1 /*
   2  * Copyright 1996-2006 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 
  26 package java.lang.reflect;
  27 
  28 import sun.reflect.FieldAccessor;
  29 import sun.reflect.Reflection;
  30 import sun.reflect.generics.repository.FieldRepository;
  31 import sun.reflect.generics.factory.CoreReflectionFactory;
  32 import sun.reflect.generics.factory.GenericsFactory;
  33 import sun.reflect.generics.scope.ClassScope;
  34 import java.lang.annotation.Annotation;
  35 import java.util.Map;
  36 import sun.reflect.annotation.AnnotationParser;
  37 
  38 
  39 /**
  40  * A {@code Field} provides information about, and dynamic access to, a
  41  * single field of a class or an interface.  The reflected field may
  42  * be a class (static) field or an instance field.
  43  *
  44  * <p>A {@code Field} permits widening conversions to occur during a get or
  45  * set access operation, but throws an {@code IllegalArgumentException} if a
  46  * narrowing conversion would occur.
  47  *
  48  * @see Member
  49  * @see java.lang.Class
  50  * @see java.lang.Class#getFields()
  51  * @see java.lang.Class#getField(String)
  52  * @see java.lang.Class#getDeclaredFields()
  53  * @see java.lang.Class#getDeclaredField(String)
  54  *
  55  * @author Kenneth Russell
  56  * @author Nakul Saraiya
  57  */
  58 public final
  59 class Field extends AccessibleObject implements Member {
  60 
  61     private Class               clazz;
  62     private int                 slot;
  63     // This is guaranteed to be interned by the VM in the 1.4
  64     // reflection implementation
  65     private String              name;
  66     private Class               type;
  67     private int                 modifiers;
  68     // Generics and annotations support
  69     private transient String    signature;
  70     // generic info repository; lazily initialized
  71     private transient FieldRepository genericInfo;
  72     private byte[]              annotations;
  73     // Cached field accessor created without override
  74     private FieldAccessor fieldAccessor;
  75     // Cached field accessor created with override
  76     private FieldAccessor overrideFieldAccessor;
  77     // For sharing of FieldAccessors. This branching structure is
  78     // currently only two levels deep (i.e., one root Field and
  79     // potentially many Field objects pointing to it.)
  80     private Field               root;
  81 
  82     // More complicated security check cache needed here than for
  83     // Class.newInstance() and Constructor.newInstance()
  84     private Class securityCheckCache;
  85     private Class securityCheckTargetClassCache;
  86 
  87     // Generics infrastructure
  88 
  89     private String getGenericSignature() {return signature;}
  90 
  91     // Accessor for factory
  92     private GenericsFactory getFactory() {
  93         Class<?> c = getDeclaringClass();
  94         // create scope and factory
  95         return CoreReflectionFactory.make(c, ClassScope.make(c));
  96     }
  97 
  98     // Accessor for generic info repository
  99     private FieldRepository getGenericInfo() {
 100         // lazily initialize repository if necessary
 101         if (genericInfo == null) {
 102             // create and cache generic info repository
 103             genericInfo = FieldRepository.make(getGenericSignature(),
 104                                                getFactory());
 105         }
 106         return genericInfo; //return cached repository
 107     }
 108 
 109 
 110     /**
 111      * Package-private constructor used by ReflectAccess to enable
 112      * instantiation of these objects in Java code from the java.lang
 113      * package via sun.reflect.LangReflectAccess.
 114      */
 115     Field(Class declaringClass,
 116           String name,
 117           Class type,
 118           int modifiers,
 119           int slot,
 120           String signature,
 121           byte[] annotations)
 122     {
 123         this.clazz = declaringClass;
 124         this.name = name;
 125         this.type = type;
 126         this.modifiers = modifiers;
 127         this.slot = slot;
 128         this.signature = signature;
 129         this.annotations = annotations;
 130     }
 131 
 132     /**
 133      * Package-private routine (exposed to java.lang.Class via
 134      * ReflectAccess) which returns a copy of this Field. The copy's
 135      * "root" field points to this Field.
 136      */
 137     Field copy() {
 138         // This routine enables sharing of FieldAccessor objects
 139         // among Field objects which refer to the same underlying
 140         // method in the VM. (All of this contortion is only necessary
 141         // because of the "accessibility" bit in AccessibleObject,
 142         // which implicitly requires that new java.lang.reflect
 143         // objects be fabricated for each reflective call on Class
 144         // objects.)
 145         Field res = new Field(clazz, name, type, modifiers, slot, signature, annotations);
 146         res.root = this;
 147         // Might as well eagerly propagate this if already present
 148         res.fieldAccessor = fieldAccessor;
 149         res.overrideFieldAccessor = overrideFieldAccessor;
 150         return res;
 151     }
 152 
 153     /**
 154      * Returns the {@code Class} object representing the class or interface
 155      * that declares the field represented by this {@code Field} object.
 156      */
 157     public Class<?> getDeclaringClass() {
 158         return clazz;
 159     }
 160 
 161     /**
 162      * Returns the name of the field represented by this {@code Field} object.
 163      */
 164     public String getName() {
 165         return name;
 166     }
 167 
 168     /**
 169      * Returns the Java language modifiers for the field represented
 170      * by this {@code Field} object, as an integer. The {@code Modifier} class should
 171      * be used to decode the modifiers.
 172      *
 173      * @see Modifier
 174      */
 175     public int getModifiers() {
 176         return modifiers;
 177     }
 178 
 179     /**
 180      * Returns {@code true} if this field represents an element of
 181      * an enumerated type; returns {@code false} otherwise.
 182      *
 183      * @return {@code true} if and only if this field represents an element of
 184      * an enumerated type.
 185      * @since 1.5
 186      */
 187     public boolean isEnumConstant() {
 188         return (getModifiers() & Modifier.ENUM) != 0;
 189     }
 190 
 191     /**
 192      * Returns {@code true} if this field is a synthetic
 193      * field; returns {@code false} otherwise.
 194      *
 195      * @return true if and only if this field is a synthetic
 196      * field as defined by the Java Language Specification.
 197      * @since 1.5
 198      */
 199     public boolean isSynthetic() {
 200         return Modifier.isSynthetic(getModifiers());
 201     }
 202 
 203     /**
 204      * Returns a {@code Class} object that identifies the
 205      * declared type for the field represented by this
 206      * {@code Field} object.
 207      *
 208      * @return a {@code Class} object identifying the declared
 209      * type of the field represented by this object
 210      */
 211     public Class<?> getType() {
 212         return type;
 213     }
 214 
 215     /**
 216      * Returns a {@code Type} object that represents the declared type for
 217      * the field represented by this {@code Field} object.
 218      *
 219      * <p>If the {@code Type} is a parameterized type, the
 220      * {@code Type} object returned must accurately reflect the
 221      * actual type parameters used in the source code.
 222      *
 223      * <p>If the type of the underlying field is a type variable or a
 224      * parameterized type, it is created. Otherwise, it is resolved.
 225      *
 226      * @return a {@code Type} object that represents the declared type for
 227      *     the field represented by this {@code Field} object
 228      * @throws GenericSignatureFormatError if the generic field
 229      *     signature does not conform to the format specified in the Java
 230      *     Virtual Machine Specification, 3rd edition
 231      * @throws TypeNotPresentException if the generic type
 232      *     signature of the underlying field refers to a non-existent
 233      *     type declaration
 234      * @throws MalformedParameterizedTypeException if the generic
 235      *     signature of the underlying field refers to a parameterized type
 236      *     that cannot be instantiated for any reason
 237      * @since 1.5
 238      */
 239     public Type getGenericType() {
 240         if (getGenericSignature() != null)
 241             return getGenericInfo().getGenericType();
 242         else
 243             return getType();
 244     }
 245 
 246 
 247     /**
 248      * Compares this {@code Field} against the specified object.  Returns
 249      * true if the objects are the same.  Two {@code Field} objects are the same if
 250      * they were declared by the same class and have the same name
 251      * and type.
 252      */
 253     public boolean equals(Object obj) {
 254         if (obj != null && obj instanceof Field) {
 255             Field other = (Field)obj;
 256             return (getDeclaringClass() == other.getDeclaringClass())
 257                 && (getName() == other.getName())
 258                 && (getType() == other.getType());
 259         }
 260         return false;
 261     }
 262 
 263     /**
 264      * Returns a hashcode for this {@code Field}.  This is computed as the
 265      * exclusive-or of the hashcodes for the underlying field's
 266      * declaring class name and its name.
 267      */
 268     public int hashCode() {
 269         return getDeclaringClass().getName().hashCode() ^ getName().hashCode();
 270     }
 271 
 272     /**
 273      * Returns a string describing this {@code Field}.  The format is
 274      * the access modifiers for the field, if any, followed
 275      * by the field type, followed by a space, followed by
 276      * the fully-qualified name of the class declaring the field,
 277      * followed by a period, followed by the name of the field.
 278      * For example:
 279      * <pre>
 280      *    public static final int java.lang.Thread.MIN_PRIORITY
 281      *    private int java.io.FileDescriptor.fd
 282      * </pre>
 283      *
 284      * <p>The modifiers are placed in canonical order as specified by
 285      * "The Java Language Specification".  This is {@code public},
 286      * {@code protected} or {@code private} first, and then other
 287      * modifiers in the following order: {@code static}, {@code final},
 288      * {@code transient}, {@code volatile}.
 289      */
 290     public String toString() {
 291         int mod = getModifiers();
 292         return (((mod == 0) ? "" : (Modifier.toString(mod) + " "))
 293             + getTypeName(getType()) + " "
 294             + getTypeName(getDeclaringClass()) + "."
 295             + getName());
 296     }
 297 
 298     /**
 299      * Returns a string describing this {@code Field}, including
 300      * its generic type.  The format is the access modifiers for the
 301      * field, if any, followed by the generic field type, followed by
 302      * a space, followed by the fully-qualified name of the class
 303      * declaring the field, followed by a period, followed by the name
 304      * of the field.
 305      *
 306      * <p>The modifiers are placed in canonical order as specified by
 307      * "The Java Language Specification".  This is {@code public},
 308      * {@code protected} or {@code private} first, and then other
 309      * modifiers in the following order: {@code static}, {@code final},
 310      * {@code transient}, {@code volatile}.
 311      *
 312      * @return a string describing this {@code Field}, including
 313      * its generic type
 314      *
 315      * @since 1.5
 316      */
 317     public String toGenericString() {
 318         int mod = getModifiers();
 319         Type fieldType = getGenericType();
 320         return (((mod == 0) ? "" : (Modifier.toString(mod) + " "))
 321             +  ((fieldType instanceof Class) ?
 322                 getTypeName((Class)fieldType): fieldType.toString())+ " "
 323             + getTypeName(getDeclaringClass()) + "."
 324             + getName());
 325     }
 326 
 327     /**
 328      * Returns the value of the field represented by this {@code Field}, on
 329      * the specified object. The value is automatically wrapped in an
 330      * object if it has a primitive type.
 331      *
 332      * <p>The underlying field's value is obtained as follows:
 333      *
 334      * <p>If the underlying field is a static field, the {@code obj} argument
 335      * is ignored; it may be null.
 336      *
 337      * <p>Otherwise, the underlying field is an instance field.  If the
 338      * specified {@code obj} argument is null, the method throws a
 339      * {@code NullPointerException}. If the specified object is not an
 340      * instance of the class or interface declaring the underlying
 341      * field, the method throws an {@code IllegalArgumentException}.
 342      *
 343      * <p>If this {@code Field} object enforces Java language access control, and
 344      * the underlying field is inaccessible, the method throws an
 345      * {@code IllegalAccessException}.
 346      * If the underlying field is static, the class that declared the
 347      * field is initialized if it has not already been initialized.
 348      *
 349      * <p>Otherwise, the value is retrieved from the underlying instance
 350      * or static field.  If the field has a primitive type, the value
 351      * is wrapped in an object before being returned, otherwise it is
 352      * returned as is.
 353      *
 354      * <p>If the field is hidden in the type of {@code obj},
 355      * the field's value is obtained according to the preceding rules.
 356      *
 357      * @param obj object from which the represented field's value is
 358      * to be extracted
 359      * @return the value of the represented field in object
 360      * {@code obj}; primitive values are wrapped in an appropriate
 361      * object before being returned
 362      *
 363      * @exception IllegalAccessException    if the underlying field
 364      *              is inaccessible.
 365      * @exception IllegalArgumentException  if the specified object is not an
 366      *              instance of the class or interface declaring the underlying
 367      *              field (or a subclass or implementor thereof).
 368      * @exception NullPointerException      if the specified object is null
 369      *              and the field is an instance field.
 370      * @exception ExceptionInInitializerError if the initialization provoked
 371      *              by this method fails.
 372      */
 373     public Object get(Object obj)
 374         throws IllegalArgumentException, IllegalAccessException
 375     {
 376         return getFieldAccessor(obj).get(obj);
 377     }
 378 
 379     /**
 380      * Gets the value of a static or instance {@code boolean} field.
 381      *
 382      * @param obj the object to extract the {@code boolean} value
 383      * from
 384      * @return the value of the {@code boolean} field
 385      *
 386      * @exception IllegalAccessException    if the underlying field
 387      *              is inaccessible.
 388      * @exception IllegalArgumentException  if the specified object is not
 389      *              an instance of the class or interface declaring the
 390      *              underlying field (or a subclass or implementor
 391      *              thereof), or if the field value cannot be
 392      *              converted to the type {@code boolean} by a
 393      *              widening conversion.
 394      * @exception NullPointerException      if the specified object is null
 395      *              and the field is an instance field.
 396      * @exception ExceptionInInitializerError if the initialization provoked
 397      *              by this method fails.
 398      * @see       Field#get
 399      */
 400     public boolean getBoolean(Object obj)
 401         throws IllegalArgumentException, IllegalAccessException
 402     {
 403         return getFieldAccessor(obj).getBoolean(obj);
 404     }
 405 
 406     /**
 407      * Gets the value of a static or instance {@code byte} field.
 408      *
 409      * @param obj the object to extract the {@code byte} value
 410      * from
 411      * @return the value of the {@code byte} field
 412      *
 413      * @exception IllegalAccessException    if the underlying field
 414      *              is inaccessible.
 415      * @exception IllegalArgumentException  if the specified object is not
 416      *              an instance of the class or interface declaring the
 417      *              underlying field (or a subclass or implementor
 418      *              thereof), or if the field value cannot be
 419      *              converted to the type {@code byte} by a
 420      *              widening conversion.
 421      * @exception NullPointerException      if the specified object is null
 422      *              and the field is an instance field.
 423      * @exception ExceptionInInitializerError if the initialization provoked
 424      *              by this method fails.
 425      * @see       Field#get
 426      */
 427     public byte getByte(Object obj)
 428         throws IllegalArgumentException, IllegalAccessException
 429     {
 430         return getFieldAccessor(obj).getByte(obj);
 431     }
 432 
 433     /**
 434      * Gets the value of a static or instance field of type
 435      * {@code char} or of another primitive type convertible to
 436      * type {@code char} via a widening conversion.
 437      *
 438      * @param obj the object to extract the {@code char} value
 439      * from
 440      * @return the value of the field converted to type {@code char}
 441      *
 442      * @exception IllegalAccessException    if the underlying field
 443      *              is inaccessible.
 444      * @exception IllegalArgumentException  if the specified object is not
 445      *              an instance of the class or interface declaring the
 446      *              underlying field (or a subclass or implementor
 447      *              thereof), or if the field value cannot be
 448      *              converted to the type {@code char} by a
 449      *              widening conversion.
 450      * @exception NullPointerException      if the specified object is null
 451      *              and the field is an instance field.
 452      * @exception ExceptionInInitializerError if the initialization provoked
 453      *              by this method fails.
 454      * @see Field#get
 455      */
 456     public char getChar(Object obj)
 457         throws IllegalArgumentException, IllegalAccessException
 458     {
 459         return getFieldAccessor(obj).getChar(obj);
 460     }
 461 
 462     /**
 463      * Gets the value of a static or instance field of type
 464      * {@code short} or of another primitive type convertible to
 465      * type {@code short} via a widening conversion.
 466      *
 467      * @param obj the object to extract the {@code short} value
 468      * from
 469      * @return the value of the field converted to type {@code short}
 470      *
 471      * @exception IllegalAccessException    if the underlying field
 472      *              is inaccessible.
 473      * @exception IllegalArgumentException  if the specified object is not
 474      *              an instance of the class or interface declaring the
 475      *              underlying field (or a subclass or implementor
 476      *              thereof), or if the field value cannot be
 477      *              converted to the type {@code short} by a
 478      *              widening conversion.
 479      * @exception NullPointerException      if the specified object is null
 480      *              and the field is an instance field.
 481      * @exception ExceptionInInitializerError if the initialization provoked
 482      *              by this method fails.
 483      * @see       Field#get
 484      */
 485     public short getShort(Object obj)
 486         throws IllegalArgumentException, IllegalAccessException
 487     {
 488         return getFieldAccessor(obj).getShort(obj);
 489     }
 490 
 491     /**
 492      * Gets the value of a static or instance field of type
 493      * {@code int} or of another primitive type convertible to
 494      * type {@code int} via a widening conversion.
 495      *
 496      * @param obj the object to extract the {@code int} value
 497      * from
 498      * @return the value of the field converted to type {@code int}
 499      *
 500      * @exception IllegalAccessException    if the underlying field
 501      *              is inaccessible.
 502      * @exception IllegalArgumentException  if the specified object is not
 503      *              an instance of the class or interface declaring the
 504      *              underlying field (or a subclass or implementor
 505      *              thereof), or if the field value cannot be
 506      *              converted to the type {@code int} by a
 507      *              widening conversion.
 508      * @exception NullPointerException      if the specified object is null
 509      *              and the field is an instance field.
 510      * @exception ExceptionInInitializerError if the initialization provoked
 511      *              by this method fails.
 512      * @see       Field#get
 513      */
 514     public int getInt(Object obj)
 515         throws IllegalArgumentException, IllegalAccessException
 516     {
 517         return getFieldAccessor(obj).getInt(obj);
 518     }
 519 
 520     /**
 521      * Gets the value of a static or instance field of type
 522      * {@code long} or of another primitive type convertible to
 523      * type {@code long} via a widening conversion.
 524      *
 525      * @param obj the object to extract the {@code long} value
 526      * from
 527      * @return the value of the field converted to type {@code long}
 528      *
 529      * @exception IllegalAccessException    if the underlying field
 530      *              is inaccessible.
 531      * @exception IllegalArgumentException  if the specified object is not
 532      *              an instance of the class or interface declaring the
 533      *              underlying field (or a subclass or implementor
 534      *              thereof), or if the field value cannot be
 535      *              converted to the type {@code long} by a
 536      *              widening conversion.
 537      * @exception NullPointerException      if the specified object is null
 538      *              and the field is an instance field.
 539      * @exception ExceptionInInitializerError if the initialization provoked
 540      *              by this method fails.
 541      * @see       Field#get
 542      */
 543     public long getLong(Object obj)
 544         throws IllegalArgumentException, IllegalAccessException
 545     {
 546         return getFieldAccessor(obj).getLong(obj);
 547     }
 548 
 549     /**
 550      * Gets the value of a static or instance field of type
 551      * {@code float} or of another primitive type convertible to
 552      * type {@code float} via a widening conversion.
 553      *
 554      * @param obj the object to extract the {@code float} value
 555      * from
 556      * @return the value of the field converted to type {@code float}
 557      *
 558      * @exception IllegalAccessException    if the underlying field
 559      *              is inaccessible.
 560      * @exception IllegalArgumentException  if the specified object is not
 561      *              an instance of the class or interface declaring the
 562      *              underlying field (or a subclass or implementor
 563      *              thereof), or if the field value cannot be
 564      *              converted to the type {@code float} by a
 565      *              widening conversion.
 566      * @exception NullPointerException      if the specified object is null
 567      *              and the field is an instance field.
 568      * @exception ExceptionInInitializerError if the initialization provoked
 569      *              by this method fails.
 570      * @see Field#get
 571      */
 572     public float getFloat(Object obj)
 573         throws IllegalArgumentException, IllegalAccessException
 574     {
 575         return getFieldAccessor(obj).getFloat(obj);
 576     }
 577 
 578     /**
 579      * Gets the value of a static or instance field of type
 580      * {@code double} or of another primitive type convertible to
 581      * type {@code double} via a widening conversion.
 582      *
 583      * @param obj the object to extract the {@code double} value
 584      * from
 585      * @return the value of the field converted to type {@code double}
 586      *
 587      * @exception IllegalAccessException    if the underlying field
 588      *              is inaccessible.
 589      * @exception IllegalArgumentException  if the specified object is not
 590      *              an instance of the class or interface declaring the
 591      *              underlying field (or a subclass or implementor
 592      *              thereof), or if the field value cannot be
 593      *              converted to the type {@code double} by a
 594      *              widening conversion.
 595      * @exception NullPointerException      if the specified object is null
 596      *              and the field is an instance field.
 597      * @exception ExceptionInInitializerError if the initialization provoked
 598      *              by this method fails.
 599      * @see       Field#get
 600      */
 601     public double getDouble(Object obj)
 602         throws IllegalArgumentException, IllegalAccessException
 603     {
 604         return getFieldAccessor(obj).getDouble(obj);
 605     }
 606 
 607     /**
 608      * Sets the field represented by this {@code Field} object on the
 609      * specified object argument to the specified new value. The new
 610      * value is automatically unwrapped if the underlying field has a
 611      * primitive type.
 612      *
 613      * <p>The operation proceeds as follows:
 614      *
 615      * <p>If the underlying field is static, the {@code obj} argument is
 616      * ignored; it may be null.
 617      *
 618      * <p>Otherwise the underlying field is an instance field.  If the
 619      * specified object argument is null, the method throws a
 620      * {@code NullPointerException}.  If the specified object argument is not
 621      * an instance of the class or interface declaring the underlying
 622      * field, the method throws an {@code IllegalArgumentException}.
 623      *
 624      * <p>If this {@code Field} object enforces Java language access control, and
 625      * the underlying field is inaccessible, the method throws an
 626      * {@code IllegalAccessException}.
 627      *
 628      * <p>If the underlying field is final, the method throws an
 629      * {@code IllegalAccessException} unless
 630      * {@code setAccessible(true)} has succeeded for this field
 631      * and this field is non-static. Setting a final field in this way
 632      * is meaningful only during deserialization or reconstruction of
 633      * instances of classes with blank final fields, before they are
 634      * made available for access by other parts of a program. Use in
 635      * any other context may have unpredictable effects, including cases
 636      * in which other parts of a program continue to use the original
 637      * value of this field.
 638      *
 639      * <p>If the underlying field is of a primitive type, an unwrapping
 640      * conversion is attempted to convert the new value to a value of
 641      * a primitive type.  If this attempt fails, the method throws an
 642      * {@code IllegalArgumentException}.
 643      *
 644      * <p>If, after possible unwrapping, the new value cannot be
 645      * converted to the type of the underlying field by an identity or
 646      * widening conversion, the method throws an
 647      * {@code IllegalArgumentException}.
 648      *
 649      * <p>If the underlying field is static, the class that declared the
 650      * field is initialized if it has not already been initialized.
 651      *
 652      * <p>The field is set to the possibly unwrapped and widened new value.
 653      *
 654      * <p>If the field is hidden in the type of {@code obj},
 655      * the field's value is set according to the preceding rules.
 656      *
 657      * @param obj the object whose field should be modified
 658      * @param value the new value for the field of {@code obj}
 659      * being modified
 660      *
 661      * @exception IllegalAccessException    if the underlying field
 662      *              is inaccessible.
 663      * @exception IllegalArgumentException  if the specified object is not an
 664      *              instance of the class or interface declaring the underlying
 665      *              field (or a subclass or implementor thereof),
 666      *              or if an unwrapping conversion fails.
 667      * @exception NullPointerException      if the specified object is null
 668      *              and the field is an instance field.
 669      * @exception ExceptionInInitializerError if the initialization provoked
 670      *              by this method fails.
 671      */
 672     public void set(Object obj, Object value)
 673         throws IllegalArgumentException, IllegalAccessException
 674     {
 675         getFieldAccessor(obj).set(obj, value);
 676     }
 677 
 678     /**
 679      * Sets the value of a field as a {@code boolean} on the specified object.
 680      * This method is equivalent to
 681      * {@code set(obj, zObj)},
 682      * where {@code zObj} is a {@code Boolean} object and
 683      * {@code zObj.booleanValue() == z}.
 684      *
 685      * @param obj the object whose field should be modified
 686      * @param z   the new value for the field of {@code obj}
 687      * being modified
 688      *
 689      * @exception IllegalAccessException    if the underlying field
 690      *              is inaccessible.
 691      * @exception IllegalArgumentException  if the specified object is not an
 692      *              instance of the class or interface declaring the underlying
 693      *              field (or a subclass or implementor thereof),
 694      *              or if an unwrapping conversion fails.
 695      * @exception NullPointerException      if the specified object is null
 696      *              and the field is an instance field.
 697      * @exception ExceptionInInitializerError if the initialization provoked
 698      *              by this method fails.
 699      * @see       Field#set
 700      */
 701     public void setBoolean(Object obj, boolean z)
 702         throws IllegalArgumentException, IllegalAccessException
 703     {
 704         getFieldAccessor(obj).setBoolean(obj, z);
 705     }
 706 
 707     /**
 708      * Sets the value of a field as a {@code byte} on the specified object.
 709      * This method is equivalent to
 710      * {@code set(obj, bObj)},
 711      * where {@code bObj} is a {@code Byte} object and
 712      * {@code bObj.byteValue() == b}.
 713      *
 714      * @param obj the object whose field should be modified
 715      * @param b   the new value for the field of {@code obj}
 716      * being modified
 717      *
 718      * @exception IllegalAccessException    if the underlying field
 719      *              is inaccessible.
 720      * @exception IllegalArgumentException  if the specified object is not an
 721      *              instance of the class or interface declaring the underlying
 722      *              field (or a subclass or implementor thereof),
 723      *              or if an unwrapping conversion fails.
 724      * @exception NullPointerException      if the specified object is null
 725      *              and the field is an instance field.
 726      * @exception ExceptionInInitializerError if the initialization provoked
 727      *              by this method fails.
 728      * @see       Field#set
 729      */
 730     public void setByte(Object obj, byte b)
 731         throws IllegalArgumentException, IllegalAccessException
 732     {
 733         getFieldAccessor(obj).setByte(obj, b);
 734     }
 735 
 736     /**
 737      * Sets the value of a field as a {@code char} on the specified object.
 738      * This method is equivalent to
 739      * {@code set(obj, cObj)},
 740      * where {@code cObj} is a {@code Character} object and
 741      * {@code cObj.charValue() == c}.
 742      *
 743      * @param obj the object whose field should be modified
 744      * @param c   the new value for the field of {@code obj}
 745      * being modified
 746      *
 747      * @exception IllegalAccessException    if the underlying field
 748      *              is inaccessible.
 749      * @exception IllegalArgumentException  if the specified object is not an
 750      *              instance of the class or interface declaring the underlying
 751      *              field (or a subclass or implementor thereof),
 752      *              or if an unwrapping conversion fails.
 753      * @exception NullPointerException      if the specified object is null
 754      *              and the field is an instance field.
 755      * @exception ExceptionInInitializerError if the initialization provoked
 756      *              by this method fails.
 757      * @see       Field#set
 758      */
 759     public void setChar(Object obj, char c)
 760         throws IllegalArgumentException, IllegalAccessException
 761     {
 762         getFieldAccessor(obj).setChar(obj, c);
 763     }
 764 
 765     /**
 766      * Sets the value of a field as a {@code short} on the specified object.
 767      * This method is equivalent to
 768      * {@code set(obj, sObj)},
 769      * where {@code sObj} is a {@code Short} object and
 770      * {@code sObj.shortValue() == s}.
 771      *
 772      * @param obj the object whose field should be modified
 773      * @param s   the new value for the field of {@code obj}
 774      * being modified
 775      *
 776      * @exception IllegalAccessException    if the underlying field
 777      *              is inaccessible.
 778      * @exception IllegalArgumentException  if the specified object is not an
 779      *              instance of the class or interface declaring the underlying
 780      *              field (or a subclass or implementor thereof),
 781      *              or if an unwrapping conversion fails.
 782      * @exception NullPointerException      if the specified object is null
 783      *              and the field is an instance field.
 784      * @exception ExceptionInInitializerError if the initialization provoked
 785      *              by this method fails.
 786      * @see       Field#set
 787      */
 788     public void setShort(Object obj, short s)
 789         throws IllegalArgumentException, IllegalAccessException
 790     {
 791         getFieldAccessor(obj).setShort(obj, s);
 792     }
 793 
 794     /**
 795      * Sets the value of a field as an {@code int} on the specified object.
 796      * This method is equivalent to
 797      * {@code set(obj, iObj)},
 798      * where {@code iObj} is a {@code Integer} object and
 799      * {@code iObj.intValue() == i}.
 800      *
 801      * @param obj the object whose field should be modified
 802      * @param i   the new value for the field of {@code obj}
 803      * being modified
 804      *
 805      * @exception IllegalAccessException    if the underlying field
 806      *              is inaccessible.
 807      * @exception IllegalArgumentException  if the specified object is not an
 808      *              instance of the class or interface declaring the underlying
 809      *              field (or a subclass or implementor thereof),
 810      *              or if an unwrapping conversion fails.
 811      * @exception NullPointerException      if the specified object is null
 812      *              and the field is an instance field.
 813      * @exception ExceptionInInitializerError if the initialization provoked
 814      *              by this method fails.
 815      * @see       Field#set
 816      */
 817     public void setInt(Object obj, int i)
 818         throws IllegalArgumentException, IllegalAccessException
 819     {
 820         getFieldAccessor(obj).setInt(obj, i);
 821     }
 822 
 823     /**
 824      * Sets the value of a field as a {@code long} on the specified object.
 825      * This method is equivalent to
 826      * {@code set(obj, lObj)},
 827      * where {@code lObj} is a {@code Long} object and
 828      * {@code lObj.longValue() == l}.
 829      *
 830      * @param obj the object whose field should be modified
 831      * @param l   the new value for the field of {@code obj}
 832      * being modified
 833      *
 834      * @exception IllegalAccessException    if the underlying field
 835      *              is inaccessible.
 836      * @exception IllegalArgumentException  if the specified object is not an
 837      *              instance of the class or interface declaring the underlying
 838      *              field (or a subclass or implementor thereof),
 839      *              or if an unwrapping conversion fails.
 840      * @exception NullPointerException      if the specified object is null
 841      *              and the field is an instance field.
 842      * @exception ExceptionInInitializerError if the initialization provoked
 843      *              by this method fails.
 844      * @see       Field#set
 845      */
 846     public void setLong(Object obj, long l)
 847         throws IllegalArgumentException, IllegalAccessException
 848     {
 849         getFieldAccessor(obj).setLong(obj, l);
 850     }
 851 
 852     /**
 853      * Sets the value of a field as a {@code float} on the specified object.
 854      * This method is equivalent to
 855      * {@code set(obj, fObj)},
 856      * where {@code fObj} is a {@code Float} object and
 857      * {@code fObj.floatValue() == f}.
 858      *
 859      * @param obj the object whose field should be modified
 860      * @param f   the new value for the field of {@code obj}
 861      * being modified
 862      *
 863      * @exception IllegalAccessException    if the underlying field
 864      *              is inaccessible.
 865      * @exception IllegalArgumentException  if the specified object is not an
 866      *              instance of the class or interface declaring the underlying
 867      *              field (or a subclass or implementor thereof),
 868      *              or if an unwrapping conversion fails.
 869      * @exception NullPointerException      if the specified object is null
 870      *              and the field is an instance field.
 871      * @exception ExceptionInInitializerError if the initialization provoked
 872      *              by this method fails.
 873      * @see       Field#set
 874      */
 875     public void setFloat(Object obj, float f)
 876         throws IllegalArgumentException, IllegalAccessException
 877     {
 878         getFieldAccessor(obj).setFloat(obj, f);
 879     }
 880 
 881     /**
 882      * Sets the value of a field as a {@code double} on the specified object.
 883      * This method is equivalent to
 884      * {@code set(obj, dObj)},
 885      * where {@code dObj} is a {@code Double} object and
 886      * {@code dObj.doubleValue() == d}.
 887      *
 888      * @param obj the object whose field should be modified
 889      * @param d   the new value for the field of {@code obj}
 890      * being modified
 891      *
 892      * @exception IllegalAccessException    if the underlying field
 893      *              is inaccessible.
 894      * @exception IllegalArgumentException  if the specified object is not an
 895      *              instance of the class or interface declaring the underlying
 896      *              field (or a subclass or implementor thereof),
 897      *              or if an unwrapping conversion fails.
 898      * @exception NullPointerException      if the specified object is null
 899      *              and the field is an instance field.
 900      * @exception ExceptionInInitializerError if the initialization provoked
 901      *              by this method fails.
 902      * @see       Field#set
 903      */
 904     public void setDouble(Object obj, double d)
 905         throws IllegalArgumentException, IllegalAccessException
 906     {
 907         getFieldAccessor(obj).setDouble(obj, d);
 908     }
 909 
 910     // Convenience routine which performs security checks
 911     private FieldAccessor getFieldAccessor(Object obj)
 912         throws IllegalAccessException
 913     {
 914         doSecurityCheck(obj);
 915         boolean ov = override;
 916         FieldAccessor a = (ov)? overrideFieldAccessor : fieldAccessor;
 917         return (a != null)? a : acquireFieldAccessor(ov);
 918     }
 919 
 920     // NOTE that there is no synchronization used here. It is correct
 921     // (though not efficient) to generate more than one FieldAccessor
 922     // for a given Field. However, avoiding synchronization will
 923     // probably make the implementation more scalable.
 924     private FieldAccessor acquireFieldAccessor(boolean overrideFinalCheck) {
 925         // First check to see if one has been created yet, and take it
 926         // if so
 927         FieldAccessor tmp = null;
 928         if (root != null) tmp = root.getFieldAccessor(overrideFinalCheck);
 929         if (tmp != null) {
 930             if (overrideFinalCheck)
 931                 overrideFieldAccessor = tmp;
 932             else
 933                 fieldAccessor = tmp;
 934         } else {
 935             // Otherwise fabricate one and propagate it up to the root
 936             tmp = reflectionFactory.newFieldAccessor(this, overrideFinalCheck);
 937             setFieldAccessor(tmp, overrideFinalCheck);
 938         }
 939         return tmp;
 940     }
 941 
 942     // Returns FieldAccessor for this Field object, not looking up
 943     // the chain to the root
 944     private FieldAccessor getFieldAccessor(boolean overrideFinalCheck) {
 945         return (overrideFinalCheck)? overrideFieldAccessor : fieldAccessor;
 946     }
 947 
 948     // Sets the FieldAccessor for this Field object and
 949     // (recursively) its root
 950     private void setFieldAccessor(FieldAccessor accessor, boolean overrideFinalCheck) {
 951         if (overrideFinalCheck)
 952             overrideFieldAccessor = accessor;
 953         else
 954             fieldAccessor = accessor;
 955         // Propagate up
 956         if (root != null) {
 957             root.setFieldAccessor(accessor, overrideFinalCheck);
 958         }
 959     }
 960 
 961     // NOTE: be very careful if you change the stack depth of this
 962     // routine. The depth of the "getCallerClass" call is hardwired so
 963     // that the compiler can have an easier time if this gets inlined.
 964     private void doSecurityCheck(Object obj) throws IllegalAccessException {
 965         if (!override) {
 966             if (!Reflection.quickCheckMemberAccess(clazz, modifiers)) {
 967                 Class caller = Reflection.getCallerClass(4);
 968                 Class targetClass = ((obj == null || !Modifier.isProtected(modifiers))
 969                                      ? clazz
 970                                      : obj.getClass());
 971 
 972                 synchronized (this) {
 973                     if ((securityCheckCache == caller)
 974                             && (securityCheckTargetClassCache == targetClass)) {
 975                         return;
 976                     }
 977                 }
 978                 Reflection.ensureMemberAccess(caller, clazz, obj, modifiers);
 979                 synchronized (this) {
 980                     securityCheckCache = caller;
 981                     securityCheckTargetClassCache = targetClass;
 982                 }
 983             }
 984         }
 985     }
 986 
 987     /*
 988      * Utility routine to paper over array type names
 989      */
 990     static String getTypeName(Class type) {
 991         if (type.isArray()) {
 992             try {
 993                 Class cl = type;
 994                 int dimensions = 0;
 995                 while (cl.isArray()) {
 996                     dimensions++;
 997                     cl = cl.getComponentType();
 998                 }
 999                 StringBuffer sb = new StringBuffer();
1000                 sb.append(cl.getName());
1001                 for (int i = 0; i < dimensions; i++) {
1002                     sb.append("[]");
1003                 }
1004                 return sb.toString();
1005             } catch (Throwable e) { /*FALLTHRU*/ }
1006         }
1007         return type.getName();
1008     }
1009 
1010     /**
1011      * @throws NullPointerException {@inheritDoc}
1012      * @since 1.5
1013      */
1014     public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
1015         if (annotationClass == null)
1016             throw new NullPointerException();
1017 
1018         return (T) declaredAnnotations().get(annotationClass);
1019     }
1020 
1021     /**
1022      * @since 1.5
1023      */
1024     public Annotation[] getDeclaredAnnotations()  {
1025         return AnnotationParser.toArray(declaredAnnotations());
1026     }
1027 
1028     private transient Map<Class, Annotation> declaredAnnotations;
1029 
1030     private synchronized  Map<Class, Annotation> declaredAnnotations() {
1031         if (declaredAnnotations == null) {
1032             declaredAnnotations = AnnotationParser.parseAnnotations(
1033                 annotations, sun.misc.SharedSecrets.getJavaLangAccess().
1034                 getConstantPool(getDeclaringClass()),
1035                 getDeclaringClass());
1036         }
1037         return declaredAnnotations;
1038     }
1039 }