Class Field
- java.lang.Object
-
- java.lang.reflect.AccessibleObject
-
- java.lang.reflect.Field
- All Implemented Interfaces:
-
AnnotatedElement
,Member
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.
- Since:
- 1.1
- See Also:
-
Member
,Class
,Class.getFields()
,Class.getField(String)
,Class.getDeclaredFields()
,Class.getDeclaredField(String)
Field Summary
Fields declared in interface java.lang.reflect.Member
DECLARED, PUBLIC
Method Summary
Modifier and Type | Method | Description |
---|---|---|
boolean | equals(Object obj) | Compares this |
Object | get(Object obj) | Returns the value of the field represented by this |
AnnotatedType | getAnnotatedType() | Returns an AnnotatedType object that represents the use of a type to specify the declared type of the field represented by this Field. |
<T extends Annotation> | getAnnotation(Class<T> annotationClass) | Returns this element's annotation for the specified type if such an annotation is present, else null. |
<T extends Annotation> | getAnnotationsByType(Class<T> annotationClass) | Returns annotations that are associated with this element. |
boolean | getBoolean(Object obj) | Gets the value of a static or instance |
byte | getByte(Object obj) | Gets the value of a static or instance |
char | getChar(Object obj) | Gets the value of a static or instance field of type |
Class<?> | getDeclaringClass() | Returns the |
double | getDouble(Object obj) | Gets the value of a static or instance field of type |
float | getFloat(Object obj) | Gets the value of a static or instance field of type |
Type | getGenericType() | Returns a |
int | getInt(Object obj) | Gets the value of a static or instance field of type |
long | getLong(Object obj) | Gets the value of a static or instance field of type |
int | getModifiers() | Returns the Java language modifiers for the field represented by this |
String | getName() | Returns the name of the field represented by this |
short | getShort(Object obj) | Gets the value of a static or instance field of type |
Class<?> | getType() | Returns a |
int | hashCode() | Returns a hashcode for this |
boolean | isEnumConstant() | Returns |
boolean | isSynthetic() | Returns |
void | set(Object obj,
Object value) | Sets the field represented by this |
void | setAccessible(boolean flag) | Set the |
void | setBoolean(Object obj,
boolean z) | Sets the value of a field as a |
void | setByte(Object obj,
byte b) | Sets the value of a field as a |
void | setChar(Object obj,
char c) | Sets the value of a field as a |
void | setDouble(Object obj,
double d) | Sets the value of a field as a |
void | setFloat(Object obj,
float f) | Sets the value of a field as a |
void | setInt(Object obj,
int i) | Sets the value of a field as an |
void | setLong(Object obj,
long l) | Sets the value of a field as a |
void | setShort(Object obj,
short s) | Sets the value of a field as a |
String | toGenericString() | Returns a string describing this |
String | toString() | Returns a string describing this |
Methods declared in class java.lang.reflect.AccessibleObject
canAccess, getAnnotations, getDeclaredAnnotation, getDeclaredAnnotations, getDeclaredAnnotationsByType, isAccessible, isAnnotationPresent, setAccessible, trySetAccessible
Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Method Detail
setAccessible
public void setAccessible(boolean flag)
Description copied from class: AccessibleObject
Set the accessible
flag for this reflected object to the indicated boolean value. A value of true
indicates that the reflected object should suppress checks for Java language access control when it is used. A value of false
indicates that the reflected object should enforce checks for Java language access control when it is used, with the variation noted in the class description.
This method may be used by a caller in class C
to enable access to a member
of declaring class
D
if any of the following hold:
-
C
andD
are in the same module. - The member is
public
andD
ispublic
in a package that the module containingD
exports
to at least the module containingC
. - The member is
protected
static
,D
ispublic
in a package that the module containingD
exports to at least the module containingC
, andC
is a subclass ofD
. -
D
is in a package that the module containingD
opens
to at least the module containingC
. All packages in unnamed and open modules are open to all modules and so this method always succeeds whenD
is in an unnamed or open module.
This method cannot be used to enable access to private members, members with default (package) access, protected instance members, or protected constructors when the declaring class is in a different module to the caller and the package containing the declaring class is not open to the caller's module.
If there is a security manager, its checkPermission
method is first called with a ReflectPermission("suppressAccessChecks")
permission.
- Overrides:
-
setAccessible
in classAccessibleObject
- Parameters:
-
flag
- the new value for theaccessible
flag - Throws:
-
InaccessibleObjectException
- if access cannot be enabled -
SecurityException
- if the request is denied by the security manager - See Also:
-
AccessibleObject.trySetAccessible()
,MethodHandles.privateLookupIn(java.lang.Class<?>, java.lang.invoke.MethodHandles.Lookup)
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
in interfaceMember
- 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.
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
in interfaceMember
- Returns:
- the Java language modifiers for the underlying member
- See Also:
Modifier
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
in interfaceMember
- 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 this Field
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, 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 thisField
object - Throws:
-
GenericSignatureFormatError
- if the generic field signature does not conform to the format specified in The Java™ Virtual Machine Specification -
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
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
in classObject
- 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:
-
Object.hashCode()
,HashMap
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
in classObject
- Returns:
- a hash code value for this object.
- See Also:
-
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)
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
.
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 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 is enforcing 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:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is inaccessible. -
IllegalArgumentException
- if the specified object is not an instance of the class or interface declaring the underlying field (or a subclass or implementor thereof). -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- 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 theboolean
value from - Returns:
- the value of the
boolean
field - Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is inaccessible. -
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 typeboolean
by a widening conversion. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
get(java.lang.Object)
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 thebyte
value from - Returns:
- the value of the
byte
field - Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is inaccessible. -
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 typebyte
by a widening conversion. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
get(java.lang.Object)
getChar
public char getChar(Object obj) throws IllegalArgumentException, IllegalAccessException
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 thechar
value from - Returns:
- the value of the field converted to type
char
- Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is inaccessible. -
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 typechar
by a widening conversion. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
get(java.lang.Object)
getShort
public short getShort(Object obj) throws IllegalArgumentException, IllegalAccessException
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 theshort
value from - Returns:
- the value of the field converted to type
short
- Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is inaccessible. -
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 typeshort
by a widening conversion. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
get(java.lang.Object)
getInt
public int getInt(Object obj) throws IllegalArgumentException, IllegalAccessException
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 theint
value from - Returns:
- the value of the field converted to type
int
- Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is inaccessible. -
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 typeint
by a widening conversion. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
get(java.lang.Object)
getLong
public long getLong(Object obj) throws IllegalArgumentException, IllegalAccessException
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 thelong
value from - Returns:
- the value of the field converted to type
long
- Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is inaccessible. -
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 typelong
by a widening conversion. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
get(java.lang.Object)
getFloat
public float getFloat(Object obj) throws IllegalArgumentException, IllegalAccessException
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 thefloat
value from - Returns:
- the value of the field converted to type
float
- Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is inaccessible. -
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 typefloat
by a widening conversion. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
get(java.lang.Object)
getDouble
public double getDouble(Object obj) throws IllegalArgumentException, IllegalAccessException
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 thedouble
value from - Returns:
- the value of the field converted to type
double
- Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is inaccessible. -
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 typedouble
by a widening conversion. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
get(java.lang.Object)
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 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 is enforcing 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
object and the 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 ofobj
being modified - Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is either inaccessible or final. -
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. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- 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 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 ofobj
being modified - Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is either inaccessible or final. -
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. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
set(java.lang.Object, java.lang.Object)
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 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 ofobj
being modified - Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is either inaccessible or final. -
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. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
set(java.lang.Object, java.lang.Object)
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 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 ofobj
being modified - Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is either inaccessible or final. -
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. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
set(java.lang.Object, java.lang.Object)
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 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 ofobj
being modified - Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is either inaccessible or final. -
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. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
set(java.lang.Object, java.lang.Object)
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 to set(obj, iObj)
, where iObj
is an Integer
object and iObj.intValue() == i
.
- Parameters:
-
obj
- the object whose field should be modified -
i
- the new value for the field ofobj
being modified - Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is either inaccessible or final. -
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. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
set(java.lang.Object, java.lang.Object)
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 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 ofobj
being modified - Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is either inaccessible or final. -
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. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
set(java.lang.Object, java.lang.Object)
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 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 ofobj
being modified - Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is either inaccessible or final. -
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. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
set(java.lang.Object, java.lang.Object)
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 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 ofobj
being modified - Throws:
-
IllegalAccessException
- if thisField
object is enforcing Java language access control and the underlying field is either inaccessible or final. -
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. -
NullPointerException
- if the specified object is null and the field is an instance field. -
ExceptionInInitializerError
- if the initialization provoked by this method fails. - See Also:
set(java.lang.Object, java.lang.Object)
getAnnotation
public <T extends Annotation> T getAnnotation(Class<T> annotationClass)
Description copied from interface: AnnotatedElement
Returns this element's annotation for the specified type if such an annotation is present, else null.
- Specified by:
-
getAnnotation
in interfaceAnnotatedElement
- Overrides:
-
getAnnotation
in classAccessibleObject
- Type Parameters:
-
T
- the type of the annotation to query for and return if present - 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
- Throws:
-
NullPointerException
- if the given annotation class is null - Since:
- 1.5
getAnnotationsByType
public <T extends Annotation> T[] getAnnotationsByType(Class<T> annotationClass)
Returns annotations that are associated with this element. If there are no annotations associated with this element, the return value is an array of length 0. The difference between this method and AnnotatedElement.getAnnotation(Class)
is that this method detects if its argument is a repeatable annotation type (JLS 9.6), and if so, attempts to find one or more annotations of that type by "looking through" a container annotation. 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:
-
getAnnotationsByType
in interfaceAnnotatedElement
- Overrides:
-
getAnnotationsByType
in classAccessibleObject
- Type Parameters:
-
T
- the type of the annotation to query for and return if present - Parameters:
-
annotationClass
- the Class object corresponding to the annotation type - Returns:
- all this element's annotations for the specified annotation type if associated with this element, else an array of length zero
- Throws:
-
NullPointerException
- if the given annotation class is null - Since:
- 1.8
getAnnotatedType
public AnnotatedType getAnnotatedType()
Returns an AnnotatedType object that represents the use of a type to specify the declared type of the field represented by this Field.
- Returns:
- an object representing the declared type of the field represented by this Field
- Since:
- 1.8