Field (Java 2 Platform SE 5.0) (original) (raw)
java.lang.reflect
Class Field
java.lang.Object
java.lang.reflect.AccessibleObject
java.lang.reflect.Field
All Implemented Interfaces:
public final class Field
extends AccessibleObject
implements Member
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.
See Also:
Member, Class, Class.getFields(), Class.getField(String), Class.getDeclaredFields(), Class.getDeclaredField(String)
Field Summary |
---|
Fields inherited from interface java.lang.reflect.Member |
---|
DECLARED, PUBLIC |
Method Summary | |
---|---|
boolean | equals(Object obj) Compares this Field against the specified object. |
Object | get(Object obj) Returns the value of the field represented by this Field, on the specified object. |
<T extends Annotation> T | getAnnotation(Class annotationClass) Returns this element's annotation for the specified type if such an annotation is present, else null. |
boolean | getBoolean(Object obj) Gets the value of a static or instance boolean field. |
byte | getByte(Object obj) Gets the value of a static or instance byte field. |
char | getChar(Object obj) Gets the value of a static or instance field of typechar or of another primitive type convertible to type char via a widening conversion. |
Annotation[] | getDeclaredAnnotations() Returns all annotations that are directly present on this element. |
Class<?> | getDeclaringClass() Returns the Class object representing the class or interface that declares the field represented by this Field object. |
double | getDouble(Object obj) Gets the value of a static or instance field of typedouble or of another primitive type convertible to type double via a widening conversion. |
float | getFloat(Object obj) Gets the value of a static or instance field of typefloat or of another primitive type convertible to type float via a widening conversion. |
Type | getGenericType() Returns a Type object that represents the declared type for the field represented by this Field object. |
int | getInt(Object obj) Gets the value of a static or instance field of typeint or of another primitive type convertible to type int via a widening conversion. |
long | getLong(Object obj) Gets the value of a static or instance field of typelong or of another primitive type convertible to type long via a widening conversion. |
int | getModifiers() Returns the Java language modifiers for the field represented by this Field object, as an integer. |
String | getName() Returns the name of the field represented by this Field object. |
short | getShort(Object obj) Gets the value of a static or instance field of typeshort or of another primitive type convertible to type short via a widening conversion. |
Class<?> | getType() Returns a Class object that identifies the declared type for the field represented by thisField object. |
int | hashCode() Returns a hashcode for this Field. |
boolean | isEnumConstant() Returns true if this field represents an element of an enumerated type; returns false otherwise. |
boolean | isSynthetic() Returns true if this field is a synthetic field; returns false otherwise. |
void | [set](../../../java/lang/reflect/Field.html#set%28java.lang.Object, java.lang.Object%29)(Object obj,Object value) Sets the field represented by this Field object on the specified object argument to the specified new value. |
void | [setBoolean](../../../java/lang/reflect/Field.html#setBoolean%28java.lang.Object, boolean%29)(Object obj, boolean z) Sets the value of a field as a boolean on the specified object. |
void | [setByte](../../../java/lang/reflect/Field.html#setByte%28java.lang.Object, byte%29)(Object obj, byte b) Sets the value of a field as a byte on the specified object. |
void | [setChar](../../../java/lang/reflect/Field.html#setChar%28java.lang.Object, char%29)(Object obj, char c) Sets the value of a field as a char on the specified object. |
void | [setDouble](../../../java/lang/reflect/Field.html#setDouble%28java.lang.Object, double%29)(Object obj, double d) Sets the value of a field as a double on the specified object. |
void | [setFloat](../../../java/lang/reflect/Field.html#setFloat%28java.lang.Object, float%29)(Object obj, float f) Sets the value of a field as a float on the specified object. |
void | [setInt](../../../java/lang/reflect/Field.html#setInt%28java.lang.Object, int%29)(Object obj, int i) Sets the value of a field as an int on the specified object. |
void | [setLong](../../../java/lang/reflect/Field.html#setLong%28java.lang.Object, long%29)(Object obj, long l) Sets the value of a field as a long on the specified object. |
void | [setShort](../../../java/lang/reflect/Field.html#setShort%28java.lang.Object, short%29)(Object obj, short s) Sets the value of a field as a short on the specified object. |
String | toGenericString() Returns a string describing this Field, including its generic type. |
String | toString() Returns a string describing this Field. |
Methods inherited from class java.lang.reflect.AccessibleObject |
---|
getAnnotations, isAccessible, isAnnotationPresent, [setAccessible](../../../java/lang/reflect/AccessibleObject.html#setAccessible%28java.lang.reflect.AccessibleObject[], boolean%29), setAccessible |
Methods inherited from class java.lang.Object |
---|
clone, finalize, getClass, notify, notifyAll, wait, wait, [wait](../../../java/lang/Object.html#wait%28long, int%29) |
Method Detail |
---|
getDeclaringClass
public Class<?> getDeclaringClass()
Returns the Class
object representing the class or interface that declares the field represented by this Field
object.
Specified by:
[getDeclaringClass](../../../java/lang/reflect/Member.html#getDeclaringClass%28%29)
in interface [Member](../../../java/lang/reflect/Member.html "interface in java.lang.reflect")
Returns:
an object representing the declaring class of the underlying member
getName
public String getName()
Returns the name of the field represented by this Field
object.
Specified by:
[getName](../../../java/lang/reflect/Member.html#getName%28%29)
in interface [Member](../../../java/lang/reflect/Member.html "interface in java.lang.reflect")
Returns:
the simple name of the underlying member
getModifiers
public int getModifiers()
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.
Specified by:
[getModifiers](../../../java/lang/reflect/Member.html#getModifiers%28%29)
in interface [Member](../../../java/lang/reflect/Member.html "interface in java.lang.reflect")
Returns:
the Java language modifiers for the underlying member
See Also:
isEnumConstant
public boolean isEnumConstant()
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
isSynthetic
public boolean isSynthetic()
Returns true if this field is a synthetic field; returns false otherwise.
Specified by:
[isSynthetic](../../../java/lang/reflect/Member.html#isSynthetic%28%29)
in interface [Member](../../../java/lang/reflect/Member.html "interface in java.lang.reflect")
Returns:
true if and only if this field is a synthetic field as defined by the Java Language Specification.
Since:
1.5
getType
public Class<?> getType()
Returns a Class
object that identifies the declared type for the field represented by thisField
object.
Returns:
a Class
object identifying the declared type of the field represented by this object
getGenericType
public Type getGenericType()
Returns a Type object that represents the declared type for the field represented by this Field object.
If the Type is a parameterized type, theType object returned must accurately reflect the actual type parameters used in the source code.
If an 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](../../../java/lang/reflect/GenericSignatureFormatError.html "class in java.lang.reflect")
- if the generic field signature does not conform to the format specified in the Java Virtual Machine Specification, 3rd edition
[TypeNotPresentException](../../../java/lang/TypeNotPresentException.html "class in java.lang")
- if the generic type signature of the underlying field refers to a non-existent type declaration
[MalformedParameterizedTypeException](../../../java/lang/reflect/MalformedParameterizedTypeException.html "class in java.lang.reflect")
- if the generic signature of the underlying field refers to a parameterized type that cannot be instantiated for any reason
Since:
1.5
equals
public boolean equals(Object obj)
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.
Overrides:
[equals](../../../java/lang/Object.html#equals%28java.lang.Object%29)
in class [Object](../../../java/lang/Object.html "class in java.lang")
Parameters:
obj
- the reference object with which to compare.
Returns:
true
if this object is the same as the obj argument; false
otherwise.
See Also:
hashCode
public int hashCode()
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.
Overrides:
[hashCode](../../../java/lang/Object.html#hashCode%28%29)
in class [Object](../../../java/lang/Object.html "class in java.lang")
Returns:
a hash code value for this object.
See Also:
Object.equals(java.lang.Object), Hashtable
toString
public String toString()
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.
Overrides:
[toString](../../../java/lang/Object.html#toString%28%29)
in class [Object](../../../java/lang/Object.html "class in java.lang")
Returns:
a string representation of the object.
toGenericString
public String toGenericString()
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
get
public Object get(Object obj) throws IllegalArgumentException, IllegalAccessException
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 aNullPointerException.
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 anIllegalAccessException
. 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 objectobj; primitive values are wrapped in an appropriate object before being returned
Throws:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- if the specified object is not an instance of the class or interface declaring the underlying field (or a subclass or implementor thereof).
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
getBoolean
public boolean getBoolean(Object obj) throws IllegalArgumentException, IllegalAccessException
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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
getByte
public byte getByte(Object obj) throws IllegalArgumentException, IllegalAccessException
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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
getChar
public char getChar(Object obj) throws IllegalArgumentException, IllegalAccessException
Gets the value of a static or instance field of typechar
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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
getShort
public short getShort(Object obj) throws IllegalArgumentException, IllegalAccessException
Gets the value of a static or instance field of typeshort
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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
getInt
public int getInt(Object obj) throws IllegalArgumentException, IllegalAccessException
Gets the value of a static or instance field of typeint
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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
getLong
public long getLong(Object obj) throws IllegalArgumentException, IllegalAccessException
Gets the value of a static or instance field of typelong
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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
getFloat
public float getFloat(Object obj) throws IllegalArgumentException, IllegalAccessException
Gets the value of a static or instance field of typefloat
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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
getDouble
public double getDouble(Object obj) throws IllegalArgumentException, IllegalAccessException
Gets the value of a static or instance field of typedouble
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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
set
public void set(Object obj, Object value) throws IllegalArgumentException, IllegalAccessException
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 aNullPointerException
. 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 anIllegalAccessException
.
If the underlying field is final, the method throws anIllegalAccessException
unlesssetAccessible(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 anIllegalArgumentException
.
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 anIllegalArgumentException
.
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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
setBoolean
public void setBoolean(Object obj, boolean z) throws IllegalArgumentException, IllegalAccessException
Sets the value of a field as a boolean
on the specified object. This method is equivalent toset(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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
[set(java.lang.Object, java.lang.Object)](../../../java/lang/reflect/Field.html#set%28java.lang.Object, java.lang.Object%29)
setByte
public void setByte(Object obj, byte b) throws IllegalArgumentException, IllegalAccessException
Sets the value of a field as a byte
on the specified object. This method is equivalent toset(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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
[set(java.lang.Object, java.lang.Object)](../../../java/lang/reflect/Field.html#set%28java.lang.Object, java.lang.Object%29)
setChar
public void setChar(Object obj, char c) throws IllegalArgumentException, IllegalAccessException
Sets the value of a field as a char
on the specified object. This method is equivalent toset(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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
[set(java.lang.Object, java.lang.Object)](../../../java/lang/reflect/Field.html#set%28java.lang.Object, java.lang.Object%29)
setShort
public void setShort(Object obj, short s) throws IllegalArgumentException, IllegalAccessException
Sets the value of a field as a short
on the specified object. This method is equivalent toset(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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
[set(java.lang.Object, java.lang.Object)](../../../java/lang/reflect/Field.html#set%28java.lang.Object, java.lang.Object%29)
setInt
public void setInt(Object obj, int i) throws IllegalArgumentException, IllegalAccessException
Sets the value of a field as an int
on the specified object. This method is equivalent toset(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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
[set(java.lang.Object, java.lang.Object)](../../../java/lang/reflect/Field.html#set%28java.lang.Object, java.lang.Object%29)
setLong
public void setLong(Object obj, long l) throws IllegalArgumentException, IllegalAccessException
Sets the value of a field as a long
on the specified object. This method is equivalent toset(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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
[set(java.lang.Object, java.lang.Object)](../../../java/lang/reflect/Field.html#set%28java.lang.Object, java.lang.Object%29)
setFloat
public void setFloat(Object obj, float f) throws IllegalArgumentException, IllegalAccessException
Sets the value of a field as a float
on the specified object. This method is equivalent toset(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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
[set(java.lang.Object, java.lang.Object)](../../../java/lang/reflect/Field.html#set%28java.lang.Object, java.lang.Object%29)
setDouble
public void setDouble(Object obj, double d) throws IllegalArgumentException, IllegalAccessException
Sets the value of a field as a double
on the specified object. This method is equivalent toset(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:
[IllegalAccessException](../../../java/lang/IllegalAccessException.html "class in java.lang")
- if the underlying field is inaccessible.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- 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.
[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")
- if the specified object is null and the field is an instance field.
[ExceptionInInitializerError](../../../java/lang/ExceptionInInitializerError.html "class in java.lang")
- if the initialization provoked by this method fails.
See Also:
[set(java.lang.Object, java.lang.Object)](../../../java/lang/reflect/Field.html#set%28java.lang.Object, java.lang.Object%29)
getAnnotation
public <T extends Annotation> T getAnnotation(Class annotationClass)
Description copied from interface: [AnnotatedElement](../../../java/lang/reflect/AnnotatedElement.html#getAnnotation%28java.lang.Class%29)
Returns this element's annotation for the specified type if such an annotation is present, else null.
Specified by:
[getAnnotation](../../../java/lang/reflect/AnnotatedElement.html#getAnnotation%28java.lang.Class%29)
in interface [AnnotatedElement](../../../java/lang/reflect/AnnotatedElement.html "interface in java.lang.reflect")
Overrides:
[getAnnotation](../../../java/lang/reflect/AccessibleObject.html#getAnnotation%28java.lang.Class%29)
in class [AccessibleObject](../../../java/lang/reflect/AccessibleObject.html "class in java.lang.reflect")
Parameters:
annotationClass
- the Class object corresponding to the annotation type
Returns:
this element's annotation for the specified annotation type if present on this element, else null
getDeclaredAnnotations
public Annotation[] getDeclaredAnnotations()
Description copied from interface: [AnnotatedElement](../../../java/lang/reflect/AnnotatedElement.html#getDeclaredAnnotations%28%29)
Returns all annotations that are directly present on this element. Unlike the other methods in this interface, this method ignores inherited annotations. (Returns an array of length zero if no annotations are directly present on this element.) The caller of this method is free to modify the returned array; it will have no effect on the arrays returned to other callers.
Specified by:
[getDeclaredAnnotations](../../../java/lang/reflect/AnnotatedElement.html#getDeclaredAnnotations%28%29)
in interface [AnnotatedElement](../../../java/lang/reflect/AnnotatedElement.html "interface in java.lang.reflect")
Overrides:
[getDeclaredAnnotations](../../../java/lang/reflect/AccessibleObject.html#getDeclaredAnnotations%28%29)
in class [AccessibleObject](../../../java/lang/reflect/AccessibleObject.html "class in java.lang.reflect")
Returns:
All annotations directly present on this element
Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 2004, 2010 Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.