 0; i < interfaces.length; i++) { 503 refs[i] = new WeakReference<>(interfaces[i]); 504 } 505 } 506 507 @Override hashCode()508 public int hashCode() { 509 return hash; 510 } 511 512 @Override equals(Object obj)513 public boolean equals(Object obj) { 514 return this == obj || 515 obj != null && 516 obj.getClass() == KeyX.class && 517 equals(refs, ((KeyX) obj).refs); 518 } 519 equals(WeakReference<Class<?>>[] refs1, WeakReference<Class<?>>[] refs2)520 private static boolean equals(WeakReference<Class<?>>[] refs1, 521 WeakReference<Class<?>>[] refs2) { 522 if (refs1.length != refs2.length) { 523 return false; 524 } 525 for (int i = 0; i < refs1.length; i++) { 526 Class<?> intf = refs1[i].get(); 527 if (intf == null || intf != refs2[i].get()) { 528 return false; 529 } 530 } 531 return true; 532 } 533 } 534 535 /** 536 * A function that maps an array of interfaces to an optimal key where 537 * Class objects representing interfaces are weakly referenced. 538 */ 539 private static final class KeyFactory 540 implements BiFunction<ClassLoader, Class<?>[], Object> 541 { 542 @Override apply(ClassLoader classLoader, Class<?>[] interfaces)543 public Object apply(ClassLoader classLoader, Class<?>[] interfaces) { 544 switch (interfaces.length) { 545 case 1: return new Key1(interfaces[0]); // the most frequent 546 case 2: return new Key2(interfaces[0], interfaces[1]); 547 case 0: return key0; 548 default: return new KeyX(interfaces); 549 } 550 } 551 } 552 553 /** 554 * A factory function that generates, defines and returns the proxy class given 555 * the ClassLoader and array of interfaces. 556 */ 557 private static final class ProxyClassFactory 558 implements BiFunction<ClassLoader, Class<?>[], Class<?>> 559 { 560 // prefix for all proxy class names 561 private static final String proxyClassNamePrefix = "$Proxy"; 562 563 // next number to use for generation of unique proxy class names 564 private static final AtomicLong nextUniqueNumber = new AtomicLong(); 565 566 @Override apply(ClassLoader loader, Class<?>[] interfaces)567 public Class<?> apply(ClassLoader loader, Class<?>[] interfaces) { 568 569 Map<Class<?>, Boolean> interfaceSet = new IdentityHashMap<>(interfaces.length); 570 for (Class<?> intf : interfaces) { 571 /* 572 * Verify that the class loader resolves the name of this 573 * interface to the same Class object. 574 */ 575 Class<?> interfaceClass = null; 576 try { 577 interfaceClass = Class.forName(intf.getName(), false, loader); 578 } catch (ClassNotFoundException e) { 579 } 580 if (interfaceClass != intf) { 581 throw new IllegalArgumentException( 582 intf + " is not visible from class loader"); 583 } 584 /* 585 * Verify that the Class object actually represents an 586 * interface. 587 */ 588 if (!interfaceClass.isInterface()) { 589 throw new IllegalArgumentException( 590 interfaceClass.getName() + " is not an interface"); 591 } 592 /* 593 * Verify that this interface is not a duplicate. 594 */ 595 if (interfaceSet.put(interfaceClass, Boolean.TRUE) != null) { 596 throw new IllegalArgumentException( 597 "repeated interface: " + interfaceClass.getName()); 598 } 599 } 600 601 String proxyPkg = null; // package to define proxy class in 602 int accessFlags = Modifier.PUBLIC | Modifier.FINAL; 603 604 /* 605 * Record the package of a non-public proxy interface so that the 606 * proxy class will be defined in the same package. Verify that 607 * all non-public proxy interfaces are in the same package. 608 */ 609 for (Class<?> intf : interfaces) { 610 int flags = intf.getModifiers(); 611 if (!Modifier.isPublic(flags)) { 612 accessFlags = Modifier.FINAL; 613 String name = intf.getName(); 614 int n = name.lastIndexOf('.'); 615 String pkg = ((n == -1) ? "" : name.substring(0, n + 1)); 616 if (proxyPkg == null) { 617 proxyPkg = pkg; 618 } else if (!pkg.equals(proxyPkg)) { 619 throw new IllegalArgumentException( 620 "non-public interfaces from different packages"); 621 } 622 } 623 } 624 625 if (proxyPkg == null) { 626 // if no non-public proxy interfaces, use the default package. 627 proxyPkg = ""; 628 } 629 630 { 631 // Android-changed: Generate the proxy directly instead of calling 632 // through to ProxyGenerator. 633 List<Method> methods = getMethods(interfaces); 634 Collections.sort(methods, ORDER_BY_SIGNATURE_AND_SUBTYPE); 635 validateReturnTypes(methods); 636 List<Class<?>[]> exceptions = deduplicateAndGetExceptions(methods); 637 638 Method[] methodsArray = methods.toArray(new Method[methods.size()]); 639 Class<?>[][] exceptionsArray = exceptions.toArray(new Class<?>[exceptions.size()][]); 640 641 /* 642 * Choose a name for the proxy class to generate. 643 */ 644 long num = nextUniqueNumber.getAndIncrement(); 645 String proxyName = proxyPkg + proxyClassNamePrefix + num; 646 647 return generateProxy(proxyName, interfaces, loader, methodsArray, 648 exceptionsArray); 649 } 650 } 651 } 652 653 /** 654 * Remove methods that have the same name, parameters and return type. This 655 * computes the exceptions of each method; this is the intersection of the 656 * exceptions of equivalent methods. 657 * 658 * @param methods the methods to find exceptions for, ordered by name and 659 * signature. 660 */ deduplicateAndGetExceptions(List<Method> methods)661 private static List<Class<?>[]> deduplicateAndGetExceptions(List<Method> methods) { 662 List<Class<?>[]> exceptions = new ArrayList<Class<?>[]>(methods.size()); 663 664 for (int i = 0; i < methods.size(); ) { 665 Method method = methods.get(i); 666 Class<?>[] exceptionTypes = method.getExceptionTypes(); 667 668 if (i > 0 && Method.ORDER_BY_SIGNATURE.compare(method, methods.get(i - 1)) == 0) { 669 exceptions.set(i - 1, intersectExceptions(exceptions.get(i - 1), exceptionTypes)); 670 methods.remove(i); 671 } else { 672 exceptions.add(exceptionTypes); 673 i++; 674 } 675 } 676 return exceptions; 677 } 678 679 /** 680 * Returns the exceptions that are declared in both {@code aExceptions} and 681 * {@code bExceptions}. If an exception type in one array is a subtype of an 682 * exception from the other, the subtype is included in the intersection. 683 */ intersectExceptions(Class<?>[] aExceptions, Class<?>[] bExceptions)684 private static Class<?>[] intersectExceptions(Class<?>[] aExceptions, Class<?>[] bExceptions) { 685 if (aExceptions.length == 0 || bExceptions.length == 0) { 686 return EmptyArray.CLASS; 687 } 688 if (Arrays.equals(aExceptions, bExceptions)) { 689 return aExceptions; 690 } 691 Set<Class<?>> intersection = new HashSet<Class<?>>(); 692 for (Class<?> a : aExceptions) { 693 for (Class<?> b : bExceptions) { 694 if (a.isAssignableFrom(b)) { 695 intersection.add(b); 696 } else if (b.isAssignableFrom(a)) { 697 intersection.add(a); 698 } 699 } 700 } 701 return intersection.toArray(new Class<?>[intersection.size()]); 702 } 703 704 /** 705 * Throws if any two methods in {@code methods} have the same name and 706 * parameters but incompatible return types. 707 * 708 * @param methods the methods to find exceptions for, ordered by name and 709 * signature. 710 */ validateReturnTypes(List<Method> methods)711 private static void validateReturnTypes(List<Method> methods) { 712 Method vs = null; 713 for (Method method : methods) { 714 if (vs == null || !vs.equalNameAndParameters(method)) { 715 vs = method; // this has a different name or parameters 716 continue; 717 } 718 Class<?> returnType = method.getReturnType(); 719 Class<?> vsReturnType = vs.getReturnType(); 720 if (returnType.isInterface() && vsReturnType.isInterface()) { 721 // all interfaces are mutually compatible 722 } else if (vsReturnType.isAssignableFrom(returnType)) { 723 vs = method; // the new return type is a subtype; use it instead 724 } else if (!returnType.isAssignableFrom(vsReturnType)) { 725 throw new IllegalArgumentException("proxied interface methods have incompatible " 726 + "return types:\n " + vs + "\n " + method); 727 } 728 } 729 } 730 getMethods(Class<?>[] interfaces)731 private static List<Method> getMethods(Class<?>[] interfaces) { 732 List<Method> result = new ArrayList<Method>(); 733 try { 734 result.add(Object.class.getMethod("equals", Object.class)); 735 result.add(Object.class.getMethod("hashCode", EmptyArray.CLASS)); 736 result.add(Object.class.getMethod("toString", EmptyArray.CLASS)); 737 } catch (NoSuchMethodException e) { 738 throw new AssertionError(); 739 } 740 741 getMethodsRecursive(interfaces, result); 742 return result; 743 } 744 745 /** 746 * Fills {@code proxiedMethods} with the methods of {@code interfaces} and 747 * the interfaces they extend. May contain duplicates. 748 */ getMethodsRecursive(Class<?>[] interfaces, List<Method> methods)749 private static void getMethodsRecursive(Class<?>[] interfaces, List<Method> methods) { 750 for (Class<?> i : interfaces) { 751 getMethodsRecursive(i.getInterfaces(), methods); 752 Collections.addAll(methods, i.getDeclaredMethods()); 753 } 754 } 755 756 757 /** 758 * Returns an instance of a proxy class for the specified interfaces 759 * that dispatches method invocations to the specified invocation 760 * handler. 761 * 762 * <p>{@code Proxy.newProxyInstance} throws 763 * {@code IllegalArgumentException} for the same reasons that 764 * {@code Proxy.getProxyClass} does. 765 * 766 * @param loader the class loader to define the proxy class 767 * @param interfaces the list of interfaces for the proxy class 768 * to implement 769 * @param h the invocation handler to dispatch method invocations to 770 * @return a proxy instance with the specified invocation handler of a 771 * proxy class that is defined by the specified class loader 772 * and that implements the specified interfaces 773 * @throws IllegalArgumentException if any of the restrictions on the 774 * parameters that may be passed to {@code getProxyClass} 775 * are violated 776 * @throws SecurityException if a security manager, <em>s</em>, is present 777 * and any of the following conditions is met: 778 * <ul> 779 * <li> the given {@code loader} is {@code null} and 780 * the caller's class loader is not {@code null} and the 781 * invocation of {@link SecurityManager#checkPermission 782 * s.checkPermission} with 783 * {@code RuntimePermission("getClassLoader")} permission 784 * denies access;</li> 785 * <li> for each proxy interface, {@code intf}, 786 * the caller's class loader is not the same as or an 787 * ancestor of the class loader for {@code intf} and 788 * invocation of {@link SecurityManager#checkPackageAccess 789 * s.checkPackageAccess()} denies access to {@code intf};</li> 790 * <li> any of the given proxy interfaces is non-public and the 791 * caller class is not in the same {@linkplain Package runtime package} 792 * as the non-public interface and the invocation of 793 * {@link SecurityManager#checkPermission s.checkPermission} with 794 * {@code ReflectPermission("newProxyInPackage.{package name}")} 795 * permission denies access.</li> 796 * </ul> 797 * @throws NullPointerException if the {@code interfaces} array 798 * argument or any of its elements are {@code null}, or 799 * if the invocation handler, {@code h}, is 800 * {@code null} 801 */ 802 @CallerSensitive newProxyInstance(ClassLoader loader, Class<?>[] interfaces, InvocationHandler h)803 public static Object newProxyInstance(ClassLoader loader, 804 Class<?>[] interfaces, 805 InvocationHandler h) 806 throws IllegalArgumentException 807 { 808 Objects.requireNonNull(h); 809 810 final Class<?>[] intfs = interfaces.clone(); 811 // Android-changed: sm is always null 812 // final SecurityManager sm = System.getSecurityManager(); 813 // if (sm != null) { 814 // checkProxyAccess(Reflection.getCallerClass(), loader, intfs); 815 // } 816 817 /* 818 * Look up or generate the designated proxy class. 819 */ 820 Class<?> cl = getProxyClass0(loader, intfs); 821 822 /* 823 * Invoke its constructor with the designated invocation handler. 824 */ 825 try { 826 // Android-changed: sm is always null 827 // if (sm != null) { 828 // checkNewProxyPermission(Reflection.getCallerClass(), cl); 829 // } 830 831 final Constructor<?> cons = cl.getConstructor(constructorParams); 832 final InvocationHandler ih = h; 833 if (!Modifier.isPublic(cl.getModifiers())) { 834 // Android-changed: Removed AccessController.doPrivileged 835 cons.setAccessible(true); 836 } 837 return cons.newInstance(new Object[]{h}); 838 } catch (IllegalAccessException|InstantiationException e) { 839 throw new InternalError(e.toString(), e); 840 } catch (InvocationTargetException e) { 841 Throwable t = e.getCause(); 842 if (t instanceof RuntimeException) { 843 throw (RuntimeException) t; 844 } else { 845 throw new InternalError(t.toString(), t); 846 } 847 } catch (NoSuchMethodException e) { 848 throw new InternalError(e.toString(), e); 849 } 850 } 851 852 /** 853 * Returns true if and only if the specified class was dynamically 854 * generated to be a proxy class using the {@code getProxyClass} 855 * method or the {@code newProxyInstance} method. 856 * 857 * <p>The reliability of this method is important for the ability 858 * to use it to make security decisions, so its implementation should 859 * not just test if the class in question extends {@code Proxy}. 860 * 861 * @param cl the class to test 862 * @return {@code true} if the class is a proxy class and 863 * {@code false} otherwise 864 * @throws NullPointerException if {@code cl} is {@code null} 865 */ isProxyClass(Class<?> cl)866 public static boolean isProxyClass(Class<?> cl) { 867 return Proxy.class.isAssignableFrom(cl) && proxyClassCache.containsValue(cl); 868 } 869 870 /** 871 * Returns the invocation handler for the specified proxy instance. 872 * 873 * @param proxy the proxy instance to return the invocation handler for 874 * @return the invocation handler for the proxy instance 875 * @throws IllegalArgumentException if the argument is not a 876 * proxy instance 877 * @throws SecurityException if a security manager, <em>s</em>, is present 878 * and the caller's class loader is not the same as or an 879 * ancestor of the class loader for the invocation handler 880 * and invocation of {@link SecurityManager#checkPackageAccess 881 * s.checkPackageAccess()} denies access to the invocation 882 * handler's class. 883 */ 884 @CallerSensitive getInvocationHandler(Object proxy)885 public static InvocationHandler getInvocationHandler(Object proxy) 886 throws IllegalArgumentException 887 { 888 /* 889 * Verify that the object is actually a proxy instance. 890 */ 891 if (!isProxyClass(proxy.getClass())) { 892 throw new IllegalArgumentException("not a proxy instance"); 893 } 894 895 final Proxy p = (Proxy) proxy; 896 final InvocationHandler ih = p.h; 897 // Android-changed, System.getSecurityManager() is always null 898 // if (System.getSecurityManager() != null) { 899 // Class<?> ihClass = ih.getClass(); 900 // Class<?> caller = Reflection.getCallerClass(); 901 // if (ReflectUtil.needsPackageAccessCheck(caller.getClassLoader(), 902 // ihClass.getClassLoader())) 903 // { 904 // ReflectUtil.checkPackageAccess(ihClass); 905 // } 906 // } 907 return ih; 908 } 909 910 // Android-changed: helper for art native code. invoke(Proxy proxy, Method method, Object[] args)911 private static Object invoke(Proxy proxy, Method method, Object[] args) throws Throwable { 912 InvocationHandler h = proxy.h; 913 return h.invoke(proxy, method, args); 914 } 915 916 @FastNative generateProxy(String name, Class<?>[] interfaces, ClassLoader loader, Method[] methods, Class<?>[][] exceptions)917 private static native Class<?> generateProxy(String name, Class<?>[] interfaces, 918 ClassLoader loader, Method[] methods, 919 Class<?>[][] exceptions); 920 921 // Temporary methods. reserved1()922 private static void reserved1() {}; reserved2()923 private static void reserved2() {}; 924 } 925