Find Usages Diff Raw Download HTML Widget Stack Overflow Q&A
Start line:  
End line:  

Snippet Preview

Snippet HTML Code

Stack Overflow Questions
1. What can cause IllegalMonitorStateException from inside a synchronized block?
We hit an extremely surprising exception today. Inside of a synchronized block, we call wait() and it throws IllegalMonitorStateException. What can cause this? This is happening in well-tested open source code: http://svn.apache.org/viewvc/river/jtsk/trunk/src/com/sun/jini/jeri/internal/mux/Mux.java?view=markup#l222 We eliminated the obvious causes: are we synchronized on the right variable...
2. Java generics - type erasure - when and what happens
I read about Java's type erasure on Sun's website (http://java.sun.com/docs/books/tutorial/java/generics/erasure.html). I have the following question : When does type erasure occur - at compile time / runtime:when the class is loaded / runtime:when the class is instantiated. A lot of sites (including the Sun tutorial mentioned above) say type erasure occurs at compile time. If the type infor...
3. Java annotations
I've created simple annotation in Java @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.FIELD) public @interface Column { String columnName(); } and class public class Table { @Column(columnName = "id") private int colId; @Column(columnName = "name") private String colName; private int noAnnotationHere; public Table(int colId, String colName, int noAnn...
4. Accessing Java static final ivar value through reflection
Can the value of a Java static final class variable be retrieved through reflection?
5. Java: get all variable names in a class
I have a class and i want to find all of it's public variables (not functions). how can i do so? thanks!
6. How can I determine the type of a generic field in Java?
I have been trying to determine the type of a field in a class. I've seen all the introspection methods but haven't quite figured out how to do it. This is going to be used to generate xml/json from a java class. I've looked at a number of the questions here but haven't found exactly what I need. Example: class Person { public final String name; public final List<Person> childre...
7. How to get the fields in an Object via reflection?
I have an object (basically a VO) in Java and I don't know its type. I need to get values which are not null in that object. How can this be done?
8. What is the best way to check if a field is final in java using reflection?
I'm writing a class, which, at some point, has to have all its fields assigned from an other item of this class. I did it through reflection: for(Field f:pg.getClass().getDeclaredFields()){ f.set(this, f.get(pg)); } The problem is, that this class contains a field, which is final. I could skip it by name, but to me that seems not elegant at all. What's the best ...
9. Java: how can i do dynamic casting of a variable from one type to another?
i would like to do dynamic casting for a java variable, the casting type is stored in a different variable. this is regular casting: String a = (String) 5; this is what i want: String theType = 'String'; String a = (theType) 5; is it possible? and if so how? thanks! update I'm trying to populate a class with a hashMap that i received. this is the constructor: public ConnectParams(...
10. Java assist newbie question
I am trying to generate some classes on the fly, and the following is my initial attempt: ClassPool cp = ClassPool.getDefault(); cp.insertClassPath(new ClassClassPath(Main.class)); CtClass entity = cp.makeClass("Entity"); try { CtField id = new CtField(CtClass.intType, "id", entity); entity.addField(id); entity.addField(CtField.make(" public String name;"...
11. How to loop over a Class attributes in Java?
How can I loop over a class attributes in java dynamically. For eg : public class MyClass { private type1 att1; private type2 att2; ... public void function() { for(var in MyClass.Attributes) { System.out.println(var.class); } } } is this possible in Java?
12. How does Hibernate find the generic type of a collection in a @OneToMany mapping?
Given a simple entity relationship: @Entity public class Single { @OneToMany public Set<Multiple> multiples; } How does Hibernate find out that the generic type of multiples is Multiple? This information is impossible to find with the standard Reflection API. I'm looking through the source code, but don't really know where to start.
13. Bean Property Access and Annotations
Are there any java libraries which allow me to utilize BeanUtils like property access bean.prop1.prop2 while allowing access to the annotations on the getter/field itself? For example, I have a bean class that looks like this: public class Child { @SomeCustomAnnotation private String name; //standard bean getter setters } public class Parent { private Child child; //standard bean...
14. Java reflection question
I am working on a project that uses reflection to get the fields of a running java application. I managed to get the fields, but I can not read or write to them. This is an example I found on the web: Class aClass = MyObject.class Field field = aClass.getField("someField"); MyObject objectInstance = new MyObject(); Object value = field.get(objectInstance); field.set(objetInstance, value); T...
15. Using reflection to change static final File.separatorChar for unit testing?
Specifically, I'm trying to create a unit test for a method which requires uses File.separatorChar to build paths on windows and unix. The code must run on both platforms, and yet I get errors with JUnit when I attempt to change this static final field. Anyone have any idea what's going on? Field field = java.io.File.class.getDeclaredField( "separatorChar" ); field.setAccessible(true); field....
16. Is it possible to read the value of a annotation in java?
this is my code: @Column(columnName="firstname") private String firstName; @Column(columnName="lastname") private String lastName; public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastNam...
17. Java: how can i set a class's field by a field name that stored in a variable
how can i set a field in a class that it's name is dynamic and stored in a string variable ? public class test { public String a1; public string a2; public test(String key) { this.key='found'; <--- error } }
18. Java Comparator given the name of the property to compare
My problem is this; I have to order a table of data. Each row of the table is an object (lets call it TableObject) stored in a List. Each column of data is a property of the class (usually a String). I have to do the typical ordering of data when the user clicks on any column. So I thought about changing the List to a TreeSet and implementing Comparator in my TableObject. The problem comes wh...
19. Does int.class equal Integer.class or Integer.TYPE in Java?
Let's imagine one retrieves the declaring type of a Field using reflection. Which of the following tests will correctly indicate whether one is dealing with an int or an Integer? Field f = ... Class<?> c = f.getDeclaringClass(); boolean isInteger; isInteger = c.equals(Integer.class); isInteger = c.equals(Integer.TYPE); isInteger = c.equals(int.class); isInteger = ( c == Integer.class)...
20. Is it possible to invoke private attributes or methods via reflection in java
I was trying to fetch the value of an static private attribute via reflection, but it fails with an error. Class class = home.Student.class; Field field = studentClass.getDeclaredField("nstance"); Object obj = field.get(null); The exception i get is something like this. java.lang.IllegalAccessException: Class com.test.ReflectionTest can not access a member of class home.Student with modifie...
21. Get a class name with generics information
In a java serialization problem, I want to save some classes name and I have some problems with generic classes. For example : - If I have ArrayList<String> listToDump = new ArrayList<String>(); - If I take the name : listToDump.getName(); or listToDump.getCanonicalName(); - I will have java.util.ArrayList or ArrayList - And I want to have java.util.ArrayList<String> or Array... 
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
  
35
  import java.util.Map;
A 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.

A Field permits widening conversions to occur during a get or set access operation, but throws an IllegalArgumentException if a narrowing conversion would occur.

Author(s):
Kenneth Russell
Nakul Saraiya
See also:
Member
java.lang.Class
java.lang.Class.getFields()
java.lang.Class.getField(java.lang.String)
java.lang.Class.getDeclaredFields()
java.lang.Class.getDeclaredField(java.lang.String)
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 ;}
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 ( == null) {
102
             // create and cache generic info repository
103
              = FieldRepository.make(getGenericSignature(),
104
                                                getFactory());
105
         }
106
         return ; //return cached repository
107
     }


    
Package-private constructor used by ReflectAccess to enable instantiation of these objects in Java code from the java.lang 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. = declaringClass;
124
         this. = name;
125
         this. = type;
126
         this. = modifiers;
127
         this. = slot;
128
         this. = signature;
129
         this. = annotations;
130
     }

    
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. 
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(, , , , , , );
146
         res.root = this;
147
         // Might as well eagerly propagate this if already present
148
         res.fieldAccessor = ;
149
         res.overrideFieldAccessor = ;
150
         return res;
151
     }

    
Returns the Class object representing the class or interface that declares the field represented by this Field object. 
156
 
157
     public Class<?> getDeclaringClass() {
158
         return ;
159
     }

    
Returns the name of the field represented by this Field object. 
163
 
164
     public String getName() {
165
         return ;
166
     }

    
Returns the Java language modifiers for the field represented by this Field object, as an integer. The Modifier class should be used to decode the modifiers.

See also:
Modifier
174
 
175
     public int getModifiers() {
176
         return ;
177
     }

    
Returns true if this field represents an element of an enumerated type; returns false otherwise.

Returns:
true if and only if this field represents an element of an enumerated type.
Since:
1.5
186
 
187
     public boolean isEnumConstant() {
188
         return (getModifiers() & .) != 0;
189
     }

    
Returns true if this field is a synthetic field; returns false otherwise.

Returns:
true if and only if this field is a synthetic field as defined by the Java Language Specification.
Since:
1.5
198
 
199
     public boolean isSynthetic() {
200
         return Modifier.isSynthetic(getModifiers());
201
     }

    
Returns a Class object that identifies the declared type for the field represented by this Field object.

Returns:
a Class object identifying the declared type of the field represented by this object
210
 
211
     public Class<?> getType() {
212
         return ;
213
     }

    
Returns a Type object that represents the declared type for the field represented by this Field object.

If the Type is a parameterized type, the Type object returned must accurately reflect the actual type parameters used in the source code.

If the type of the underlying field is a type variable or a parameterized type, it is created. Otherwise, it is resolved.

Returns:
a Type object that represents the declared type for the field represented by this Field object
Throws:
GenericSignatureFormatError if the generic field signature does not conform to the format specified in the Java Virtual Machine Specification, 3rd edition
java.lang.TypeNotPresentException if the generic type signature of the underlying field refers to a non-existent type declaration
MalformedParameterizedTypeException if the generic signature of the underlying field refers to a parameterized type that cannot be instantiated for any reason
Since:
1.5
238
 
239
     public Type getGenericType() {
240
         if (getGenericSignature() != null)
241
             return getGenericInfo().getGenericType();
242
         else
243
             return getType();
244
     }


    
Compares this Field against the specified object. Returns true if the objects are the same. Two Field objects are the same if they were declared by the same class and have the same name 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
     }

    
Returns a hashcode for this Field. This is computed as the exclusive-or of the hashcodes for the underlying field's declaring class name and its name. 
267
 
268
     public int hashCode() {
269
         return getDeclaringClass().getName().hashCode() ^ getName().hashCode();
270
     }

    
Returns a string describing this 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: 
    public static final int java.lang.Thread.MIN_PRIORITY
    private int java.io.FileDescriptor.fd

The modifiers are placed in canonical order as specified by "The Java Language Specification". This is public, protected or private first, and then other modifiers in the following order: static, final, transient, 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
     }

    
Returns a string describing this 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.

The modifiers are placed in canonical order as specified by "The Java Language Specification". This is public, protected or private first, and then other modifiers in the following order: static, final, transient, volatile.

Returns:
a string describing this Field, including its generic type
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
     }

    
Returns the value of the field represented by this Field, on the specified object. The value is automatically wrapped in an object if it has a primitive type.

The underlying field's value is obtained as follows:

If the underlying field is a static field, the obj argument is ignored; it may be null.

Otherwise, the underlying field is an instance field. If the specified obj argument is null, the method throws a NullPointerException. If the specified object is not an instance of the class or interface declaring the underlying field, the method throws an IllegalArgumentException.

If this Field object enforces Java language access control, and the underlying field is inaccessible, the method throws an IllegalAccessException. If the underlying field is static, the class that declared the field is initialized if it has not already been initialized.

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.

If the field is hidden in the type of obj, the field's value is obtained according to the preceding rules.

Parameters:
obj object from which the represented field's value is to be extracted
Returns:
the value of the represented field in object obj; primitive values are wrapped in an appropriate object before being returned
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.IllegalArgumentException if the specified object is not an instance of the class or interface declaring the underlying field (or a subclass or implementor thereof).
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
372
 
373
     public Object get(Object obj)
375
     {
376
         return getFieldAccessor(obj).get(obj);
377
     }

    
Gets the value of a static or instance boolean field.

Parameters:
obj the object to extract the boolean value from
Returns:
the value of the boolean field
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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 boolean by a widening conversion.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
get(java.lang.Object)
399
 
400
     public boolean getBoolean(Object obj)
402
     {
403
         return getFieldAccessor(obj).getBoolean(obj);
404
     }

    
Gets the value of a static or instance byte field.

Parameters:
obj the object to extract the byte value from
Returns:
the value of the byte field
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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 byte by a widening conversion.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
get(java.lang.Object)
426
 
427
     public byte getByte(Object obj)
429
     {
430
         return getFieldAccessor(obj).getByte(obj);
431
     }

    
Gets the value of a static or instance field of type char or of another primitive type convertible to type char via a widening conversion.

Parameters:
obj the object to extract the char value from
Returns:
the value of the field converted to type char
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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 char by a widening conversion.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
get(java.lang.Object)
455
 
456
     public char getChar(Object obj)
458
     {
459
         return getFieldAccessor(obj).getChar(obj);
460
     }

    
Gets the value of a static or instance field of type short or of another primitive type convertible to type short via a widening conversion.

Parameters:
obj the object to extract the short value from
Returns:
the value of the field converted to type short
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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 short by a widening conversion.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
get(java.lang.Object)
484
 
485
     public short getShort(Object obj)
487
     {
488
         return getFieldAccessor(obj).getShort(obj);
489
     }

    
Gets the value of a static or instance field of type int or of another primitive type convertible to type int via a widening conversion.

Parameters:
obj the object to extract the int value from
Returns:
the value of the field converted to type int
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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 int by a widening conversion.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
get(java.lang.Object)
513
 
514
     public int getInt(Object obj)
516
     {
517
         return getFieldAccessor(obj).getInt(obj);
518
     }

    
Gets the value of a static or instance field of type long or of another primitive type convertible to type long via a widening conversion.

Parameters:
obj the object to extract the long value from
Returns:
the value of the field converted to type long
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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 long by a widening conversion.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
get(java.lang.Object)
542
 
543
     public long getLong(Object obj)
545
     {
546
         return getFieldAccessor(obj).getLong(obj);
547
     }

    
Gets the value of a static or instance field of type float or of another primitive type convertible to type float via a widening conversion.

Parameters:
obj the object to extract the float value from
Returns:
the value of the field converted to type float
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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 float by a widening conversion.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
get(java.lang.Object)
571
 
572
     public float getFloat(Object obj)
574
     {
575
         return getFieldAccessor(obj).getFloat(obj);
576
     }

    
Gets the value of a static or instance field of type double or of another primitive type convertible to type double via a widening conversion.

Parameters:
obj the object to extract the double value from
Returns:
the value of the field converted to type double
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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 double by a widening conversion.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
get(java.lang.Object)
600
 
601
     public double getDouble(Object obj)
603
     {
604
         return getFieldAccessor(obj).getDouble(obj);
605
     }

    
Sets the field represented by this 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.

The operation proceeds as follows:

If the underlying field is static, the obj argument is ignored; it may be null.

Otherwise the underlying field is an instance field. If the specified object argument is null, the method throws a NullPointerException. If the specified object argument is not an instance of the class or interface declaring the underlying field, the method throws an IllegalArgumentException.

If this Field object enforces Java language access control, and the underlying field is inaccessible, the method throws an IllegalAccessException.

If the underlying field is final, the method throws an IllegalAccessException unless setAccessible(true) has succeeded for this field and this field is non-static. Setting a final field in this way 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.

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 IllegalArgumentException.

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 IllegalArgumentException.

If the underlying field is static, the class that declared the field is initialized if it has not already been initialized.

The field is set to the possibly unwrapped and widened new value.

If the field is hidden in the type of obj, the field's value is set according to the preceding rules.

Parameters:
obj the object whose field should be modified
value the new value for the field of obj being modified
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
671
 
672
     public void set(Object obj, Object value)
674
     {
675
         getFieldAccessor(obj).set(obj, value);
676
     }

    
Sets the value of a field as a boolean on the specified object. This method is equivalent to set(obj, zObj), where zObj is a Boolean object and zObj.booleanValue() == z.

Parameters:
obj the object whose field should be modified
z the new value for the field of obj being modified
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
set(java.lang.Object,java.lang.Object)
700
 
701
     public void setBoolean(Object obj, boolean z)
703
     {
704
         getFieldAccessor(obj).setBoolean(obj, z);
705
     }

    
Sets the value of a field as a byte on the specified object. This method is equivalent to set(obj, bObj), where bObj is a Byte object and bObj.byteValue() == b.

Parameters:
obj the object whose field should be modified
b the new value for the field of obj being modified
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
set(java.lang.Object,java.lang.Object)
729
 
730
     public void setByte(Object obj, byte b)
732
     {
733
         getFieldAccessor(obj).setByte(obj, b);
734
     }

    
Sets the value of a field as a char on the specified object. This method is equivalent to set(obj, cObj), where cObj is a Character object and cObj.charValue() == c.

Parameters:
obj the object whose field should be modified
c the new value for the field of obj being modified
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
set(java.lang.Object,java.lang.Object)
758
 
759
     public void setChar(Object obj, char c)
761
     {
762
         getFieldAccessor(obj).setChar(obj, c);
763
     }

    
Sets the value of a field as a short on the specified object. This method is equivalent to set(obj, sObj), where sObj is a Short object and sObj.shortValue() == s.

Parameters:
obj the object whose field should be modified
s the new value for the field of obj being modified
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
set(java.lang.Object,java.lang.Object)
787
 
788
     public void setShort(Object obj, short s)
790
     {
791
         getFieldAccessor(obj).setShort(obj, s);
792
     }

    
Sets the value of a field as an int on the specified object. This method is equivalent to set(obj, iObj), where iObj is a Integer object and iObj.intValue() == i.

Parameters:
obj the object whose field should be modified
i the new value for the field of obj being modified
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
set(java.lang.Object,java.lang.Object)
816
 
817
     public void setInt(Object obj, int i)
819
     {
820
         getFieldAccessor(obj).setInt(obj, i);
821
     }

    
Sets the value of a field as a long on the specified object. This method is equivalent to set(obj, lObj), where lObj is a Long object and lObj.longValue() == l.

Parameters:
obj the object whose field should be modified
l the new value for the field of obj being modified
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
set(java.lang.Object,java.lang.Object)
845
 
846
     public void setLong(Object obj, long l)
848
     {
849
         getFieldAccessor(obj).setLong(obj, l);
850
     }

    
Sets the value of a field as a float on the specified object. This method is equivalent to set(obj, fObj), where fObj is a Float object and fObj.floatValue() == f.

Parameters:
obj the object whose field should be modified
f the new value for the field of obj being modified
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
set(java.lang.Object,java.lang.Object)
874
 
875
     public void setFloat(Object obj, float f)
877
     {
878
         getFieldAccessor(obj).setFloat(obj, f);
879
     }

    
Sets the value of a field as a double on the specified object. This method is equivalent to set(obj, dObj), where dObj is a Double object and dObj.doubleValue() == d.

Parameters:
obj the object whose field should be modified
d the new value for the field of obj being modified
Throws:
java.lang.IllegalAccessException if the underlying field is inaccessible.
java.lang.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.
java.lang.NullPointerException if the specified object is null and the field is an instance field.
java.lang.ExceptionInInitializerError if the initialization provoked by this method fails.
See also:
set(java.lang.Object,java.lang.Object)
903
 
904
     public void setDouble(Object obj, double d)
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 = ;
916
         FieldAccessor a = (ov)?  : ;
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 ( != null) tmp = .getFieldAccessor(overrideFinalCheck);
929
         if (tmp != null) {
930
             if (overrideFinalCheck)
931
                  = tmp;
932
             else
933
                  = tmp;
934
         } else {
935
             // Otherwise fabricate one and propagate it up to the root
936
             tmp = .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)?  : ;
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
              = accessor;
953
         else
954
              = accessor;
955
         // Propagate up
956
         if ( != null) {
957
             .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 (!) {
966
             if (!Reflection.quickCheckMemberAccess(, )) {
967
                 Class caller = Reflection.getCallerClass(4);
968
                 Class targetClass = ((obj == null || !Modifier.isProtected())
969
                                      ? 
970
                                      : obj.getClass());
971
 
972
                 synchronized (this) {
973
                     if (( == caller)
974
                             && ( == targetClass)) {
975
                         return;
976
                     }
977
                 }
978
                 Reflection.ensureMemberAccess(caller, , obj, );
979
                 synchronized (this) {
980
                      = caller;
981
                      = 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
    }

    

Throws:
java.lang.NullPointerException
Since:
1.5
1014
    public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
1015
        if (annotationClass == null)
1016
            throw new NullPointerException();
1018
        return (T) declaredAnnotations().get(annotationClass);
1019
    }
1021
    private static final Annotation[] EMPTY_ANNOTATION_ARRAY=new Annotation[0];

    

Since:
1.5
1026
    public Annotation[] getDeclaredAnnotations()  {
1028
    }
1030
    private transient Map<Class, Annotation> declaredAnnotations;
1032
    private synchronized  Map<Class, Annotation> declaredAnnotations() {
1033
        if ( == null) {
1034
             = AnnotationParser.parseAnnotations(
1035
                , sun.misc.SharedSecrets.getJavaLangAccess().
1036
                getConstantPool(getDeclaringClass()),
1037
                getDeclaringClass());
1038
        }
1039
        return ;
1040
    }
New to GrepCode? Check out our FAQ X