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J. Duke319a3b92007-12-01 00:00:00 +00001/*
2 * Copyright 1994-2006 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26package java.lang;
27
28import java.lang.reflect.Array;
29import java.lang.reflect.GenericArrayType;
30import java.lang.reflect.Member;
31import java.lang.reflect.Field;
32import java.lang.reflect.Method;
33import java.lang.reflect.Constructor;
34import java.lang.reflect.GenericDeclaration;
35import java.lang.reflect.Modifier;
36import java.lang.reflect.Type;
37import java.lang.reflect.TypeVariable;
38import java.lang.reflect.InvocationTargetException;
39import java.lang.ref.SoftReference;
40import java.io.InputStream;
41import java.io.ObjectStreamField;
42import java.security.AccessController;
43import java.security.PrivilegedAction;
44import java.util.ArrayList;
45import java.util.Arrays;
46import java.util.Collection;
47import java.util.HashSet;
48import java.util.Iterator;
49import java.util.List;
50import java.util.LinkedList;
51import java.util.LinkedHashSet;
52import java.util.Set;
53import java.util.Map;
54import java.util.HashMap;
55import sun.misc.Unsafe;
56import sun.reflect.ConstantPool;
57import sun.reflect.Reflection;
58import sun.reflect.ReflectionFactory;
59import sun.reflect.SignatureIterator;
60import sun.reflect.generics.factory.CoreReflectionFactory;
61import sun.reflect.generics.factory.GenericsFactory;
62import sun.reflect.generics.repository.ClassRepository;
63import sun.reflect.generics.repository.MethodRepository;
64import sun.reflect.generics.repository.ConstructorRepository;
65import sun.reflect.generics.scope.ClassScope;
66import sun.security.util.SecurityConstants;
67import java.lang.annotation.Annotation;
68import sun.reflect.annotation.*;
69
70/**
71 * Instances of the class {@code Class} represent classes and
72 * interfaces in a running Java application. An enum is a kind of
73 * class and an annotation is a kind of interface. Every array also
74 * belongs to a class that is reflected as a {@code Class} object
75 * that is shared by all arrays with the same element type and number
76 * of dimensions. The primitive Java types ({@code boolean},
77 * {@code byte}, {@code char}, {@code short},
78 * {@code int}, {@code long}, {@code float}, and
79 * {@code double}), and the keyword {@code void} are also
80 * represented as {@code Class} objects.
81 *
82 * <p> {@code Class} has no public constructor. Instead {@code Class}
83 * objects are constructed automatically by the Java Virtual Machine as classes
84 * are loaded and by calls to the {@code defineClass} method in the class
85 * loader.
86 *
87 * <p> The following example uses a {@code Class} object to print the
88 * class name of an object:
89 *
90 * <p> <blockquote><pre>
91 * void printClassName(Object obj) {
92 * System.out.println("The class of " + obj +
93 * " is " + obj.getClass().getName());
94 * }
95 * </pre></blockquote>
96 *
97 * <p> It is also possible to get the {@code Class} object for a named
98 * type (or for void) using a class literal
99 * (JLS Section <A HREF="http://java.sun.com/docs/books/jls/second_edition/html/expressions.doc.html#251530">15.8.2</A>).
100 * For example:
101 *
102 * <p> <blockquote>
103 * {@code System.out.println("The name of class Foo is: "+Foo.class.getName());}
104 * </blockquote>
105 *
106 * @param <T> the type of the class modeled by this {@code Class}
107 * object. For example, the type of {@code String.class} is {@code
108 * Class<String>}. Use {@code Class<?>} if the class being modeled is
109 * unknown.
110 *
111 * @author unascribed
112 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
113 * @since JDK1.0
114 */
115public final
116 class Class<T> implements java.io.Serializable,
117 java.lang.reflect.GenericDeclaration,
118 java.lang.reflect.Type,
119 java.lang.reflect.AnnotatedElement {
120 private static final int ANNOTATION= 0x00002000;
121 private static final int ENUM = 0x00004000;
122 private static final int SYNTHETIC = 0x00001000;
123
124 private static native void registerNatives();
125 static {
126 registerNatives();
127 }
128
129 /*
130 * Constructor. Only the Java Virtual Machine creates Class
131 * objects.
132 */
133 private Class() {}
134
135
136 /**
137 * Converts the object to a string. The string representation is the
138 * string "class" or "interface", followed by a space, and then by the
139 * fully qualified name of the class in the format returned by
140 * {@code getName}. If this {@code Class} object represents a
141 * primitive type, this method returns the name of the primitive type. If
142 * this {@code Class} object represents void this method returns
143 * "void".
144 *
145 * @return a string representation of this class object.
146 */
147 public String toString() {
148 return (isInterface() ? "interface " : (isPrimitive() ? "" : "class "))
149 + getName();
150 }
151
152
153 /**
154 * Returns the {@code Class} object associated with the class or
155 * interface with the given string name. Invoking this method is
156 * equivalent to:
157 *
158 * <blockquote>
159 * {@code Class.forName(className, true, currentLoader)}
160 * </blockquote>
161 *
162 * where {@code currentLoader} denotes the defining class loader of
163 * the current class.
164 *
165 * <p> For example, the following code fragment returns the
166 * runtime {@code Class} descriptor for the class named
167 * {@code java.lang.Thread}:
168 *
169 * <blockquote>
170 * {@code Class t = Class.forName("java.lang.Thread")}
171 * </blockquote>
172 * <p>
173 * A call to {@code forName("X")} causes the class named
174 * {@code X} to be initialized.
175 *
176 * @param className the fully qualified name of the desired class.
177 * @return the {@code Class} object for the class with the
178 * specified name.
179 * @exception LinkageError if the linkage fails
180 * @exception ExceptionInInitializerError if the initialization provoked
181 * by this method fails
182 * @exception ClassNotFoundException if the class cannot be located
183 */
184 public static Class<?> forName(String className)
185 throws ClassNotFoundException {
186 return forName0(className, true, ClassLoader.getCallerClassLoader());
187 }
188
189
190 /**
191 * Returns the {@code Class} object associated with the class or
192 * interface with the given string name, using the given class loader.
193 * Given the fully qualified name for a class or interface (in the same
194 * format returned by {@code getName}) this method attempts to
195 * locate, load, and link the class or interface. The specified class
196 * loader is used to load the class or interface. If the parameter
197 * {@code loader} is null, the class is loaded through the bootstrap
198 * class loader. The class is initialized only if the
199 * {@code initialize} parameter is {@code true} and if it has
200 * not been initialized earlier.
201 *
202 * <p> If {@code name} denotes a primitive type or void, an attempt
203 * will be made to locate a user-defined class in the unnamed package whose
204 * name is {@code name}. Therefore, this method cannot be used to
205 * obtain any of the {@code Class} objects representing primitive
206 * types or void.
207 *
208 * <p> If {@code name} denotes an array class, the component type of
209 * the array class is loaded but not initialized.
210 *
211 * <p> For example, in an instance method the expression:
212 *
213 * <blockquote>
214 * {@code Class.forName("Foo")}
215 * </blockquote>
216 *
217 * is equivalent to:
218 *
219 * <blockquote>
220 * {@code Class.forName("Foo", true, this.getClass().getClassLoader())}
221 * </blockquote>
222 *
223 * Note that this method throws errors related to loading, linking or
224 * initializing as specified in Sections 12.2, 12.3 and 12.4 of <em>The
225 * Java Language Specification</em>.
226 * Note that this method does not check whether the requested class
227 * is accessible to its caller.
228 *
229 * <p> If the {@code loader} is {@code null}, and a security
230 * manager is present, and the caller's class loader is not null, then this
231 * method calls the security manager's {@code checkPermission} method
232 * with a {@code RuntimePermission("getClassLoader")} permission to
233 * ensure it's ok to access the bootstrap class loader.
234 *
235 * @param name fully qualified name of the desired class
236 * @param initialize whether the class must be initialized
237 * @param loader class loader from which the class must be loaded
238 * @return class object representing the desired class
239 *
240 * @exception LinkageError if the linkage fails
241 * @exception ExceptionInInitializerError if the initialization provoked
242 * by this method fails
243 * @exception ClassNotFoundException if the class cannot be located by
244 * the specified class loader
245 *
246 * @see java.lang.Class#forName(String)
247 * @see java.lang.ClassLoader
248 * @since 1.2
249 */
250 public static Class<?> forName(String name, boolean initialize,
251 ClassLoader loader)
252 throws ClassNotFoundException
253 {
254 if (loader == null) {
255 SecurityManager sm = System.getSecurityManager();
256 if (sm != null) {
257 ClassLoader ccl = ClassLoader.getCallerClassLoader();
258 if (ccl != null) {
259 sm.checkPermission(
260 SecurityConstants.GET_CLASSLOADER_PERMISSION);
261 }
262 }
263 }
264 return forName0(name, initialize, loader);
265 }
266
267 /** Called after security checks have been made. */
268 private static native Class forName0(String name, boolean initialize,
269 ClassLoader loader)
270 throws ClassNotFoundException;
271
272 /**
273 * Creates a new instance of the class represented by this {@code Class}
274 * object. The class is instantiated as if by a {@code new}
275 * expression with an empty argument list. The class is initialized if it
276 * has not already been initialized.
277 *
278 * <p>Note that this method propagates any exception thrown by the
279 * nullary constructor, including a checked exception. Use of
280 * this method effectively bypasses the compile-time exception
281 * checking that would otherwise be performed by the compiler.
282 * The {@link
283 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
284 * Constructor.newInstance} method avoids this problem by wrapping
285 * any exception thrown by the constructor in a (checked) {@link
286 * java.lang.reflect.InvocationTargetException}.
287 *
288 * @return a newly allocated instance of the class represented by this
289 * object.
290 * @exception IllegalAccessException if the class or its nullary
291 * constructor is not accessible.
292 * @exception InstantiationException
293 * if this {@code Class} represents an abstract class,
294 * an interface, an array class, a primitive type, or void;
295 * or if the class has no nullary constructor;
296 * or if the instantiation fails for some other reason.
297 * @exception ExceptionInInitializerError if the initialization
298 * provoked by this method fails.
299 * @exception SecurityException
300 * If a security manager, <i>s</i>, is present and any of the
301 * following conditions is met:
302 *
303 * <ul>
304 *
305 * <li> invocation of
306 * {@link SecurityManager#checkMemberAccess
307 * s.checkMemberAccess(this, Member.PUBLIC)} denies
308 * creation of new instances of this class
309 *
310 * <li> the caller's class loader is not the same as or an
311 * ancestor of the class loader for the current class and
312 * invocation of {@link SecurityManager#checkPackageAccess
313 * s.checkPackageAccess()} denies access to the package
314 * of this class
315 *
316 * </ul>
317 *
318 */
319 public T newInstance()
320 throws InstantiationException, IllegalAccessException
321 {
322 if (System.getSecurityManager() != null) {
323 checkMemberAccess(Member.PUBLIC, ClassLoader.getCallerClassLoader());
324 }
325 return newInstance0();
326 }
327
328 private T newInstance0()
329 throws InstantiationException, IllegalAccessException
330 {
331 // NOTE: the following code may not be strictly correct under
332 // the current Java memory model.
333
334 // Constructor lookup
335 if (cachedConstructor == null) {
336 if (this == Class.class) {
337 throw new IllegalAccessException(
338 "Can not call newInstance() on the Class for java.lang.Class"
339 );
340 }
341 try {
342 Class[] empty = {};
343 final Constructor<T> c = getConstructor0(empty, Member.DECLARED);
344 // Disable accessibility checks on the constructor
345 // since we have to do the security check here anyway
346 // (the stack depth is wrong for the Constructor's
347 // security check to work)
348 java.security.AccessController.doPrivileged
349 (new java.security.PrivilegedAction() {
350 public Object run() {
351 c.setAccessible(true);
352 return null;
353 }
354 });
355 cachedConstructor = c;
356 } catch (NoSuchMethodException e) {
357 throw new InstantiationException(getName());
358 }
359 }
360 Constructor<T> tmpConstructor = cachedConstructor;
361 // Security check (same as in java.lang.reflect.Constructor)
362 int modifiers = tmpConstructor.getModifiers();
363 if (!Reflection.quickCheckMemberAccess(this, modifiers)) {
364 Class caller = Reflection.getCallerClass(3);
365 if (newInstanceCallerCache != caller) {
366 Reflection.ensureMemberAccess(caller, this, null, modifiers);
367 newInstanceCallerCache = caller;
368 }
369 }
370 // Run constructor
371 try {
372 return tmpConstructor.newInstance((Object[])null);
373 } catch (InvocationTargetException e) {
374 Unsafe.getUnsafe().throwException(e.getTargetException());
375 // Not reached
376 return null;
377 }
378 }
379 private volatile transient Constructor<T> cachedConstructor;
380 private volatile transient Class newInstanceCallerCache;
381
382
383 /**
384 * Determines if the specified {@code Object} is assignment-compatible
385 * with the object represented by this {@code Class}. This method is
386 * the dynamic equivalent of the Java language {@code instanceof}
387 * operator. The method returns {@code true} if the specified
388 * {@code Object} argument is non-null and can be cast to the
389 * reference type represented by this {@code Class} object without
390 * raising a {@code ClassCastException.} It returns {@code false}
391 * otherwise.
392 *
393 * <p> Specifically, if this {@code Class} object represents a
394 * declared class, this method returns {@code true} if the specified
395 * {@code Object} argument is an instance of the represented class (or
396 * of any of its subclasses); it returns {@code false} otherwise. If
397 * this {@code Class} object represents an array class, this method
398 * returns {@code true} if the specified {@code Object} argument
399 * can be converted to an object of the array class by an identity
400 * conversion or by a widening reference conversion; it returns
401 * {@code false} otherwise. If this {@code Class} object
402 * represents an interface, this method returns {@code true} if the
403 * class or any superclass of the specified {@code Object} argument
404 * implements this interface; it returns {@code false} otherwise. If
405 * this {@code Class} object represents a primitive type, this method
406 * returns {@code false}.
407 *
408 * @param obj the object to check
409 * @return true if {@code obj} is an instance of this class
410 *
411 * @since JDK1.1
412 */
413 public native boolean isInstance(Object obj);
414
415
416 /**
417 * Determines if the class or interface represented by this
418 * {@code Class} object is either the same as, or is a superclass or
419 * superinterface of, the class or interface represented by the specified
420 * {@code Class} parameter. It returns {@code true} if so;
421 * otherwise it returns {@code false}. If this {@code Class}
422 * object represents a primitive type, this method returns
423 * {@code true} if the specified {@code Class} parameter is
424 * exactly this {@code Class} object; otherwise it returns
425 * {@code false}.
426 *
427 * <p> Specifically, this method tests whether the type represented by the
428 * specified {@code Class} parameter can be converted to the type
429 * represented by this {@code Class} object via an identity conversion
430 * or via a widening reference conversion. See <em>The Java Language
431 * Specification</em>, sections 5.1.1 and 5.1.4 , for details.
432 *
433 * @param cls the {@code Class} object to be checked
434 * @return the {@code boolean} value indicating whether objects of the
435 * type {@code cls} can be assigned to objects of this class
436 * @exception NullPointerException if the specified Class parameter is
437 * null.
438 * @since JDK1.1
439 */
440 public native boolean isAssignableFrom(Class<?> cls);
441
442
443 /**
444 * Determines if the specified {@code Class} object represents an
445 * interface type.
446 *
447 * @return {@code true} if this object represents an interface;
448 * {@code false} otherwise.
449 */
450 public native boolean isInterface();
451
452
453 /**
454 * Determines if this {@code Class} object represents an array class.
455 *
456 * @return {@code true} if this object represents an array class;
457 * {@code false} otherwise.
458 * @since JDK1.1
459 */
460 public native boolean isArray();
461
462
463 /**
464 * Determines if the specified {@code Class} object represents a
465 * primitive type.
466 *
467 * <p> There are nine predefined {@code Class} objects to represent
468 * the eight primitive types and void. These are created by the Java
469 * Virtual Machine, and have the same names as the primitive types that
470 * they represent, namely {@code boolean}, {@code byte},
471 * {@code char}, {@code short}, {@code int},
472 * {@code long}, {@code float}, and {@code double}.
473 *
474 * <p> These objects may only be accessed via the following public static
475 * final variables, and are the only {@code Class} objects for which
476 * this method returns {@code true}.
477 *
478 * @return true if and only if this class represents a primitive type
479 *
480 * @see java.lang.Boolean#TYPE
481 * @see java.lang.Character#TYPE
482 * @see java.lang.Byte#TYPE
483 * @see java.lang.Short#TYPE
484 * @see java.lang.Integer#TYPE
485 * @see java.lang.Long#TYPE
486 * @see java.lang.Float#TYPE
487 * @see java.lang.Double#TYPE
488 * @see java.lang.Void#TYPE
489 * @since JDK1.1
490 */
491 public native boolean isPrimitive();
492
493 /**
494 * Returns true if this {@code Class} object represents an annotation
495 * type. Note that if this method returns true, {@link #isInterface()}
496 * would also return true, as all annotation types are also interfaces.
497 *
498 * @return {@code true} if this class object represents an annotation
499 * type; {@code false} otherwise
500 * @since 1.5
501 */
502 public boolean isAnnotation() {
503 return (getModifiers() & ANNOTATION) != 0;
504 }
505
506 /**
507 * Returns {@code true} if this class is a synthetic class;
508 * returns {@code false} otherwise.
509 * @return {@code true} if and only if this class is a synthetic class as
510 * defined by the Java Language Specification.
511 * @since 1.5
512 */
513 public boolean isSynthetic() {
514 return (getModifiers() & SYNTHETIC) != 0;
515 }
516
517 /**
518 * Returns the name of the entity (class, interface, array class,
519 * primitive type, or void) represented by this {@code Class} object,
520 * as a {@code String}.
521 *
522 * <p> If this class object represents a reference type that is not an
523 * array type then the binary name of the class is returned, as specified
524 * by the Java Language Specification, Second Edition.
525 *
526 * <p> If this class object represents a primitive type or void, then the
527 * name returned is a {@code String} equal to the Java language
528 * keyword corresponding to the primitive type or void.
529 *
530 * <p> If this class object represents a class of arrays, then the internal
531 * form of the name consists of the name of the element type preceded by
532 * one or more '{@code [}' characters representing the depth of the array
533 * nesting. The encoding of element type names is as follows:
534 *
535 * <blockquote><table summary="Element types and encodings">
536 * <tr><th> Element Type <th> &nbsp;&nbsp;&nbsp; <th> Encoding
537 * <tr><td> boolean <td> &nbsp;&nbsp;&nbsp; <td align=center> Z
538 * <tr><td> byte <td> &nbsp;&nbsp;&nbsp; <td align=center> B
539 * <tr><td> char <td> &nbsp;&nbsp;&nbsp; <td align=center> C
540 * <tr><td> class or interface
541 * <td> &nbsp;&nbsp;&nbsp; <td align=center> L<i>classname</i>;
542 * <tr><td> double <td> &nbsp;&nbsp;&nbsp; <td align=center> D
543 * <tr><td> float <td> &nbsp;&nbsp;&nbsp; <td align=center> F
544 * <tr><td> int <td> &nbsp;&nbsp;&nbsp; <td align=center> I
545 * <tr><td> long <td> &nbsp;&nbsp;&nbsp; <td align=center> J
546 * <tr><td> short <td> &nbsp;&nbsp;&nbsp; <td align=center> S
547 * </table></blockquote>
548 *
549 * <p> The class or interface name <i>classname</i> is the binary name of
550 * the class specified above.
551 *
552 * <p> Examples:
553 * <blockquote><pre>
554 * String.class.getName()
555 * returns "java.lang.String"
556 * byte.class.getName()
557 * returns "byte"
558 * (new Object[3]).getClass().getName()
559 * returns "[Ljava.lang.Object;"
560 * (new int[3][4][5][6][7][8][9]).getClass().getName()
561 * returns "[[[[[[[I"
562 * </pre></blockquote>
563 *
564 * @return the name of the class or interface
565 * represented by this object.
566 */
567 public String getName() {
568 if (name == null)
569 name = getName0();
570 return name;
571 }
572
573 // cache the name to reduce the number of calls into the VM
574 private transient String name;
575 private native String getName0();
576
577 /**
578 * Returns the class loader for the class. Some implementations may use
579 * null to represent the bootstrap class loader. This method will return
580 * null in such implementations if this class was loaded by the bootstrap
581 * class loader.
582 *
583 * <p> If a security manager is present, and the caller's class loader is
584 * not null and the caller's class loader is not the same as or an ancestor of
585 * the class loader for the class whose class loader is requested, then
586 * this method calls the security manager's {@code checkPermission}
587 * method with a {@code RuntimePermission("getClassLoader")}
588 * permission to ensure it's ok to access the class loader for the class.
589 *
590 * <p>If this object
591 * represents a primitive type or void, null is returned.
592 *
593 * @return the class loader that loaded the class or interface
594 * represented by this object.
595 * @throws SecurityException
596 * if a security manager exists and its
597 * {@code checkPermission} method denies
598 * access to the class loader for the class.
599 * @see java.lang.ClassLoader
600 * @see SecurityManager#checkPermission
601 * @see java.lang.RuntimePermission
602 */
603 public ClassLoader getClassLoader() {
604 ClassLoader cl = getClassLoader0();
605 if (cl == null)
606 return null;
607 SecurityManager sm = System.getSecurityManager();
608 if (sm != null) {
609 ClassLoader ccl = ClassLoader.getCallerClassLoader();
610 if (ccl != null && ccl != cl && !cl.isAncestor(ccl)) {
611 sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);
612 }
613 }
614 return cl;
615 }
616
617 // Package-private to allow ClassLoader access
618 native ClassLoader getClassLoader0();
619
620
621 /**
622 * Returns an array of {@code TypeVariable} objects that represent the
623 * type variables declared by the generic declaration represented by this
624 * {@code GenericDeclaration} object, in declaration order. Returns an
625 * array of length 0 if the underlying generic declaration declares no type
626 * variables.
627 *
628 * @return an array of {@code TypeVariable} objects that represent
629 * the type variables declared by this generic declaration
630 * @throws GenericSignatureFormatError if the generic
631 * signature of this generic declaration does not conform to
632 * the format specified in the Java Virtual Machine Specification,
633 * 3rd edition
634 * @since 1.5
635 */
636 public TypeVariable<Class<T>>[] getTypeParameters() {
637 if (getGenericSignature() != null)
638 return (TypeVariable<Class<T>>[])getGenericInfo().getTypeParameters();
639 else
640 return (TypeVariable<Class<T>>[])new TypeVariable[0];
641 }
642
643
644 /**
645 * Returns the {@code Class} representing the superclass of the entity
646 * (class, interface, primitive type or void) represented by this
647 * {@code Class}. If this {@code Class} represents either the
648 * {@code Object} class, an interface, a primitive type, or void, then
649 * null is returned. If this object represents an array class then the
650 * {@code Class} object representing the {@code Object} class is
651 * returned.
652 *
653 * @return the superclass of the class represented by this object.
654 */
655 public native Class<? super T> getSuperclass();
656
657
658 /**
659 * Returns the {@code Type} representing the direct superclass of
660 * the entity (class, interface, primitive type or void) represented by
661 * this {@code Class}.
662 *
663 * <p>If the superclass is a parameterized type, the {@code Type}
664 * object returned must accurately reflect the actual type
665 * parameters used in the source code. The parameterized type
666 * representing the superclass is created if it had not been
667 * created before. See the declaration of {@link
668 * java.lang.reflect.ParameterizedType ParameterizedType} for the
669 * semantics of the creation process for parameterized types. If
670 * this {@code Class} represents either the {@code Object}
671 * class, an interface, a primitive type, or void, then null is
672 * returned. If this object represents an array class then the
673 * {@code Class} object representing the {@code Object} class is
674 * returned.
675 *
676 * @throws GenericSignatureFormatError if the generic
677 * class signature does not conform to the format specified in the
678 * Java Virtual Machine Specification, 3rd edition
679 * @throws TypeNotPresentException if the generic superclass
680 * refers to a non-existent type declaration
681 * @throws MalformedParameterizedTypeException if the
682 * generic superclass refers to a parameterized type that cannot be
683 * instantiated for any reason
684 * @return the superclass of the class represented by this object
685 * @since 1.5
686 */
687 public Type getGenericSuperclass() {
688 if (getGenericSignature() != null) {
689 // Historical irregularity:
690 // Generic signature marks interfaces with superclass = Object
691 // but this API returns null for interfaces
692 if (isInterface())
693 return null;
694 return getGenericInfo().getSuperclass();
695 } else
696 return getSuperclass();
697 }
698
699 /**
700 * Gets the package for this class. The class loader of this class is used
701 * to find the package. If the class was loaded by the bootstrap class
702 * loader the set of packages loaded from CLASSPATH is searched to find the
703 * package of the class. Null is returned if no package object was created
704 * by the class loader of this class.
705 *
706 * <p> Packages have attributes for versions and specifications only if the
707 * information was defined in the manifests that accompany the classes, and
708 * if the class loader created the package instance with the attributes
709 * from the manifest.
710 *
711 * @return the package of the class, or null if no package
712 * information is available from the archive or codebase.
713 */
714 public Package getPackage() {
715 return Package.getPackage(this);
716 }
717
718
719 /**
720 * Determines the interfaces implemented by the class or interface
721 * represented by this object.
722 *
723 * <p> If this object represents a class, the return value is an array
724 * containing objects representing all interfaces implemented by the
725 * class. The order of the interface objects in the array corresponds to
726 * the order of the interface names in the {@code implements} clause
727 * of the declaration of the class represented by this object. For
728 * example, given the declaration:
729 * <blockquote>
730 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
731 * </blockquote>
732 * suppose the value of {@code s} is an instance of
733 * {@code Shimmer}; the value of the expression:
734 * <blockquote>
735 * {@code s.getClass().getInterfaces()[0]}
736 * </blockquote>
737 * is the {@code Class} object that represents interface
738 * {@code FloorWax}; and the value of:
739 * <blockquote>
740 * {@code s.getClass().getInterfaces()[1]}
741 * </blockquote>
742 * is the {@code Class} object that represents interface
743 * {@code DessertTopping}.
744 *
745 * <p> If this object represents an interface, the array contains objects
746 * representing all interfaces extended by the interface. The order of the
747 * interface objects in the array corresponds to the order of the interface
748 * names in the {@code extends} clause of the declaration of the
749 * interface represented by this object.
750 *
751 * <p> If this object represents a class or interface that implements no
752 * interfaces, the method returns an array of length 0.
753 *
754 * <p> If this object represents a primitive type or void, the method
755 * returns an array of length 0.
756 *
757 * @return an array of interfaces implemented by this class.
758 */
759 public native Class<?>[] getInterfaces();
760
761 /**
762 * Returns the {@code Type}s representing the interfaces
763 * directly implemented by the class or interface represented by
764 * this object.
765 *
766 * <p>If a superinterface is a parameterized type, the
767 * {@code Type} object returned for it must accurately reflect
768 * the actual type parameters used in the source code. The
769 * parameterized type representing each superinterface is created
770 * if it had not been created before. See the declaration of
771 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
772 * for the semantics of the creation process for parameterized
773 * types.
774 *
775 * <p> If this object represents a class, the return value is an
776 * array containing objects representing all interfaces
777 * implemented by the class. The order of the interface objects in
778 * the array corresponds to the order of the interface names in
779 * the {@code implements} clause of the declaration of the class
780 * represented by this object. In the case of an array class, the
781 * interfaces {@code Cloneable} and {@code Serializable} are
782 * returned in that order.
783 *
784 * <p>If this object represents an interface, the array contains
785 * objects representing all interfaces directly extended by the
786 * interface. The order of the interface objects in the array
787 * corresponds to the order of the interface names in the
788 * {@code extends} clause of the declaration of the interface
789 * represented by this object.
790 *
791 * <p>If this object represents a class or interface that
792 * implements no interfaces, the method returns an array of length
793 * 0.
794 *
795 * <p>If this object represents a primitive type or void, the
796 * method returns an array of length 0.
797 *
798 * @throws GenericSignatureFormatError
799 * if the generic class signature does not conform to the format
800 * specified in the Java Virtual Machine Specification, 3rd edition
801 * @throws TypeNotPresentException if any of the generic
802 * superinterfaces refers to a non-existent type declaration
803 * @throws MalformedParameterizedTypeException if any of the
804 * generic superinterfaces refer to a parameterized type that cannot
805 * be instantiated for any reason
806 * @return an array of interfaces implemented by this class
807 * @since 1.5
808 */
809 public Type[] getGenericInterfaces() {
810 if (getGenericSignature() != null)
811 return getGenericInfo().getSuperInterfaces();
812 else
813 return getInterfaces();
814 }
815
816
817 /**
818 * Returns the {@code Class} representing the component type of an
819 * array. If this class does not represent an array class this method
820 * returns null.
821 *
822 * @return the {@code Class} representing the component type of this
823 * class if this class is an array
824 * @see java.lang.reflect.Array
825 * @since JDK1.1
826 */
827 public native Class<?> getComponentType();
828
829
830 /**
831 * Returns the Java language modifiers for this class or interface, encoded
832 * in an integer. The modifiers consist of the Java Virtual Machine's
833 * constants for {@code public}, {@code protected},
834 * {@code private}, {@code final}, {@code static},
835 * {@code abstract} and {@code interface}; they should be decoded
836 * using the methods of class {@code Modifier}.
837 *
838 * <p> If the underlying class is an array class, then its
839 * {@code public}, {@code private} and {@code protected}
840 * modifiers are the same as those of its component type. If this
841 * {@code Class} represents a primitive type or void, its
842 * {@code public} modifier is always {@code true}, and its
843 * {@code protected} and {@code private} modifiers are always
844 * {@code false}. If this object represents an array class, a
845 * primitive type or void, then its {@code final} modifier is always
846 * {@code true} and its interface modifier is always
847 * {@code false}. The values of its other modifiers are not determined
848 * by this specification.
849 *
850 * <p> The modifier encodings are defined in <em>The Java Virtual Machine
851 * Specification</em>, table 4.1.
852 *
853 * @return the {@code int} representing the modifiers for this class
854 * @see java.lang.reflect.Modifier
855 * @since JDK1.1
856 */
857 public native int getModifiers();
858
859
860 /**
861 * Gets the signers of this class.
862 *
863 * @return the signers of this class, or null if there are no signers. In
864 * particular, this method returns null if this object represents
865 * a primitive type or void.
866 * @since JDK1.1
867 */
868 public native Object[] getSigners();
869
870
871 /**
872 * Set the signers of this class.
873 */
874 native void setSigners(Object[] signers);
875
876
877 /**
878 * If this {@code Class} object represents a local or anonymous
879 * class within a method, returns a {@link
880 * java.lang.reflect.Method Method} object representing the
881 * immediately enclosing method of the underlying class. Returns
882 * {@code null} otherwise.
883 *
884 * In particular, this method returns {@code null} if the underlying
885 * class is a local or anonymous class immediately enclosed by a type
886 * declaration, instance initializer or static initializer.
887 *
888 * @return the immediately enclosing method of the underlying class, if
889 * that class is a local or anonymous class; otherwise {@code null}.
890 * @since 1.5
891 */
892 public Method getEnclosingMethod() {
893 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
894
895 if (enclosingInfo == null)
896 return null;
897 else {
898 if (!enclosingInfo.isMethod())
899 return null;
900
901 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
902 getFactory());
903 Class returnType = toClass(typeInfo.getReturnType());
904 Type [] parameterTypes = typeInfo.getParameterTypes();
905 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
906
907 // Convert Types to Classes; returned types *should*
908 // be class objects since the methodDescriptor's used
909 // don't have generics information
910 for(int i = 0; i < parameterClasses.length; i++)
911 parameterClasses[i] = toClass(parameterTypes[i]);
912
913 /*
914 * Loop over all declared methods; match method name,
915 * number of and type of parameters, *and* return
916 * type. Matching return type is also necessary
917 * because of covariant returns, etc.
918 */
919 for(Method m: enclosingInfo.getEnclosingClass().getDeclaredMethods()) {
920 if (m.getName().equals(enclosingInfo.getName()) ) {
921 Class<?>[] candidateParamClasses = m.getParameterTypes();
922 if (candidateParamClasses.length == parameterClasses.length) {
923 boolean matches = true;
924 for(int i = 0; i < candidateParamClasses.length; i++) {
925 if (!candidateParamClasses[i].equals(parameterClasses[i])) {
926 matches = false;
927 break;
928 }
929 }
930
931 if (matches) { // finally, check return type
932 if (m.getReturnType().equals(returnType) )
933 return m;
934 }
935 }
936 }
937 }
938
939 throw new InternalError("Enclosing method not found");
940 }
941 }
942
943 private native Object[] getEnclosingMethod0();
944
945 private EnclosingMethodInfo getEnclosingMethodInfo() {
946 Object[] enclosingInfo = getEnclosingMethod0();
947 if (enclosingInfo == null)
948 return null;
949 else {
950 return new EnclosingMethodInfo(enclosingInfo);
951 }
952 }
953
954 private final static class EnclosingMethodInfo {
955 private Class<?> enclosingClass;
956 private String name;
957 private String descriptor;
958
959 private EnclosingMethodInfo(Object[] enclosingInfo) {
960 if (enclosingInfo.length != 3)
961 throw new InternalError("Malformed enclosing method information");
962 try {
963 // The array is expected to have three elements:
964
965 // the immediately enclosing class
966 enclosingClass = (Class<?>) enclosingInfo[0];
967 assert(enclosingClass != null);
968
969 // the immediately enclosing method or constructor's
970 // name (can be null).
971 name = (String) enclosingInfo[1];
972
973 // the immediately enclosing method or constructor's
974 // descriptor (null iff name is).
975 descriptor = (String) enclosingInfo[2];
976 assert((name != null && descriptor != null) || name == descriptor);
977 } catch (ClassCastException cce) {
978 throw new InternalError("Invalid type in enclosing method information");
979 }
980 }
981
982 boolean isPartial() {
983 return enclosingClass == null || name == null || descriptor == null;
984 }
985
986 boolean isConstructor() { return !isPartial() && "<init>".equals(name); }
987
988 boolean isMethod() { return !isPartial() && !isConstructor() && !"<clinit>".equals(name); }
989
990 Class<?> getEnclosingClass() { return enclosingClass; }
991
992 String getName() { return name; }
993
994 String getDescriptor() { return descriptor; }
995
996 }
997
998 private static Class toClass(Type o) {
999 if (o instanceof GenericArrayType)
1000 return Array.newInstance(toClass(((GenericArrayType)o).getGenericComponentType()),
1001 0)
1002 .getClass();
1003 return (Class)o;
1004 }
1005
1006 /**
1007 * If this {@code Class} object represents a local or anonymous
1008 * class within a constructor, returns a {@link
1009 * java.lang.reflect.Constructor Constructor} object representing
1010 * the immediately enclosing constructor of the underlying
1011 * class. Returns {@code null} otherwise. In particular, this
1012 * method returns {@code null} if the underlying class is a local
1013 * or anonymous class immediately enclosed by a type declaration,
1014 * instance initializer or static initializer.
1015 *
1016 * @return the immediately enclosing constructor of the underlying class, if
1017 * that class is a local or anonymous class; otherwise {@code null}.
1018 * @since 1.5
1019 */
1020 public Constructor<?> getEnclosingConstructor() {
1021 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1022
1023 if (enclosingInfo == null)
1024 return null;
1025 else {
1026 if (!enclosingInfo.isConstructor())
1027 return null;
1028
1029 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1030 getFactory());
1031 Type [] parameterTypes = typeInfo.getParameterTypes();
1032 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1033
1034 // Convert Types to Classes; returned types *should*
1035 // be class objects since the methodDescriptor's used
1036 // don't have generics information
1037 for(int i = 0; i < parameterClasses.length; i++)
1038 parameterClasses[i] = toClass(parameterTypes[i]);
1039
1040 /*
1041 * Loop over all declared constructors; match number
1042 * of and type of parameters.
1043 */
1044 for(Constructor c: enclosingInfo.getEnclosingClass().getDeclaredConstructors()) {
1045 Class<?>[] candidateParamClasses = c.getParameterTypes();
1046 if (candidateParamClasses.length == parameterClasses.length) {
1047 boolean matches = true;
1048 for(int i = 0; i < candidateParamClasses.length; i++) {
1049 if (!candidateParamClasses[i].equals(parameterClasses[i])) {
1050 matches = false;
1051 break;
1052 }
1053 }
1054
1055 if (matches)
1056 return c;
1057 }
1058 }
1059
1060 throw new InternalError("Enclosing constructor not found");
1061 }
1062 }
1063
1064
1065 /**
1066 * If the class or interface represented by this {@code Class} object
1067 * is a member of another class, returns the {@code Class} object
1068 * representing the class in which it was declared. This method returns
1069 * null if this class or interface is not a member of any other class. If
1070 * this {@code Class} object represents an array class, a primitive
1071 * type, or void,then this method returns null.
1072 *
1073 * @return the declaring class for this class
1074 * @since JDK1.1
1075 */
1076 public native Class<?> getDeclaringClass();
1077
1078
1079 /**
1080 * Returns the immediately enclosing class of the underlying
1081 * class. If the underlying class is a top level class this
1082 * method returns {@code null}.
1083 * @return the immediately enclosing class of the underlying class
1084 * @since 1.5
1085 */
1086 public Class<?> getEnclosingClass() {
1087 // There are five kinds of classes (or interfaces):
1088 // a) Top level classes
1089 // b) Nested classes (static member classes)
1090 // c) Inner classes (non-static member classes)
1091 // d) Local classes (named classes declared within a method)
1092 // e) Anonymous classes
1093
1094
1095 // JVM Spec 4.8.6: A class must have an EnclosingMethod
1096 // attribute if and only if it is a local class or an
1097 // anonymous class.
1098 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1099
1100 if (enclosingInfo == null) {
1101 // This is a top level or a nested class or an inner class (a, b, or c)
1102 return getDeclaringClass();
1103 } else {
1104 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1105 // This is a local class or an anonymous class (d or e)
1106 if (enclosingClass == this || enclosingClass == null)
1107 throw new InternalError("Malformed enclosing method information");
1108 else
1109 return enclosingClass;
1110 }
1111 }
1112
1113 /**
1114 * Returns the simple name of the underlying class as given in the
1115 * source code. Returns an empty string if the underlying class is
1116 * anonymous.
1117 *
1118 * <p>The simple name of an array is the simple name of the
1119 * component type with "[]" appended. In particular the simple
1120 * name of an array whose component type is anonymous is "[]".
1121 *
1122 * @return the simple name of the underlying class
1123 * @since 1.5
1124 */
1125 public String getSimpleName() {
1126 if (isArray())
1127 return getComponentType().getSimpleName()+"[]";
1128
1129 String simpleName = getSimpleBinaryName();
1130 if (simpleName == null) { // top level class
1131 simpleName = getName();
1132 return simpleName.substring(simpleName.lastIndexOf(".")+1); // strip the package name
1133 }
1134 // According to JLS3 "Binary Compatibility" (13.1) the binary
1135 // name of non-package classes (not top level) is the binary
1136 // name of the immediately enclosing class followed by a '$' followed by:
1137 // (for nested and inner classes): the simple name.
1138 // (for local classes): 1 or more digits followed by the simple name.
1139 // (for anonymous classes): 1 or more digits.
1140
1141 // Since getSimpleBinaryName() will strip the binary name of
1142 // the immediatly enclosing class, we are now looking at a
1143 // string that matches the regular expression "\$[0-9]*"
1144 // followed by a simple name (considering the simple of an
1145 // anonymous class to be the empty string).
1146
1147 // Remove leading "\$[0-9]*" from the name
1148 int length = simpleName.length();
1149 if (length < 1 || simpleName.charAt(0) != '$')
1150 throw new InternalError("Malformed class name");
1151 int index = 1;
1152 while (index < length && isAsciiDigit(simpleName.charAt(index)))
1153 index++;
1154 // Eventually, this is the empty string iff this is an anonymous class
1155 return simpleName.substring(index);
1156 }
1157
1158 /**
1159 * Character.isDigit answers {@code true} to some non-ascii
1160 * digits. This one does not.
1161 */
1162 private static boolean isAsciiDigit(char c) {
1163 return '0' <= c && c <= '9';
1164 }
1165
1166 /**
1167 * Returns the canonical name of the underlying class as
1168 * defined by the Java Language Specification. Returns null if
1169 * the underlying class does not have a canonical name (i.e., if
1170 * it is a local or anonymous class or an array whose component
1171 * type does not have a canonical name).
1172 * @return the canonical name of the underlying class if it exists, and
1173 * {@code null} otherwise.
1174 * @since 1.5
1175 */
1176 public String getCanonicalName() {
1177 if (isArray()) {
1178 String canonicalName = getComponentType().getCanonicalName();
1179 if (canonicalName != null)
1180 return canonicalName + "[]";
1181 else
1182 return null;
1183 }
1184 if (isLocalOrAnonymousClass())
1185 return null;
1186 Class<?> enclosingClass = getEnclosingClass();
1187 if (enclosingClass == null) { // top level class
1188 return getName();
1189 } else {
1190 String enclosingName = enclosingClass.getCanonicalName();
1191 if (enclosingName == null)
1192 return null;
1193 return enclosingName + "." + getSimpleName();
1194 }
1195 }
1196
1197 /**
1198 * Returns {@code true} if and only if the underlying class
1199 * is an anonymous class.
1200 *
1201 * @return {@code true} if and only if this class is an anonymous class.
1202 * @since 1.5
1203 */
1204 public boolean isAnonymousClass() {
1205 return "".equals(getSimpleName());
1206 }
1207
1208 /**
1209 * Returns {@code true} if and only if the underlying class
1210 * is a local class.
1211 *
1212 * @return {@code true} if and only if this class is a local class.
1213 * @since 1.5
1214 */
1215 public boolean isLocalClass() {
1216 return isLocalOrAnonymousClass() && !isAnonymousClass();
1217 }
1218
1219 /**
1220 * Returns {@code true} if and only if the underlying class
1221 * is a member class.
1222 *
1223 * @return {@code true} if and only if this class is a member class.
1224 * @since 1.5
1225 */
1226 public boolean isMemberClass() {
1227 return getSimpleBinaryName() != null && !isLocalOrAnonymousClass();
1228 }
1229
1230 /**
1231 * Returns the "simple binary name" of the underlying class, i.e.,
1232 * the binary name without the leading enclosing class name.
1233 * Returns {@code null} if the underlying class is a top level
1234 * class.
1235 */
1236 private String getSimpleBinaryName() {
1237 Class<?> enclosingClass = getEnclosingClass();
1238 if (enclosingClass == null) // top level class
1239 return null;
1240 // Otherwise, strip the enclosing class' name
1241 try {
1242 return getName().substring(enclosingClass.getName().length());
1243 } catch (IndexOutOfBoundsException ex) {
1244 throw new InternalError("Malformed class name");
1245 }
1246 }
1247
1248 /**
1249 * Returns {@code true} if this is a local class or an anonymous
1250 * class. Returns {@code false} otherwise.
1251 */
1252 private boolean isLocalOrAnonymousClass() {
1253 // JVM Spec 4.8.6: A class must have an EnclosingMethod
1254 // attribute if and only if it is a local class or an
1255 // anonymous class.
1256 return getEnclosingMethodInfo() != null;
1257 }
1258
1259 /**
1260 * Returns an array containing {@code Class} objects representing all
1261 * the public classes and interfaces that are members of the class
1262 * represented by this {@code Class} object. This includes public
1263 * class and interface members inherited from superclasses and public class
1264 * and interface members declared by the class. This method returns an
1265 * array of length 0 if this {@code Class} object has no public member
1266 * classes or interfaces. This method also returns an array of length 0 if
1267 * this {@code Class} object represents a primitive type, an array
1268 * class, or void.
1269 *
1270 * @return the array of {@code Class} objects representing the public
1271 * members of this class
1272 * @exception SecurityException
1273 * If a security manager, <i>s</i>, is present and any of the
1274 * following conditions is met:
1275 *
1276 * <ul>
1277 *
1278 * <li> invocation of
1279 * {@link SecurityManager#checkMemberAccess
1280 * s.checkMemberAccess(this, Member.PUBLIC)} method
1281 * denies access to the classes within this class
1282 *
1283 * <li> the caller's class loader is not the same as or an
1284 * ancestor of the class loader for the current class and
1285 * invocation of {@link SecurityManager#checkPackageAccess
1286 * s.checkPackageAccess()} denies access to the package
1287 * of this class
1288 *
1289 * </ul>
1290 *
1291 * @since JDK1.1
1292 */
1293 public Class<?>[] getClasses() {
1294 // be very careful not to change the stack depth of this
1295 // checkMemberAccess call for security reasons
1296 // see java.lang.SecurityManager.checkMemberAccess
1297 checkMemberAccess(Member.PUBLIC, ClassLoader.getCallerClassLoader());
1298
1299 // Privileged so this implementation can look at DECLARED classes,
1300 // something the caller might not have privilege to do. The code here
1301 // is allowed to look at DECLARED classes because (1) it does not hand
1302 // out anything other than public members and (2) public member access
1303 // has already been ok'd by the SecurityManager.
1304
1305 Class[] result = (Class[]) java.security.AccessController.doPrivileged
1306 (new java.security.PrivilegedAction() {
1307 public Object run() {
1308 java.util.List<Class> list = new java.util.ArrayList();
1309 Class currentClass = Class.this;
1310 while (currentClass != null) {
1311 Class[] members = currentClass.getDeclaredClasses();
1312 for (int i = 0; i < members.length; i++) {
1313 if (Modifier.isPublic(members[i].getModifiers())) {
1314 list.add(members[i]);
1315 }
1316 }
1317 currentClass = currentClass.getSuperclass();
1318 }
1319 Class[] empty = {};
1320 return list.toArray(empty);
1321 }
1322 });
1323
1324 return result;
1325 }
1326
1327
1328 /**
1329 * Returns an array containing {@code Field} objects reflecting all
1330 * the accessible public fields of the class or interface represented by
1331 * this {@code Class} object. The elements in the array returned are
1332 * not sorted and are not in any particular order. This method returns an
1333 * array of length 0 if the class or interface has no accessible public
1334 * fields, or if it represents an array class, a primitive type, or void.
1335 *
1336 * <p> Specifically, if this {@code Class} object represents a class,
1337 * this method returns the public fields of this class and of all its
1338 * superclasses. If this {@code Class} object represents an
1339 * interface, this method returns the fields of this interface and of all
1340 * its superinterfaces.
1341 *
1342 * <p> The implicit length field for array class is not reflected by this
1343 * method. User code should use the methods of class {@code Array} to
1344 * manipulate arrays.
1345 *
1346 * <p> See <em>The Java Language Specification</em>, sections 8.2 and 8.3.
1347 *
1348 * @return the array of {@code Field} objects representing the
1349 * public fields
1350 * @exception SecurityException
1351 * If a security manager, <i>s</i>, is present and any of the
1352 * following conditions is met:
1353 *
1354 * <ul>
1355 *
1356 * <li> invocation of
1357 * {@link SecurityManager#checkMemberAccess
1358 * s.checkMemberAccess(this, Member.PUBLIC)} denies
1359 * access to the fields within this class
1360 *
1361 * <li> the caller's class loader is not the same as or an
1362 * ancestor of the class loader for the current class and
1363 * invocation of {@link SecurityManager#checkPackageAccess
1364 * s.checkPackageAccess()} denies access to the package
1365 * of this class
1366 *
1367 * </ul>
1368 *
1369 * @since JDK1.1
1370 */
1371 public Field[] getFields() throws SecurityException {
1372 // be very careful not to change the stack depth of this
1373 // checkMemberAccess call for security reasons
1374 // see java.lang.SecurityManager.checkMemberAccess
1375 checkMemberAccess(Member.PUBLIC, ClassLoader.getCallerClassLoader());
1376 return copyFields(privateGetPublicFields(null));
1377 }
1378
1379
1380 /**
1381 * Returns an array containing {@code Method} objects reflecting all
1382 * the public <em>member</em> methods of the class or interface represented
1383 * by this {@code Class} object, including those declared by the class
1384 * or interface and those inherited from superclasses and
1385 * superinterfaces. Array classes return all the (public) member methods
1386 * inherited from the {@code Object} class. The elements in the array
1387 * returned are not sorted and are not in any particular order. This
1388 * method returns an array of length 0 if this {@code Class} object
1389 * represents a class or interface that has no public member methods, or if
1390 * this {@code Class} object represents a primitive type or void.
1391 *
1392 * <p> The class initialization method {@code <clinit>} is not
1393 * included in the returned array. If the class declares multiple public
1394 * member methods with the same parameter types, they are all included in
1395 * the returned array.
1396 *
1397 * <p> See <em>The Java Language Specification</em>, sections 8.2 and 8.4.
1398 *
1399 * @return the array of {@code Method} objects representing the
1400 * public methods of this class
1401 * @exception SecurityException
1402 * If a security manager, <i>s</i>, is present and any of the
1403 * following conditions is met:
1404 *
1405 * <ul>
1406 *
1407 * <li> invocation of
1408 * {@link SecurityManager#checkMemberAccess
1409 * s.checkMemberAccess(this, Member.PUBLIC)} denies
1410 * access to the methods within this class
1411 *
1412 * <li> the caller's class loader is not the same as or an
1413 * ancestor of the class loader for the current class and
1414 * invocation of {@link SecurityManager#checkPackageAccess
1415 * s.checkPackageAccess()} denies access to the package
1416 * of this class
1417 *
1418 * </ul>
1419 *
1420 * @since JDK1.1
1421 */
1422 public Method[] getMethods() throws SecurityException {
1423 // be very careful not to change the stack depth of this
1424 // checkMemberAccess call for security reasons
1425 // see java.lang.SecurityManager.checkMemberAccess
1426 checkMemberAccess(Member.PUBLIC, ClassLoader.getCallerClassLoader());
1427 return copyMethods(privateGetPublicMethods());
1428 }
1429
1430
1431 /**
1432 * Returns an array containing {@code Constructor} objects reflecting
1433 * all the public constructors of the class represented by this
1434 * {@code Class} object. An array of length 0 is returned if the
1435 * class has no public constructors, or if the class is an array class, or
1436 * if the class reflects a primitive type or void.
1437 *
1438 * Note that while this method returns an array of {@code
1439 * Constructor<T>} objects (that is an array of constructors from
1440 * this class), the return type of this method is {@code
1441 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
1442 * might be expected. This less informative return type is
1443 * necessary since after being returned from this method, the
1444 * array could be modified to hold {@code Constructor} objects for
1445 * different classes, which would violate the type guarantees of
1446 * {@code Constructor<T>[]}.
1447 *
1448 * @return the array of {@code Constructor} objects representing the
1449 * public constructors of this class
1450 * @exception SecurityException
1451 * If a security manager, <i>s</i>, is present and any of the
1452 * following conditions is met:
1453 *
1454 * <ul>
1455 *
1456 * <li> invocation of
1457 * {@link SecurityManager#checkMemberAccess
1458 * s.checkMemberAccess(this, Member.PUBLIC)} denies
1459 * access to the constructors within this class
1460 *
1461 * <li> the caller's class loader is not the same as or an
1462 * ancestor of the class loader for the current class and
1463 * invocation of {@link SecurityManager#checkPackageAccess
1464 * s.checkPackageAccess()} denies access to the package
1465 * of this class
1466 *
1467 * </ul>
1468 *
1469 * @since JDK1.1
1470 */
1471 public Constructor<?>[] getConstructors() throws SecurityException {
1472 // be very careful not to change the stack depth of this
1473 // checkMemberAccess call for security reasons
1474 // see java.lang.SecurityManager.checkMemberAccess
1475 checkMemberAccess(Member.PUBLIC, ClassLoader.getCallerClassLoader());
1476 return copyConstructors(privateGetDeclaredConstructors(true));
1477 }
1478
1479
1480 /**
1481 * Returns a {@code Field} object that reflects the specified public
1482 * member field of the class or interface represented by this
1483 * {@code Class} object. The {@code name} parameter is a
1484 * {@code String} specifying the simple name of the desired field.
1485 *
1486 * <p> The field to be reflected is determined by the algorithm that
1487 * follows. Let C be the class represented by this object:
1488 * <OL>
1489 * <LI> If C declares a public field with the name specified, that is the
1490 * field to be reflected.</LI>
1491 * <LI> If no field was found in step 1 above, this algorithm is applied
1492 * recursively to each direct superinterface of C. The direct
1493 * superinterfaces are searched in the order they were declared.</LI>
1494 * <LI> If no field was found in steps 1 and 2 above, and C has a
1495 * superclass S, then this algorithm is invoked recursively upon S.
1496 * If C has no superclass, then a {@code NoSuchFieldException}
1497 * is thrown.</LI>
1498 * </OL>
1499 *
1500 * <p> See <em>The Java Language Specification</em>, sections 8.2 and 8.3.
1501 *
1502 * @param name the field name
1503 * @return the {@code Field} object of this class specified by
1504 * {@code name}
1505 * @exception NoSuchFieldException if a field with the specified name is
1506 * not found.
1507 * @exception NullPointerException if {@code name} is {@code null}
1508 * @exception SecurityException
1509 * If a security manager, <i>s</i>, is present and any of the
1510 * following conditions is met:
1511 *
1512 * <ul>
1513 *
1514 * <li> invocation of
1515 * {@link SecurityManager#checkMemberAccess
1516 * s.checkMemberAccess(this, Member.PUBLIC)} denies
1517 * access to the field
1518 *
1519 * <li> the caller's class loader is not the same as or an
1520 * ancestor of the class loader for the current class and
1521 * invocation of {@link SecurityManager#checkPackageAccess
1522 * s.checkPackageAccess()} denies access to the package
1523 * of this class
1524 *
1525 * </ul>
1526 *
1527 * @since JDK1.1
1528 */
1529 public Field getField(String name)
1530 throws NoSuchFieldException, SecurityException {
1531 // be very careful not to change the stack depth of this
1532 // checkMemberAccess call for security reasons
1533 // see java.lang.SecurityManager.checkMemberAccess
1534 checkMemberAccess(Member.PUBLIC, ClassLoader.getCallerClassLoader());
1535 Field field = getField0(name);
1536 if (field == null) {
1537 throw new NoSuchFieldException(name);
1538 }
1539 return field;
1540 }
1541
1542
1543 /**
1544 * Returns a {@code Method} object that reflects the specified public
1545 * member method of the class or interface represented by this
1546 * {@code Class} object. The {@code name} parameter is a
1547 * {@code String} specifying the simple name of the desired method. The
1548 * {@code parameterTypes} parameter is an array of {@code Class}
1549 * objects that identify the method's formal parameter types, in declared
1550 * order. If {@code parameterTypes} is {@code null}, it is
1551 * treated as if it were an empty array.
1552 *
1553 * <p> If the {@code name} is "{@code <init>};"or "{@code <clinit>}" a
1554 * {@code NoSuchMethodException} is raised. Otherwise, the method to
1555 * be reflected is determined by the algorithm that follows. Let C be the
1556 * class represented by this object:
1557 * <OL>
1558 * <LI> C is searched for any <I>matching methods</I>. If no matching
1559 * method is found, the algorithm of step 1 is invoked recursively on
1560 * the superclass of C.</LI>
1561 * <LI> If no method was found in step 1 above, the superinterfaces of C
1562 * are searched for a matching method. If any such method is found, it
1563 * is reflected.</LI>
1564 * </OL>
1565 *
1566 * To find a matching method in a class C:&nbsp; If C declares exactly one
1567 * public method with the specified name and exactly the same formal
1568 * parameter types, that is the method reflected. If more than one such
1569 * method is found in C, and one of these methods has a return type that is
1570 * more specific than any of the others, that method is reflected;
1571 * otherwise one of the methods is chosen arbitrarily.
1572 *
1573 * <p>Note that there may be more than one matching method in a
1574 * class because while the Java language forbids a class to
1575 * declare multiple methods with the same signature but different
1576 * return types, the Java virtual machine does not. This
1577 * increased flexibility in the virtual machine can be used to
1578 * implement various language features. For example, covariant
1579 * returns can be implemented with {@linkplain
1580 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
1581 * method and the method being overridden would have the same
1582 * signature but different return types.
1583 *
1584 * <p> See <em>The Java Language Specification</em>, sections 8.2 and 8.4.
1585 *
1586 * @param name the name of the method
1587 * @param parameterTypes the list of parameters
1588 * @return the {@code Method} object that matches the specified
1589 * {@code name} and {@code parameterTypes}
1590 * @exception NoSuchMethodException if a matching method is not found
1591 * or if the name is "&lt;init&gt;"or "&lt;clinit&gt;".
1592 * @exception NullPointerException if {@code name} is {@code null}
1593 * @exception SecurityException
1594 * If a security manager, <i>s</i>, is present and any of the
1595 * following conditions is met:
1596 *
1597 * <ul>
1598 *
1599 * <li> invocation of
1600 * {@link SecurityManager#checkMemberAccess
1601 * s.checkMemberAccess(this, Member.PUBLIC)} denies
1602 * access to the method
1603 *
1604 * <li> the caller's class loader is not the same as or an
1605 * ancestor of the class loader for the current class and
1606 * invocation of {@link SecurityManager#checkPackageAccess
1607 * s.checkPackageAccess()} denies access to the package
1608 * of this class
1609 *
1610 * </ul>
1611 *
1612 * @since JDK1.1
1613 */
1614 public Method getMethod(String name, Class<?>... parameterTypes)
1615 throws NoSuchMethodException, SecurityException {
1616 // be very careful not to change the stack depth of this
1617 // checkMemberAccess call for security reasons
1618 // see java.lang.SecurityManager.checkMemberAccess
1619 checkMemberAccess(Member.PUBLIC, ClassLoader.getCallerClassLoader());
1620 Method method = getMethod0(name, parameterTypes);
1621 if (method == null) {
1622 throw new NoSuchMethodException(getName() + "." + name + argumentTypesToString(parameterTypes));
1623 }
1624 return method;
1625 }
1626
1627
1628 /**
1629 * Returns a {@code Constructor} object that reflects the specified
1630 * public constructor of the class represented by this {@code Class}
1631 * object. The {@code parameterTypes} parameter is an array of
1632 * {@code Class} objects that identify the constructor's formal
1633 * parameter types, in declared order.
1634 *
1635 * If this {@code Class} object represents an inner class
1636 * declared in a non-static context, the formal parameter types
1637 * include the explicit enclosing instance as the first parameter.
1638 *
1639 * <p> The constructor to reflect is the public constructor of the class
1640 * represented by this {@code Class} object whose formal parameter
1641 * types match those specified by {@code parameterTypes}.
1642 *
1643 * @param parameterTypes the parameter array
1644 * @return the {@code Constructor} object of the public constructor that
1645 * matches the specified {@code parameterTypes}
1646 * @exception NoSuchMethodException if a matching method is not found.
1647 * @exception SecurityException
1648 * If a security manager, <i>s</i>, is present and any of the
1649 * following conditions is met:
1650 *
1651 * <ul>
1652 *
1653 * <li> invocation of
1654 * {@link SecurityManager#checkMemberAccess
1655 * s.checkMemberAccess(this, Member.PUBLIC)} denies
1656 * access to the constructor
1657 *
1658 * <li> the caller's class loader is not the same as or an
1659 * ancestor of the class loader for the current class and
1660 * invocation of {@link SecurityManager#checkPackageAccess
1661 * s.checkPackageAccess()} denies access to the package
1662 * of this class
1663 *
1664 * </ul>
1665 *
1666 * @since JDK1.1
1667 */
1668 public Constructor<T> getConstructor(Class<?>... parameterTypes)
1669 throws NoSuchMethodException, SecurityException {
1670 // be very careful not to change the stack depth of this
1671 // checkMemberAccess call for security reasons
1672 // see java.lang.SecurityManager.checkMemberAccess
1673 checkMemberAccess(Member.PUBLIC, ClassLoader.getCallerClassLoader());
1674 return getConstructor0(parameterTypes, Member.PUBLIC);
1675 }
1676
1677
1678 /**
1679 * Returns an array of {@code Class} objects reflecting all the
1680 * classes and interfaces declared as members of the class represented by
1681 * this {@code Class} object. This includes public, protected, default
1682 * (package) access, and private classes and interfaces declared by the
1683 * class, but excludes inherited classes and interfaces. This method
1684 * returns an array of length 0 if the class declares no classes or
1685 * interfaces as members, or if this {@code Class} object represents a
1686 * primitive type, an array class, or void.
1687 *
1688 * @return the array of {@code Class} objects representing all the
1689 * declared members of this class
1690 * @exception SecurityException
1691 * If a security manager, <i>s</i>, is present and any of the
1692 * following conditions is met:
1693 *
1694 * <ul>
1695 *
1696 * <li> invocation of
1697 * {@link SecurityManager#checkMemberAccess
1698 * s.checkMemberAccess(this, Member.DECLARED)} denies
1699 * access to the declared classes within this class
1700 *
1701 * <li> the caller's class loader is not the same as or an
1702 * ancestor of the class loader for the current class and
1703 * invocation of {@link SecurityManager#checkPackageAccess
1704 * s.checkPackageAccess()} denies access to the package
1705 * of this class
1706 *
1707 * </ul>
1708 *
1709 * @since JDK1.1
1710 */
1711 public Class<?>[] getDeclaredClasses() throws SecurityException {
1712 // be very careful not to change the stack depth of this
1713 // checkMemberAccess call for security reasons
1714 // see java.lang.SecurityManager.checkMemberAccess
1715 checkMemberAccess(Member.DECLARED, ClassLoader.getCallerClassLoader());
1716 return getDeclaredClasses0();
1717 }
1718
1719
1720 /**
1721 * Returns an array of {@code Field} objects reflecting all the fields
1722 * declared by the class or interface represented by this
1723 * {@code Class} object. This includes public, protected, default
1724 * (package) access, and private fields, but excludes inherited fields.
1725 * The elements in the array returned are not sorted and are not in any
1726 * particular order. This method returns an array of length 0 if the class
1727 * or interface declares no fields, or if this {@code Class} object
1728 * represents a primitive type, an array class, or void.
1729 *
1730 * <p> See <em>The Java Language Specification</em>, sections 8.2 and 8.3.
1731 *
1732 * @return the array of {@code Field} objects representing all the
1733 * declared fields of this class
1734 * @exception SecurityException
1735 * If a security manager, <i>s</i>, is present and any of the
1736 * following conditions is met:
1737 *
1738 * <ul>
1739 *
1740 * <li> invocation of
1741 * {@link SecurityManager#checkMemberAccess
1742 * s.checkMemberAccess(this, Member.DECLARED)} denies
1743 * access to the declared fields within this class
1744 *
1745 * <li> the caller's class loader is not the same as or an
1746 * ancestor of the class loader for the current class and
1747 * invocation of {@link SecurityManager#checkPackageAccess
1748 * s.checkPackageAccess()} denies access to the package
1749 * of this class
1750 *
1751 * </ul>
1752 *
1753 * @since JDK1.1
1754 */
1755 public Field[] getDeclaredFields() throws SecurityException {
1756 // be very careful not to change the stack depth of this
1757 // checkMemberAccess call for security reasons
1758 // see java.lang.SecurityManager.checkMemberAccess
1759 checkMemberAccess(Member.DECLARED, ClassLoader.getCallerClassLoader());
1760 return copyFields(privateGetDeclaredFields(false));
1761 }
1762
1763
1764 /**
1765 * Returns an array of {@code Method} objects reflecting all the
1766 * methods declared by the class or interface represented by this
1767 * {@code Class} object. This includes public, protected, default
1768 * (package) access, and private methods, but excludes inherited methods.
1769 * The elements in the array returned are not sorted and are not in any
1770 * particular order. This method returns an array of length 0 if the class
1771 * or interface declares no methods, or if this {@code Class} object
1772 * represents a primitive type, an array class, or void. The class
1773 * initialization method {@code <clinit>} is not included in the
1774 * returned array. If the class declares multiple public member methods
1775 * with the same parameter types, they are all included in the returned
1776 * array.
1777 *
1778 * <p> See <em>The Java Language Specification</em>, section 8.2.
1779 *
1780 * @return the array of {@code Method} objects representing all the
1781 * declared methods of this class
1782 * @exception SecurityException
1783 * If a security manager, <i>s</i>, is present and any of the
1784 * following conditions is met:
1785 *
1786 * <ul>
1787 *
1788 * <li> invocation of
1789 * {@link SecurityManager#checkMemberAccess
1790 * s.checkMemberAccess(this, Member.DECLARED)} denies
1791 * access to the declared methods within this class
1792 *
1793 * <li> the caller's class loader is not the same as or an
1794 * ancestor of the class loader for the current class and
1795 * invocation of {@link SecurityManager#checkPackageAccess
1796 * s.checkPackageAccess()} denies access to the package
1797 * of this class
1798 *
1799 * </ul>
1800 *
1801 * @since JDK1.1
1802 */
1803 public Method[] getDeclaredMethods() throws SecurityException {
1804 // be very careful not to change the stack depth of this
1805 // checkMemberAccess call for security reasons
1806 // see java.lang.SecurityManager.checkMemberAccess
1807 checkMemberAccess(Member.DECLARED, ClassLoader.getCallerClassLoader());
1808 return copyMethods(privateGetDeclaredMethods(false));
1809 }
1810
1811
1812 /**
1813 * Returns an array of {@code Constructor} objects reflecting all the
1814 * constructors declared by the class represented by this
1815 * {@code Class} object. These are public, protected, default
1816 * (package) access, and private constructors. The elements in the array
1817 * returned are not sorted and are not in any particular order. If the
1818 * class has a default constructor, it is included in the returned array.
1819 * This method returns an array of length 0 if this {@code Class}
1820 * object represents an interface, a primitive type, an array class, or
1821 * void.
1822 *
1823 * <p> See <em>The Java Language Specification</em>, section 8.2.
1824 *
1825 * @return the array of {@code Constructor} objects representing all the
1826 * declared constructors of this class
1827 * @exception SecurityException
1828 * If a security manager, <i>s</i>, is present and any of the
1829 * following conditions is met:
1830 *
1831 * <ul>
1832 *
1833 * <li> invocation of
1834 * {@link SecurityManager#checkMemberAccess
1835 * s.checkMemberAccess(this, Member.DECLARED)} denies
1836 * access to the declared constructors within this class
1837 *
1838 * <li> the caller's class loader is not the same as or an
1839 * ancestor of the class loader for the current class and
1840 * invocation of {@link SecurityManager#checkPackageAccess
1841 * s.checkPackageAccess()} denies access to the package
1842 * of this class
1843 *
1844 * </ul>
1845 *
1846 * @since JDK1.1
1847 */
1848 public Constructor<?>[] getDeclaredConstructors() throws SecurityException {
1849 // be very careful not to change the stack depth of this
1850 // checkMemberAccess call for security reasons
1851 // see java.lang.SecurityManager.checkMemberAccess
1852 checkMemberAccess(Member.DECLARED, ClassLoader.getCallerClassLoader());
1853 return copyConstructors(privateGetDeclaredConstructors(false));
1854 }
1855
1856
1857 /**
1858 * Returns a {@code Field} object that reflects the specified declared
1859 * field of the class or interface represented by this {@code Class}
1860 * object. The {@code name} parameter is a {@code String} that
1861 * specifies the simple name of the desired field. Note that this method
1862 * will not reflect the {@code length} field of an array class.
1863 *
1864 * @param name the name of the field
1865 * @return the {@code Field} object for the specified field in this
1866 * class
1867 * @exception NoSuchFieldException if a field with the specified name is
1868 * not found.
1869 * @exception NullPointerException if {@code name} is {@code null}
1870 * @exception SecurityException
1871 * If a security manager, <i>s</i>, is present and any of the
1872 * following conditions is met:
1873 *
1874 * <ul>
1875 *
1876 * <li> invocation of
1877 * {@link SecurityManager#checkMemberAccess
1878 * s.checkMemberAccess(this, Member.DECLARED)} denies
1879 * access to the declared field
1880 *
1881 * <li> the caller's class loader is not the same as or an
1882 * ancestor of the class loader for the current class and
1883 * invocation of {@link SecurityManager#checkPackageAccess
1884 * s.checkPackageAccess()} denies access to the package
1885 * of this class
1886 *
1887 * </ul>
1888 *
1889 * @since JDK1.1
1890 */
1891 public Field getDeclaredField(String name)
1892 throws NoSuchFieldException, SecurityException {
1893 // be very careful not to change the stack depth of this
1894 // checkMemberAccess call for security reasons
1895 // see java.lang.SecurityManager.checkMemberAccess
1896 checkMemberAccess(Member.DECLARED, ClassLoader.getCallerClassLoader());
1897 Field field = searchFields(privateGetDeclaredFields(false), name);
1898 if (field == null) {
1899 throw new NoSuchFieldException(name);
1900 }
1901 return field;
1902 }
1903
1904
1905 /**
1906 * Returns a {@code Method} object that reflects the specified
1907 * declared method of the class or interface represented by this
1908 * {@code Class} object. The {@code name} parameter is a
1909 * {@code String} that specifies the simple name of the desired
1910 * method, and the {@code parameterTypes} parameter is an array of
1911 * {@code Class} objects that identify the method's formal parameter
1912 * types, in declared order. If more than one method with the same
1913 * parameter types is declared in a class, and one of these methods has a
1914 * return type that is more specific than any of the others, that method is
1915 * returned; otherwise one of the methods is chosen arbitrarily. If the
1916 * name is "&lt;init&gt;"or "&lt;clinit&gt;" a {@code NoSuchMethodException}
1917 * is raised.
1918 *
1919 * @param name the name of the method
1920 * @param parameterTypes the parameter array
1921 * @return the {@code Method} object for the method of this class
1922 * matching the specified name and parameters
1923 * @exception NoSuchMethodException if a matching method is not found.
1924 * @exception NullPointerException if {@code name} is {@code null}
1925 * @exception SecurityException
1926 * If a security manager, <i>s</i>, is present and any of the
1927 * following conditions is met:
1928 *
1929 * <ul>
1930 *
1931 * <li> invocation of
1932 * {@link SecurityManager#checkMemberAccess
1933 * s.checkMemberAccess(this, Member.DECLARED)} denies
1934 * access to the declared method
1935 *
1936 * <li> the caller's class loader is not the same as or an
1937 * ancestor of the class loader for the current class and
1938 * invocation of {@link SecurityManager#checkPackageAccess
1939 * s.checkPackageAccess()} denies access to the package
1940 * of this class
1941 *
1942 * </ul>
1943 *
1944 * @since JDK1.1
1945 */
1946 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
1947 throws NoSuchMethodException, SecurityException {
1948 // be very careful not to change the stack depth of this
1949 // checkMemberAccess call for security reasons
1950 // see java.lang.SecurityManager.checkMemberAccess
1951 checkMemberAccess(Member.DECLARED, ClassLoader.getCallerClassLoader());
1952 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
1953 if (method == null) {
1954 throw new NoSuchMethodException(getName() + "." + name + argumentTypesToString(parameterTypes));
1955 }
1956 return method;
1957 }
1958
1959
1960 /**
1961 * Returns a {@code Constructor} object that reflects the specified
1962 * constructor of the class or interface represented by this
1963 * {@code Class} object. The {@code parameterTypes} parameter is
1964 * an array of {@code Class} objects that identify the constructor's
1965 * formal parameter types, in declared order.
1966 *
1967 * If this {@code Class} object represents an inner class
1968 * declared in a non-static context, the formal parameter types
1969 * include the explicit enclosing instance as the first parameter.
1970 *
1971 * @param parameterTypes the parameter array
1972 * @return The {@code Constructor} object for the constructor with the
1973 * specified parameter list
1974 * @exception NoSuchMethodException if a matching method is not found.
1975 * @exception SecurityException
1976 * If a security manager, <i>s</i>, is present and any of the
1977 * following conditions is met:
1978 *
1979 * <ul>
1980 *
1981 * <li> invocation of
1982 * {@link SecurityManager#checkMemberAccess
1983 * s.checkMemberAccess(this, Member.DECLARED)} denies
1984 * access to the declared constructor
1985 *
1986 * <li> the caller's class loader is not the same as or an
1987 * ancestor of the class loader for the current class and
1988 * invocation of {@link SecurityManager#checkPackageAccess
1989 * s.checkPackageAccess()} denies access to the package
1990 * of this class
1991 *
1992 * </ul>
1993 *
1994 * @since JDK1.1
1995 */
1996 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
1997 throws NoSuchMethodException, SecurityException {
1998 // be very careful not to change the stack depth of this
1999 // checkMemberAccess call for security reasons
2000 // see java.lang.SecurityManager.checkMemberAccess
2001 checkMemberAccess(Member.DECLARED, ClassLoader.getCallerClassLoader());
2002 return getConstructor0(parameterTypes, Member.DECLARED);
2003 }
2004
2005 /**
2006 * Finds a resource with a given name. The rules for searching resources
2007 * associated with a given class are implemented by the defining
2008 * {@linkplain ClassLoader class loader} of the class. This method
2009 * delegates to this object's class loader. If this object was loaded by
2010 * the bootstrap class loader, the method delegates to {@link
2011 * ClassLoader#getSystemResourceAsStream}.
2012 *
2013 * <p> Before delegation, an absolute resource name is constructed from the
2014 * given resource name using this algorithm:
2015 *
2016 * <ul>
2017 *
2018 * <li> If the {@code name} begins with a {@code '/'}
2019 * (<tt>'&#92;u002f'</tt>), then the absolute name of the resource is the
2020 * portion of the {@code name} following the {@code '/'}.
2021 *
2022 * <li> Otherwise, the absolute name is of the following form:
2023 *
2024 * <blockquote>
2025 * {@code modified_package_name/name}
2026 * </blockquote>
2027 *
2028 * <p> Where the {@code modified_package_name} is the package name of this
2029 * object with {@code '/'} substituted for {@code '.'}
2030 * (<tt>'&#92;u002e'</tt>).
2031 *
2032 * </ul>
2033 *
2034 * @param name name of the desired resource
2035 * @return A {@link java.io.InputStream} object or {@code null} if
2036 * no resource with this name is found
2037 * @throws NullPointerException If {@code name} is {@code null}
2038 * @since JDK1.1
2039 */
2040 public InputStream getResourceAsStream(String name) {
2041 name = resolveName(name);
2042 ClassLoader cl = getClassLoader0();
2043 if (cl==null) {
2044 // A system class.
2045 return ClassLoader.getSystemResourceAsStream(name);
2046 }
2047 return cl.getResourceAsStream(name);
2048 }
2049
2050 /**
2051 * Finds a resource with a given name. The rules for searching resources
2052 * associated with a given class are implemented by the defining
2053 * {@linkplain ClassLoader class loader} of the class. This method
2054 * delegates to this object's class loader. If this object was loaded by
2055 * the bootstrap class loader, the method delegates to {@link
2056 * ClassLoader#getSystemResource}.
2057 *
2058 * <p> Before delegation, an absolute resource name is constructed from the
2059 * given resource name using this algorithm:
2060 *
2061 * <ul>
2062 *
2063 * <li> If the {@code name} begins with a {@code '/'}
2064 * (<tt>'&#92;u002f'</tt>), then the absolute name of the resource is the
2065 * portion of the {@code name} following the {@code '/'}.
2066 *
2067 * <li> Otherwise, the absolute name is of the following form:
2068 *
2069 * <blockquote>
2070 * {@code modified_package_name/name}
2071 * </blockquote>
2072 *
2073 * <p> Where the {@code modified_package_name} is the package name of this
2074 * object with {@code '/'} substituted for {@code '.'}
2075 * (<tt>'&#92;u002e'</tt>).
2076 *
2077 * </ul>
2078 *
2079 * @param name name of the desired resource
2080 * @return A {@link java.net.URL} object or {@code null} if no
2081 * resource with this name is found
2082 * @since JDK1.1
2083 */
2084 public java.net.URL getResource(String name) {
2085 name = resolveName(name);
2086 ClassLoader cl = getClassLoader0();
2087 if (cl==null) {
2088 // A system class.
2089 return ClassLoader.getSystemResource(name);
2090 }
2091 return cl.getResource(name);
2092 }
2093
2094
2095
2096 /** protection domain returned when the internal domain is null */
2097 private static java.security.ProtectionDomain allPermDomain;
2098
2099
2100 /**
2101 * Returns the {@code ProtectionDomain} of this class. If there is a
2102 * security manager installed, this method first calls the security
2103 * manager's {@code checkPermission} method with a
2104 * {@code RuntimePermission("getProtectionDomain")} permission to
2105 * ensure it's ok to get the
2106 * {@code ProtectionDomain}.
2107 *
2108 * @return the ProtectionDomain of this class
2109 *
2110 * @throws SecurityException
2111 * if a security manager exists and its
2112 * {@code checkPermission} method doesn't allow
2113 * getting the ProtectionDomain.
2114 *
2115 * @see java.security.ProtectionDomain
2116 * @see SecurityManager#checkPermission
2117 * @see java.lang.RuntimePermission
2118 * @since 1.2
2119 */
2120 public java.security.ProtectionDomain getProtectionDomain() {
2121 SecurityManager sm = System.getSecurityManager();
2122 if (sm != null) {
2123 sm.checkPermission(SecurityConstants.GET_PD_PERMISSION);
2124 }
2125 java.security.ProtectionDomain pd = getProtectionDomain0();
2126 if (pd == null) {
2127 if (allPermDomain == null) {
2128 java.security.Permissions perms =
2129 new java.security.Permissions();
2130 perms.add(SecurityConstants.ALL_PERMISSION);
2131 allPermDomain =
2132 new java.security.ProtectionDomain(null, perms);
2133 }
2134 pd = allPermDomain;
2135 }
2136 return pd;
2137 }
2138
2139
2140 /**
2141 * Returns the ProtectionDomain of this class.
2142 */
2143 private native java.security.ProtectionDomain getProtectionDomain0();
2144
2145
2146 /**
2147 * Set the ProtectionDomain for this class. Called by
2148 * ClassLoader.defineClass.
2149 */
2150 native void setProtectionDomain0(java.security.ProtectionDomain pd);
2151
2152
2153 /*
2154 * Return the Virtual Machine's Class object for the named
2155 * primitive type.
2156 */
2157 static native Class getPrimitiveClass(String name);
2158
2159
2160 /*
2161 * Check if client is allowed to access members. If access is denied,
2162 * throw a SecurityException.
2163 *
2164 * Be very careful not to change the stack depth of this checkMemberAccess
2165 * call for security reasons.
2166 * See java.lang.SecurityManager.checkMemberAccess.
2167 *
2168 * <p> Default policy: allow all clients access with normal Java access
2169 * control.
2170 */
2171 private void checkMemberAccess(int which, ClassLoader ccl) {
2172 SecurityManager s = System.getSecurityManager();
2173 if (s != null) {
2174 s.checkMemberAccess(this, which);
2175 ClassLoader cl = getClassLoader0();
2176 if ((ccl != null) && (ccl != cl) &&
2177 ((cl == null) || !cl.isAncestor(ccl))) {
2178 String name = this.getName();
2179 int i = name.lastIndexOf('.');
2180 if (i != -1) {
2181 s.checkPackageAccess(name.substring(0, i));
2182 }
2183 }
2184 }
2185 }
2186
2187 /**
2188 * Add a package name prefix if the name is not absolute Remove leading "/"
2189 * if name is absolute
2190 */
2191 private String resolveName(String name) {
2192 if (name == null) {
2193 return name;
2194 }
2195 if (!name.startsWith("/")) {
2196 Class c = this;
2197 while (c.isArray()) {
2198 c = c.getComponentType();
2199 }
2200 String baseName = c.getName();
2201 int index = baseName.lastIndexOf('.');
2202 if (index != -1) {
2203 name = baseName.substring(0, index).replace('.', '/')
2204 +"/"+name;
2205 }
2206 } else {
2207 name = name.substring(1);
2208 }
2209 return name;
2210 }
2211
2212 /**
2213 * Reflection support.
2214 */
2215
2216 // Caches for certain reflective results
2217 private static boolean useCaches = true;
2218 private volatile transient SoftReference declaredFields;
2219 private volatile transient SoftReference publicFields;
2220 private volatile transient SoftReference declaredMethods;
2221 private volatile transient SoftReference publicMethods;
2222 private volatile transient SoftReference declaredConstructors;
2223 private volatile transient SoftReference publicConstructors;
2224 // Intermediate results for getFields and getMethods
2225 private volatile transient SoftReference declaredPublicFields;
2226 private volatile transient SoftReference declaredPublicMethods;
2227
2228 // Incremented by the VM on each call to JVM TI RedefineClasses()
2229 // that redefines this class or a superclass.
2230 private volatile transient int classRedefinedCount = 0;
2231
2232 // Value of classRedefinedCount when we last cleared the cached values
2233 // that are sensitive to class redefinition.
2234 private volatile transient int lastRedefinedCount = 0;
2235
2236 // Clears cached values that might possibly have been obsoleted by
2237 // a class redefinition.
2238 private void clearCachesOnClassRedefinition() {
2239 if (lastRedefinedCount != classRedefinedCount) {
2240 declaredFields = publicFields = declaredPublicFields = null;
2241 declaredMethods = publicMethods = declaredPublicMethods = null;
2242 declaredConstructors = publicConstructors = null;
2243 annotations = declaredAnnotations = null;
2244
2245 // Use of "volatile" (and synchronization by caller in the case
2246 // of annotations) ensures that no thread sees the update to
2247 // lastRedefinedCount before seeing the caches cleared.
2248 // We do not guard against brief windows during which multiple
2249 // threads might redundantly work to fill an empty cache.
2250 lastRedefinedCount = classRedefinedCount;
2251 }
2252 }
2253
2254 // Generic signature handling
2255 private native String getGenericSignature();
2256
2257 // Generic info repository; lazily initialized
2258 private transient ClassRepository genericInfo;
2259
2260 // accessor for factory
2261 private GenericsFactory getFactory() {
2262 // create scope and factory
2263 return CoreReflectionFactory.make(this, ClassScope.make(this));
2264 }
2265
2266 // accessor for generic info repository
2267 private ClassRepository getGenericInfo() {
2268 // lazily initialize repository if necessary
2269 if (genericInfo == null) {
2270 // create and cache generic info repository
2271 genericInfo = ClassRepository.make(getGenericSignature(),
2272 getFactory());
2273 }
2274 return genericInfo; //return cached repository
2275 }
2276
2277 // Annotations handling
2278 private native byte[] getRawAnnotations();
2279
2280 native ConstantPool getConstantPool();
2281
2282 //
2283 //
2284 // java.lang.reflect.Field handling
2285 //
2286 //
2287
2288 // Returns an array of "root" fields. These Field objects must NOT
2289 // be propagated to the outside world, but must instead be copied
2290 // via ReflectionFactory.copyField.
2291 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2292 checkInitted();
2293 Field[] res = null;
2294 if (useCaches) {
2295 clearCachesOnClassRedefinition();
2296 if (publicOnly) {
2297 if (declaredPublicFields != null) {
2298 res = (Field[]) declaredPublicFields.get();
2299 }
2300 } else {
2301 if (declaredFields != null) {
2302 res = (Field[]) declaredFields.get();
2303 }
2304 }
2305 if (res != null) return res;
2306 }
2307 // No cached value available; request value from VM
2308 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2309 if (useCaches) {
2310 if (publicOnly) {
2311 declaredPublicFields = new SoftReference(res);
2312 } else {
2313 declaredFields = new SoftReference(res);
2314 }
2315 }
2316 return res;
2317 }
2318
2319 // Returns an array of "root" fields. These Field objects must NOT
2320 // be propagated to the outside world, but must instead be copied
2321 // via ReflectionFactory.copyField.
2322 private Field[] privateGetPublicFields(Set traversedInterfaces) {
2323 checkInitted();
2324 Field[] res = null;
2325 if (useCaches) {
2326 clearCachesOnClassRedefinition();
2327 if (publicFields != null) {
2328 res = (Field[]) publicFields.get();
2329 }
2330 if (res != null) return res;
2331 }
2332
2333 // No cached value available; compute value recursively.
2334 // Traverse in correct order for getField().
2335 List fields = new ArrayList();
2336 if (traversedInterfaces == null) {
2337 traversedInterfaces = new HashSet();
2338 }
2339
2340 // Local fields
2341 Field[] tmp = privateGetDeclaredFields(true);
2342 addAll(fields, tmp);
2343
2344 // Direct superinterfaces, recursively
2345 Class[] interfaces = getInterfaces();
2346 for (int i = 0; i < interfaces.length; i++) {
2347 Class c = interfaces[i];
2348 if (!traversedInterfaces.contains(c)) {
2349 traversedInterfaces.add(c);
2350 addAll(fields, c.privateGetPublicFields(traversedInterfaces));
2351 }
2352 }
2353
2354 // Direct superclass, recursively
2355 if (!isInterface()) {
2356 Class c = getSuperclass();
2357 if (c != null) {
2358 addAll(fields, c.privateGetPublicFields(traversedInterfaces));
2359 }
2360 }
2361
2362 res = new Field[fields.size()];
2363 fields.toArray(res);
2364 if (useCaches) {
2365 publicFields = new SoftReference(res);
2366 }
2367 return res;
2368 }
2369
2370 private static void addAll(Collection c, Field[] o) {
2371 for (int i = 0; i < o.length; i++) {
2372 c.add(o[i]);
2373 }
2374 }
2375
2376
2377 //
2378 //
2379 // java.lang.reflect.Constructor handling
2380 //
2381 //
2382
2383 // Returns an array of "root" constructors. These Constructor
2384 // objects must NOT be propagated to the outside world, but must
2385 // instead be copied via ReflectionFactory.copyConstructor.
2386 private Constructor[] privateGetDeclaredConstructors(boolean publicOnly) {
2387 checkInitted();
2388 Constructor[] res = null;
2389 if (useCaches) {
2390 clearCachesOnClassRedefinition();
2391 if (publicOnly) {
2392 if (publicConstructors != null) {
2393 res = (Constructor[]) publicConstructors.get();
2394 }
2395 } else {
2396 if (declaredConstructors != null) {
2397 res = (Constructor[]) declaredConstructors.get();
2398 }
2399 }
2400 if (res != null) return res;
2401 }
2402 // No cached value available; request value from VM
2403 if (isInterface()) {
2404 res = new Constructor[0];
2405 } else {
2406 res = getDeclaredConstructors0(publicOnly);
2407 }
2408 if (useCaches) {
2409 if (publicOnly) {
2410 publicConstructors = new SoftReference(res);
2411 } else {
2412 declaredConstructors = new SoftReference(res);
2413 }
2414 }
2415 return res;
2416 }
2417
2418 //
2419 //
2420 // java.lang.reflect.Method handling
2421 //
2422 //
2423
2424 // Returns an array of "root" methods. These Method objects must NOT
2425 // be propagated to the outside world, but must instead be copied
2426 // via ReflectionFactory.copyMethod.
2427 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
2428 checkInitted();
2429 Method[] res = null;
2430 if (useCaches) {
2431 clearCachesOnClassRedefinition();
2432 if (publicOnly) {
2433 if (declaredPublicMethods != null) {
2434 res = (Method[]) declaredPublicMethods.get();
2435 }
2436 } else {
2437 if (declaredMethods != null) {
2438 res = (Method[]) declaredMethods.get();
2439 }
2440 }
2441 if (res != null) return res;
2442 }
2443 // No cached value available; request value from VM
2444 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
2445 if (useCaches) {
2446 if (publicOnly) {
2447 declaredPublicMethods = new SoftReference(res);
2448 } else {
2449 declaredMethods = new SoftReference(res);
2450 }
2451 }
2452 return res;
2453 }
2454
2455 static class MethodArray {
2456 private Method[] methods;
2457 private int length;
2458
2459 MethodArray() {
2460 methods = new Method[20];
2461 length = 0;
2462 }
2463
2464 void add(Method m) {
2465 if (length == methods.length) {
2466 methods = Arrays.copyOf(methods, 2 * methods.length);
2467 }
2468 methods[length++] = m;
2469 }
2470
2471 void addAll(Method[] ma) {
2472 for (int i = 0; i < ma.length; i++) {
2473 add(ma[i]);
2474 }
2475 }
2476
2477 void addAll(MethodArray ma) {
2478 for (int i = 0; i < ma.length(); i++) {
2479 add(ma.get(i));
2480 }
2481 }
2482
2483 void addIfNotPresent(Method newMethod) {
2484 for (int i = 0; i < length; i++) {
2485 Method m = methods[i];
2486 if (m == newMethod || (m != null && m.equals(newMethod))) {
2487 return;
2488 }
2489 }
2490 add(newMethod);
2491 }
2492
2493 void addAllIfNotPresent(MethodArray newMethods) {
2494 for (int i = 0; i < newMethods.length(); i++) {
2495 Method m = newMethods.get(i);
2496 if (m != null) {
2497 addIfNotPresent(m);
2498 }
2499 }
2500 }
2501
2502 int length() {
2503 return length;
2504 }
2505
2506 Method get(int i) {
2507 return methods[i];
2508 }
2509
2510 void removeByNameAndSignature(Method toRemove) {
2511 for (int i = 0; i < length; i++) {
2512 Method m = methods[i];
2513 if (m != null &&
2514 m.getReturnType() == toRemove.getReturnType() &&
2515 m.getName() == toRemove.getName() &&
2516 arrayContentsEq(m.getParameterTypes(),
2517 toRemove.getParameterTypes())) {
2518 methods[i] = null;
2519 }
2520 }
2521 }
2522
2523 void compactAndTrim() {
2524 int newPos = 0;
2525 // Get rid of null slots
2526 for (int pos = 0; pos < length; pos++) {
2527 Method m = methods[pos];
2528 if (m != null) {
2529 if (pos != newPos) {
2530 methods[newPos] = m;
2531 }
2532 newPos++;
2533 }
2534 }
2535 if (newPos != methods.length) {
2536 methods = Arrays.copyOf(methods, newPos);
2537 }
2538 }
2539
2540 Method[] getArray() {
2541 return methods;
2542 }
2543 }
2544
2545
2546 // Returns an array of "root" methods. These Method objects must NOT
2547 // be propagated to the outside world, but must instead be copied
2548 // via ReflectionFactory.copyMethod.
2549 private Method[] privateGetPublicMethods() {
2550 checkInitted();
2551 Method[] res = null;
2552 if (useCaches) {
2553 clearCachesOnClassRedefinition();
2554 if (publicMethods != null) {
2555 res = (Method[]) publicMethods.get();
2556 }
2557 if (res != null) return res;
2558 }
2559
2560 // No cached value available; compute value recursively.
2561 // Start by fetching public declared methods
2562 MethodArray methods = new MethodArray();
2563 {
2564 Method[] tmp = privateGetDeclaredMethods(true);
2565 methods.addAll(tmp);
2566 }
2567 // Now recur over superclass and direct superinterfaces.
2568 // Go over superinterfaces first so we can more easily filter
2569 // out concrete implementations inherited from superclasses at
2570 // the end.
2571 MethodArray inheritedMethods = new MethodArray();
2572 Class[] interfaces = getInterfaces();
2573 for (int i = 0; i < interfaces.length; i++) {
2574 inheritedMethods.addAll(interfaces[i].privateGetPublicMethods());
2575 }
2576 if (!isInterface()) {
2577 Class c = getSuperclass();
2578 if (c != null) {
2579 MethodArray supers = new MethodArray();
2580 supers.addAll(c.privateGetPublicMethods());
2581 // Filter out concrete implementations of any
2582 // interface methods
2583 for (int i = 0; i < supers.length(); i++) {
2584 Method m = supers.get(i);
2585 if (m != null && !Modifier.isAbstract(m.getModifiers())) {
2586 inheritedMethods.removeByNameAndSignature(m);
2587 }
2588 }
2589 // Insert superclass's inherited methods before
2590 // superinterfaces' to satisfy getMethod's search
2591 // order
2592 supers.addAll(inheritedMethods);
2593 inheritedMethods = supers;
2594 }
2595 }
2596 // Filter out all local methods from inherited ones
2597 for (int i = 0; i < methods.length(); i++) {
2598 Method m = methods.get(i);
2599 inheritedMethods.removeByNameAndSignature(m);
2600 }
2601 methods.addAllIfNotPresent(inheritedMethods);
2602 methods.compactAndTrim();
2603 res = methods.getArray();
2604 if (useCaches) {
2605 publicMethods = new SoftReference(res);
2606 }
2607 return res;
2608 }
2609
2610
2611 //
2612 // Helpers for fetchers of one field, method, or constructor
2613 //
2614
2615 private Field searchFields(Field[] fields, String name) {
2616 String internedName = name.intern();
2617 for (int i = 0; i < fields.length; i++) {
2618 if (fields[i].getName() == internedName) {
2619 return getReflectionFactory().copyField(fields[i]);
2620 }
2621 }
2622 return null;
2623 }
2624
2625 private Field getField0(String name) throws NoSuchFieldException {
2626 // Note: the intent is that the search algorithm this routine
2627 // uses be equivalent to the ordering imposed by
2628 // privateGetPublicFields(). It fetches only the declared
2629 // public fields for each class, however, to reduce the number
2630 // of Field objects which have to be created for the common
2631 // case where the field being requested is declared in the
2632 // class which is being queried.
2633 Field res = null;
2634 // Search declared public fields
2635 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
2636 return res;
2637 }
2638 // Direct superinterfaces, recursively
2639 Class[] interfaces = getInterfaces();
2640 for (int i = 0; i < interfaces.length; i++) {
2641 Class c = interfaces[i];
2642 if ((res = c.getField0(name)) != null) {
2643 return res;
2644 }
2645 }
2646 // Direct superclass, recursively
2647 if (!isInterface()) {
2648 Class c = getSuperclass();
2649 if (c != null) {
2650 if ((res = c.getField0(name)) != null) {
2651 return res;
2652 }
2653 }
2654 }
2655 return null;
2656 }
2657
2658 private static Method searchMethods(Method[] methods,
2659 String name,
2660 Class[] parameterTypes)
2661 {
2662 Method res = null;
2663 String internedName = name.intern();
2664 for (int i = 0; i < methods.length; i++) {
2665 Method m = methods[i];
2666 if (m.getName() == internedName
2667 && arrayContentsEq(parameterTypes, m.getParameterTypes())
2668 && (res == null
2669 || res.getReturnType().isAssignableFrom(m.getReturnType())))
2670 res = m;
2671 }
2672
2673 return (res == null ? res : getReflectionFactory().copyMethod(res));
2674 }
2675
2676
2677 private Method getMethod0(String name, Class[] parameterTypes) {
2678 // Note: the intent is that the search algorithm this routine
2679 // uses be equivalent to the ordering imposed by
2680 // privateGetPublicMethods(). It fetches only the declared
2681 // public methods for each class, however, to reduce the
2682 // number of Method objects which have to be created for the
2683 // common case where the method being requested is declared in
2684 // the class which is being queried.
2685 Method res = null;
2686 // Search declared public methods
2687 if ((res = searchMethods(privateGetDeclaredMethods(true),
2688 name,
2689 parameterTypes)) != null) {
2690 return res;
2691 }
2692 // Search superclass's methods
2693 if (!isInterface()) {
2694 Class c = getSuperclass();
2695 if (c != null) {
2696 if ((res = c.getMethod0(name, parameterTypes)) != null) {
2697 return res;
2698 }
2699 }
2700 }
2701 // Search superinterfaces' methods
2702 Class[] interfaces = getInterfaces();
2703 for (int i = 0; i < interfaces.length; i++) {
2704 Class c = interfaces[i];
2705 if ((res = c.getMethod0(name, parameterTypes)) != null) {
2706 return res;
2707 }
2708 }
2709 // Not found
2710 return null;
2711 }
2712
2713 private Constructor<T> getConstructor0(Class[] parameterTypes,
2714 int which) throws NoSuchMethodException
2715 {
2716 Constructor[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
2717 for (int i = 0; i < constructors.length; i++) {
2718 if (arrayContentsEq(parameterTypes,
2719 constructors[i].getParameterTypes())) {
2720 return getReflectionFactory().copyConstructor(constructors[i]);
2721 }
2722 }
2723 throw new NoSuchMethodException(getName() + ".<init>" + argumentTypesToString(parameterTypes));
2724 }
2725
2726 //
2727 // Other helpers and base implementation
2728 //
2729
2730 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
2731 if (a1 == null) {
2732 return a2 == null || a2.length == 0;
2733 }
2734
2735 if (a2 == null) {
2736 return a1.length == 0;
2737 }
2738
2739 if (a1.length != a2.length) {
2740 return false;
2741 }
2742
2743 for (int i = 0; i < a1.length; i++) {
2744 if (a1[i] != a2[i]) {
2745 return false;
2746 }
2747 }
2748
2749 return true;
2750 }
2751
2752 private static Field[] copyFields(Field[] arg) {
2753 Field[] out = new Field[arg.length];
2754 ReflectionFactory fact = getReflectionFactory();
2755 for (int i = 0; i < arg.length; i++) {
2756 out[i] = fact.copyField(arg[i]);
2757 }
2758 return out;
2759 }
2760
2761 private static Method[] copyMethods(Method[] arg) {
2762 Method[] out = new Method[arg.length];
2763 ReflectionFactory fact = getReflectionFactory();
2764 for (int i = 0; i < arg.length; i++) {
2765 out[i] = fact.copyMethod(arg[i]);
2766 }
2767 return out;
2768 }
2769
2770 private static Constructor[] copyConstructors(Constructor[] arg) {
2771 Constructor[] out = new Constructor[arg.length];
2772 ReflectionFactory fact = getReflectionFactory();
2773 for (int i = 0; i < arg.length; i++) {
2774 out[i] = fact.copyConstructor(arg[i]);
2775 }
2776 return out;
2777 }
2778
2779 private native Field[] getDeclaredFields0(boolean publicOnly);
2780 private native Method[] getDeclaredMethods0(boolean publicOnly);
2781 private native Constructor[] getDeclaredConstructors0(boolean publicOnly);
2782 private native Class[] getDeclaredClasses0();
2783
2784 private static String argumentTypesToString(Class[] argTypes) {
2785 StringBuilder buf = new StringBuilder();
2786 buf.append("(");
2787 if (argTypes != null) {
2788 for (int i = 0; i < argTypes.length; i++) {
2789 if (i > 0) {
2790 buf.append(", ");
2791 }
2792 Class c = argTypes[i];
2793 buf.append((c == null) ? "null" : c.getName());
2794 }
2795 }
2796 buf.append(")");
2797 return buf.toString();
2798 }
2799
2800 /** use serialVersionUID from JDK 1.1 for interoperability */
2801 private static final long serialVersionUID = 3206093459760846163L;
2802
2803
2804 /**
2805 * Class Class is special cased within the Serialization Stream Protocol.
2806 *
2807 * A Class instance is written initially into an ObjectOutputStream in the
2808 * following format:
2809 * <pre>
2810 * {@code TC_CLASS} ClassDescriptor
2811 * A ClassDescriptor is a special cased serialization of
2812 * a {@code java.io.ObjectStreamClass} instance.
2813 * </pre>
2814 * A new handle is generated for the initial time the class descriptor
2815 * is written into the stream. Future references to the class descriptor
2816 * are written as references to the initial class descriptor instance.
2817 *
2818 * @see java.io.ObjectStreamClass
2819 */
2820 private static final ObjectStreamField[] serialPersistentFields =
2821 new ObjectStreamField[0];
2822
2823
2824 /**
2825 * Returns the assertion status that would be assigned to this
2826 * class if it were to be initialized at the time this method is invoked.
2827 * If this class has had its assertion status set, the most recent
2828 * setting will be returned; otherwise, if any package default assertion
2829 * status pertains to this class, the most recent setting for the most
2830 * specific pertinent package default assertion status is returned;
2831 * otherwise, if this class is not a system class (i.e., it has a
2832 * class loader) its class loader's default assertion status is returned;
2833 * otherwise, the system class default assertion status is returned.
2834 * <p>
2835 * Few programmers will have any need for this method; it is provided
2836 * for the benefit of the JRE itself. (It allows a class to determine at
2837 * the time that it is initialized whether assertions should be enabled.)
2838 * Note that this method is not guaranteed to return the actual
2839 * assertion status that was (or will be) associated with the specified
2840 * class when it was (or will be) initialized.
2841 *
2842 * @return the desired assertion status of the specified class.
2843 * @see java.lang.ClassLoader#setClassAssertionStatus
2844 * @see java.lang.ClassLoader#setPackageAssertionStatus
2845 * @see java.lang.ClassLoader#setDefaultAssertionStatus
2846 * @since 1.4
2847 */
2848 public boolean desiredAssertionStatus() {
2849 ClassLoader loader = getClassLoader();
2850 // If the loader is null this is a system class, so ask the VM
2851 if (loader == null)
2852 return desiredAssertionStatus0(this);
2853
2854 synchronized(loader) {
2855 // If the classloader has been initialized with
2856 // the assertion directives, ask it. Otherwise,
2857 // ask the VM.
2858 return (loader.classAssertionStatus == null ?
2859 desiredAssertionStatus0(this) :
2860 loader.desiredAssertionStatus(getName()));
2861 }
2862 }
2863
2864 // Retrieves the desired assertion status of this class from the VM
2865 private static native boolean desiredAssertionStatus0(Class clazz);
2866
2867 /**
2868 * Returns true if and only if this class was declared as an enum in the
2869 * source code.
2870 *
2871 * @return true if and only if this class was declared as an enum in the
2872 * source code
2873 * @since 1.5
2874 */
2875 public boolean isEnum() {
2876 // An enum must both directly extend java.lang.Enum and have
2877 // the ENUM bit set; classes for specialized enum constants
2878 // don't do the former.
2879 return (this.getModifiers() & ENUM) != 0 &&
2880 this.getSuperclass() == java.lang.Enum.class;
2881 }
2882
2883 // Fetches the factory for reflective objects
2884 private static ReflectionFactory getReflectionFactory() {
2885 if (reflectionFactory == null) {
2886 reflectionFactory = (ReflectionFactory)
2887 java.security.AccessController.doPrivileged
2888 (new sun.reflect.ReflectionFactory.GetReflectionFactoryAction());
2889 }
2890 return reflectionFactory;
2891 }
2892 private static ReflectionFactory reflectionFactory;
2893
2894 // To be able to query system properties as soon as they're available
2895 private static boolean initted = false;
2896 private static void checkInitted() {
2897 if (initted) return;
2898 AccessController.doPrivileged(new PrivilegedAction() {
2899 public Object run() {
2900 // Tests to ensure the system properties table is fully
2901 // initialized. This is needed because reflection code is
2902 // called very early in the initialization process (before
2903 // command-line arguments have been parsed and therefore
2904 // these user-settable properties installed.) We assume that
2905 // if System.out is non-null then the System class has been
2906 // fully initialized and that the bulk of the startup code
2907 // has been run.
2908
2909 if (System.out == null) {
2910 // java.lang.System not yet fully initialized
2911 return null;
2912 }
2913
2914 String val =
2915 System.getProperty("sun.reflect.noCaches");
2916 if (val != null && val.equals("true")) {
2917 useCaches = false;
2918 }
2919
2920 initted = true;
2921 return null;
2922 }
2923 });
2924 }
2925
2926 /**
2927 * Returns the elements of this enum class or null if this
2928 * Class object does not represent an enum type.
2929 *
2930 * @return an array containing the values comprising the enum class
2931 * represented by this Class object in the order they're
2932 * declared, or null if this Class object does not
2933 * represent an enum type
2934 * @since 1.5
2935 */
2936 public T[] getEnumConstants() {
2937 T[] values = getEnumConstantsShared();
2938 return (values != null) ? values.clone() : null;
2939 }
2940
2941 /**
2942 * Returns the elements of this enum class or null if this
2943 * Class object does not represent an enum type;
2944 * identical to getEnumConstantsShared except that
2945 * the result is uncloned, cached, and shared by all callers.
2946 */
2947 T[] getEnumConstantsShared() {
2948 if (enumConstants == null) {
2949 if (!isEnum()) return null;
2950 try {
2951 final Method values = getMethod("values");
2952 java.security.AccessController.doPrivileged
2953 (new java.security.PrivilegedAction() {
2954 public Object run() {
2955 values.setAccessible(true);
2956 return null;
2957 }
2958 });
2959 enumConstants = (T[])values.invoke(null);
2960 }
2961 // These can happen when users concoct enum-like classes
2962 // that don't comply with the enum spec.
2963 catch (InvocationTargetException ex) { return null; }
2964 catch (NoSuchMethodException ex) { return null; }
2965 catch (IllegalAccessException ex) { return null; }
2966 }
2967 return enumConstants;
2968 }
2969 private volatile transient T[] enumConstants = null;
2970
2971 /**
2972 * Returns a map from simple name to enum constant. This package-private
2973 * method is used internally by Enum to implement
2974 * public static <T extends Enum<T>> T valueOf(Class<T>, String)
2975 * efficiently. Note that the map is returned by this method is
2976 * created lazily on first use. Typically it won't ever get created.
2977 */
2978 Map<String, T> enumConstantDirectory() {
2979 if (enumConstantDirectory == null) {
2980 T[] universe = getEnumConstantsShared();
2981 if (universe == null)
2982 throw new IllegalArgumentException(
2983 getName() + " is not an enum type");
2984 Map<String, T> m = new HashMap<String, T>(2 * universe.length);
2985 for (T constant : universe)
2986 m.put(((Enum)constant).name(), constant);
2987 enumConstantDirectory = m;
2988 }
2989 return enumConstantDirectory;
2990 }
2991 private volatile transient Map<String, T> enumConstantDirectory = null;
2992
2993 /**
2994 * Casts an object to the class or interface represented
2995 * by this {@code Class} object.
2996 *
2997 * @param obj the object to be cast
2998 * @return the object after casting, or null if obj is null
2999 *
3000 * @throws ClassCastException if the object is not
3001 * null and is not assignable to the type T.
3002 *
3003 * @since 1.5
3004 */
3005 public T cast(Object obj) {
3006 if (obj != null && !isInstance(obj))
3007 throw new ClassCastException(cannotCastMsg(obj));
3008 return (T) obj;
3009 }
3010
3011 private String cannotCastMsg(Object obj) {
3012 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3013 }
3014
3015 /**
3016 * Casts this {@code Class} object to represent a subclass of the class
3017 * represented by the specified class object. Checks that that the cast
3018 * is valid, and throws a {@code ClassCastException} if it is not. If
3019 * this method succeeds, it always returns a reference to this class object.
3020 *
3021 * <p>This method is useful when a client needs to "narrow" the type of
3022 * a {@code Class} object to pass it to an API that restricts the
3023 * {@code Class} objects that it is willing to accept. A cast would
3024 * generate a compile-time warning, as the correctness of the cast
3025 * could not be checked at runtime (because generic types are implemented
3026 * by erasure).
3027 *
3028 * @return this {@code Class} object, cast to represent a subclass of
3029 * the specified class object.
3030 * @throws ClassCastException if this {@code Class} object does not
3031 * represent a subclass of the specified class (here "subclass" includes
3032 * the class itself).
3033 * @since 1.5
3034 */
3035 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3036 if (clazz.isAssignableFrom(this))
3037 return (Class<? extends U>) this;
3038 else
3039 throw new ClassCastException(this.toString());
3040 }
3041
3042 /**
3043 * @throws NullPointerException {@inheritDoc}
3044 * @since 1.5
3045 */
3046 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3047 if (annotationClass == null)
3048 throw new NullPointerException();
3049
3050 initAnnotationsIfNecessary();
3051 return (A) annotations.get(annotationClass);
3052 }
3053
3054 /**
3055 * @throws NullPointerException {@inheritDoc}
3056 * @since 1.5
3057 */
3058 public boolean isAnnotationPresent(
3059 Class<? extends Annotation> annotationClass) {
3060 if (annotationClass == null)
3061 throw new NullPointerException();
3062
3063 return getAnnotation(annotationClass) != null;
3064 }
3065
3066
3067 private static Annotation[] EMPTY_ANNOTATIONS_ARRAY = new Annotation[0];
3068
3069 /**
3070 * @since 1.5
3071 */
3072 public Annotation[] getAnnotations() {
3073 initAnnotationsIfNecessary();
3074 return annotations.values().toArray(EMPTY_ANNOTATIONS_ARRAY);
3075 }
3076
3077 /**
3078 * @since 1.5
3079 */
3080 public Annotation[] getDeclaredAnnotations() {
3081 initAnnotationsIfNecessary();
3082 return declaredAnnotations.values().toArray(EMPTY_ANNOTATIONS_ARRAY);
3083 }
3084
3085 // Annotations cache
3086 private transient Map<Class, Annotation> annotations;
3087 private transient Map<Class, Annotation> declaredAnnotations;
3088
3089 private synchronized void initAnnotationsIfNecessary() {
3090 clearCachesOnClassRedefinition();
3091 if (annotations != null)
3092 return;
3093 declaredAnnotations = AnnotationParser.parseAnnotations(
3094 getRawAnnotations(), getConstantPool(), this);
3095 Class<?> superClass = getSuperclass();
3096 if (superClass == null) {
3097 annotations = declaredAnnotations;
3098 } else {
3099 annotations = new HashMap<Class, Annotation>();
3100 superClass.initAnnotationsIfNecessary();
3101 for (Map.Entry<Class, Annotation> e : superClass.annotations.entrySet()) {
3102 Class annotationClass = e.getKey();
3103 if (AnnotationType.getInstance(annotationClass).isInherited())
3104 annotations.put(annotationClass, e.getValue());
3105 }
3106 annotations.putAll(declaredAnnotations);
3107 }
3108 }
3109
3110 // Annotation types cache their internal (AnnotationType) form
3111
3112 private AnnotationType annotationType;
3113
3114 void setAnnotationType(AnnotationType type) {
3115 annotationType = type;
3116 }
3117
3118 AnnotationType getAnnotationType() {
3119 return annotationType;
3120 }
3121}