Field.java 42.9 KB
Newer Older
D
duke 已提交
1
/*
2
 * Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved.
D
duke 已提交
3 4 5 6
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
7
 * published by the Free Software Foundation.  Oracle designates this
D
duke 已提交
8
 * particular file as subject to the "Classpath" exception as provided
9
 * by Oracle in the LICENSE file that accompanied this code.
D
duke 已提交
10 11 12 13 14 15 16 17 18 19 20
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
21 22 23
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
D
duke 已提交
24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
 */

package java.lang.reflect;

import sun.reflect.FieldAccessor;
import sun.reflect.Reflection;
import sun.reflect.generics.repository.FieldRepository;
import sun.reflect.generics.factory.CoreReflectionFactory;
import sun.reflect.generics.factory.GenericsFactory;
import sun.reflect.generics.scope.ClassScope;
import java.lang.annotation.Annotation;
import java.util.Map;
import sun.reflect.annotation.AnnotationParser;


/**
 * A {@code Field} provides information about, and dynamic access to, a
 * single field of a class or an interface.  The reflected field may
 * be a class (static) field or an instance field.
 *
 * <p>A {@code Field} permits widening conversions to occur during a get or
 * set access operation, but throws an {@code IllegalArgumentException} if a
 * narrowing conversion would occur.
 *
 * @see Member
 * @see java.lang.Class
 * @see java.lang.Class#getFields()
 * @see java.lang.Class#getField(String)
 * @see java.lang.Class#getDeclaredFields()
 * @see java.lang.Class#getDeclaredField(String)
 *
 * @author Kenneth Russell
 * @author Nakul Saraiya
 */
public final
class Field extends AccessibleObject implements Member {

61
    private Class<?>            clazz;
D
duke 已提交
62 63 64 65
    private int                 slot;
    // This is guaranteed to be interned by the VM in the 1.4
    // reflection implementation
    private String              name;
66
    private Class<?>            type;
D
duke 已提交
67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109
    private int                 modifiers;
    // Generics and annotations support
    private transient String    signature;
    // generic info repository; lazily initialized
    private transient FieldRepository genericInfo;
    private byte[]              annotations;
    // Cached field accessor created without override
    private FieldAccessor fieldAccessor;
    // Cached field accessor created with override
    private FieldAccessor overrideFieldAccessor;
    // For sharing of FieldAccessors. This branching structure is
    // currently only two levels deep (i.e., one root Field and
    // potentially many Field objects pointing to it.)
    private Field               root;

    // Generics infrastructure

    private String getGenericSignature() {return signature;}

    // Accessor for factory
    private GenericsFactory getFactory() {
        Class<?> c = getDeclaringClass();
        // create scope and factory
        return CoreReflectionFactory.make(c, ClassScope.make(c));
    }

    // Accessor for generic info repository
    private FieldRepository getGenericInfo() {
        // lazily initialize repository if necessary
        if (genericInfo == null) {
            // create and cache generic info repository
            genericInfo = FieldRepository.make(getGenericSignature(),
                                               getFactory());
        }
        return genericInfo; //return cached repository
    }


    /**
     * Package-private constructor used by ReflectAccess to enable
     * instantiation of these objects in Java code from the java.lang
     * package via sun.reflect.LangReflectAccess.
     */
110
    Field(Class<?> declaringClass,
D
duke 已提交
111
          String name,
112
          Class<?> type,
D
duke 已提交
113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337
          int modifiers,
          int slot,
          String signature,
          byte[] annotations)
    {
        this.clazz = declaringClass;
        this.name = name;
        this.type = type;
        this.modifiers = modifiers;
        this.slot = slot;
        this.signature = signature;
        this.annotations = annotations;
    }

    /**
     * Package-private routine (exposed to java.lang.Class via
     * ReflectAccess) which returns a copy of this Field. The copy's
     * "root" field points to this Field.
     */
    Field copy() {
        // This routine enables sharing of FieldAccessor objects
        // among Field objects which refer to the same underlying
        // method in the VM. (All of this contortion is only necessary
        // because of the "accessibility" bit in AccessibleObject,
        // which implicitly requires that new java.lang.reflect
        // objects be fabricated for each reflective call on Class
        // objects.)
        Field res = new Field(clazz, name, type, modifiers, slot, signature, annotations);
        res.root = this;
        // Might as well eagerly propagate this if already present
        res.fieldAccessor = fieldAccessor;
        res.overrideFieldAccessor = overrideFieldAccessor;
        return res;
    }

    /**
     * Returns the {@code Class} object representing the class or interface
     * that declares the field represented by this {@code Field} object.
     */
    public Class<?> getDeclaringClass() {
        return clazz;
    }

    /**
     * Returns the name of the field represented by this {@code Field} object.
     */
    public String getName() {
        return name;
    }

    /**
     * Returns the Java language modifiers for the field represented
     * by this {@code Field} object, as an integer. The {@code Modifier} class should
     * be used to decode the modifiers.
     *
     * @see Modifier
     */
    public int getModifiers() {
        return modifiers;
    }

    /**
     * Returns {@code true} if this field represents an element of
     * an enumerated type; returns {@code false} otherwise.
     *
     * @return {@code true} if and only if this field represents an element of
     * an enumerated type.
     * @since 1.5
     */
    public boolean isEnumConstant() {
        return (getModifiers() & Modifier.ENUM) != 0;
    }

    /**
     * Returns {@code true} if this field is a synthetic
     * field; returns {@code false} otherwise.
     *
     * @return true if and only if this field is a synthetic
     * field as defined by the Java Language Specification.
     * @since 1.5
     */
    public boolean isSynthetic() {
        return Modifier.isSynthetic(getModifiers());
    }

    /**
     * Returns a {@code Class} object that identifies the
     * declared type for the field represented by this
     * {@code Field} object.
     *
     * @return a {@code Class} object identifying the declared
     * type of the field represented by this object
     */
    public Class<?> getType() {
        return type;
    }

    /**
     * Returns a {@code Type} object that represents the declared type for
     * the field represented by this {@code Field} object.
     *
     * <p>If the {@code Type} is a parameterized type, the
     * {@code Type} object returned must accurately reflect the
     * actual type parameters used in the source code.
     *
     * <p>If the type of the underlying field is a type variable or a
     * parameterized type, it is created. Otherwise, it is resolved.
     *
     * @return a {@code Type} object that represents the declared type for
     *     the field represented by this {@code Field} object
     * @throws GenericSignatureFormatError if the generic field
     *     signature does not conform to the format specified in the Java
     *     Virtual Machine Specification, 3rd edition
     * @throws TypeNotPresentException if the generic type
     *     signature of the underlying field refers to a non-existent
     *     type declaration
     * @throws MalformedParameterizedTypeException if the generic
     *     signature of the underlying field refers to a parameterized type
     *     that cannot be instantiated for any reason
     * @since 1.5
     */
    public Type getGenericType() {
        if (getGenericSignature() != null)
            return getGenericInfo().getGenericType();
        else
            return getType();
    }


    /**
     * Compares this {@code Field} against the specified object.  Returns
     * true if the objects are the same.  Two {@code Field} objects are the same if
     * they were declared by the same class and have the same name
     * and type.
     */
    public boolean equals(Object obj) {
        if (obj != null && obj instanceof Field) {
            Field other = (Field)obj;
            return (getDeclaringClass() == other.getDeclaringClass())
                && (getName() == other.getName())
                && (getType() == other.getType());
        }
        return false;
    }

    /**
     * Returns a hashcode for this {@code Field}.  This is computed as the
     * exclusive-or of the hashcodes for the underlying field's
     * declaring class name and its name.
     */
    public int hashCode() {
        return getDeclaringClass().getName().hashCode() ^ getName().hashCode();
    }

    /**
     * Returns a string describing this {@code Field}.  The format is
     * the access modifiers for the field, if any, followed
     * by the field type, followed by a space, followed by
     * the fully-qualified name of the class declaring the field,
     * followed by a period, followed by the name of the field.
     * For example:
     * <pre>
     *    public static final int java.lang.Thread.MIN_PRIORITY
     *    private int java.io.FileDescriptor.fd
     * </pre>
     *
     * <p>The modifiers are placed in canonical order as specified by
     * "The Java Language Specification".  This is {@code public},
     * {@code protected} or {@code private} first, and then other
     * modifiers in the following order: {@code static}, {@code final},
     * {@code transient}, {@code volatile}.
     */
    public String toString() {
        int mod = getModifiers();
        return (((mod == 0) ? "" : (Modifier.toString(mod) + " "))
            + getTypeName(getType()) + " "
            + getTypeName(getDeclaringClass()) + "."
            + getName());
    }

    /**
     * Returns a string describing this {@code Field}, including
     * its generic type.  The format is the access modifiers for the
     * field, if any, followed by the generic field type, followed by
     * a space, followed by the fully-qualified name of the class
     * declaring the field, followed by a period, followed by the name
     * of the field.
     *
     * <p>The modifiers are placed in canonical order as specified by
     * "The Java Language Specification".  This is {@code public},
     * {@code protected} or {@code private} first, and then other
     * modifiers in the following order: {@code static}, {@code final},
     * {@code transient}, {@code volatile}.
     *
     * @return a string describing this {@code Field}, including
     * its generic type
     *
     * @since 1.5
     */
    public String toGenericString() {
        int mod = getModifiers();
        Type fieldType = getGenericType();
        return (((mod == 0) ? "" : (Modifier.toString(mod) + " "))
            +  ((fieldType instanceof Class) ?
                getTypeName((Class)fieldType): fieldType.toString())+ " "
            + getTypeName(getDeclaringClass()) + "."
            + getName());
    }

    /**
     * Returns the value of the field represented by this {@code Field}, on
     * the specified object. The value is automatically wrapped in an
     * object if it has a primitive type.
     *
     * <p>The underlying field's value is obtained as follows:
     *
     * <p>If the underlying field is a static field, the {@code obj} argument
     * is ignored; it may be null.
     *
     * <p>Otherwise, the underlying field is an instance field.  If the
     * specified {@code obj} argument is null, the method throws a
     * {@code NullPointerException}. If the specified object is not an
     * instance of the class or interface declaring the underlying
     * field, the method throws an {@code IllegalArgumentException}.
     *
338
     * <p>If this {@code Field} object is enforcing Java language access control, and
D
duke 已提交
339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357
     * the underlying field is inaccessible, the method throws an
     * {@code IllegalAccessException}.
     * If the underlying field is static, the class that declared the
     * field is initialized if it has not already been initialized.
     *
     * <p>Otherwise, the value is retrieved from the underlying instance
     * or static field.  If the field has a primitive type, the value
     * is wrapped in an object before being returned, otherwise it is
     * returned as is.
     *
     * <p>If the field is hidden in the type of {@code obj},
     * the field's value is obtained according to the preceding rules.
     *
     * @param obj object from which the represented field's value is
     * to be extracted
     * @return the value of the represented field in object
     * {@code obj}; primitive values are wrapped in an appropriate
     * object before being returned
     *
358 359 360
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is inaccessible.
D
duke 已提交
361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381
     * @exception IllegalArgumentException  if the specified object is not an
     *              instance of the class or interface declaring the underlying
     *              field (or a subclass or implementor thereof).
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     */
    public Object get(Object obj)
        throws IllegalArgumentException, IllegalAccessException
    {
        return getFieldAccessor(obj).get(obj);
    }

    /**
     * Gets the value of a static or instance {@code boolean} field.
     *
     * @param obj the object to extract the {@code boolean} value
     * from
     * @return the value of the {@code boolean} field
     *
382 383 384
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is inaccessible.
D
duke 已提交
385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409
     * @exception IllegalArgumentException  if the specified object is not
     *              an instance of the class or interface declaring the
     *              underlying field (or a subclass or implementor
     *              thereof), or if the field value cannot be
     *              converted to the type {@code boolean} by a
     *              widening conversion.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#get
     */
    public boolean getBoolean(Object obj)
        throws IllegalArgumentException, IllegalAccessException
    {
        return getFieldAccessor(obj).getBoolean(obj);
    }

    /**
     * Gets the value of a static or instance {@code byte} field.
     *
     * @param obj the object to extract the {@code byte} value
     * from
     * @return the value of the {@code byte} field
     *
410 411 412
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is inaccessible.
D
duke 已提交
413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439
     * @exception IllegalArgumentException  if the specified object is not
     *              an instance of the class or interface declaring the
     *              underlying field (or a subclass or implementor
     *              thereof), or if the field value cannot be
     *              converted to the type {@code byte} by a
     *              widening conversion.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#get
     */
    public byte getByte(Object obj)
        throws IllegalArgumentException, IllegalAccessException
    {
        return getFieldAccessor(obj).getByte(obj);
    }

    /**
     * Gets the value of a static or instance field of type
     * {@code char} or of another primitive type convertible to
     * type {@code char} via a widening conversion.
     *
     * @param obj the object to extract the {@code char} value
     * from
     * @return the value of the field converted to type {@code char}
     *
440 441 442
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is inaccessible.
D
duke 已提交
443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469
     * @exception IllegalArgumentException  if the specified object is not
     *              an instance of the class or interface declaring the
     *              underlying field (or a subclass or implementor
     *              thereof), or if the field value cannot be
     *              converted to the type {@code char} by a
     *              widening conversion.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see Field#get
     */
    public char getChar(Object obj)
        throws IllegalArgumentException, IllegalAccessException
    {
        return getFieldAccessor(obj).getChar(obj);
    }

    /**
     * Gets the value of a static or instance field of type
     * {@code short} or of another primitive type convertible to
     * type {@code short} via a widening conversion.
     *
     * @param obj the object to extract the {@code short} value
     * from
     * @return the value of the field converted to type {@code short}
     *
470 471 472
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is inaccessible.
D
duke 已提交
473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499
     * @exception IllegalArgumentException  if the specified object is not
     *              an instance of the class or interface declaring the
     *              underlying field (or a subclass or implementor
     *              thereof), or if the field value cannot be
     *              converted to the type {@code short} by a
     *              widening conversion.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#get
     */
    public short getShort(Object obj)
        throws IllegalArgumentException, IllegalAccessException
    {
        return getFieldAccessor(obj).getShort(obj);
    }

    /**
     * Gets the value of a static or instance field of type
     * {@code int} or of another primitive type convertible to
     * type {@code int} via a widening conversion.
     *
     * @param obj the object to extract the {@code int} value
     * from
     * @return the value of the field converted to type {@code int}
     *
500 501 502
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is inaccessible.
D
duke 已提交
503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529
     * @exception IllegalArgumentException  if the specified object is not
     *              an instance of the class or interface declaring the
     *              underlying field (or a subclass or implementor
     *              thereof), or if the field value cannot be
     *              converted to the type {@code int} by a
     *              widening conversion.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#get
     */
    public int getInt(Object obj)
        throws IllegalArgumentException, IllegalAccessException
    {
        return getFieldAccessor(obj).getInt(obj);
    }

    /**
     * Gets the value of a static or instance field of type
     * {@code long} or of another primitive type convertible to
     * type {@code long} via a widening conversion.
     *
     * @param obj the object to extract the {@code long} value
     * from
     * @return the value of the field converted to type {@code long}
     *
530 531 532
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is inaccessible.
D
duke 已提交
533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559
     * @exception IllegalArgumentException  if the specified object is not
     *              an instance of the class or interface declaring the
     *              underlying field (or a subclass or implementor
     *              thereof), or if the field value cannot be
     *              converted to the type {@code long} by a
     *              widening conversion.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#get
     */
    public long getLong(Object obj)
        throws IllegalArgumentException, IllegalAccessException
    {
        return getFieldAccessor(obj).getLong(obj);
    }

    /**
     * Gets the value of a static or instance field of type
     * {@code float} or of another primitive type convertible to
     * type {@code float} via a widening conversion.
     *
     * @param obj the object to extract the {@code float} value
     * from
     * @return the value of the field converted to type {@code float}
     *
560 561 562
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is inaccessible.
D
duke 已提交
563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589
     * @exception IllegalArgumentException  if the specified object is not
     *              an instance of the class or interface declaring the
     *              underlying field (or a subclass or implementor
     *              thereof), or if the field value cannot be
     *              converted to the type {@code float} by a
     *              widening conversion.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see Field#get
     */
    public float getFloat(Object obj)
        throws IllegalArgumentException, IllegalAccessException
    {
        return getFieldAccessor(obj).getFloat(obj);
    }

    /**
     * Gets the value of a static or instance field of type
     * {@code double} or of another primitive type convertible to
     * type {@code double} via a widening conversion.
     *
     * @param obj the object to extract the {@code double} value
     * from
     * @return the value of the field converted to type {@code double}
     *
590 591 592
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is inaccessible.
D
duke 已提交
593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627
     * @exception IllegalArgumentException  if the specified object is not
     *              an instance of the class or interface declaring the
     *              underlying field (or a subclass or implementor
     *              thereof), or if the field value cannot be
     *              converted to the type {@code double} by a
     *              widening conversion.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#get
     */
    public double getDouble(Object obj)
        throws IllegalArgumentException, IllegalAccessException
    {
        return getFieldAccessor(obj).getDouble(obj);
    }

    /**
     * Sets the field represented by this {@code Field} object on the
     * specified object argument to the specified new value. The new
     * value is automatically unwrapped if the underlying field has a
     * primitive type.
     *
     * <p>The operation proceeds as follows:
     *
     * <p>If the underlying field is static, the {@code obj} argument is
     * ignored; it may be null.
     *
     * <p>Otherwise the underlying field is an instance field.  If the
     * specified object argument is null, the method throws a
     * {@code NullPointerException}.  If the specified object argument is not
     * an instance of the class or interface declaring the underlying
     * field, the method throws an {@code IllegalArgumentException}.
     *
628
     * <p>If this {@code Field} object is enforcing Java language access control, and
D
duke 已提交
629 630 631 632
     * the underlying field is inaccessible, the method throws an
     * {@code IllegalAccessException}.
     *
     * <p>If the underlying field is final, the method throws an
633 634 635
     * {@code IllegalAccessException} unless {@code setAccessible(true)}
     * has succeeded for this {@code Field} object
     * and the field is non-static. Setting a final field in this way
D
duke 已提交
636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664
     * is meaningful only during deserialization or reconstruction of
     * instances of classes with blank final fields, before they are
     * made available for access by other parts of a program. Use in
     * any other context may have unpredictable effects, including cases
     * in which other parts of a program continue to use the original
     * value of this field.
     *
     * <p>If the underlying field is of a primitive type, an unwrapping
     * conversion is attempted to convert the new value to a value of
     * a primitive type.  If this attempt fails, the method throws an
     * {@code IllegalArgumentException}.
     *
     * <p>If, after possible unwrapping, the new value cannot be
     * converted to the type of the underlying field by an identity or
     * widening conversion, the method throws an
     * {@code IllegalArgumentException}.
     *
     * <p>If the underlying field is static, the class that declared the
     * field is initialized if it has not already been initialized.
     *
     * <p>The field is set to the possibly unwrapped and widened new value.
     *
     * <p>If the field is hidden in the type of {@code obj},
     * the field's value is set according to the preceding rules.
     *
     * @param obj the object whose field should be modified
     * @param value the new value for the field of {@code obj}
     * being modified
     *
665 666 667
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is either inaccessible or final.
D
duke 已提交
668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693
     * @exception IllegalArgumentException  if the specified object is not an
     *              instance of the class or interface declaring the underlying
     *              field (or a subclass or implementor thereof),
     *              or if an unwrapping conversion fails.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     */
    public void set(Object obj, Object value)
        throws IllegalArgumentException, IllegalAccessException
    {
        getFieldAccessor(obj).set(obj, value);
    }

    /**
     * Sets the value of a field as a {@code boolean} on the specified object.
     * This method is equivalent to
     * {@code set(obj, zObj)},
     * where {@code zObj} is a {@code Boolean} object and
     * {@code zObj.booleanValue() == z}.
     *
     * @param obj the object whose field should be modified
     * @param z   the new value for the field of {@code obj}
     * being modified
     *
694 695 696
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is either inaccessible or final.
D
duke 已提交
697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723
     * @exception IllegalArgumentException  if the specified object is not an
     *              instance of the class or interface declaring the underlying
     *              field (or a subclass or implementor thereof),
     *              or if an unwrapping conversion fails.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#set
     */
    public void setBoolean(Object obj, boolean z)
        throws IllegalArgumentException, IllegalAccessException
    {
        getFieldAccessor(obj).setBoolean(obj, z);
    }

    /**
     * Sets the value of a field as a {@code byte} on the specified object.
     * This method is equivalent to
     * {@code set(obj, bObj)},
     * where {@code bObj} is a {@code Byte} object and
     * {@code bObj.byteValue() == b}.
     *
     * @param obj the object whose field should be modified
     * @param b   the new value for the field of {@code obj}
     * being modified
     *
724 725 726
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is either inaccessible or final.
D
duke 已提交
727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753
     * @exception IllegalArgumentException  if the specified object is not an
     *              instance of the class or interface declaring the underlying
     *              field (or a subclass or implementor thereof),
     *              or if an unwrapping conversion fails.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#set
     */
    public void setByte(Object obj, byte b)
        throws IllegalArgumentException, IllegalAccessException
    {
        getFieldAccessor(obj).setByte(obj, b);
    }

    /**
     * Sets the value of a field as a {@code char} on the specified object.
     * This method is equivalent to
     * {@code set(obj, cObj)},
     * where {@code cObj} is a {@code Character} object and
     * {@code cObj.charValue() == c}.
     *
     * @param obj the object whose field should be modified
     * @param c   the new value for the field of {@code obj}
     * being modified
     *
754 755 756
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is either inaccessible or final.
D
duke 已提交
757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783
     * @exception IllegalArgumentException  if the specified object is not an
     *              instance of the class or interface declaring the underlying
     *              field (or a subclass or implementor thereof),
     *              or if an unwrapping conversion fails.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#set
     */
    public void setChar(Object obj, char c)
        throws IllegalArgumentException, IllegalAccessException
    {
        getFieldAccessor(obj).setChar(obj, c);
    }

    /**
     * Sets the value of a field as a {@code short} on the specified object.
     * This method is equivalent to
     * {@code set(obj, sObj)},
     * where {@code sObj} is a {@code Short} object and
     * {@code sObj.shortValue() == s}.
     *
     * @param obj the object whose field should be modified
     * @param s   the new value for the field of {@code obj}
     * being modified
     *
784 785 786
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is either inaccessible or final.
D
duke 已提交
787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813
     * @exception IllegalArgumentException  if the specified object is not an
     *              instance of the class or interface declaring the underlying
     *              field (or a subclass or implementor thereof),
     *              or if an unwrapping conversion fails.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#set
     */
    public void setShort(Object obj, short s)
        throws IllegalArgumentException, IllegalAccessException
    {
        getFieldAccessor(obj).setShort(obj, s);
    }

    /**
     * Sets the value of a field as an {@code int} on the specified object.
     * This method is equivalent to
     * {@code set(obj, iObj)},
     * where {@code iObj} is a {@code Integer} object and
     * {@code iObj.intValue() == i}.
     *
     * @param obj the object whose field should be modified
     * @param i   the new value for the field of {@code obj}
     * being modified
     *
814 815 816
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is either inaccessible or final.
D
duke 已提交
817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843
     * @exception IllegalArgumentException  if the specified object is not an
     *              instance of the class or interface declaring the underlying
     *              field (or a subclass or implementor thereof),
     *              or if an unwrapping conversion fails.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#set
     */
    public void setInt(Object obj, int i)
        throws IllegalArgumentException, IllegalAccessException
    {
        getFieldAccessor(obj).setInt(obj, i);
    }

    /**
     * Sets the value of a field as a {@code long} on the specified object.
     * This method is equivalent to
     * {@code set(obj, lObj)},
     * where {@code lObj} is a {@code Long} object and
     * {@code lObj.longValue() == l}.
     *
     * @param obj the object whose field should be modified
     * @param l   the new value for the field of {@code obj}
     * being modified
     *
844 845 846
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is either inaccessible or final.
D
duke 已提交
847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873
     * @exception IllegalArgumentException  if the specified object is not an
     *              instance of the class or interface declaring the underlying
     *              field (or a subclass or implementor thereof),
     *              or if an unwrapping conversion fails.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#set
     */
    public void setLong(Object obj, long l)
        throws IllegalArgumentException, IllegalAccessException
    {
        getFieldAccessor(obj).setLong(obj, l);
    }

    /**
     * Sets the value of a field as a {@code float} on the specified object.
     * This method is equivalent to
     * {@code set(obj, fObj)},
     * where {@code fObj} is a {@code Float} object and
     * {@code fObj.floatValue() == f}.
     *
     * @param obj the object whose field should be modified
     * @param f   the new value for the field of {@code obj}
     * being modified
     *
874 875 876
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is either inaccessible or final.
D
duke 已提交
877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903
     * @exception IllegalArgumentException  if the specified object is not an
     *              instance of the class or interface declaring the underlying
     *              field (or a subclass or implementor thereof),
     *              or if an unwrapping conversion fails.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#set
     */
    public void setFloat(Object obj, float f)
        throws IllegalArgumentException, IllegalAccessException
    {
        getFieldAccessor(obj).setFloat(obj, f);
    }

    /**
     * Sets the value of a field as a {@code double} on the specified object.
     * This method is equivalent to
     * {@code set(obj, dObj)},
     * where {@code dObj} is a {@code Double} object and
     * {@code dObj.doubleValue() == d}.
     *
     * @param obj the object whose field should be modified
     * @param d   the new value for the field of {@code obj}
     * being modified
     *
904 905 906
     * @exception IllegalAccessException    if this {@code Field} object
     *              is enforcing Java language access control and the underlying
     *              field is either inaccessible or final.
D
duke 已提交
907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951
     * @exception IllegalArgumentException  if the specified object is not an
     *              instance of the class or interface declaring the underlying
     *              field (or a subclass or implementor thereof),
     *              or if an unwrapping conversion fails.
     * @exception NullPointerException      if the specified object is null
     *              and the field is an instance field.
     * @exception ExceptionInInitializerError if the initialization provoked
     *              by this method fails.
     * @see       Field#set
     */
    public void setDouble(Object obj, double d)
        throws IllegalArgumentException, IllegalAccessException
    {
        getFieldAccessor(obj).setDouble(obj, d);
    }

    // Convenience routine which performs security checks
    private FieldAccessor getFieldAccessor(Object obj)
        throws IllegalAccessException
    {
        doSecurityCheck(obj);
        boolean ov = override;
        FieldAccessor a = (ov)? overrideFieldAccessor : fieldAccessor;
        return (a != null)? a : acquireFieldAccessor(ov);
    }

    // NOTE that there is no synchronization used here. It is correct
    // (though not efficient) to generate more than one FieldAccessor
    // for a given Field. However, avoiding synchronization will
    // probably make the implementation more scalable.
    private FieldAccessor acquireFieldAccessor(boolean overrideFinalCheck) {
        // First check to see if one has been created yet, and take it
        // if so
        FieldAccessor tmp = null;
        if (root != null) tmp = root.getFieldAccessor(overrideFinalCheck);
        if (tmp != null) {
            if (overrideFinalCheck)
                overrideFieldAccessor = tmp;
            else
                fieldAccessor = tmp;
        } else {
            // Otherwise fabricate one and propagate it up to the root
            tmp = reflectionFactory.newFieldAccessor(this, overrideFinalCheck);
            setFieldAccessor(tmp, overrideFinalCheck);
        }
952

D
duke 已提交
953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980
        return tmp;
    }

    // Returns FieldAccessor for this Field object, not looking up
    // the chain to the root
    private FieldAccessor getFieldAccessor(boolean overrideFinalCheck) {
        return (overrideFinalCheck)? overrideFieldAccessor : fieldAccessor;
    }

    // Sets the FieldAccessor for this Field object and
    // (recursively) its root
    private void setFieldAccessor(FieldAccessor accessor, boolean overrideFinalCheck) {
        if (overrideFinalCheck)
            overrideFieldAccessor = accessor;
        else
            fieldAccessor = accessor;
        // Propagate up
        if (root != null) {
            root.setFieldAccessor(accessor, overrideFinalCheck);
        }
    }

    // NOTE: be very careful if you change the stack depth of this
    // routine. The depth of the "getCallerClass" call is hardwired so
    // that the compiler can have an easier time if this gets inlined.
    private void doSecurityCheck(Object obj) throws IllegalAccessException {
        if (!override) {
            if (!Reflection.quickCheckMemberAccess(clazz, modifiers)) {
981
                Class<?> caller = Reflection.getCallerClass(4);
D
duke 已提交
982

983
                checkAccess(caller, clazz, obj, modifiers);
D
duke 已提交
984 985 986 987 988 989 990
            }
        }
    }

    /*
     * Utility routine to paper over array type names
     */
991
    static String getTypeName(Class<?> type) {
D
duke 已提交
992 993
        if (type.isArray()) {
            try {
994
                Class<?> cl = type;
D
duke 已提交
995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025
                int dimensions = 0;
                while (cl.isArray()) {
                    dimensions++;
                    cl = cl.getComponentType();
                }
                StringBuffer sb = new StringBuffer();
                sb.append(cl.getName());
                for (int i = 0; i < dimensions; i++) {
                    sb.append("[]");
                }
                return sb.toString();
            } catch (Throwable e) { /*FALLTHRU*/ }
        }
        return type.getName();
    }

    /**
     * @throws NullPointerException {@inheritDoc}
     * @since 1.5
     */
    public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
        if (annotationClass == null)
            throw new NullPointerException();

        return (T) declaredAnnotations().get(annotationClass);
    }

    /**
     * @since 1.5
     */
    public Annotation[] getDeclaredAnnotations()  {
1026
        return AnnotationParser.toArray(declaredAnnotations());
D
duke 已提交
1027 1028
    }

1029
    private transient Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
D
duke 已提交
1030

1031
    private synchronized  Map<Class<? extends Annotation>, Annotation> declaredAnnotations() {
D
duke 已提交
1032 1033 1034 1035 1036 1037 1038 1039 1040
        if (declaredAnnotations == null) {
            declaredAnnotations = AnnotationParser.parseAnnotations(
                annotations, sun.misc.SharedSecrets.getJavaLangAccess().
                getConstantPool(getDeclaringClass()),
                getDeclaringClass());
        }
        return declaredAnnotations;
    }
}