1 /*
   2  * Copyright (c) 1994, 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.lang.annotation.Annotation;
  29 import java.lang.module.ModuleReader;
  30 import java.lang.ref.SoftReference;
  31 import java.io.IOException;
  32 import java.io.InputStream;
  33 import java.io.ObjectStreamField;
  34 import java.lang.reflect.AnnotatedElement;
  35 import java.lang.reflect.AnnotatedType;
  36 import java.lang.reflect.Array;
  37 import java.lang.reflect.Constructor;
  38 import java.lang.reflect.Executable;
  39 import java.lang.reflect.Field;
  40 import java.lang.reflect.GenericArrayType;
  41 import java.lang.reflect.GenericDeclaration;
  42 import java.lang.reflect.InvocationTargetException;
  43 import java.lang.reflect.Member;
  44 import java.lang.reflect.Method;
  45 import java.lang.reflect.Modifier;
  46 import java.lang.reflect.Proxy;
  47 import java.lang.reflect.Type;
  48 import java.lang.reflect.TypeVariable;
  49 import java.net.URL;
  50 import java.security.AccessController;
  51 import java.security.PrivilegedAction;
  52 import java.util.ArrayList;
  53 import java.util.Collection;
  54 import java.util.HashMap;
  55 import java.util.HashSet;
  56 import java.util.LinkedHashMap;
  57 import java.util.List;
  58 import java.util.Map;
  59 import java.util.Objects;
  60 import java.util.Set;
  61 import java.util.StringJoiner;
  62 
  63 import jdk.internal.HotSpotIntrinsicCandidate;
  64 import jdk.internal.loader.BootLoader;
  65 import jdk.internal.loader.BuiltinClassLoader;
  66 import jdk.internal.misc.Unsafe;
  67 import jdk.internal.misc.VM;
  68 import jdk.internal.module.Resources;
  69 import jdk.internal.reflect.CallerSensitive;
  70 import jdk.internal.reflect.ConstantPool;
  71 import jdk.internal.reflect.Reflection;
  72 import jdk.internal.reflect.ReflectionFactory;
  73 import jdk.internal.vm.annotation.ForceInline;
  74 import sun.reflect.generics.factory.CoreReflectionFactory;
  75 import sun.reflect.generics.factory.GenericsFactory;
  76 import sun.reflect.generics.repository.ClassRepository;
  77 import sun.reflect.generics.repository.MethodRepository;
  78 import sun.reflect.generics.repository.ConstructorRepository;
  79 import sun.reflect.generics.scope.ClassScope;
  80 import sun.security.util.SecurityConstants;
  81 import sun.reflect.annotation.*;
  82 import sun.reflect.misc.ReflectUtil;
  83 
  84 /**
  85  * Instances of the class {@code Class} represent classes and
  86  * interfaces in a running Java application.  An enum is a kind of
  87  * class and an annotation is a kind of interface.  Every array also
  88  * belongs to a class that is reflected as a {@code Class} object
  89  * that is shared by all arrays with the same element type and number
  90  * of dimensions.  The primitive Java types ({@code boolean},
  91  * {@code byte}, {@code char}, {@code short},
  92  * {@code int}, {@code long}, {@code float}, and
  93  * {@code double}), and the keyword {@code void} are also
  94  * represented as {@code Class} objects.
  95  *
  96  * <p> {@code Class} has no public constructor. Instead {@code Class}
  97  * objects are constructed automatically by the Java Virtual Machine as classes
  98  * are loaded and by calls to the {@code defineClass} method in the class
  99  * loader.
 100  *
 101  * <p> The following example uses a {@code Class} object to print the
 102  * class name of an object:
 103  *
 104  * <blockquote><pre>
 105  *     void printClassName(Object obj) {
 106  *         System.out.println("The class of " + obj +
 107  *                            " is " + obj.getClass().getName());
 108  *     }
 109  * </pre></blockquote>
 110  *
 111  * <p> It is also possible to get the {@code Class} object for a named
 112  * type (or for void) using a class literal.  See Section 15.8.2 of
 113  * <cite>The Java&trade; Language Specification</cite>.
 114  * For example:
 115  *
 116  * <blockquote>
 117  *     {@code System.out.println("The name of class Foo is: "+Foo.class.getName());}
 118  * </blockquote>
 119  *
 120  * @param <T> the type of the class modeled by this {@code Class}
 121  * object.  For example, the type of {@code String.class} is {@code
 122  * Class<String>}.  Use {@code Class<?>} if the class being modeled is
 123  * unknown.
 124  *
 125  * @author  unascribed
 126  * @see     java.lang.ClassLoader#defineClass(byte[], int, int)
 127  * @since   1.0
 128  */
 129 public final class Class<T> implements java.io.Serializable,
 130                               GenericDeclaration,
 131                               Type,
 132                               AnnotatedElement {
 133     private static final int ANNOTATION= 0x00002000;
 134     private static final int ENUM      = 0x00004000;
 135     private static final int SYNTHETIC = 0x00001000;
 136 
 137     private static native void registerNatives();
 138     static {
 139         registerNatives();
 140     }
 141 
 142     /*
 143      * Private constructor. Only the Java Virtual Machine creates Class objects.
 144      * This constructor is not used and prevents the default constructor being
 145      * generated.
 146      */
 147     private Class(ClassLoader loader, Class<?> arrayComponentType) {
 148         // Initialize final field for classLoader.  The initialization value of non-null
 149         // prevents future JIT optimizations from assuming this final field is null.
 150         classLoader = loader;
 151         componentType = arrayComponentType;
 152     }
 153 
 154     /**
 155      * Converts the object to a string. The string representation is the
 156      * string "class" or "interface", followed by a space, and then by the
 157      * fully qualified name of the class in the format returned by
 158      * {@code getName}.  If this {@code Class} object represents a
 159      * primitive type, this method returns the name of the primitive type.  If
 160      * this {@code Class} object represents void this method returns
 161      * "void". If this {@code Class} object represents an array type,
 162      * this method returns "class " followed by {@code getName}.
 163      *
 164      * @return a string representation of this class object.
 165      */
 166     public String toString() {
 167         return (isInterface() ? "interface " : (isPrimitive() ? "" : "class "))
 168             + getName();
 169     }
 170 
 171     /**
 172      * Returns a string describing this {@code Class}, including
 173      * information about modifiers and type parameters.
 174      *
 175      * The string is formatted as a list of type modifiers, if any,
 176      * followed by the kind of type (empty string for primitive types
 177      * and {@code class}, {@code enum}, {@code interface}, or
 178      * <code>@</code>{@code interface}, as appropriate), followed
 179      * by the type's name, followed by an angle-bracketed
 180      * comma-separated list of the type's type parameters, if any.
 181      *
 182      * A space is used to separate modifiers from one another and to
 183      * separate any modifiers from the kind of type. The modifiers
 184      * occur in canonical order. If there are no type parameters, the
 185      * type parameter list is elided.
 186      *
 187      * For an array type, the string starts with the type name,
 188      * followed by an angle-bracketed comma-separated list of the
 189      * type's type parameters, if any, followed by a sequence of
 190      * {@code []} characters, one set of brackets per dimension of
 191      * the array.
 192      *
 193      * <p>Note that since information about the runtime representation
 194      * of a type is being generated, modifiers not present on the
 195      * originating source code or illegal on the originating source
 196      * code may be present.
 197      *
 198      * @return a string describing this {@code Class}, including
 199      * information about modifiers and type parameters
 200      *
 201      * @since 1.8
 202      */
 203     public String toGenericString() {
 204         if (isPrimitive()) {
 205             return toString();
 206         } else {
 207             StringBuilder sb = new StringBuilder();
 208             Class<?> component = this;
 209             int arrayDepth = 0;
 210 
 211             if (isArray()) {
 212                 do {
 213                     arrayDepth++;
 214                     component = component.getComponentType();
 215                 } while (component.isArray());
 216                 sb.append(component.getName());
 217             } else {
 218                 // Class modifiers are a superset of interface modifiers
 219                 int modifiers = getModifiers() & Modifier.classModifiers();
 220                 if (modifiers != 0) {
 221                     sb.append(Modifier.toString(modifiers));
 222                     sb.append(' ');
 223                 }
 224 
 225                 if (isAnnotation()) {
 226                     sb.append('@');
 227                 }
 228                 if (isInterface()) { // Note: all annotation types are interfaces
 229                     sb.append("interface");
 230                 } else {
 231                     if (isEnum())
 232                         sb.append("enum");
 233                     else
 234                         sb.append("class");
 235                 }
 236                 sb.append(' ');
 237                 sb.append(getName());
 238             }
 239 
 240             TypeVariable<?>[] typeparms = component.getTypeParameters();
 241             if (typeparms.length > 0) {
 242                 StringJoiner sj = new StringJoiner(",", "<", ">");
 243                 for(TypeVariable<?> typeparm: typeparms) {
 244                     sj.add(typeparm.getTypeName());
 245                 }
 246                 sb.append(sj.toString());
 247             }
 248 
 249             for (int i = 0; i < arrayDepth; i++)
 250                 sb.append("[]");
 251 
 252             return sb.toString();
 253         }
 254     }
 255 
 256     /**
 257      * Returns the {@code Class} object associated with the class or
 258      * interface with the given string name.  Invoking this method is
 259      * equivalent to:
 260      *
 261      * <blockquote>
 262      *  {@code Class.forName(className, true, currentLoader)}
 263      * </blockquote>
 264      *
 265      * where {@code currentLoader} denotes the defining class loader of
 266      * the current class.
 267      *
 268      * <p> For example, the following code fragment returns the
 269      * runtime {@code Class} descriptor for the class named
 270      * {@code java.lang.Thread}:
 271      *
 272      * <blockquote>
 273      *   {@code Class t = Class.forName("java.lang.Thread")}
 274      * </blockquote>
 275      * <p>
 276      * A call to {@code forName("X")} causes the class named
 277      * {@code X} to be initialized.
 278      *
 279      * @param      className   the fully qualified name of the desired class.
 280      * @return     the {@code Class} object for the class with the
 281      *             specified name.
 282      * @exception LinkageError if the linkage fails
 283      * @exception ExceptionInInitializerError if the initialization provoked
 284      *            by this method fails
 285      * @exception ClassNotFoundException if the class cannot be located
 286      */
 287     @CallerSensitive
 288     public static Class<?> forName(String className)
 289                 throws ClassNotFoundException {
 290         Class<?> caller = Reflection.getCallerClass();
 291         return forName0(className, true, ClassLoader.getClassLoader(caller), caller);
 292     }
 293 
 294 
 295     /**
 296      * Returns the {@code Class} object associated with the class or
 297      * interface with the given string name, using the given class loader.
 298      * Given the fully qualified name for a class or interface (in the same
 299      * format returned by {@code getName}) this method attempts to
 300      * locate, load, and link the class or interface.  The specified class
 301      * loader is used to load the class or interface.  If the parameter
 302      * {@code loader} is null, the class is loaded through the bootstrap
 303      * class loader.  The class is initialized only if the
 304      * {@code initialize} parameter is {@code true} and if it has
 305      * not been initialized earlier.
 306      *
 307      * <p> If {@code name} denotes a primitive type or void, an attempt
 308      * will be made to locate a user-defined class in the unnamed package whose
 309      * name is {@code name}. Therefore, this method cannot be used to
 310      * obtain any of the {@code Class} objects representing primitive
 311      * types or void.
 312      *
 313      * <p> If {@code name} denotes an array class, the component type of
 314      * the array class is loaded but not initialized.
 315      *
 316      * <p> For example, in an instance method the expression:
 317      *
 318      * <blockquote>
 319      *  {@code Class.forName("Foo")}
 320      * </blockquote>
 321      *
 322      * is equivalent to:
 323      *
 324      * <blockquote>
 325      *  {@code Class.forName("Foo", true, this.getClass().getClassLoader())}
 326      * </blockquote>
 327      *
 328      * Note that this method throws errors related to loading, linking or
 329      * initializing as specified in Sections 12.2, 12.3 and 12.4 of <em>The
 330      * Java Language Specification</em>.
 331      * Note that this method does not check whether the requested class
 332      * is accessible to its caller.
 333      *
 334      * @param name       fully qualified name of the desired class
 335      * @param initialize if {@code true} the class will be initialized.
 336      *                   See Section 12.4 of <em>The Java Language Specification</em>.
 337      * @param loader     class loader from which the class must be loaded
 338      * @return           class object representing the desired class
 339      *
 340      * @exception LinkageError if the linkage fails
 341      * @exception ExceptionInInitializerError if the initialization provoked
 342      *            by this method fails
 343      * @exception ClassNotFoundException if the class cannot be located by
 344      *            the specified class loader
 345      * @exception SecurityException
 346      *            if a security manager is present, and the {@code loader} is
 347      *            {@code null}, and the caller's class loader is not
 348      *            {@code null}, and the caller does not have the
 349      *            {@link RuntimePermission}{@code ("getClassLoader")}
 350      *
 351      * @see       java.lang.Class#forName(String)
 352      * @see       java.lang.ClassLoader
 353      * @since     1.2
 354      */
 355     @CallerSensitive
 356     public static Class<?> forName(String name, boolean initialize,
 357                                    ClassLoader loader)
 358         throws ClassNotFoundException
 359     {
 360         Class<?> caller = null;
 361         SecurityManager sm = System.getSecurityManager();
 362         if (sm != null) {
 363             // Reflective call to get caller class is only needed if a security manager
 364             // is present.  Avoid the overhead of making this call otherwise.
 365             caller = Reflection.getCallerClass();
 366             if (VM.isSystemDomainLoader(loader)) {
 367                 ClassLoader ccl = ClassLoader.getClassLoader(caller);
 368                 if (!VM.isSystemDomainLoader(ccl)) {
 369                     sm.checkPermission(
 370                         SecurityConstants.GET_CLASSLOADER_PERMISSION);
 371                 }
 372             }
 373         }
 374         return forName0(name, initialize, loader, caller);
 375     }
 376 
 377     /** Called after security check for system loader access checks have been made. */
 378     private static native Class<?> forName0(String name, boolean initialize,
 379                                             ClassLoader loader,
 380                                             Class<?> caller)
 381         throws ClassNotFoundException;
 382 
 383 
 384     /**
 385      * Returns the {@code Class} with the given <a href="ClassLoader.html#name">
 386      * binary name</a> in the given module.
 387      *
 388      * <p> This method attempts to locate, load, and link the class or interface.
 389      * It does not run the class initializer.  If the class is not found, this
 390      * method returns {@code null}. </p>
 391      *
 392      * <p> If the class loader of the given module defines other modules and
 393      * the given name is a class defined in a different module, this method
 394      * returns {@code null} after the class is loaded. </p>
 395      *
 396      * <p> This method does not check whether the requested class is
 397      * accessible to its caller. </p>
 398      *
 399      * @apiNote
 400      * This method returns {@code null} on failure rather than
 401      * throwing a {@link ClassNotFoundException}, as is done by
 402      * the {@link #forName(String, boolean, ClassLoader)} method.
 403      * The security check is a stack-based permission check if the caller
 404      * loads a class in another module.
 405      *
 406      * @param  module   A module
 407      * @param  name     The <a href="ClassLoader.html#name">binary name</a>
 408      *                  of the class
 409      * @return {@code Class} object of the given name defined in the given module;
 410      *         {@code null} if not found.
 411      *
 412      * @throws NullPointerException if the given module or name is {@code null}
 413      *
 414      * @throws LinkageError if the linkage fails
 415      *
 416      * @throws SecurityException
 417      *         <ul>
 418      *         <li> if the caller is not the specified module and
 419      *         {@code RuntimePermission("getClassLoader")} permission is denied; or</li>
 420      *         <li> access to the module content is denied. For example,
 421      *         permission check will be performed when a class loader calls
 422      *         {@link ModuleReader#open(String)} to read the bytes of a class file
 423      *         in a module.</li>
 424      *         </ul>
 425      *
 426      * @since 9
 427      * @spec JPMS
 428      */
 429     @CallerSensitive
 430     public static Class<?> forName(Module module, String name) {
 431         Objects.requireNonNull(module);
 432         Objects.requireNonNull(name);
 433 
 434         Class<?> caller = Reflection.getCallerClass();
 435         if (caller != null && caller.getModule() != module) {
 436             // if caller is null, Class.forName is the last java frame on the stack.
 437             // java.base has all permissions
 438             SecurityManager sm = System.getSecurityManager();
 439             if (sm != null) {
 440                 sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);
 441             }
 442         }
 443 
 444         PrivilegedAction<ClassLoader> pa = module::getClassLoader;
 445         ClassLoader cl = AccessController.doPrivileged(pa);
 446         if (cl != null) {
 447             return cl.loadClass(module, name);
 448         } else {
 449             return BootLoader.loadClass(module, name);
 450         }
 451     }
 452 
 453     /**
 454      * Creates a new instance of the class represented by this {@code Class}
 455      * object.  The class is instantiated as if by a {@code new}
 456      * expression with an empty argument list.  The class is initialized if it
 457      * has not already been initialized.
 458      *
 459      * @deprecated This method propagates any exception thrown by the
 460      * nullary constructor, including a checked exception.  Use of
 461      * this method effectively bypasses the compile-time exception
 462      * checking that would otherwise be performed by the compiler.
 463      * The {@link
 464      * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
 465      * Constructor.newInstance} method avoids this problem by wrapping
 466      * any exception thrown by the constructor in a (checked) {@link
 467      * java.lang.reflect.InvocationTargetException}.
 468      *
 469      * <p>The call
 470      *
 471      * <pre>{@code
 472      * clazz.newInstance()
 473      * }</pre>
 474      *
 475      * can be replaced by
 476      *
 477      * <pre>{@code
 478      * clazz.getDeclaredConstructor().newInstance()
 479      * }</pre>
 480      *
 481      * The latter sequence of calls is inferred to be able to throw
 482      * the additional exception types {@link
 483      * InvocationTargetException} and {@link
 484      * NoSuchMethodException}. Both of these exception types are
 485      * subclasses of {@link ReflectiveOperationException}.
 486      *
 487      * @return  a newly allocated instance of the class represented by this
 488      *          object.
 489      * @throws  IllegalAccessException  if the class or its nullary
 490      *          constructor is not accessible.
 491      * @throws  InstantiationException
 492      *          if this {@code Class} represents an abstract class,
 493      *          an interface, an array class, a primitive type, or void;
 494      *          or if the class has no nullary constructor;
 495      *          or if the instantiation fails for some other reason.
 496      * @throws  ExceptionInInitializerError if the initialization
 497      *          provoked by this method fails.
 498      * @throws  SecurityException
 499      *          If a security manager, <i>s</i>, is present and
 500      *          the caller's class loader is not the same as or an
 501      *          ancestor of the class loader for the current class and
 502      *          invocation of {@link SecurityManager#checkPackageAccess
 503      *          s.checkPackageAccess()} denies access to the package
 504      *          of this class.
 505      */
 506     @CallerSensitive
 507     @Deprecated(since="9")
 508     public T newInstance()
 509         throws InstantiationException, IllegalAccessException
 510     {
 511         SecurityManager sm = System.getSecurityManager();
 512         if (sm != null) {
 513             checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), false);
 514         }
 515 
 516         // NOTE: the following code may not be strictly correct under
 517         // the current Java memory model.
 518 
 519         // Constructor lookup
 520         if (cachedConstructor == null) {
 521             if (this == Class.class) {
 522                 throw new IllegalAccessException(
 523                     "Can not call newInstance() on the Class for java.lang.Class"
 524                 );
 525             }
 526             try {
 527                 Class<?>[] empty = {};
 528                 final Constructor<T> c = getReflectionFactory().copyConstructor(
 529                     getConstructor0(empty, Member.DECLARED));
 530                 // Disable accessibility checks on the constructor
 531                 // since we have to do the security check here anyway
 532                 // (the stack depth is wrong for the Constructor's
 533                 // security check to work)
 534                 java.security.AccessController.doPrivileged(
 535                     new java.security.PrivilegedAction<>() {
 536                         public Void run() {
 537                                 c.setAccessible(true);
 538                                 return null;
 539                             }
 540                         });
 541                 cachedConstructor = c;
 542             } catch (NoSuchMethodException e) {
 543                 throw (InstantiationException)
 544                     new InstantiationException(getName()).initCause(e);
 545             }
 546         }
 547         Constructor<T> tmpConstructor = cachedConstructor;
 548         // Security check (same as in java.lang.reflect.Constructor)
 549         Class<?> caller = Reflection.getCallerClass();
 550         if (newInstanceCallerCache != caller) {
 551             int modifiers = tmpConstructor.getModifiers();
 552             Reflection.ensureMemberAccess(caller, this, this, modifiers);
 553             newInstanceCallerCache = caller;
 554         }
 555         // Run constructor
 556         try {
 557             return tmpConstructor.newInstance((Object[])null);
 558         } catch (InvocationTargetException e) {
 559             Unsafe.getUnsafe().throwException(e.getTargetException());
 560             // Not reached
 561             return null;
 562         }
 563     }
 564     private transient volatile Constructor<T> cachedConstructor;
 565     private transient volatile Class<?>       newInstanceCallerCache;
 566 
 567 
 568     /**
 569      * Determines if the specified {@code Object} is assignment-compatible
 570      * with the object represented by this {@code Class}.  This method is
 571      * the dynamic equivalent of the Java language {@code instanceof}
 572      * operator. The method returns {@code true} if the specified
 573      * {@code Object} argument is non-null and can be cast to the
 574      * reference type represented by this {@code Class} object without
 575      * raising a {@code ClassCastException.} It returns {@code false}
 576      * otherwise.
 577      *
 578      * <p> Specifically, if this {@code Class} object represents a
 579      * declared class, this method returns {@code true} if the specified
 580      * {@code Object} argument is an instance of the represented class (or
 581      * of any of its subclasses); it returns {@code false} otherwise. If
 582      * this {@code Class} object represents an array class, this method
 583      * returns {@code true} if the specified {@code Object} argument
 584      * can be converted to an object of the array class by an identity
 585      * conversion or by a widening reference conversion; it returns
 586      * {@code false} otherwise. If this {@code Class} object
 587      * represents an interface, this method returns {@code true} if the
 588      * class or any superclass of the specified {@code Object} argument
 589      * implements this interface; it returns {@code false} otherwise. If
 590      * this {@code Class} object represents a primitive type, this method
 591      * returns {@code false}.
 592      *
 593      * @param   obj the object to check
 594      * @return  true if {@code obj} is an instance of this class
 595      *
 596      * @since 1.1
 597      */
 598     @HotSpotIntrinsicCandidate
 599     public native boolean isInstance(Object obj);
 600 
 601 
 602     /**
 603      * Determines if the class or interface represented by this
 604      * {@code Class} object is either the same as, or is a superclass or
 605      * superinterface of, the class or interface represented by the specified
 606      * {@code Class} parameter. It returns {@code true} if so;
 607      * otherwise it returns {@code false}. If this {@code Class}
 608      * object represents a primitive type, this method returns
 609      * {@code true} if the specified {@code Class} parameter is
 610      * exactly this {@code Class} object; otherwise it returns
 611      * {@code false}.
 612      *
 613      * <p> Specifically, this method tests whether the type represented by the
 614      * specified {@code Class} parameter can be converted to the type
 615      * represented by this {@code Class} object via an identity conversion
 616      * or via a widening reference conversion. See <em>The Java Language
 617      * Specification</em>, sections 5.1.1 and 5.1.4 , for details.
 618      *
 619      * @param cls the {@code Class} object to be checked
 620      * @return the {@code boolean} value indicating whether objects of the
 621      * type {@code cls} can be assigned to objects of this class
 622      * @exception NullPointerException if the specified Class parameter is
 623      *            null.
 624      * @since 1.1
 625      */
 626     @HotSpotIntrinsicCandidate
 627     public native boolean isAssignableFrom(Class<?> cls);
 628 
 629 
 630     /**
 631      * Determines if the specified {@code Class} object represents an
 632      * interface type.
 633      *
 634      * @return  {@code true} if this object represents an interface;
 635      *          {@code false} otherwise.
 636      */
 637     @HotSpotIntrinsicCandidate
 638     public native boolean isInterface();
 639 
 640 
 641     /**
 642      * Determines if this {@code Class} object represents an array class.
 643      *
 644      * @return  {@code true} if this object represents an array class;
 645      *          {@code false} otherwise.
 646      * @since   1.1
 647      */
 648     @HotSpotIntrinsicCandidate
 649     public native boolean isArray();
 650 
 651 
 652     /**
 653      * Determines if the specified {@code Class} object represents a
 654      * primitive type.
 655      *
 656      * <p> There are nine predefined {@code Class} objects to represent
 657      * the eight primitive types and void.  These are created by the Java
 658      * Virtual Machine, and have the same names as the primitive types that
 659      * they represent, namely {@code boolean}, {@code byte},
 660      * {@code char}, {@code short}, {@code int},
 661      * {@code long}, {@code float}, and {@code double}.
 662      *
 663      * <p> These objects may only be accessed via the following public static
 664      * final variables, and are the only {@code Class} objects for which
 665      * this method returns {@code true}.
 666      *
 667      * @return true if and only if this class represents a primitive type
 668      *
 669      * @see     java.lang.Boolean#TYPE
 670      * @see     java.lang.Character#TYPE
 671      * @see     java.lang.Byte#TYPE
 672      * @see     java.lang.Short#TYPE
 673      * @see     java.lang.Integer#TYPE
 674      * @see     java.lang.Long#TYPE
 675      * @see     java.lang.Float#TYPE
 676      * @see     java.lang.Double#TYPE
 677      * @see     java.lang.Void#TYPE
 678      * @since 1.1
 679      */
 680     @HotSpotIntrinsicCandidate
 681     public native boolean isPrimitive();
 682 
 683     /**
 684      * Returns true if this {@code Class} object represents an annotation
 685      * type.  Note that if this method returns true, {@link #isInterface()}
 686      * would also return true, as all annotation types are also interfaces.
 687      *
 688      * @return {@code true} if this class object represents an annotation
 689      *      type; {@code false} otherwise
 690      * @since 1.5
 691      */
 692     public boolean isAnnotation() {
 693         return (getModifiers() & ANNOTATION) != 0;
 694     }
 695 
 696     /**
 697      * Returns {@code true} if this class is a synthetic class;
 698      * returns {@code false} otherwise.
 699      * @return {@code true} if and only if this class is a synthetic class as
 700      *         defined by the Java Language Specification.
 701      * @jls 13.1 The Form of a Binary
 702      * @since 1.5
 703      */
 704     public boolean isSynthetic() {
 705         return (getModifiers() & SYNTHETIC) != 0;
 706     }
 707 
 708     /**
 709      * Returns the  name of the entity (class, interface, array class,
 710      * primitive type, or void) represented by this {@code Class} object,
 711      * as a {@code String}.
 712      *
 713      * <p> If this class object represents a reference type that is not an
 714      * array type then the binary name of the class is returned, as specified
 715      * by
 716      * <cite>The Java&trade; Language Specification</cite>.
 717      *
 718      * <p> If this class object represents a primitive type or void, then the
 719      * name returned is a {@code String} equal to the Java language
 720      * keyword corresponding to the primitive type or void.
 721      *
 722      * <p> If this class object represents a class of arrays, then the internal
 723      * form of the name consists of the name of the element type preceded by
 724      * one or more '{@code [}' characters representing the depth of the array
 725      * nesting.  The encoding of element type names is as follows:
 726      *
 727      * <blockquote><table class="borderless">
 728      * <caption style="display:none">Element types and encodings</caption>
 729      * <thead>
 730      * <tr><th style="padding-right:3em;"> Element Type <th> Encoding
 731      * </thead>
 732      * <tbody>
 733      * <tr><td> boolean      <td style="text-align:center"> Z
 734      * <tr><td> byte         <td style="text-align:center"> B
 735      * <tr><td> char         <td style="text-align:center"> C
 736      * <tr><td> class or interface
 737      *                       <td style="text-align:center"> L<i>classname</i>;
 738      * <tr><td> double       <td style="text-align:center"> D
 739      * <tr><td> float        <td style="text-align:center"> F
 740      * <tr><td> int          <td style="text-align:center"> I
 741      * <tr><td> long         <td style="text-align:center"> J
 742      * <tr><td> short        <td style="text-align:center"> S
 743      * </tbody>
 744      * </table></blockquote>
 745      *
 746      * <p> The class or interface name <i>classname</i> is the binary name of
 747      * the class specified above.
 748      *
 749      * <p> Examples:
 750      * <blockquote><pre>
 751      * String.class.getName()
 752      *     returns "java.lang.String"
 753      * byte.class.getName()
 754      *     returns "byte"
 755      * (new Object[3]).getClass().getName()
 756      *     returns "[Ljava.lang.Object;"
 757      * (new int[3][4][5][6][7][8][9]).getClass().getName()
 758      *     returns "[[[[[[[I"
 759      * </pre></blockquote>
 760      *
 761      * @return  the name of the class or interface
 762      *          represented by this object.
 763      */
 764     public String getName() {
 765         String name = this.name;
 766         if (name == null)
 767             this.name = name = getName0();
 768         return name;
 769     }
 770 
 771     // cache the name to reduce the number of calls into the VM
 772     private transient String name;
 773     private native String getName0();
 774 
 775     /**
 776      * Returns the class loader for the class.  Some implementations may use
 777      * null to represent the bootstrap class loader. This method will return
 778      * null in such implementations if this class was loaded by the bootstrap
 779      * class loader.
 780      *
 781      * <p>If this object
 782      * represents a primitive type or void, null is returned.
 783      *
 784      * @return  the class loader that loaded the class or interface
 785      *          represented by this object.
 786      * @throws  SecurityException
 787      *          if a security manager is present, and the caller's class loader
 788      *          is not {@code null} and is not the same as or an ancestor of the
 789      *          class loader for the class whose class loader is requested,
 790      *          and the caller does not have the
 791      *          {@link RuntimePermission}{@code ("getClassLoader")}
 792      * @see java.lang.ClassLoader
 793      * @see SecurityManager#checkPermission
 794      * @see java.lang.RuntimePermission
 795      */
 796     @CallerSensitive
 797     @ForceInline // to ensure Reflection.getCallerClass optimization
 798     public ClassLoader getClassLoader() {
 799         ClassLoader cl = getClassLoader0();
 800         if (cl == null)
 801             return null;
 802         SecurityManager sm = System.getSecurityManager();
 803         if (sm != null) {
 804             ClassLoader.checkClassLoaderPermission(cl, Reflection.getCallerClass());
 805         }
 806         return cl;
 807     }
 808 
 809     // Package-private to allow ClassLoader access
 810     ClassLoader getClassLoader0() { return classLoader; }
 811 
 812     /**
 813      * Returns the module that this class or interface is a member of.
 814      *
 815      * If this class represents an array type then this method returns the
 816      * {@code Module} for the element type. If this class represents a
 817      * primitive type or void, then the {@code Module} object for the
 818      * {@code java.base} module is returned.
 819      *
 820      * If this class is in an unnamed module then the {@link
 821      * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
 822      * loader for this class is returned.
 823      *
 824      * @return the module that this class or interface is a member of
 825      *
 826      * @since 9
 827      * @spec JPMS
 828      */
 829     public Module getModule() {
 830         return module;
 831     }
 832 
 833     // set by VM
 834     private transient Module module;
 835 
 836     // Initialized in JVM not by private constructor
 837     // This field is filtered from reflection access, i.e. getDeclaredField
 838     // will throw NoSuchFieldException
 839     private final ClassLoader classLoader;
 840 
 841     /**
 842      * Returns an array of {@code TypeVariable} objects that represent the
 843      * type variables declared by the generic declaration represented by this
 844      * {@code GenericDeclaration} object, in declaration order.  Returns an
 845      * array of length 0 if the underlying generic declaration declares no type
 846      * variables.
 847      *
 848      * @return an array of {@code TypeVariable} objects that represent
 849      *     the type variables declared by this generic declaration
 850      * @throws java.lang.reflect.GenericSignatureFormatError if the generic
 851      *     signature of this generic declaration does not conform to
 852      *     the format specified in
 853      *     <cite>The Java&trade; Virtual Machine Specification</cite>
 854      * @since 1.5
 855      */
 856     @SuppressWarnings("unchecked")
 857     public TypeVariable<Class<T>>[] getTypeParameters() {
 858         ClassRepository info = getGenericInfo();
 859         if (info != null)
 860             return (TypeVariable<Class<T>>[])info.getTypeParameters();
 861         else
 862             return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
 863     }
 864 
 865 
 866     /**
 867      * Returns the {@code Class} representing the direct superclass of the
 868      * entity (class, interface, primitive type or void) represented by
 869      * this {@code Class}.  If this {@code Class} represents either the
 870      * {@code Object} class, an interface, a primitive type, or void, then
 871      * null is returned.  If this object represents an array class then the
 872      * {@code Class} object representing the {@code Object} class is
 873      * returned.
 874      *
 875      * @return the direct superclass of the class represented by this object
 876      */
 877     @HotSpotIntrinsicCandidate
 878     public native Class<? super T> getSuperclass();
 879 
 880 
 881     /**
 882      * Returns the {@code Type} representing the direct superclass of
 883      * the entity (class, interface, primitive type or void) represented by
 884      * this {@code Class}.
 885      *
 886      * <p>If the superclass is a parameterized type, the {@code Type}
 887      * object returned must accurately reflect the actual type
 888      * parameters used in the source code. The parameterized type
 889      * representing the superclass is created if it had not been
 890      * created before. See the declaration of {@link
 891      * java.lang.reflect.ParameterizedType ParameterizedType} for the
 892      * semantics of the creation process for parameterized types.  If
 893      * this {@code Class} represents either the {@code Object}
 894      * class, an interface, a primitive type, or void, then null is
 895      * returned.  If this object represents an array class then the
 896      * {@code Class} object representing the {@code Object} class is
 897      * returned.
 898      *
 899      * @throws java.lang.reflect.GenericSignatureFormatError if the generic
 900      *     class signature does not conform to the format specified in
 901      *     <cite>The Java&trade; Virtual Machine Specification</cite>
 902      * @throws TypeNotPresentException if the generic superclass
 903      *     refers to a non-existent type declaration
 904      * @throws java.lang.reflect.MalformedParameterizedTypeException if the
 905      *     generic superclass refers to a parameterized type that cannot be
 906      *     instantiated  for any reason
 907      * @return the direct superclass of the class represented by this object
 908      * @since 1.5
 909      */
 910     public Type getGenericSuperclass() {
 911         ClassRepository info = getGenericInfo();
 912         if (info == null) {
 913             return getSuperclass();
 914         }
 915 
 916         // Historical irregularity:
 917         // Generic signature marks interfaces with superclass = Object
 918         // but this API returns null for interfaces
 919         if (isInterface()) {
 920             return null;
 921         }
 922 
 923         return info.getSuperclass();
 924     }
 925 
 926     /**
 927      * Gets the package of this class.
 928      *
 929      * <p>If this class represents an array type, a primitive type or void,
 930      * this method returns {@code null}.
 931      *
 932      * @return the package of this class.
 933      * @revised 9
 934      * @spec JPMS
 935      */
 936     public Package getPackage() {
 937         if (isPrimitive() || isArray()) {
 938             return null;
 939         }
 940         ClassLoader cl = getClassLoader0();
 941         return cl != null ? cl.definePackage(this)
 942                           : BootLoader.definePackage(this);
 943     }
 944 
 945     /**
 946      * Returns the fully qualified package name.
 947      *
 948      * <p> If this class is a top level class, then this method returns the fully
 949      * qualified name of the package that the class is a member of, or the
 950      * empty string if the class is in an unnamed package.
 951      *
 952      * <p> If this class is a member class, then this method is equivalent to
 953      * invoking {@code getPackageName()} on the {@link #getEnclosingClass
 954      * enclosing class}.
 955      *
 956      * <p> If this class is a {@link #isLocalClass local class} or an {@link
 957      * #isAnonymousClass() anonymous class}, then this method is equivalent to
 958      * invoking {@code getPackageName()} on the {@link #getDeclaringClass
 959      * declaring class} of the {@link #getEnclosingMethod enclosing method} or
 960      * {@link #getEnclosingConstructor enclosing constructor}.
 961      *
 962      * <p> If this class represents an array type then this method returns the
 963      * package name of the element type. If this class represents a primitive
 964      * type or void then the package name "{@code java.lang}" is returned.
 965      *
 966      * @return the fully qualified package name
 967      *
 968      * @since 9
 969      * @spec JPMS
 970      * @jls 6.7  Fully Qualified Names
 971      */
 972     public String getPackageName() {
 973         String pn = this.packageName;
 974         if (pn == null) {
 975             Class<?> c = this;
 976             while (c.isArray()) {
 977                 c = c.getComponentType();
 978             }
 979             if (c.isPrimitive()) {
 980                 pn = "java.lang";
 981             } else {
 982                 String cn = c.getName();
 983                 int dot = cn.lastIndexOf('.');
 984                 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
 985             }
 986             this.packageName = pn;
 987         }
 988         return pn;
 989     }
 990 
 991     // cached package name
 992     private transient String packageName;
 993 
 994     /**
 995      * Returns the interfaces directly implemented by the class or interface
 996      * represented by this object.
 997      *
 998      * <p>If this object represents a class, the return value is an array
 999      * containing objects representing all interfaces directly implemented by
1000      * the class.  The order of the interface objects in the array corresponds
1001      * to the order of the interface names in the {@code implements} clause of
1002      * the declaration of the class represented by this object.  For example,
1003      * given the declaration:
1004      * <blockquote>
1005      * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1006      * </blockquote>
1007      * suppose the value of {@code s} is an instance of
1008      * {@code Shimmer}; the value of the expression:
1009      * <blockquote>
1010      * {@code s.getClass().getInterfaces()[0]}
1011      * </blockquote>
1012      * is the {@code Class} object that represents interface
1013      * {@code FloorWax}; and the value of:
1014      * <blockquote>
1015      * {@code s.getClass().getInterfaces()[1]}
1016      * </blockquote>
1017      * is the {@code Class} object that represents interface
1018      * {@code DessertTopping}.
1019      *
1020      * <p>If this object represents an interface, the array contains objects
1021      * representing all interfaces directly extended by the interface.  The
1022      * order of the interface objects in the array corresponds to the order of
1023      * the interface names in the {@code extends} clause of the declaration of
1024      * the interface represented by this object.
1025      *
1026      * <p>If this object represents a class or interface that implements no
1027      * interfaces, the method returns an array of length 0.
1028      *
1029      * <p>If this object represents a primitive type or void, the method
1030      * returns an array of length 0.
1031      *
1032      * <p>If this {@code Class} object represents an array type, the
1033      * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1034      * returned in that order.
1035      *
1036      * @return an array of interfaces directly implemented by this class
1037      */
1038     public Class<?>[] getInterfaces() {
1039         // defensively copy before handing over to user code
1040         return getInterfaces(true);
1041     }
1042 
1043     private Class<?>[] getInterfaces(boolean cloneArray) {
1044         ReflectionData<T> rd = reflectionData();
1045         if (rd == null) {
1046             // no cloning required
1047             return getInterfaces0();
1048         } else {
1049             Class<?>[] interfaces = rd.interfaces;
1050             if (interfaces == null) {
1051                 interfaces = getInterfaces0();
1052                 rd.interfaces = interfaces;
1053             }
1054             // defensively copy if requested
1055             return cloneArray ? interfaces.clone() : interfaces;
1056         }
1057     }
1058 
1059     private native Class<?>[] getInterfaces0();
1060 
1061     /**
1062      * Returns the {@code Type}s representing the interfaces
1063      * directly implemented by the class or interface represented by
1064      * this object.
1065      *
1066      * <p>If a superinterface is a parameterized type, the
1067      * {@code Type} object returned for it must accurately reflect
1068      * the actual type parameters used in the source code. The
1069      * parameterized type representing each superinterface is created
1070      * if it had not been created before. See the declaration of
1071      * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1072      * for the semantics of the creation process for parameterized
1073      * types.
1074      *
1075      * <p>If this object represents a class, the return value is an array
1076      * containing objects representing all interfaces directly implemented by
1077      * the class.  The order of the interface objects in the array corresponds
1078      * to the order of the interface names in the {@code implements} clause of
1079      * the declaration of the class represented by this object.
1080      *
1081      * <p>If this object represents an interface, the array contains objects
1082      * representing all interfaces directly extended by the interface.  The
1083      * order of the interface objects in the array corresponds to the order of
1084      * the interface names in the {@code extends} clause of the declaration of
1085      * the interface represented by this object.
1086      *
1087      * <p>If this object represents a class or interface that implements no
1088      * interfaces, the method returns an array of length 0.
1089      *
1090      * <p>If this object represents a primitive type or void, the method
1091      * returns an array of length 0.
1092      *
1093      * <p>If this {@code Class} object represents an array type, the
1094      * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1095      * returned in that order.
1096      *
1097      * @throws java.lang.reflect.GenericSignatureFormatError
1098      *     if the generic class signature does not conform to the format
1099      *     specified in
1100      *     <cite>The Java&trade; Virtual Machine Specification</cite>
1101      * @throws TypeNotPresentException if any of the generic
1102      *     superinterfaces refers to a non-existent type declaration
1103      * @throws java.lang.reflect.MalformedParameterizedTypeException
1104      *     if any of the generic superinterfaces refer to a parameterized
1105      *     type that cannot be instantiated for any reason
1106      * @return an array of interfaces directly implemented by this class
1107      * @since 1.5
1108      */
1109     public Type[] getGenericInterfaces() {
1110         ClassRepository info = getGenericInfo();
1111         return (info == null) ?  getInterfaces() : info.getSuperInterfaces();
1112     }
1113 
1114 
1115     /**
1116      * Returns the {@code Class} representing the component type of an
1117      * array.  If this class does not represent an array class this method
1118      * returns null.
1119      *
1120      * @return the {@code Class} representing the component type of this
1121      * class if this class is an array
1122      * @see     java.lang.reflect.Array
1123      * @since 1.1
1124      */
1125     public Class<?> getComponentType() {
1126         // Only return for array types. Storage may be reused for Class for instance types.
1127         if (isArray()) {
1128             return componentType;
1129         } else {
1130             return null;
1131         }
1132     }
1133 
1134     private final Class<?> componentType;
1135 
1136 
1137     /**
1138      * Returns the Java language modifiers for this class or interface, encoded
1139      * in an integer. The modifiers consist of the Java Virtual Machine's
1140      * constants for {@code public}, {@code protected},
1141      * {@code private}, {@code final}, {@code static},
1142      * {@code abstract} and {@code interface}; they should be decoded
1143      * using the methods of class {@code Modifier}.
1144      *
1145      * <p> If the underlying class is an array class, then its
1146      * {@code public}, {@code private} and {@code protected}
1147      * modifiers are the same as those of its component type.  If this
1148      * {@code Class} represents a primitive type or void, its
1149      * {@code public} modifier is always {@code true}, and its
1150      * {@code protected} and {@code private} modifiers are always
1151      * {@code false}. If this object represents an array class, a
1152      * primitive type or void, then its {@code final} modifier is always
1153      * {@code true} and its interface modifier is always
1154      * {@code false}. The values of its other modifiers are not determined
1155      * by this specification.
1156      *
1157      * <p> The modifier encodings are defined in <em>The Java Virtual Machine
1158      * Specification</em>, table 4.1.
1159      *
1160      * @return the {@code int} representing the modifiers for this class
1161      * @see     java.lang.reflect.Modifier
1162      * @since 1.1
1163      */
1164     @HotSpotIntrinsicCandidate
1165     public native int getModifiers();
1166 
1167 
1168     /**
1169      * Gets the signers of this class.
1170      *
1171      * @return  the signers of this class, or null if there are no signers.  In
1172      *          particular, this method returns null if this object represents
1173      *          a primitive type or void.
1174      * @since   1.1
1175      */
1176     public native Object[] getSigners();
1177 
1178 
1179     /**
1180      * Set the signers of this class.
1181      */
1182     native void setSigners(Object[] signers);
1183 
1184 
1185     /**
1186      * If this {@code Class} object represents a local or anonymous
1187      * class within a method, returns a {@link
1188      * java.lang.reflect.Method Method} object representing the
1189      * immediately enclosing method of the underlying class. Returns
1190      * {@code null} otherwise.
1191      *
1192      * In particular, this method returns {@code null} if the underlying
1193      * class is a local or anonymous class immediately enclosed by a type
1194      * declaration, instance initializer or static initializer.
1195      *
1196      * @return the immediately enclosing method of the underlying class, if
1197      *     that class is a local or anonymous class; otherwise {@code null}.
1198      *
1199      * @throws SecurityException
1200      *         If a security manager, <i>s</i>, is present and any of the
1201      *         following conditions is met:
1202      *
1203      *         <ul>
1204      *
1205      *         <li> the caller's class loader is not the same as the
1206      *         class loader of the enclosing class and invocation of
1207      *         {@link SecurityManager#checkPermission
1208      *         s.checkPermission} method with
1209      *         {@code RuntimePermission("accessDeclaredMembers")}
1210      *         denies access to the methods within the enclosing class
1211      *
1212      *         <li> the caller's class loader is not the same as or an
1213      *         ancestor of the class loader for the enclosing class and
1214      *         invocation of {@link SecurityManager#checkPackageAccess
1215      *         s.checkPackageAccess()} denies access to the package
1216      *         of the enclosing class
1217      *
1218      *         </ul>
1219      * @since 1.5
1220      */
1221     @CallerSensitive
1222     public Method getEnclosingMethod() throws SecurityException {
1223         EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1224 
1225         if (enclosingInfo == null)
1226             return null;
1227         else {
1228             if (!enclosingInfo.isMethod())
1229                 return null;
1230 
1231             MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1232                                                               getFactory());
1233             Class<?>   returnType       = toClass(typeInfo.getReturnType());
1234             Type []    parameterTypes   = typeInfo.getParameterTypes();
1235             Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1236 
1237             // Convert Types to Classes; returned types *should*
1238             // be class objects since the methodDescriptor's used
1239             // don't have generics information
1240             for(int i = 0; i < parameterClasses.length; i++)
1241                 parameterClasses[i] = toClass(parameterTypes[i]);
1242 
1243             // Perform access check
1244             final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1245             SecurityManager sm = System.getSecurityManager();
1246             if (sm != null) {
1247                 enclosingCandidate.checkMemberAccess(sm, Member.DECLARED,
1248                                                      Reflection.getCallerClass(), true);
1249             }
1250             Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1251 
1252             /*
1253              * Loop over all declared methods; match method name,
1254              * number of and type of parameters, *and* return
1255              * type.  Matching return type is also necessary
1256              * because of covariant returns, etc.
1257              */
1258             ReflectionFactory fact = getReflectionFactory();
1259             for (Method m : candidates) {
1260                 if (m.getName().equals(enclosingInfo.getName()) &&
1261                     arrayContentsEq(parameterClasses,
1262                                     fact.getExecutableSharedParameterTypes(m))) {
1263                     // finally, check return type
1264                     if (m.getReturnType().equals(returnType)) {
1265                         return fact.copyMethod(m);
1266                     }
1267                 }
1268             }
1269 
1270             throw new InternalError("Enclosing method not found");
1271         }
1272     }
1273 
1274     private native Object[] getEnclosingMethod0();
1275 
1276     private EnclosingMethodInfo getEnclosingMethodInfo() {
1277         Object[] enclosingInfo = getEnclosingMethod0();
1278         if (enclosingInfo == null)
1279             return null;
1280         else {
1281             return new EnclosingMethodInfo(enclosingInfo);
1282         }
1283     }
1284 
1285     private static final class EnclosingMethodInfo {
1286         private final Class<?> enclosingClass;
1287         private final String name;
1288         private final String descriptor;
1289 
1290         static void validate(Object[] enclosingInfo) {
1291             if (enclosingInfo.length != 3)
1292                 throw new InternalError("Malformed enclosing method information");
1293             try {
1294                 // The array is expected to have three elements:
1295 
1296                 // the immediately enclosing class
1297                 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1298                 assert(enclosingClass != null);
1299 
1300                 // the immediately enclosing method or constructor's
1301                 // name (can be null).
1302                 String name = (String)enclosingInfo[1];
1303 
1304                 // the immediately enclosing method or constructor's
1305                 // descriptor (null iff name is).
1306                 String descriptor = (String)enclosingInfo[2];
1307                 assert((name != null && descriptor != null) || name == descriptor);
1308             } catch (ClassCastException cce) {
1309                 throw new InternalError("Invalid type in enclosing method information", cce);
1310             }
1311         }
1312 
1313         EnclosingMethodInfo(Object[] enclosingInfo) {
1314             validate(enclosingInfo);
1315             this.enclosingClass = (Class<?>)enclosingInfo[0];
1316             this.name = (String)enclosingInfo[1];
1317             this.descriptor = (String)enclosingInfo[2];
1318         }
1319 
1320         boolean isPartial() {
1321             return enclosingClass == null || name == null || descriptor == null;
1322         }
1323 
1324         boolean isConstructor() { return !isPartial() && "<init>".equals(name); }
1325 
1326         boolean isMethod() { return !isPartial() && !isConstructor() && !"<clinit>".equals(name); }
1327 
1328         Class<?> getEnclosingClass() { return enclosingClass; }
1329 
1330         String getName() { return name; }
1331 
1332         String getDescriptor() { return descriptor; }
1333 
1334     }
1335 
1336     private static Class<?> toClass(Type o) {
1337         if (o instanceof GenericArrayType)
1338             return Array.newInstance(toClass(((GenericArrayType)o).getGenericComponentType()),
1339                                      0)
1340                 .getClass();
1341         return (Class<?>)o;
1342      }
1343 
1344     /**
1345      * If this {@code Class} object represents a local or anonymous
1346      * class within a constructor, returns a {@link
1347      * java.lang.reflect.Constructor Constructor} object representing
1348      * the immediately enclosing constructor of the underlying
1349      * class. Returns {@code null} otherwise.  In particular, this
1350      * method returns {@code null} if the underlying class is a local
1351      * or anonymous class immediately enclosed by a type declaration,
1352      * instance initializer or static initializer.
1353      *
1354      * @return the immediately enclosing constructor of the underlying class, if
1355      *     that class is a local or anonymous class; otherwise {@code null}.
1356      * @throws SecurityException
1357      *         If a security manager, <i>s</i>, is present and any of the
1358      *         following conditions is met:
1359      *
1360      *         <ul>
1361      *
1362      *         <li> the caller's class loader is not the same as the
1363      *         class loader of the enclosing class and invocation of
1364      *         {@link SecurityManager#checkPermission
1365      *         s.checkPermission} method with
1366      *         {@code RuntimePermission("accessDeclaredMembers")}
1367      *         denies access to the constructors within the enclosing class
1368      *
1369      *         <li> the caller's class loader is not the same as or an
1370      *         ancestor of the class loader for the enclosing class and
1371      *         invocation of {@link SecurityManager#checkPackageAccess
1372      *         s.checkPackageAccess()} denies access to the package
1373      *         of the enclosing class
1374      *
1375      *         </ul>
1376      * @since 1.5
1377      */
1378     @CallerSensitive
1379     public Constructor<?> getEnclosingConstructor() throws SecurityException {
1380         EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1381 
1382         if (enclosingInfo == null)
1383             return null;
1384         else {
1385             if (!enclosingInfo.isConstructor())
1386                 return null;
1387 
1388             ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1389                                                                         getFactory());
1390             Type []    parameterTypes   = typeInfo.getParameterTypes();
1391             Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1392 
1393             // Convert Types to Classes; returned types *should*
1394             // be class objects since the methodDescriptor's used
1395             // don't have generics information
1396             for(int i = 0; i < parameterClasses.length; i++)
1397                 parameterClasses[i] = toClass(parameterTypes[i]);
1398 
1399             // Perform access check
1400             final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1401             SecurityManager sm = System.getSecurityManager();
1402             if (sm != null) {
1403                 enclosingCandidate.checkMemberAccess(sm, Member.DECLARED,
1404                                                      Reflection.getCallerClass(), true);
1405             }
1406 
1407             Constructor<?>[] candidates = enclosingCandidate
1408                     .privateGetDeclaredConstructors(false);
1409             /*
1410              * Loop over all declared constructors; match number
1411              * of and type of parameters.
1412              */
1413             ReflectionFactory fact = getReflectionFactory();
1414             for (Constructor<?> c : candidates) {
1415                 if (arrayContentsEq(parameterClasses,
1416                                     fact.getExecutableSharedParameterTypes(c))) {
1417                     return fact.copyConstructor(c);
1418                 }
1419             }
1420 
1421             throw new InternalError("Enclosing constructor not found");
1422         }
1423     }
1424 
1425 
1426     /**
1427      * If the class or interface represented by this {@code Class} object
1428      * is a member of another class, returns the {@code Class} object
1429      * representing the class in which it was declared.  This method returns
1430      * null if this class or interface is not a member of any other class.  If
1431      * this {@code Class} object represents an array class, a primitive
1432      * type, or void,then this method returns null.
1433      *
1434      * @return the declaring class for this class
1435      * @throws SecurityException
1436      *         If a security manager, <i>s</i>, is present and the caller's
1437      *         class loader is not the same as or an ancestor of the class
1438      *         loader for the declaring class and invocation of {@link
1439      *         SecurityManager#checkPackageAccess s.checkPackageAccess()}
1440      *         denies access to the package of the declaring class
1441      * @since 1.1
1442      */
1443     @CallerSensitive
1444     public Class<?> getDeclaringClass() throws SecurityException {
1445         final Class<?> candidate = getDeclaringClass0();
1446 
1447         if (candidate != null) {
1448             SecurityManager sm = System.getSecurityManager();
1449             if (sm != null) {
1450                 candidate.checkPackageAccess(sm,
1451                     ClassLoader.getClassLoader(Reflection.getCallerClass()), true);
1452             }
1453         }
1454         return candidate;
1455     }
1456 
1457     private native Class<?> getDeclaringClass0();
1458 
1459 
1460     /**
1461      * Returns the immediately enclosing class of the underlying
1462      * class.  If the underlying class is a top level class this
1463      * method returns {@code null}.
1464      * @return the immediately enclosing class of the underlying class
1465      * @exception  SecurityException
1466      *             If a security manager, <i>s</i>, is present and the caller's
1467      *             class loader is not the same as or an ancestor of the class
1468      *             loader for the enclosing class and invocation of {@link
1469      *             SecurityManager#checkPackageAccess s.checkPackageAccess()}
1470      *             denies access to the package of the enclosing class
1471      * @since 1.5
1472      */
1473     @CallerSensitive
1474     public Class<?> getEnclosingClass() throws SecurityException {
1475         // There are five kinds of classes (or interfaces):
1476         // a) Top level classes
1477         // b) Nested classes (static member classes)
1478         // c) Inner classes (non-static member classes)
1479         // d) Local classes (named classes declared within a method)
1480         // e) Anonymous classes
1481 
1482 
1483         // JVM Spec 4.7.7: A class must have an EnclosingMethod
1484         // attribute if and only if it is a local class or an
1485         // anonymous class.
1486         EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1487         Class<?> enclosingCandidate;
1488 
1489         if (enclosingInfo == null) {
1490             // This is a top level or a nested class or an inner class (a, b, or c)
1491             enclosingCandidate = getDeclaringClass0();
1492         } else {
1493             Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1494             // This is a local class or an anonymous class (d or e)
1495             if (enclosingClass == this || enclosingClass == null)
1496                 throw new InternalError("Malformed enclosing method information");
1497             else
1498                 enclosingCandidate = enclosingClass;
1499         }
1500 
1501         if (enclosingCandidate != null) {
1502             SecurityManager sm = System.getSecurityManager();
1503             if (sm != null) {
1504                 enclosingCandidate.checkPackageAccess(sm,
1505                     ClassLoader.getClassLoader(Reflection.getCallerClass()), true);
1506             }
1507         }
1508         return enclosingCandidate;
1509     }
1510 
1511     /**
1512      * Returns the simple name of the underlying class as given in the
1513      * source code. Returns an empty string if the underlying class is
1514      * anonymous.
1515      *
1516      * <p>The simple name of an array is the simple name of the
1517      * component type with "[]" appended.  In particular the simple
1518      * name of an array whose component type is anonymous is "[]".
1519      *
1520      * @return the simple name of the underlying class
1521      * @since 1.5
1522      */
1523     public String getSimpleName() {
1524         if (isArray())
1525             return getComponentType().getSimpleName()+"[]";
1526 
1527         String simpleName = getSimpleBinaryName();
1528         if (simpleName == null) { // top level class
1529             simpleName = getName();
1530             return simpleName.substring(simpleName.lastIndexOf('.')+1); // strip the package name
1531         }
1532         return simpleName;
1533     }
1534 
1535     /**
1536      * Return an informative string for the name of this type.
1537      *
1538      * @return an informative string for the name of this type
1539      * @since 1.8
1540      */
1541     public String getTypeName() {
1542         if (isArray()) {
1543             try {
1544                 Class<?> cl = this;
1545                 int dimensions = 0;
1546                 while (cl.isArray()) {
1547                     dimensions++;
1548                     cl = cl.getComponentType();
1549                 }
1550                 StringBuilder sb = new StringBuilder();
1551                 sb.append(cl.getName());
1552                 for (int i = 0; i < dimensions; i++) {
1553                     sb.append("[]");
1554                 }
1555                 return sb.toString();
1556             } catch (Throwable e) { /*FALLTHRU*/ }
1557         }
1558         return getName();
1559     }
1560 
1561     /**
1562      * Returns the canonical name of the underlying class as
1563      * defined by the Java Language Specification.  Returns null if
1564      * the underlying class does not have a canonical name (i.e., if
1565      * it is a local or anonymous class or an array whose component
1566      * type does not have a canonical name).
1567      * @return the canonical name of the underlying class if it exists, and
1568      * {@code null} otherwise.
1569      * @since 1.5
1570      */
1571     public String getCanonicalName() {
1572         if (isArray()) {
1573             String canonicalName = getComponentType().getCanonicalName();
1574             if (canonicalName != null)
1575                 return canonicalName + "[]";
1576             else
1577                 return null;
1578         }
1579         if (isLocalOrAnonymousClass())
1580             return null;
1581         Class<?> enclosingClass = getEnclosingClass();
1582         if (enclosingClass == null) { // top level class
1583             return getName();
1584         } else {
1585             String enclosingName = enclosingClass.getCanonicalName();
1586             if (enclosingName == null)
1587                 return null;
1588             return enclosingName + "." + getSimpleName();
1589         }
1590     }
1591 
1592     /**
1593      * Returns {@code true} if and only if the underlying class
1594      * is an anonymous class.
1595      *
1596      * @return {@code true} if and only if this class is an anonymous class.
1597      * @since 1.5
1598      */
1599     public boolean isAnonymousClass() {
1600         return !isArray() && isLocalOrAnonymousClass() &&
1601                 getSimpleBinaryName0() == null;
1602     }
1603 
1604     /**
1605      * Returns {@code true} if and only if the underlying class
1606      * is a local class.
1607      *
1608      * @return {@code true} if and only if this class is a local class.
1609      * @since 1.5
1610      */
1611     public boolean isLocalClass() {
1612         return isLocalOrAnonymousClass() &&
1613                 (isArray() || getSimpleBinaryName0() != null);
1614     }
1615 
1616     /**
1617      * Returns {@code true} if and only if the underlying class
1618      * is a member class.
1619      *
1620      * @return {@code true} if and only if this class is a member class.
1621      * @since 1.5
1622      */
1623     public boolean isMemberClass() {
1624         return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1625     }
1626 
1627     /**
1628      * Returns the "simple binary name" of the underlying class, i.e.,
1629      * the binary name without the leading enclosing class name.
1630      * Returns {@code null} if the underlying class is a top level
1631      * class.
1632      */
1633     private String getSimpleBinaryName() {
1634         if (isTopLevelClass())
1635             return null;
1636         String name = getSimpleBinaryName0();
1637         if (name == null) // anonymous class
1638             return "";
1639         return name;
1640     }
1641 
1642     private native String getSimpleBinaryName0();
1643 
1644     /**
1645      * Returns {@code true} if this is a top level class.  Returns {@code false}
1646      * otherwise.
1647      */
1648     private boolean isTopLevelClass() {
1649         return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1650     }
1651 
1652     /**
1653      * Returns {@code true} if this is a local class or an anonymous
1654      * class.  Returns {@code false} otherwise.
1655      */
1656     private boolean isLocalOrAnonymousClass() {
1657         // JVM Spec 4.7.7: A class must have an EnclosingMethod
1658         // attribute if and only if it is a local class or an
1659         // anonymous class.
1660         return hasEnclosingMethodInfo();
1661     }
1662 
1663     private boolean hasEnclosingMethodInfo() {
1664         Object[] enclosingInfo = getEnclosingMethod0();
1665         if (enclosingInfo != null) {
1666             EnclosingMethodInfo.validate(enclosingInfo);
1667             return true;
1668         }
1669         return false;
1670     }
1671 
1672     /**
1673      * Returns an array containing {@code Class} objects representing all
1674      * the public classes and interfaces that are members of the class
1675      * represented by this {@code Class} object.  This includes public
1676      * class and interface members inherited from superclasses and public class
1677      * and interface members declared by the class.  This method returns an
1678      * array of length 0 if this {@code Class} object has no public member
1679      * classes or interfaces.  This method also returns an array of length 0 if
1680      * this {@code Class} object represents a primitive type, an array
1681      * class, or void.
1682      *
1683      * @return the array of {@code Class} objects representing the public
1684      *         members of this class
1685      * @throws SecurityException
1686      *         If a security manager, <i>s</i>, is present and
1687      *         the caller's class loader is not the same as or an
1688      *         ancestor of the class loader for the current class and
1689      *         invocation of {@link SecurityManager#checkPackageAccess
1690      *         s.checkPackageAccess()} denies access to the package
1691      *         of this class.
1692      *
1693      * @since 1.1
1694      */
1695     @CallerSensitive
1696     public Class<?>[] getClasses() {
1697         SecurityManager sm = System.getSecurityManager();
1698         if (sm != null) {
1699             checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), false);
1700         }
1701 
1702         // Privileged so this implementation can look at DECLARED classes,
1703         // something the caller might not have privilege to do.  The code here
1704         // is allowed to look at DECLARED classes because (1) it does not hand
1705         // out anything other than public members and (2) public member access
1706         // has already been ok'd by the SecurityManager.
1707 
1708         return java.security.AccessController.doPrivileged(
1709             new java.security.PrivilegedAction<>() {
1710                 public Class<?>[] run() {
1711                     List<Class<?>> list = new ArrayList<>();
1712                     Class<?> currentClass = Class.this;
1713                     while (currentClass != null) {
1714                         for (Class<?> m : currentClass.getDeclaredClasses()) {
1715                             if (Modifier.isPublic(m.getModifiers())) {
1716                                 list.add(m);
1717                             }
1718                         }
1719                         currentClass = currentClass.getSuperclass();
1720                     }
1721                     return list.toArray(new Class<?>[0]);
1722                 }
1723             });
1724     }
1725 
1726 
1727     /**
1728      * Returns an array containing {@code Field} objects reflecting all
1729      * the accessible public fields of the class or interface represented by
1730      * this {@code Class} object.
1731      *
1732      * <p> If this {@code Class} object represents a class or interface with
1733      * no accessible public fields, then this method returns an array of length
1734      * 0.
1735      *
1736      * <p> If this {@code Class} object represents a class, then this method
1737      * returns the public fields of the class and of all its superclasses and
1738      * superinterfaces.
1739      *
1740      * <p> If this {@code Class} object represents an interface, then this
1741      * method returns the fields of the interface and of all its
1742      * superinterfaces.
1743      *
1744      * <p> If this {@code Class} object represents an array type, a primitive
1745      * type, or void, then this method returns an array of length 0.
1746      *
1747      * <p> The elements in the returned array are not sorted and are not in any
1748      * particular order.
1749      *
1750      * @return the array of {@code Field} objects representing the
1751      *         public fields
1752      * @throws SecurityException
1753      *         If a security manager, <i>s</i>, is present and
1754      *         the caller's class loader is not the same as or an
1755      *         ancestor of the class loader for the current class and
1756      *         invocation of {@link SecurityManager#checkPackageAccess
1757      *         s.checkPackageAccess()} denies access to the package
1758      *         of this class.
1759      *
1760      * @since 1.1
1761      * @jls 8.2 Class Members
1762      * @jls 8.3 Field Declarations
1763      */
1764     @CallerSensitive
1765     public Field[] getFields() throws SecurityException {
1766         SecurityManager sm = System.getSecurityManager();
1767         if (sm != null) {
1768             checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
1769         }
1770         return copyFields(privateGetPublicFields(null));
1771     }
1772 
1773 
1774     /**
1775      * Returns an array containing {@code Method} objects reflecting all the
1776      * public methods of the class or interface represented by this {@code
1777      * Class} object, including those declared by the class or interface and
1778      * those inherited from superclasses and superinterfaces.
1779      *
1780      * <p> If this {@code Class} object represents an array type, then the
1781      * returned array has a {@code Method} object for each of the public
1782      * methods inherited by the array type from {@code Object}. It does not
1783      * contain a {@code Method} object for {@code clone()}.
1784      *
1785      * <p> If this {@code Class} object represents an interface then the
1786      * returned array does not contain any implicitly declared methods from
1787      * {@code Object}. Therefore, if no methods are explicitly declared in
1788      * this interface or any of its superinterfaces then the returned array
1789      * has length 0. (Note that a {@code Class} object which represents a class
1790      * always has public methods, inherited from {@code Object}.)
1791      *
1792      * <p> The returned array never contains methods with names "{@code <init>}"
1793      * or "{@code <clinit>}".
1794      *
1795      * <p> The elements in the returned array are not sorted and are not in any
1796      * particular order.
1797      *
1798      * <p> Generally, the result is computed as with the following 4 step algorithm.
1799      * Let C be the class or interface represented by this {@code Class} object:
1800      * <ol>
1801      * <li> A union of methods is composed of:
1802      *   <ol type="a">
1803      *   <li> C's declared public instance and static methods as returned by
1804      *        {@link #getDeclaredMethods()} and filtered to include only public
1805      *        methods.</li>
1806      *   <li> If C is a class other than {@code Object}, then include the result
1807      *        of invoking this algorithm recursively on the superclass of C.</li>
1808      *   <li> Include the results of invoking this algorithm recursively on all
1809      *        direct superinterfaces of C, but include only instance methods.</li>
1810      *   </ol></li>
1811      * <li> Union from step 1 is partitioned into subsets of methods with same
1812      *      signature (name, parameter types) and return type.</li>
1813      * <li> Within each such subset only the most specific methods are selected.
1814      *      Let method M be a method from a set of methods with same signature
1815      *      and return type. M is most specific if there is no such method
1816      *      N != M from the same set, such that N is more specific than M.
1817      *      N is more specific than M if:
1818      *   <ol type="a">
1819      *   <li> N is declared by a class and M is declared by an interface; or</li>
1820      *   <li> N and M are both declared by classes or both by interfaces and
1821      *        N's declaring type is the same as or a subtype of M's declaring type
1822      *        (clearly, if M's and N's declaring types are the same type, then
1823      *        M and N are the same method).</li>
1824      *   </ol></li>
1825      * <li> The result of this algorithm is the union of all selected methods from
1826      *      step 3.</li>
1827      * </ol>
1828      *
1829      * @apiNote There may be more than one method with a particular name
1830      * and parameter types in a class because while the Java language forbids a
1831      * class to declare multiple methods with the same signature but different
1832      * return types, the Java virtual machine does not.  This
1833      * increased flexibility in the virtual machine can be used to
1834      * implement various language features.  For example, covariant
1835      * returns can be implemented with {@linkplain
1836      * java.lang.reflect.Method#isBridge bridge methods}; the bridge
1837      * method and the overriding method would have the same
1838      * signature but different return types.
1839      *
1840      * @return the array of {@code Method} objects representing the
1841      *         public methods of this class
1842      * @throws SecurityException
1843      *         If a security manager, <i>s</i>, is present and
1844      *         the caller's class loader is not the same as or an
1845      *         ancestor of the class loader for the current class and
1846      *         invocation of {@link SecurityManager#checkPackageAccess
1847      *         s.checkPackageAccess()} denies access to the package
1848      *         of this class.
1849      *
1850      * @jls 8.2 Class Members
1851      * @jls 8.4 Method Declarations
1852      * @since 1.1
1853      */
1854     @CallerSensitive
1855     public Method[] getMethods() throws SecurityException {
1856         SecurityManager sm = System.getSecurityManager();
1857         if (sm != null) {
1858             checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
1859         }
1860         return copyMethods(privateGetPublicMethods());
1861     }
1862 
1863 
1864     /**
1865      * Returns an array containing {@code Constructor} objects reflecting
1866      * all the public constructors of the class represented by this
1867      * {@code Class} object.  An array of length 0 is returned if the
1868      * class has no public constructors, or if the class is an array class, or
1869      * if the class reflects a primitive type or void.
1870      *
1871      * Note that while this method returns an array of {@code
1872      * Constructor<T>} objects (that is an array of constructors from
1873      * this class), the return type of this method is {@code
1874      * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
1875      * might be expected.  This less informative return type is
1876      * necessary since after being returned from this method, the
1877      * array could be modified to hold {@code Constructor} objects for
1878      * different classes, which would violate the type guarantees of
1879      * {@code Constructor<T>[]}.
1880      *
1881      * @return the array of {@code Constructor} objects representing the
1882      *         public constructors of this class
1883      * @throws SecurityException
1884      *         If a security manager, <i>s</i>, is present and
1885      *         the caller's class loader is not the same as or an
1886      *         ancestor of the class loader for the current class and
1887      *         invocation of {@link SecurityManager#checkPackageAccess
1888      *         s.checkPackageAccess()} denies access to the package
1889      *         of this class.
1890      *
1891      * @since 1.1
1892      */
1893     @CallerSensitive
1894     public Constructor<?>[] getConstructors() throws SecurityException {
1895         SecurityManager sm = System.getSecurityManager();
1896         if (sm != null) {
1897             checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
1898         }
1899         return copyConstructors(privateGetDeclaredConstructors(true));
1900     }
1901 
1902 
1903     /**
1904      * Returns a {@code Field} object that reflects the specified public member
1905      * field of the class or interface represented by this {@code Class}
1906      * object. The {@code name} parameter is a {@code String} specifying the
1907      * simple name of the desired field.
1908      *
1909      * <p> The field to be reflected is determined by the algorithm that
1910      * follows.  Let C be the class or interface represented by this object:
1911      *
1912      * <OL>
1913      * <LI> If C declares a public field with the name specified, that is the
1914      *      field to be reflected.</LI>
1915      * <LI> If no field was found in step 1 above, this algorithm is applied
1916      *      recursively to each direct superinterface of C. The direct
1917      *      superinterfaces are searched in the order they were declared.</LI>
1918      * <LI> If no field was found in steps 1 and 2 above, and C has a
1919      *      superclass S, then this algorithm is invoked recursively upon S.
1920      *      If C has no superclass, then a {@code NoSuchFieldException}
1921      *      is thrown.</LI>
1922      * </OL>
1923      *
1924      * <p> If this {@code Class} object represents an array type, then this
1925      * method does not find the {@code length} field of the array type.
1926      *
1927      * @param name the field name
1928      * @return the {@code Field} object of this class specified by
1929      *         {@code name}
1930      * @throws NoSuchFieldException if a field with the specified name is
1931      *         not found.
1932      * @throws NullPointerException if {@code name} is {@code null}
1933      * @throws SecurityException
1934      *         If a security manager, <i>s</i>, is present and
1935      *         the caller's class loader is not the same as or an
1936      *         ancestor of the class loader for the current class and
1937      *         invocation of {@link SecurityManager#checkPackageAccess
1938      *         s.checkPackageAccess()} denies access to the package
1939      *         of this class.
1940      *
1941      * @since 1.1
1942      * @jls 8.2 Class Members
1943      * @jls 8.3 Field Declarations
1944      */
1945     @CallerSensitive
1946     public Field getField(String name)
1947         throws NoSuchFieldException, SecurityException {
1948         Objects.requireNonNull(name);
1949         SecurityManager sm = System.getSecurityManager();
1950         if (sm != null) {
1951             checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
1952         }
1953         Field field = getField0(name);
1954         if (field == null) {
1955             throw new NoSuchFieldException(name);
1956         }
1957         return getReflectionFactory().copyField(field);
1958     }
1959 
1960 
1961     /**
1962      * Returns a {@code Method} object that reflects the specified public
1963      * member method of the class or interface represented by this
1964      * {@code Class} object. The {@code name} parameter is a
1965      * {@code String} specifying the simple name of the desired method. The
1966      * {@code parameterTypes} parameter is an array of {@code Class}
1967      * objects that identify the method's formal parameter types, in declared
1968      * order. If {@code parameterTypes} is {@code null}, it is
1969      * treated as if it were an empty array.
1970      *
1971      * <p> If this {@code Class} object represents an array type, then this
1972      * method finds any public method inherited by the array type from
1973      * {@code Object} except method {@code clone()}.
1974      *
1975      * <p> If this {@code Class} object represents an interface then this
1976      * method does not find any implicitly declared method from
1977      * {@code Object}. Therefore, if no methods are explicitly declared in
1978      * this interface or any of its superinterfaces, then this method does not
1979      * find any method.
1980      *
1981      * <p> This method does not find any method with name "{@code <init>}" or
1982      * "{@code <clinit>}".
1983      *
1984      * <p> Generally, the method to be reflected is determined by the 4 step
1985      * algorithm that follows.
1986      * Let C be the class or interface represented by this {@code Class} object:
1987      * <ol>
1988      * <li> A union of methods is composed of:
1989      *   <ol type="a">
1990      *   <li> C's declared public instance and static methods as returned by
1991      *        {@link #getDeclaredMethods()} and filtered to include only public
1992      *        methods that match given {@code name} and {@code parameterTypes}</li>
1993      *   <li> If C is a class other than {@code Object}, then include the result
1994      *        of invoking this algorithm recursively on the superclass of C.</li>
1995      *   <li> Include the results of invoking this algorithm recursively on all
1996      *        direct superinterfaces of C, but include only instance methods.</li>
1997      *   </ol></li>
1998      * <li> This union is partitioned into subsets of methods with same
1999      *      return type (the selection of methods from step 1 also guarantees that
2000      *      they have the same method name and parameter types).</li>
2001      * <li> Within each such subset only the most specific methods are selected.
2002      *      Let method M be a method from a set of methods with same VM
2003      *      signature (return type, name, parameter types).
2004      *      M is most specific if there is no such method N != M from the same
2005      *      set, such that N is more specific than M. N is more specific than M
2006      *      if:
2007      *   <ol type="a">
2008      *   <li> N is declared by a class and M is declared by an interface; or</li>
2009      *   <li> N and M are both declared by classes or both by interfaces and
2010      *        N's declaring type is the same as or a subtype of M's declaring type
2011      *        (clearly, if M's and N's declaring types are the same type, then
2012      *        M and N are the same method).</li>
2013      *   </ol></li>
2014      * <li> The result of this algorithm is chosen arbitrarily from the methods
2015      *      with most specific return type among all selected methods from step 3.
2016      *      Let R be a return type of a method M from the set of all selected methods
2017      *      from step 3. M is a method with most specific return type if there is
2018      *      no such method N != M from the same set, having return type S != R,
2019      *      such that S is a subtype of R as determined by
2020      *      R.class.{@link #isAssignableFrom}(S.class).
2021      * </ol>
2022      *
2023      * @apiNote There may be more than one method with matching name and
2024      * parameter types in a class because while the Java language forbids a
2025      * class to declare multiple methods with the same signature but different
2026      * return types, the Java virtual machine does not.  This
2027      * increased flexibility in the virtual machine can be used to
2028      * implement various language features.  For example, covariant
2029      * returns can be implemented with {@linkplain
2030      * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2031      * method and the overriding method would have the same
2032      * signature but different return types. This method would return the
2033      * overriding method as it would have a more specific return type.
2034      *
2035      * @param name the name of the method
2036      * @param parameterTypes the list of parameters
2037      * @return the {@code Method} object that matches the specified
2038      *         {@code name} and {@code parameterTypes}
2039      * @throws NoSuchMethodException if a matching method is not found
2040      *         or if the name is "&lt;init&gt;"or "&lt;clinit&gt;".
2041      * @throws NullPointerException if {@code name} is {@code null}
2042      * @throws SecurityException
2043      *         If a security manager, <i>s</i>, is present and
2044      *         the caller's class loader is not the same as or an
2045      *         ancestor of the class loader for the current class and
2046      *         invocation of {@link SecurityManager#checkPackageAccess
2047      *         s.checkPackageAccess()} denies access to the package
2048      *         of this class.
2049      *
2050      * @jls 8.2 Class Members
2051      * @jls 8.4 Method Declarations
2052      * @since 1.1
2053      */
2054     @CallerSensitive
2055     public Method getMethod(String name, Class<?>... parameterTypes)
2056         throws NoSuchMethodException, SecurityException {
2057         Objects.requireNonNull(name);
2058         SecurityManager sm = System.getSecurityManager();
2059         if (sm != null) {
2060             checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
2061         }
2062         Method method = getMethod0(name, parameterTypes);
2063         if (method == null) {
2064             throw new NoSuchMethodException(methodToString(name, parameterTypes));
2065         }
2066         return getReflectionFactory().copyMethod(method);
2067     }
2068 
2069     /**
2070      * Returns a {@code Method} object that reflects the specified public
2071      * member method of the class or interface represented by this
2072      * {@code Class} object.
2073      *
2074      * @param name the name of the method
2075      * @param parameterTypes the list of parameters
2076      * @return the {@code Method} object that matches the specified
2077      *         {@code name} and {@code parameterTypes}; {@code null}
2078      *         if the method is not found or the name is
2079      *         "&lt;init&gt;"or "&lt;clinit&gt;".
2080      */
2081     Method getMethodOrNull(String name, Class<?>... parameterTypes) {
2082         Objects.requireNonNull(name);
2083         Method method = getMethod0(name, parameterTypes);
2084         return method == null ? null : getReflectionFactory().copyMethod(method);
2085     }
2086 
2087 
2088     /**
2089      * Returns a {@code Constructor} object that reflects the specified
2090      * public constructor of the class represented by this {@code Class}
2091      * object. The {@code parameterTypes} parameter is an array of
2092      * {@code Class} objects that identify the constructor's formal
2093      * parameter types, in declared order.
2094      *
2095      * If this {@code Class} object represents an inner class
2096      * declared in a non-static context, the formal parameter types
2097      * include the explicit enclosing instance as the first parameter.
2098      *
2099      * <p> The constructor to reflect is the public constructor of the class
2100      * represented by this {@code Class} object whose formal parameter
2101      * types match those specified by {@code parameterTypes}.
2102      *
2103      * @param parameterTypes the parameter array
2104      * @return the {@code Constructor} object of the public constructor that
2105      *         matches the specified {@code parameterTypes}
2106      * @throws NoSuchMethodException if a matching method is not found.
2107      * @throws SecurityException
2108      *         If a security manager, <i>s</i>, is present and
2109      *         the caller's class loader is not the same as or an
2110      *         ancestor of the class loader for the current class and
2111      *         invocation of {@link SecurityManager#checkPackageAccess
2112      *         s.checkPackageAccess()} denies access to the package
2113      *         of this class.
2114      *
2115      * @since 1.1
2116      */
2117     @CallerSensitive
2118     public Constructor<T> getConstructor(Class<?>... parameterTypes)
2119         throws NoSuchMethodException, SecurityException
2120     {
2121         SecurityManager sm = System.getSecurityManager();
2122         if (sm != null) {
2123             checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
2124         }
2125         return getReflectionFactory().copyConstructor(
2126             getConstructor0(parameterTypes, Member.PUBLIC));
2127     }
2128 
2129 
2130     /**
2131      * Returns an array of {@code Class} objects reflecting all the
2132      * classes and interfaces declared as members of the class represented by
2133      * this {@code Class} object. This includes public, protected, default
2134      * (package) access, and private classes and interfaces declared by the
2135      * class, but excludes inherited classes and interfaces.  This method
2136      * returns an array of length 0 if the class declares no classes or
2137      * interfaces as members, or if this {@code Class} object represents a
2138      * primitive type, an array class, or void.
2139      *
2140      * @return the array of {@code Class} objects representing all the
2141      *         declared members of this class
2142      * @throws SecurityException
2143      *         If a security manager, <i>s</i>, is present and any of the
2144      *         following conditions is met:
2145      *
2146      *         <ul>
2147      *
2148      *         <li> the caller's class loader is not the same as the
2149      *         class loader of this class and invocation of
2150      *         {@link SecurityManager#checkPermission
2151      *         s.checkPermission} method with
2152      *         {@code RuntimePermission("accessDeclaredMembers")}
2153      *         denies access to the declared classes within this class
2154      *
2155      *         <li> the caller's class loader is not the same as or an
2156      *         ancestor of the class loader for the current class and
2157      *         invocation of {@link SecurityManager#checkPackageAccess
2158      *         s.checkPackageAccess()} denies access to the package
2159      *         of this class
2160      *
2161      *         </ul>
2162      *
2163      * @since 1.1
2164      */
2165     @CallerSensitive
2166     public Class<?>[] getDeclaredClasses() throws SecurityException {
2167         SecurityManager sm = System.getSecurityManager();
2168         if (sm != null) {
2169             checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), false);
2170         }
2171         return getDeclaredClasses0();
2172     }
2173 
2174 
2175     /**
2176      * Returns an array of {@code Field} objects reflecting all the fields
2177      * declared by the class or interface represented by this
2178      * {@code Class} object. This includes public, protected, default
2179      * (package) access, and private fields, but excludes inherited fields.
2180      *
2181      * <p> If this {@code Class} object represents a class or interface with no
2182      * declared fields, then this method returns an array of length 0.
2183      *
2184      * <p> If this {@code Class} object represents an array type, a primitive
2185      * type, or void, then this method returns an array of length 0.
2186      *
2187      * <p> The elements in the returned array are not sorted and are not in any
2188      * particular order.
2189      *
2190      * @return  the array of {@code Field} objects representing all the
2191      *          declared fields of this class
2192      * @throws  SecurityException
2193      *          If a security manager, <i>s</i>, is present and any of the
2194      *          following conditions is met:
2195      *
2196      *          <ul>
2197      *
2198      *          <li> the caller's class loader is not the same as the
2199      *          class loader of this class and invocation of
2200      *          {@link SecurityManager#checkPermission
2201      *          s.checkPermission} method with
2202      *          {@code RuntimePermission("accessDeclaredMembers")}
2203      *          denies access to the declared fields within this class
2204      *
2205      *          <li> the caller's class loader is not the same as or an
2206      *          ancestor of the class loader for the current class and
2207      *          invocation of {@link SecurityManager#checkPackageAccess
2208      *          s.checkPackageAccess()} denies access to the package
2209      *          of this class
2210      *
2211      *          </ul>
2212      *
2213      * @since 1.1
2214      * @jls 8.2 Class Members
2215      * @jls 8.3 Field Declarations
2216      */
2217     @CallerSensitive
2218     public Field[] getDeclaredFields() throws SecurityException {
2219         SecurityManager sm = System.getSecurityManager();
2220         if (sm != null) {
2221             checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2222         }
2223         return copyFields(privateGetDeclaredFields(false));
2224     }
2225 
2226 
2227     /**
2228      *
2229      * Returns an array containing {@code Method} objects reflecting all the
2230      * declared methods of the class or interface represented by this {@code
2231      * Class} object, including public, protected, default (package)
2232      * access, and private methods, but excluding inherited methods.
2233      *
2234      * <p> If this {@code Class} object represents a type that has multiple
2235      * declared methods with the same name and parameter types, but different
2236      * return types, then the returned array has a {@code Method} object for
2237      * each such method.
2238      *
2239      * <p> If this {@code Class} object represents a type that has a class
2240      * initialization method {@code <clinit>}, then the returned array does
2241      * <em>not</em> have a corresponding {@code Method} object.
2242      *
2243      * <p> If this {@code Class} object represents a class or interface with no
2244      * declared methods, then the returned array has length 0.
2245      *
2246      * <p> If this {@code Class} object represents an array type, a primitive
2247      * type, or void, then the returned array has length 0.
2248      *
2249      * <p> The elements in the returned array are not sorted and are not in any
2250      * particular order.
2251      *
2252      * @return  the array of {@code Method} objects representing all the
2253      *          declared methods of this class
2254      * @throws  SecurityException
2255      *          If a security manager, <i>s</i>, is present and any of the
2256      *          following conditions is met:
2257      *
2258      *          <ul>
2259      *
2260      *          <li> the caller's class loader is not the same as the
2261      *          class loader of this class and invocation of
2262      *          {@link SecurityManager#checkPermission
2263      *          s.checkPermission} method with
2264      *          {@code RuntimePermission("accessDeclaredMembers")}
2265      *          denies access to the declared methods within this class
2266      *
2267      *          <li> the caller's class loader is not the same as or an
2268      *          ancestor of the class loader for the current class and
2269      *          invocation of {@link SecurityManager#checkPackageAccess
2270      *          s.checkPackageAccess()} denies access to the package
2271      *          of this class
2272      *
2273      *          </ul>
2274      *
2275      * @jls 8.2 Class Members
2276      * @jls 8.4 Method Declarations
2277      * @since 1.1
2278      */
2279     @CallerSensitive
2280     public Method[] getDeclaredMethods() throws SecurityException {
2281         SecurityManager sm = System.getSecurityManager();
2282         if (sm != null) {
2283             checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2284         }
2285         return copyMethods(privateGetDeclaredMethods(false));
2286     }
2287 
2288 
2289     /**
2290      * Returns an array of {@code Constructor} objects reflecting all the
2291      * constructors declared by the class represented by this
2292      * {@code Class} object. These are public, protected, default
2293      * (package) access, and private constructors.  The elements in the array
2294      * returned are not sorted and are not in any particular order.  If the
2295      * class has a default constructor, it is included in the returned array.
2296      * This method returns an array of length 0 if this {@code Class}
2297      * object represents an interface, a primitive type, an array class, or
2298      * void.
2299      *
2300      * <p> See <em>The Java Language Specification</em>, section 8.2.
2301      *
2302      * @return  the array of {@code Constructor} objects representing all the
2303      *          declared constructors of this class
2304      * @throws  SecurityException
2305      *          If a security manager, <i>s</i>, is present and any of the
2306      *          following conditions is met:
2307      *
2308      *          <ul>
2309      *
2310      *          <li> the caller's class loader is not the same as the
2311      *          class loader of this class and invocation of
2312      *          {@link SecurityManager#checkPermission
2313      *          s.checkPermission} method with
2314      *          {@code RuntimePermission("accessDeclaredMembers")}
2315      *          denies access to the declared constructors within this class
2316      *
2317      *          <li> the caller's class loader is not the same as or an
2318      *          ancestor of the class loader for the current class and
2319      *          invocation of {@link SecurityManager#checkPackageAccess
2320      *          s.checkPackageAccess()} denies access to the package
2321      *          of this class
2322      *
2323      *          </ul>
2324      *
2325      * @since 1.1
2326      */
2327     @CallerSensitive
2328     public Constructor<?>[] getDeclaredConstructors() throws SecurityException {
2329         SecurityManager sm = System.getSecurityManager();
2330         if (sm != null) {
2331             checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2332         }
2333         return copyConstructors(privateGetDeclaredConstructors(false));
2334     }
2335 
2336 
2337     /**
2338      * Returns a {@code Field} object that reflects the specified declared
2339      * field of the class or interface represented by this {@code Class}
2340      * object. The {@code name} parameter is a {@code String} that specifies
2341      * the simple name of the desired field.
2342      *
2343      * <p> If this {@code Class} object represents an array type, then this
2344      * method does not find the {@code length} field of the array type.
2345      *
2346      * @param name the name of the field
2347      * @return  the {@code Field} object for the specified field in this
2348      *          class
2349      * @throws  NoSuchFieldException if a field with the specified name is
2350      *          not found.
2351      * @throws  NullPointerException if {@code name} is {@code null}
2352      * @throws  SecurityException
2353      *          If a security manager, <i>s</i>, is present and any of the
2354      *          following conditions is met:
2355      *
2356      *          <ul>
2357      *
2358      *          <li> the caller's class loader is not the same as the
2359      *          class loader of this class and invocation of
2360      *          {@link SecurityManager#checkPermission
2361      *          s.checkPermission} method with
2362      *          {@code RuntimePermission("accessDeclaredMembers")}
2363      *          denies access to the declared field
2364      *
2365      *          <li> the caller's class loader is not the same as or an
2366      *          ancestor of the class loader for the current class and
2367      *          invocation of {@link SecurityManager#checkPackageAccess
2368      *          s.checkPackageAccess()} denies access to the package
2369      *          of this class
2370      *
2371      *          </ul>
2372      *
2373      * @since 1.1
2374      * @jls 8.2 Class Members
2375      * @jls 8.3 Field Declarations
2376      */
2377     @CallerSensitive
2378     public Field getDeclaredField(String name)
2379         throws NoSuchFieldException, SecurityException {
2380         Objects.requireNonNull(name);
2381         SecurityManager sm = System.getSecurityManager();
2382         if (sm != null) {
2383             checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2384         }
2385         Field field = searchFields(privateGetDeclaredFields(false), name);
2386         if (field == null) {
2387             throw new NoSuchFieldException(name);
2388         }
2389         return getReflectionFactory().copyField(field);
2390     }
2391 
2392 
2393     /**
2394      * Returns a {@code Method} object that reflects the specified
2395      * declared method of the class or interface represented by this
2396      * {@code Class} object. The {@code name} parameter is a
2397      * {@code String} that specifies the simple name of the desired
2398      * method, and the {@code parameterTypes} parameter is an array of
2399      * {@code Class} objects that identify the method's formal parameter
2400      * types, in declared order.  If more than one method with the same
2401      * parameter types is declared in a class, and one of these methods has a
2402      * return type that is more specific than any of the others, that method is
2403      * returned; otherwise one of the methods is chosen arbitrarily.  If the
2404      * name is "&lt;init&gt;"or "&lt;clinit&gt;" a {@code NoSuchMethodException}
2405      * is raised.
2406      *
2407      * <p> If this {@code Class} object represents an array type, then this
2408      * method does not find the {@code clone()} method.
2409      *
2410      * @param name the name of the method
2411      * @param parameterTypes the parameter array
2412      * @return  the {@code Method} object for the method of this class
2413      *          matching the specified name and parameters
2414      * @throws  NoSuchMethodException if a matching method is not found.
2415      * @throws  NullPointerException if {@code name} is {@code null}
2416      * @throws  SecurityException
2417      *          If a security manager, <i>s</i>, is present and any of the
2418      *          following conditions is met:
2419      *
2420      *          <ul>
2421      *
2422      *          <li> the caller's class loader is not the same as the
2423      *          class loader of this class and invocation of
2424      *          {@link SecurityManager#checkPermission
2425      *          s.checkPermission} method with
2426      *          {@code RuntimePermission("accessDeclaredMembers")}
2427      *          denies access to the declared method
2428      *
2429      *          <li> the caller's class loader is not the same as or an
2430      *          ancestor of the class loader for the current class and
2431      *          invocation of {@link SecurityManager#checkPackageAccess
2432      *          s.checkPackageAccess()} denies access to the package
2433      *          of this class
2434      *
2435      *          </ul>
2436      *
2437      * @jls 8.2 Class Members
2438      * @jls 8.4 Method Declarations
2439      * @since 1.1
2440      */
2441     @CallerSensitive
2442     public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2443         throws NoSuchMethodException, SecurityException {
2444         Objects.requireNonNull(name);
2445         SecurityManager sm = System.getSecurityManager();
2446         if (sm != null) {
2447             checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2448         }
2449         Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2450         if (method == null) {
2451             throw new NoSuchMethodException(methodToString(name, parameterTypes));
2452         }
2453         return getReflectionFactory().copyMethod(method);
2454     }
2455 
2456 
2457     /**
2458      * Returns a {@code Constructor} object that reflects the specified
2459      * constructor of the class or interface represented by this
2460      * {@code Class} object.  The {@code parameterTypes} parameter is
2461      * an array of {@code Class} objects that identify the constructor's
2462      * formal parameter types, in declared order.
2463      *
2464      * If this {@code Class} object represents an inner class
2465      * declared in a non-static context, the formal parameter types
2466      * include the explicit enclosing instance as the first parameter.
2467      *
2468      * @param parameterTypes the parameter array
2469      * @return  The {@code Constructor} object for the constructor with the
2470      *          specified parameter list
2471      * @throws  NoSuchMethodException if a matching method is not found.
2472      * @throws  SecurityException
2473      *          If a security manager, <i>s</i>, is present and any of the
2474      *          following conditions is met:
2475      *
2476      *          <ul>
2477      *
2478      *          <li> the caller's class loader is not the same as the
2479      *          class loader of this class and invocation of
2480      *          {@link SecurityManager#checkPermission
2481      *          s.checkPermission} method with
2482      *          {@code RuntimePermission("accessDeclaredMembers")}
2483      *          denies access to the declared constructor
2484      *
2485      *          <li> the caller's class loader is not the same as or an
2486      *          ancestor of the class loader for the current class and
2487      *          invocation of {@link SecurityManager#checkPackageAccess
2488      *          s.checkPackageAccess()} denies access to the package
2489      *          of this class
2490      *
2491      *          </ul>
2492      *
2493      * @since 1.1
2494      */
2495     @CallerSensitive
2496     public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2497         throws NoSuchMethodException, SecurityException
2498     {
2499         SecurityManager sm = System.getSecurityManager();
2500         if (sm != null) {
2501             checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2502         }
2503 
2504         return getReflectionFactory().copyConstructor(
2505             getConstructor0(parameterTypes, Member.DECLARED));
2506     }
2507 
2508     /**
2509      * Finds a resource with a given name.
2510      *
2511      * <p> If this class is in a named {@link Module Module} then this method
2512      * will attempt to find the resource in the module. This is done by
2513      * delegating to the module's class loader {@link
2514      * ClassLoader#findResource(String,String) findResource(String,String)}
2515      * method, invoking it with the module name and the absolute name of the
2516      * resource. Resources in named modules are subject to the rules for
2517      * encapsulation specified in the {@code Module} {@link
2518      * Module#getResourceAsStream getResourceAsStream} method and so this
2519      * method returns {@code null} when the resource is a
2520      * non-"{@code .class}" resource in a package that is not open to the
2521      * caller's module.
2522      *
2523      * <p> Otherwise, if this class is not in a named module then the rules for
2524      * searching resources associated with a given class are implemented by the
2525      * defining {@linkplain ClassLoader class loader} of the class.  This method
2526      * delegates to this object's class loader.  If this object was loaded by
2527      * the bootstrap class loader, the method delegates to {@link
2528      * ClassLoader#getSystemResourceAsStream}.
2529      *
2530      * <p> Before delegation, an absolute resource name is constructed from the
2531      * given resource name using this algorithm:
2532      *
2533      * <ul>
2534      *
2535      * <li> If the {@code name} begins with a {@code '/'}
2536      * (<code>'\u002f'</code>), then the absolute name of the resource is the
2537      * portion of the {@code name} following the {@code '/'}.
2538      *
2539      * <li> Otherwise, the absolute name is of the following form:
2540      *
2541      * <blockquote>
2542      *   {@code modified_package_name/name}
2543      * </blockquote>
2544      *
2545      * <p> Where the {@code modified_package_name} is the package name of this
2546      * object with {@code '/'} substituted for {@code '.'}
2547      * (<code>'\u002e'</code>).
2548      *
2549      * </ul>
2550      *
2551      * @param  name name of the desired resource
2552      * @return  A {@link java.io.InputStream} object; {@code null} if no
2553      *          resource with this name is found, the resource is in a package
2554      *          that is not {@link Module#isOpen(String, Module) open} to at
2555      *          least the caller module, or access to the resource is denied
2556      *          by the security manager.
2557      * @throws  NullPointerException If {@code name} is {@code null}
2558      *
2559      * @see Module#getResourceAsStream(String)
2560      * @since  1.1
2561      * @revised 9
2562      * @spec JPMS
2563      */
2564     @CallerSensitive
2565     public InputStream getResourceAsStream(String name) {
2566         name = resolveName(name);
2567 
2568         Module thisModule = getModule();
2569         if (thisModule.isNamed()) {
2570             // check if resource can be located by caller
2571             if (Resources.canEncapsulate(name)
2572                 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2573                 return null;
2574             }
2575 
2576             // resource not encapsulated or in package open to caller
2577             String mn = thisModule.getName();
2578             ClassLoader cl = getClassLoader0();
2579             try {
2580 
2581                 // special-case built-in class loaders to avoid the
2582                 // need for a URL connection
2583                 if (cl == null) {
2584                     return BootLoader.findResourceAsStream(mn, name);
2585                 } else if (cl instanceof BuiltinClassLoader) {
2586                     return ((BuiltinClassLoader) cl).findResourceAsStream(mn, name);
2587                 } else {
2588                     URL url = cl.findResource(mn, name);
2589                     return (url != null) ? url.openStream() : null;
2590                 }
2591 
2592             } catch (IOException | SecurityException e) {
2593                 return null;
2594             }
2595         }
2596 
2597         // unnamed module
2598         ClassLoader cl = getClassLoader0();
2599         if (cl == null) {
2600             return ClassLoader.getSystemResourceAsStream(name);
2601         } else {
2602             return cl.getResourceAsStream(name);
2603         }
2604     }
2605 
2606     /**
2607      * Finds a resource with a given name.
2608      *
2609      * <p> If this class is in a named {@link Module Module} then this method
2610      * will attempt to find the resource in the module. This is done by
2611      * delegating to the module's class loader {@link
2612      * ClassLoader#findResource(String,String) findResource(String,String)}
2613      * method, invoking it with the module name and the absolute name of the
2614      * resource. Resources in named modules are subject to the rules for
2615      * encapsulation specified in the {@code Module} {@link
2616      * Module#getResourceAsStream getResourceAsStream} method and so this
2617      * method returns {@code null} when the resource is a
2618      * non-"{@code .class}" resource in a package that is not open to the
2619      * caller's module.
2620      *
2621      * <p> Otherwise, if this class is not in a named module then the rules for
2622      * searching resources associated with a given class are implemented by the
2623      * defining {@linkplain ClassLoader class loader} of the class.  This method
2624      * delegates to this object's class loader. If this object was loaded by
2625      * the bootstrap class loader, the method delegates to {@link
2626      * ClassLoader#getSystemResource}.
2627      *
2628      * <p> Before delegation, an absolute resource name is constructed from the
2629      * given resource name using this algorithm:
2630      *
2631      * <ul>
2632      *
2633      * <li> If the {@code name} begins with a {@code '/'}
2634      * (<code>'\u002f'</code>), then the absolute name of the resource is the
2635      * portion of the {@code name} following the {@code '/'}.
2636      *
2637      * <li> Otherwise, the absolute name is of the following form:
2638      *
2639      * <blockquote>
2640      *   {@code modified_package_name/name}
2641      * </blockquote>
2642      *
2643      * <p> Where the {@code modified_package_name} is the package name of this
2644      * object with {@code '/'} substituted for {@code '.'}
2645      * (<code>'\u002e'</code>).
2646      *
2647      * </ul>
2648      *
2649      * @param  name name of the desired resource
2650      * @return A {@link java.net.URL} object; {@code null} if no resource with
2651      *         this name is found, the resource cannot be located by a URL, the
2652      *         resource is in a package that is not
2653      *         {@link Module#isOpen(String, Module) open} to at least the caller
2654      *         module, or access to the resource is denied by the security
2655      *         manager.
2656      * @throws NullPointerException If {@code name} is {@code null}
2657      * @since  1.1
2658      * @revised 9
2659      * @spec JPMS
2660      */
2661     @CallerSensitive
2662     public URL getResource(String name) {
2663         name = resolveName(name);
2664 
2665         Module thisModule = getModule();
2666         if (thisModule.isNamed()) {
2667             // check if resource can be located by caller
2668             if (Resources.canEncapsulate(name)
2669                 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2670                 return null;
2671             }
2672 
2673             // resource not encapsulated or in package open to caller
2674             String mn = thisModule.getName();
2675             ClassLoader cl = getClassLoader0();
2676             try {
2677                 if (cl == null) {
2678                     return BootLoader.findResource(mn, name);
2679                 } else {
2680                     return cl.findResource(mn, name);
2681                 }
2682             } catch (IOException ioe) {
2683                 return null;
2684             }
2685         }
2686 
2687         // unnamed module
2688         ClassLoader cl = getClassLoader0();
2689         if (cl == null) {
2690             return ClassLoader.getSystemResource(name);
2691         } else {
2692             return cl.getResource(name);
2693         }
2694     }
2695 
2696     /**
2697      * Returns true if a resource with the given name can be located by the
2698      * given caller. All resources in a module can be located by code in
2699      * the module. For other callers, then the package needs to be open to
2700      * the caller.
2701      */
2702     private boolean isOpenToCaller(String name, Class<?> caller) {
2703         // assert getModule().isNamed();
2704         Module thisModule = getModule();
2705         Module callerModule = (caller != null) ? caller.getModule() : null;
2706         if (callerModule != thisModule) {
2707             String pn = Resources.toPackageName(name);
2708             if (thisModule.getDescriptor().packages().contains(pn)) {
2709                 if (callerModule == null && !thisModule.isOpen(pn)) {
2710                     // no caller, package not open
2711                     return false;
2712                 }
2713                 if (!thisModule.isOpen(pn, callerModule)) {
2714                     // package not open to caller
2715                     return false;
2716                 }
2717             }
2718         }
2719         return true;
2720     }
2721 
2722 
2723     /** protection domain returned when the internal domain is null */
2724     private static java.security.ProtectionDomain allPermDomain;
2725 
2726     /**
2727      * Returns the {@code ProtectionDomain} of this class.  If there is a
2728      * security manager installed, this method first calls the security
2729      * manager's {@code checkPermission} method with a
2730      * {@code RuntimePermission("getProtectionDomain")} permission to
2731      * ensure it's ok to get the
2732      * {@code ProtectionDomain}.
2733      *
2734      * @return the ProtectionDomain of this class
2735      *
2736      * @throws SecurityException
2737      *        if a security manager exists and its
2738      *        {@code checkPermission} method doesn't allow
2739      *        getting the ProtectionDomain.
2740      *
2741      * @see java.security.ProtectionDomain
2742      * @see SecurityManager#checkPermission
2743      * @see java.lang.RuntimePermission
2744      * @since 1.2
2745      */
2746     public java.security.ProtectionDomain getProtectionDomain() {
2747         SecurityManager sm = System.getSecurityManager();
2748         if (sm != null) {
2749             sm.checkPermission(SecurityConstants.GET_PD_PERMISSION);
2750         }
2751         java.security.ProtectionDomain pd = getProtectionDomain0();
2752         if (pd == null) {
2753             if (allPermDomain == null) {
2754                 java.security.Permissions perms =
2755                     new java.security.Permissions();
2756                 perms.add(SecurityConstants.ALL_PERMISSION);
2757                 allPermDomain =
2758                     new java.security.ProtectionDomain(null, perms);
2759             }
2760             pd = allPermDomain;
2761         }
2762         return pd;
2763     }
2764 
2765 
2766     /**
2767      * Returns the ProtectionDomain of this class.
2768      */
2769     private native java.security.ProtectionDomain getProtectionDomain0();
2770 
2771     /*
2772      * Return the Virtual Machine's Class object for the named
2773      * primitive type.
2774      */
2775     static native Class<?> getPrimitiveClass(String name);
2776 
2777     /*
2778      * Check if client is allowed to access members.  If access is denied,
2779      * throw a SecurityException.
2780      *
2781      * This method also enforces package access.
2782      *
2783      * <p> Default policy: allow all clients access with normal Java access
2784      * control.
2785      *
2786      * <p> NOTE: should only be called if a SecurityManager is installed
2787      */
2788     private void checkMemberAccess(SecurityManager sm, int which,
2789                                    Class<?> caller, boolean checkProxyInterfaces) {
2790         /* Default policy allows access to all {@link Member#PUBLIC} members,
2791          * as well as access to classes that have the same class loader as the caller.
2792          * In all other cases, it requires RuntimePermission("accessDeclaredMembers")
2793          * permission.
2794          */
2795         final ClassLoader ccl = ClassLoader.getClassLoader(caller);
2796         if (which != Member.PUBLIC) {
2797             final ClassLoader cl = getClassLoader0();
2798             if (ccl != cl) {
2799                 sm.checkPermission(SecurityConstants.CHECK_MEMBER_ACCESS_PERMISSION);
2800             }
2801         }
2802         this.checkPackageAccess(sm, ccl, checkProxyInterfaces);
2803     }
2804 
2805     /*
2806      * Checks if a client loaded in ClassLoader ccl is allowed to access this
2807      * class under the current package access policy. If access is denied,
2808      * throw a SecurityException.
2809      *
2810      * NOTE: this method should only be called if a SecurityManager is active
2811      */
2812     private void checkPackageAccess(SecurityManager sm, final ClassLoader ccl,
2813                                     boolean checkProxyInterfaces) {
2814         final ClassLoader cl = getClassLoader0();
2815 
2816         if (ReflectUtil.needsPackageAccessCheck(ccl, cl)) {
2817             String pkg = this.getPackageName();
2818             if (pkg != null && !pkg.isEmpty()) {
2819                 // skip the package access check on a proxy class in default proxy package
2820                 if (!Proxy.isProxyClass(this) || ReflectUtil.isNonPublicProxyClass(this)) {
2821                     sm.checkPackageAccess(pkg);
2822                 }
2823             }
2824         }
2825         // check package access on the proxy interfaces
2826         if (checkProxyInterfaces && Proxy.isProxyClass(this)) {
2827             ReflectUtil.checkProxyPackageAccess(ccl, this.getInterfaces());
2828         }
2829     }
2830 
2831     /**
2832      * Add a package name prefix if the name is not absolute Remove leading "/"
2833      * if name is absolute
2834      */
2835     private String resolveName(String name) {
2836         if (!name.startsWith("/")) {
2837             Class<?> c = this;
2838             while (c.isArray()) {
2839                 c = c.getComponentType();
2840             }
2841             String baseName = c.getPackageName();
2842             if (baseName != null && !baseName.isEmpty()) {
2843                 name = baseName.replace('.', '/') + "/" + name;
2844             }
2845         } else {
2846             name = name.substring(1);
2847         }
2848         return name;
2849     }
2850 
2851     /**
2852      * Atomic operations support.
2853      */
2854     private static class Atomic {
2855         // initialize Unsafe machinery here, since we need to call Class.class instance method
2856         // and have to avoid calling it in the static initializer of the Class class...
2857         private static final Unsafe unsafe = Unsafe.getUnsafe();
2858         // offset of Class.reflectionData instance field
2859         private static final long reflectionDataOffset;
2860         // offset of Class.annotationType instance field
2861         private static final long annotationTypeOffset;
2862         // offset of Class.annotationData instance field
2863         private static final long annotationDataOffset;
2864 
2865         static {
2866             reflectionDataOffset = objectFieldOffset("reflectionData");
2867             annotationTypeOffset = objectFieldOffset("annotationType");
2868             annotationDataOffset = objectFieldOffset("annotationData");
2869         }
2870 
2871         private static long objectFieldOffset(String fieldName) {
2872             return unsafe.objectFieldOffset(Class.class, fieldName);
2873         }
2874 
2875         static <T> boolean casReflectionData(Class<?> clazz,
2876                                              SoftReference<ReflectionData<T>> oldData,
2877                                              SoftReference<ReflectionData<T>> newData) {
2878             return unsafe.compareAndSetObject(clazz, reflectionDataOffset, oldData, newData);
2879         }
2880 
2881         static <T> boolean casAnnotationType(Class<?> clazz,
2882                                              AnnotationType oldType,
2883                                              AnnotationType newType) {
2884             return unsafe.compareAndSetObject(clazz, annotationTypeOffset, oldType, newType);
2885         }
2886 
2887         static <T> boolean casAnnotationData(Class<?> clazz,
2888                                              AnnotationData oldData,
2889                                              AnnotationData newData) {
2890             return unsafe.compareAndSetObject(clazz, annotationDataOffset, oldData, newData);
2891         }
2892     }
2893 
2894     /**
2895      * Reflection support.
2896      */
2897 
2898     // reflection data that might get invalidated when JVM TI RedefineClasses() is called
2899     private static class ReflectionData<T> {
2900         volatile Field[] declaredFields;
2901         volatile Field[] publicFields;
2902         volatile Method[] declaredMethods;
2903         volatile Method[] publicMethods;
2904         volatile Constructor<T>[] declaredConstructors;
2905         volatile Constructor<T>[] publicConstructors;
2906         // Intermediate results for getFields and getMethods
2907         volatile Field[] declaredPublicFields;
2908         volatile Method[] declaredPublicMethods;
2909         volatile Class<?>[] interfaces;
2910 
2911         // Value of classRedefinedCount when we created this ReflectionData instance
2912         final int redefinedCount;
2913 
2914         ReflectionData(int redefinedCount) {
2915             this.redefinedCount = redefinedCount;
2916         }
2917     }
2918 
2919     private transient volatile SoftReference<ReflectionData<T>> reflectionData;
2920 
2921     // Incremented by the VM on each call to JVM TI RedefineClasses()
2922     // that redefines this class or a superclass.
2923     private transient volatile int classRedefinedCount;
2924 
2925     // Lazily create and cache ReflectionData
2926     private ReflectionData<T> reflectionData() {
2927         SoftReference<ReflectionData<T>> reflectionData = this.reflectionData;
2928         int classRedefinedCount = this.classRedefinedCount;
2929         ReflectionData<T> rd;
2930         if (reflectionData != null &&
2931             (rd = reflectionData.get()) != null &&
2932             rd.redefinedCount == classRedefinedCount) {
2933             return rd;
2934         }
2935         // else no SoftReference or cleared SoftReference or stale ReflectionData
2936         // -> create and replace new instance
2937         return newReflectionData(reflectionData, classRedefinedCount);
2938     }
2939 
2940     private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData,
2941                                                 int classRedefinedCount) {
2942         while (true) {
2943             ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2944             // try to CAS it...
2945             if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) {
2946                 return rd;
2947             }
2948             // else retry
2949             oldReflectionData = this.reflectionData;
2950             classRedefinedCount = this.classRedefinedCount;
2951             if (oldReflectionData != null &&
2952                 (rd = oldReflectionData.get()) != null &&
2953                 rd.redefinedCount == classRedefinedCount) {
2954                 return rd;
2955             }
2956         }
2957     }
2958 
2959     // Generic signature handling
2960     private native String getGenericSignature0();
2961 
2962     // Generic info repository; lazily initialized
2963     private transient volatile ClassRepository genericInfo;
2964 
2965     // accessor for factory
2966     private GenericsFactory getFactory() {
2967         // create scope and factory
2968         return CoreReflectionFactory.make(this, ClassScope.make(this));
2969     }
2970 
2971     // accessor for generic info repository;
2972     // generic info is lazily initialized
2973     private ClassRepository getGenericInfo() {
2974         ClassRepository genericInfo = this.genericInfo;
2975         if (genericInfo == null) {
2976             String signature = getGenericSignature0();
2977             if (signature == null) {
2978                 genericInfo = ClassRepository.NONE;
2979             } else {
2980                 genericInfo = ClassRepository.make(signature, getFactory());
2981             }
2982             this.genericInfo = genericInfo;
2983         }
2984         return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2985     }
2986 
2987     // Annotations handling
2988     native byte[] getRawAnnotations();
2989     // Since 1.8
2990     native byte[] getRawTypeAnnotations();
2991     static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2992         return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2993     }
2994 
2995     native ConstantPool getConstantPool();
2996 
2997     //
2998     //
2999     // java.lang.reflect.Field handling
3000     //
3001     //
3002 
3003     // Returns an array of "root" fields. These Field objects must NOT
3004     // be propagated to the outside world, but must instead be copied
3005     // via ReflectionFactory.copyField.
3006     private Field[] privateGetDeclaredFields(boolean publicOnly) {
3007         Field[] res;
3008         ReflectionData<T> rd = reflectionData();
3009         if (rd != null) {
3010             res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
3011             if (res != null) return res;
3012         }
3013         // No cached value available; request value from VM
3014         res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
3015         if (rd != null) {
3016             if (publicOnly) {
3017                 rd.declaredPublicFields = res;
3018             } else {
3019                 rd.declaredFields = res;
3020             }
3021         }
3022         return res;
3023     }
3024 
3025     // Returns an array of "root" fields. These Field objects must NOT
3026     // be propagated to the outside world, but must instead be copied
3027     // via ReflectionFactory.copyField.
3028     private Field[] privateGetPublicFields(Set<Class<?>> traversedInterfaces) {
3029         Field[] res;
3030         ReflectionData<T> rd = reflectionData();
3031         if (rd != null) {
3032             res = rd.publicFields;
3033             if (res != null) return res;
3034         }
3035 
3036         // No cached value available; compute value recursively.
3037         // Traverse in correct order for getField().
3038         List<Field> fields = new ArrayList<>();
3039         if (traversedInterfaces == null) {
3040             traversedInterfaces = new HashSet<>();
3041         }
3042 
3043         // Local fields
3044         Field[] tmp = privateGetDeclaredFields(true);
3045         addAll(fields, tmp);
3046 
3047         // Direct superinterfaces, recursively
3048         for (Class<?> c : getInterfaces()) {
3049             if (!traversedInterfaces.contains(c)) {
3050                 traversedInterfaces.add(c);
3051                 addAll(fields, c.privateGetPublicFields(traversedInterfaces));
3052             }
3053         }
3054 
3055         // Direct superclass, recursively
3056         if (!isInterface()) {
3057             Class<?> c = getSuperclass();
3058             if (c != null) {
3059                 addAll(fields, c.privateGetPublicFields(traversedInterfaces));
3060             }
3061         }
3062 
3063         res = new Field[fields.size()];
3064         fields.toArray(res);
3065         if (rd != null) {
3066             rd.publicFields = res;
3067         }
3068         return res;
3069     }
3070 
3071     private static void addAll(Collection<Field> c, Field[] o) {
3072         for (Field f : o) {
3073             c.add(f);
3074         }
3075     }
3076 
3077 
3078     //
3079     //
3080     // java.lang.reflect.Constructor handling
3081     //
3082     //
3083 
3084     // Returns an array of "root" constructors. These Constructor
3085     // objects must NOT be propagated to the outside world, but must
3086     // instead be copied via ReflectionFactory.copyConstructor.
3087     private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
3088         Constructor<T>[] res;
3089         ReflectionData<T> rd = reflectionData();
3090         if (rd != null) {
3091             res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3092             if (res != null) return res;
3093         }
3094         // No cached value available; request value from VM
3095         if (isInterface()) {
3096             @SuppressWarnings("unchecked")
3097             Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3098             res = temporaryRes;
3099         } else {
3100             res = getDeclaredConstructors0(publicOnly);
3101         }
3102         if (rd != null) {
3103             if (publicOnly) {
3104                 rd.publicConstructors = res;
3105             } else {
3106                 rd.declaredConstructors = res;
3107             }
3108         }
3109         return res;
3110     }
3111 
3112     //
3113     //
3114     // java.lang.reflect.Method handling
3115     //
3116     //
3117 
3118     // Returns an array of "root" methods. These Method objects must NOT
3119     // be propagated to the outside world, but must instead be copied
3120     // via ReflectionFactory.copyMethod.
3121     private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3122         Method[] res;
3123         ReflectionData<T> rd = reflectionData();
3124         if (rd != null) {
3125             res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3126             if (res != null) return res;
3127         }
3128         // No cached value available; request value from VM
3129         res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3130         if (rd != null) {
3131             if (publicOnly) {
3132                 rd.declaredPublicMethods = res;
3133             } else {
3134                 rd.declaredMethods = res;
3135             }
3136         }
3137         return res;
3138     }
3139 
3140     // Returns an array of "root" methods. These Method objects must NOT
3141     // be propagated to the outside world, but must instead be copied
3142     // via ReflectionFactory.copyMethod.
3143     private Method[] privateGetPublicMethods() {
3144         Method[] res;
3145         ReflectionData<T> rd = reflectionData();
3146         if (rd != null) {
3147             res = rd.publicMethods;
3148             if (res != null) return res;
3149         }
3150 
3151         // No cached value available; compute value recursively.
3152         // Start by fetching public declared methods...
3153         PublicMethods pms = new PublicMethods();
3154         for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3155             pms.merge(m);
3156         }
3157         // ...then recur over superclass methods...
3158         Class<?> sc = getSuperclass();
3159         if (sc != null) {
3160             for (Method m : sc.privateGetPublicMethods()) {
3161                 pms.merge(m);
3162             }
3163         }
3164         // ...and finally over direct superinterfaces.
3165         for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3166             for (Method m : intf.privateGetPublicMethods()) {
3167                 // static interface methods are not inherited
3168                 if (!Modifier.isStatic(m.getModifiers())) {
3169                     pms.merge(m);
3170                 }
3171             }
3172         }
3173 
3174         res = pms.toArray();
3175         if (rd != null) {
3176             rd.publicMethods = res;
3177         }
3178         return res;
3179     }
3180 
3181 
3182     //
3183     // Helpers for fetchers of one field, method, or constructor
3184     //
3185 
3186     // This method does not copy the returned Field object!
3187     private static Field searchFields(Field[] fields, String name) {
3188         for (Field field : fields) {
3189             if (field.getName().equals(name)) {
3190                 return field;
3191             }
3192         }
3193         return null;
3194     }
3195 
3196     // Returns a "root" Field object. This Field object must NOT
3197     // be propagated to the outside world, but must instead be copied
3198     // via ReflectionFactory.copyField.
3199     private Field getField0(String name) {
3200         // Note: the intent is that the search algorithm this routine
3201         // uses be equivalent to the ordering imposed by
3202         // privateGetPublicFields(). It fetches only the declared
3203         // public fields for each class, however, to reduce the number
3204         // of Field objects which have to be created for the common
3205         // case where the field being requested is declared in the
3206         // class which is being queried.
3207         Field res;
3208         // Search declared public fields
3209         if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3210             return res;
3211         }
3212         // Direct superinterfaces, recursively
3213         Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3214         for (Class<?> c : interfaces) {
3215             if ((res = c.getField0(name)) != null) {
3216                 return res;
3217             }
3218         }
3219         // Direct superclass, recursively
3220         if (!isInterface()) {
3221             Class<?> c = getSuperclass();
3222             if (c != null) {
3223                 if ((res = c.getField0(name)) != null) {
3224                     return res;
3225                 }
3226             }
3227         }
3228         return null;
3229     }
3230 
3231     // This method does not copy the returned Method object!
3232     private static Method searchMethods(Method[] methods,
3233                                         String name,
3234                                         Class<?>[] parameterTypes)
3235     {
3236         ReflectionFactory fact = getReflectionFactory();
3237         Method res = null;
3238         for (Method m : methods) {
3239             if (m.getName().equals(name)
3240                 && arrayContentsEq(parameterTypes,
3241                                    fact.getExecutableSharedParameterTypes(m))
3242                 && (res == null
3243                     || (res.getReturnType() != m.getReturnType()
3244                         && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3245                 res = m;
3246         }
3247         return res;
3248     }
3249 
3250     private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3251 
3252     // Returns a "root" Method object. This Method object must NOT
3253     // be propagated to the outside world, but must instead be copied
3254     // via ReflectionFactory.copyMethod.
3255     private Method getMethod0(String name, Class<?>[] parameterTypes) {
3256         PublicMethods.MethodList res = getMethodsRecursive(
3257             name,
3258             parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3259             /* includeStatic */ true);
3260         return res == null ? null : res.getMostSpecific();
3261     }
3262 
3263     // Returns a list of "root" Method objects. These Method objects must NOT
3264     // be propagated to the outside world, but must instead be copied
3265     // via ReflectionFactory.copyMethod.
3266     private PublicMethods.MethodList getMethodsRecursive(String name,
3267                                                          Class<?>[] parameterTypes,
3268                                                          boolean includeStatic) {
3269         // 1st check declared public methods
3270         Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
3271         PublicMethods.MethodList res = PublicMethods.MethodList
3272             .filter(methods, name, parameterTypes, includeStatic);
3273         // if there is at least one match among declared methods, we need not
3274         // search any further as such match surely overrides matching methods
3275         // declared in superclass(es) or interface(s).
3276         if (res != null) {
3277             return res;
3278         }
3279 
3280         // if there was no match among declared methods,
3281         // we must consult the superclass (if any) recursively...
3282         Class<?> sc = getSuperclass();
3283         if (sc != null) {
3284             res = sc.getMethodsRecursive(name, parameterTypes, includeStatic);
3285         }
3286 
3287         // ...and coalesce the superclass methods with methods obtained
3288         // from directly implemented interfaces excluding static methods...
3289         for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3290             res = PublicMethods.MethodList.merge(
3291                 res, intf.getMethodsRecursive(name, parameterTypes,
3292                                               /* includeStatic */ false));
3293         }
3294 
3295         return res;
3296     }
3297 
3298     // Returns a "root" Constructor object. This Constructor object must NOT
3299     // be propagated to the outside world, but must instead be copied
3300     // via ReflectionFactory.copyConstructor.
3301     private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3302                                         int which) throws NoSuchMethodException
3303     {
3304         ReflectionFactory fact = getReflectionFactory();
3305         Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3306         for (Constructor<T> constructor : constructors) {
3307             if (arrayContentsEq(parameterTypes,
3308                                 fact.getExecutableSharedParameterTypes(constructor))) {
3309                 return constructor;
3310             }
3311         }
3312         throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3313     }
3314 
3315     //
3316     // Other helpers and base implementation
3317     //
3318 
3319     private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3320         if (a1 == null) {
3321             return a2 == null || a2.length == 0;
3322         }
3323 
3324         if (a2 == null) {
3325             return a1.length == 0;
3326         }
3327 
3328         if (a1.length != a2.length) {
3329             return false;
3330         }
3331 
3332         for (int i = 0; i < a1.length; i++) {
3333             if (a1[i] != a2[i]) {
3334                 return false;
3335             }
3336         }
3337 
3338         return true;
3339     }
3340 
3341     private static Field[] copyFields(Field[] arg) {
3342         Field[] out = new Field[arg.length];
3343         ReflectionFactory fact = getReflectionFactory();
3344         for (int i = 0; i < arg.length; i++) {
3345             out[i] = fact.copyField(arg[i]);
3346         }
3347         return out;
3348     }
3349 
3350     private static Method[] copyMethods(Method[] arg) {
3351         Method[] out = new Method[arg.length];
3352         ReflectionFactory fact = getReflectionFactory();
3353         for (int i = 0; i < arg.length; i++) {
3354             out[i] = fact.copyMethod(arg[i]);
3355         }
3356         return out;
3357     }
3358 
3359     private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3360         Constructor<U>[] out = arg.clone();
3361         ReflectionFactory fact = getReflectionFactory();
3362         for (int i = 0; i < out.length; i++) {
3363             out[i] = fact.copyConstructor(out[i]);
3364         }
3365         return out;
3366     }
3367 
3368     private native Field[]       getDeclaredFields0(boolean publicOnly);
3369     private native Method[]      getDeclaredMethods0(boolean publicOnly);
3370     private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3371     private native Class<?>[]   getDeclaredClasses0();
3372 
3373     /**
3374      * Helper method to get the method name from arguments.
3375      */
3376     private String methodToString(String name, Class<?>[] argTypes) {
3377         StringJoiner sj = new StringJoiner(", ", getName() + "." + name + "(", ")");
3378         if (argTypes != null) {
3379             for (int i = 0; i < argTypes.length; i++) {
3380                 Class<?> c = argTypes[i];
3381                 sj.add((c == null) ? "null" : c.getName());
3382             }
3383         }
3384         return sj.toString();
3385     }
3386 
3387     /** use serialVersionUID from JDK 1.1 for interoperability */
3388     private static final long serialVersionUID = 3206093459760846163L;
3389 
3390 
3391     /**
3392      * Class Class is special cased within the Serialization Stream Protocol.
3393      *
3394      * A Class instance is written initially into an ObjectOutputStream in the
3395      * following format:
3396      * <pre>
3397      *      {@code TC_CLASS} ClassDescriptor
3398      *      A ClassDescriptor is a special cased serialization of
3399      *      a {@code java.io.ObjectStreamClass} instance.
3400      * </pre>
3401      * A new handle is generated for the initial time the class descriptor
3402      * is written into the stream. Future references to the class descriptor
3403      * are written as references to the initial class descriptor instance.
3404      *
3405      * @see java.io.ObjectStreamClass
3406      */
3407     private static final ObjectStreamField[] serialPersistentFields =
3408         new ObjectStreamField[0];
3409 
3410 
3411     /**
3412      * Returns the assertion status that would be assigned to this
3413      * class if it were to be initialized at the time this method is invoked.
3414      * If this class has had its assertion status set, the most recent
3415      * setting will be returned; otherwise, if any package default assertion
3416      * status pertains to this class, the most recent setting for the most
3417      * specific pertinent package default assertion status is returned;
3418      * otherwise, if this class is not a system class (i.e., it has a
3419      * class loader) its class loader's default assertion status is returned;
3420      * otherwise, the system class default assertion status is returned.
3421      * <p>
3422      * Few programmers will have any need for this method; it is provided
3423      * for the benefit of the JRE itself.  (It allows a class to determine at
3424      * the time that it is initialized whether assertions should be enabled.)
3425      * Note that this method is not guaranteed to return the actual
3426      * assertion status that was (or will be) associated with the specified
3427      * class when it was (or will be) initialized.
3428      *
3429      * @return the desired assertion status of the specified class.
3430      * @see    java.lang.ClassLoader#setClassAssertionStatus
3431      * @see    java.lang.ClassLoader#setPackageAssertionStatus
3432      * @see    java.lang.ClassLoader#setDefaultAssertionStatus
3433      * @since  1.4
3434      */
3435     public boolean desiredAssertionStatus() {
3436         ClassLoader loader = getClassLoader0();
3437         // If the loader is null this is a system class, so ask the VM
3438         if (loader == null)
3439             return desiredAssertionStatus0(this);
3440 
3441         // If the classloader has been initialized with the assertion
3442         // directives, ask it. Otherwise, ask the VM.
3443         synchronized(loader.assertionLock) {
3444             if (loader.classAssertionStatus != null) {
3445                 return loader.desiredAssertionStatus(getName());
3446             }
3447         }
3448         return desiredAssertionStatus0(this);
3449     }
3450 
3451     // Retrieves the desired assertion status of this class from the VM
3452     private static native boolean desiredAssertionStatus0(Class<?> clazz);
3453 
3454     /**
3455      * Returns true if and only if this class was declared as an enum in the
3456      * source code.
3457      *
3458      * @return true if and only if this class was declared as an enum in the
3459      *     source code
3460      * @since 1.5
3461      */
3462     public boolean isEnum() {
3463         // An enum must both directly extend java.lang.Enum and have
3464         // the ENUM bit set; classes for specialized enum constants
3465         // don't do the former.
3466         return (this.getModifiers() & ENUM) != 0 &&
3467         this.getSuperclass() == java.lang.Enum.class;
3468     }
3469 
3470     // Fetches the factory for reflective objects
3471     private static ReflectionFactory getReflectionFactory() {
3472         if (reflectionFactory == null) {
3473             reflectionFactory =
3474                 java.security.AccessController.doPrivileged
3475                     (new ReflectionFactory.GetReflectionFactoryAction());
3476         }
3477         return reflectionFactory;
3478     }
3479     private static ReflectionFactory reflectionFactory;
3480 
3481     /**
3482      * Returns the elements of this enum class or null if this
3483      * Class object does not represent an enum type.
3484      *
3485      * @return an array containing the values comprising the enum class
3486      *     represented by this Class object in the order they're
3487      *     declared, or null if this Class object does not
3488      *     represent an enum type
3489      * @since 1.5
3490      */
3491     public T[] getEnumConstants() {
3492         T[] values = getEnumConstantsShared();
3493         return (values != null) ? values.clone() : null;
3494     }
3495 
3496     /**
3497      * Returns the elements of this enum class or null if this
3498      * Class object does not represent an enum type;
3499      * identical to getEnumConstants except that the result is
3500      * uncloned, cached, and shared by all callers.
3501      */
3502     T[] getEnumConstantsShared() {
3503         T[] constants = enumConstants;
3504         if (constants == null) {
3505             if (!isEnum()) return null;
3506             try {
3507                 final Method values = getMethod("values");
3508                 java.security.AccessController.doPrivileged(
3509                     new java.security.PrivilegedAction<>() {
3510                         public Void run() {
3511                                 values.setAccessible(true);
3512                                 return null;
3513                             }
3514                         });
3515                 @SuppressWarnings("unchecked")
3516                 T[] temporaryConstants = (T[])values.invoke(null);
3517                 enumConstants = constants = temporaryConstants;
3518             }
3519             // These can happen when users concoct enum-like classes
3520             // that don't comply with the enum spec.
3521             catch (InvocationTargetException | NoSuchMethodException |
3522                    IllegalAccessException ex) { return null; }
3523         }
3524         return constants;
3525     }
3526     private transient volatile T[] enumConstants;
3527 
3528     /**
3529      * Returns a map from simple name to enum constant.  This package-private
3530      * method is used internally by Enum to implement
3531      * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3532      * efficiently.  Note that the map is returned by this method is
3533      * created lazily on first use.  Typically it won't ever get created.
3534      */
3535     Map<String, T> enumConstantDirectory() {
3536         Map<String, T> directory = enumConstantDirectory;
3537         if (directory == null) {
3538             T[] universe = getEnumConstantsShared();
3539             if (universe == null)
3540                 throw new IllegalArgumentException(
3541                     getName() + " is not an enum type");
3542             directory = new HashMap<>(2 * universe.length);
3543             for (T constant : universe) {
3544                 directory.put(((Enum<?>)constant).name(), constant);
3545             }
3546             enumConstantDirectory = directory;
3547         }
3548         return directory;
3549     }
3550     private transient volatile Map<String, T> enumConstantDirectory;
3551 
3552     /**
3553      * Casts an object to the class or interface represented
3554      * by this {@code Class} object.
3555      *
3556      * @param obj the object to be cast
3557      * @return the object after casting, or null if obj is null
3558      *
3559      * @throws ClassCastException if the object is not
3560      * null and is not assignable to the type T.
3561      *
3562      * @since 1.5
3563      */
3564     @SuppressWarnings("unchecked")
3565     @HotSpotIntrinsicCandidate
3566     public T cast(Object obj) {
3567         if (obj != null && !isInstance(obj))
3568             throw new ClassCastException(cannotCastMsg(obj));
3569         return (T) obj;
3570     }
3571 
3572     private String cannotCastMsg(Object obj) {
3573         return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3574     }
3575 
3576     /**
3577      * Casts this {@code Class} object to represent a subclass of the class
3578      * represented by the specified class object.  Checks that the cast
3579      * is valid, and throws a {@code ClassCastException} if it is not.  If
3580      * this method succeeds, it always returns a reference to this class object.
3581      *
3582      * <p>This method is useful when a client needs to "narrow" the type of
3583      * a {@code Class} object to pass it to an API that restricts the
3584      * {@code Class} objects that it is willing to accept.  A cast would
3585      * generate a compile-time warning, as the correctness of the cast
3586      * could not be checked at runtime (because generic types are implemented
3587      * by erasure).
3588      *
3589      * @param <U> the type to cast this class object to
3590      * @param clazz the class of the type to cast this class object to
3591      * @return this {@code Class} object, cast to represent a subclass of
3592      *    the specified class object.
3593      * @throws ClassCastException if this {@code Class} object does not
3594      *    represent a subclass of the specified class (here "subclass" includes
3595      *    the class itself).
3596      * @since 1.5
3597      */
3598     @SuppressWarnings("unchecked")
3599     public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3600         if (clazz.isAssignableFrom(this))
3601             return (Class<? extends U>) this;
3602         else
3603             throw new ClassCastException(this.toString());
3604     }
3605 
3606     /**
3607      * @throws NullPointerException {@inheritDoc}
3608      * @since 1.5
3609      */
3610     @SuppressWarnings("unchecked")
3611     public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3612         Objects.requireNonNull(annotationClass);
3613 
3614         return (A) annotationData().annotations.get(annotationClass);
3615     }
3616 
3617     /**
3618      * {@inheritDoc}
3619      * @throws NullPointerException {@inheritDoc}
3620      * @since 1.5
3621      */
3622     @Override
3623     public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3624         return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3625     }
3626 
3627     /**
3628      * @throws NullPointerException {@inheritDoc}
3629      * @since 1.8
3630      */
3631     @Override
3632     public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3633         Objects.requireNonNull(annotationClass);
3634 
3635         AnnotationData annotationData = annotationData();
3636         return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3637                                                           this,
3638                                                           annotationClass);
3639     }
3640 
3641     /**
3642      * @since 1.5
3643      */
3644     public Annotation[] getAnnotations() {
3645         return AnnotationParser.toArray(annotationData().annotations);
3646     }
3647 
3648     /**
3649      * @throws NullPointerException {@inheritDoc}
3650      * @since 1.8
3651      */
3652     @Override
3653     @SuppressWarnings("unchecked")
3654     public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3655         Objects.requireNonNull(annotationClass);
3656 
3657         return (A) annotationData().declaredAnnotations.get(annotationClass);
3658     }
3659 
3660     /**
3661      * @throws NullPointerException {@inheritDoc}
3662      * @since 1.8
3663      */
3664     @Override
3665     public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3666         Objects.requireNonNull(annotationClass);
3667 
3668         return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3669                                                                  annotationClass);
3670     }
3671 
3672     /**
3673      * @since 1.5
3674      */
3675     public Annotation[] getDeclaredAnnotations()  {
3676         return AnnotationParser.toArray(annotationData().declaredAnnotations);
3677     }
3678 
3679     // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3680     private static class AnnotationData {
3681         final Map<Class<? extends Annotation>, Annotation> annotations;
3682         final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3683 
3684         // Value of classRedefinedCount when we created this AnnotationData instance
3685         final int redefinedCount;
3686 
3687         AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3688                        Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3689                        int redefinedCount) {
3690             this.annotations = annotations;
3691             this.declaredAnnotations = declaredAnnotations;
3692             this.redefinedCount = redefinedCount;
3693         }
3694     }
3695 
3696     // Annotations cache
3697     @SuppressWarnings("UnusedDeclaration")
3698     private transient volatile AnnotationData annotationData;
3699 
3700     private AnnotationData annotationData() {
3701         while (true) { // retry loop
3702             AnnotationData annotationData = this.annotationData;
3703             int classRedefinedCount = this.classRedefinedCount;
3704             if (annotationData != null &&
3705                 annotationData.redefinedCount == classRedefinedCount) {
3706                 return annotationData;
3707             }
3708             // null or stale annotationData -> optimistically create new instance
3709             AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3710             // try to install it
3711             if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3712                 // successfully installed new AnnotationData
3713                 return newAnnotationData;
3714             }
3715         }
3716     }
3717 
3718     private AnnotationData createAnnotationData(int classRedefinedCount) {
3719         Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3720             AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3721         Class<?> superClass = getSuperclass();
3722         Map<Class<? extends Annotation>, Annotation> annotations = null;
3723         if (superClass != null) {
3724             Map<Class<? extends Annotation>, Annotation> superAnnotations =
3725                 superClass.annotationData().annotations;
3726             for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3727                 Class<? extends Annotation> annotationClass = e.getKey();
3728                 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3729                     if (annotations == null) { // lazy construction
3730                         annotations = new LinkedHashMap<>((Math.max(
3731                                 declaredAnnotations.size(),
3732                                 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3733                             ) * 4 + 2) / 3
3734                         );
3735                     }
3736                     annotations.put(annotationClass, e.getValue());
3737                 }
3738             }
3739         }
3740         if (annotations == null) {
3741             // no inherited annotations -> share the Map with declaredAnnotations
3742             annotations = declaredAnnotations;
3743         } else {
3744             // at least one inherited annotation -> declared may override inherited
3745             annotations.putAll(declaredAnnotations);
3746         }
3747         return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3748     }
3749 
3750     // Annotation types cache their internal (AnnotationType) form
3751 
3752     @SuppressWarnings("UnusedDeclaration")
3753     private transient volatile AnnotationType annotationType;
3754 
3755     boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3756         return Atomic.casAnnotationType(this, oldType, newType);
3757     }
3758 
3759     AnnotationType getAnnotationType() {
3760         return annotationType;
3761     }
3762 
3763     Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3764         return annotationData().declaredAnnotations;
3765     }
3766 
3767     /* Backing store of user-defined values pertaining to this class.
3768      * Maintained by the ClassValue class.
3769      */
3770     transient ClassValue.ClassValueMap classValueMap;
3771 
3772     /**
3773      * Returns an {@code AnnotatedType} object that represents the use of a
3774      * type to specify the superclass of the entity represented by this {@code
3775      * Class} object. (The <em>use</em> of type Foo to specify the superclass
3776      * in '...  extends Foo' is distinct from the <em>declaration</em> of type
3777      * Foo.)
3778      *
3779      * <p> If this {@code Class} object represents a type whose declaration
3780      * does not explicitly indicate an annotated superclass, then the return
3781      * value is an {@code AnnotatedType} object representing an element with no
3782      * annotations.
3783      *
3784      * <p> If this {@code Class} represents either the {@code Object} class, an
3785      * interface type, an array type, a primitive type, or void, the return
3786      * value is {@code null}.
3787      *
3788      * @return an object representing the superclass
3789      * @since 1.8
3790      */
3791     public AnnotatedType getAnnotatedSuperclass() {
3792         if (this == Object.class ||
3793                 isInterface() ||
3794                 isArray() ||
3795                 isPrimitive() ||
3796                 this == Void.TYPE) {
3797             return null;
3798         }
3799 
3800         return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3801     }
3802 
3803     /**
3804      * Returns an array of {@code AnnotatedType} objects that represent the use
3805      * of types to specify superinterfaces of the entity represented by this
3806      * {@code Class} object. (The <em>use</em> of type Foo to specify a
3807      * superinterface in '... implements Foo' is distinct from the
3808      * <em>declaration</em> of type Foo.)
3809      *
3810      * <p> If this {@code Class} object represents a class, the return value is
3811      * an array containing objects representing the uses of interface types to
3812      * specify interfaces implemented by the class. The order of the objects in
3813      * the array corresponds to the order of the interface types used in the
3814      * 'implements' clause of the declaration of this {@code Class} object.
3815      *
3816      * <p> If this {@code Class} object represents an interface, the return
3817      * value is an array containing objects representing the uses of interface
3818      * types to specify interfaces directly extended by the interface. The
3819      * order of the objects in the array corresponds to the order of the
3820      * interface types used in the 'extends' clause of the declaration of this
3821      * {@code Class} object.
3822      *
3823      * <p> If this {@code Class} object represents a class or interface whose
3824      * declaration does not explicitly indicate any annotated superinterfaces,
3825      * the return value is an array of length 0.
3826      *
3827      * <p> If this {@code Class} object represents either the {@code Object}
3828      * class, an array type, a primitive type, or void, the return value is an
3829      * array of length 0.
3830      *
3831      * @return an array representing the superinterfaces
3832      * @since 1.8
3833      */
3834     public AnnotatedType[] getAnnotatedInterfaces() {
3835          return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3836     }
3837 }