Field Summary

Method Summary

Method Details

• setAccessible

  public void setAccessible(boolean flag)

  Description copied from class: AccessibleObject

  Set theaccessible flag for this reflected object tothe indicated boolean value. A value oftrue indicates thatthe reflected object should suppress checks for Java language accesscontrol when it is used. A value offalse indicates thatthe reflected object should enforce checks for Java language accesscontrol when it is used, with the variation noted in the class description.

  This method may be used by a caller in classC to enableaccess to amember ofdeclaring classD if any of the following hold:

  • C andD are in the same module.
  • The member ispublic andD ispublic in a package that the module containingDexports to at least the module containingC.
  • The member isprotectedstatic,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 containingDopens 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 may be used byJNI codewith no caller class on the stack to enable access to amemberofdeclaring classD if and only if:

  • The member ispublic andD ispublic in a package that the module containingDexports unconditionally.

  This method cannot be used to enable access to private members,members with default (package) access, protected instance members, orprotected constructors when the declaring class is in a different moduleto the caller and the package containing the declaring class is not opento the caller's module.

  This method cannot be used to enablewriteaccess to anon-modifiable final field. The following fieldsare non-modifiable:

  • static final fields declared in any class or interface
  • final fields declared in ahidden class
  • final fields declared in arecord

  Theaccessible flag whentrue suppresses Java language accesscontrol checks to only enableread access tothese non-modifiable final fields.

  Overrides:

  setAccessible in class AccessibleObject

  Parameters:

  flag - the new value for theaccessible flag

  Throws:

  InaccessibleObjectException - if access cannot be enabled

  External Specifications

  • Java Native Interface Specification

  See Also:

  • AccessibleObject.trySetAccessible()
  • MethodHandles.privateLookupIn(Class, MethodHandles.Lookup)

• getDeclaringClass

  public Class<?> getDeclaringClass()

  Returns theClass object representing the class or interfacethat declares the field represented by thisField object.

  Specified by:

  getDeclaringClass in interface Member

  Returns:

  an object representing the declaring class of theunderlying member

• getName

  public String getName()

  Returns the name of the field represented by thisField object.

  Specified by:

  getName in interface Member

  Returns:

  the simple name of the underlying member

• getModifiers

  public int getModifiers()

  Returns the Java language modifiers for the field representedby thisField object, as an integer. TheModifier class shouldbe used to decode the modifiers.

  Specified by:

  getModifiers in interface Member

  Returns:

  the Java language modifiers for the underlying member

  SeeJava Language Specification:

  8.3 Field Declarations
  9.3 Field (Constant) Declarations
  

  See Also:

  • Modifier
  • accessFlags()

• accessFlags

  public Set<AccessFlag> accessFlags()

  Returns an unmodifiable set of theaccess flags for this field, possibly empty.

  Specified by:

  accessFlags in interface Member

  Returns:

  an unmodifiable set of theaccess flags for this field, possibly empty

  SeeJava Virtual Machine Specification:

  4.5 Fields
  

  Since:

  20

  See Also:

  • getModifiers()

• isEnumConstant

  public boolean isEnumConstant()

  Returnstrue if this field represents an element ofan enumerated class; returnsfalse otherwise.

  Returns:

  true if and only if this field represents an element ofan enumerated class.

  SeeJava Language Specification:

  8.9.1 Enum Constants
  

  Since:

  1.5

• isSynthetic

  public boolean isSynthetic()

  Returnstrue if this field is a syntheticfield; returnsfalse otherwise.

  Specified by:

  isSynthetic in interface Member

  Returns:

  true if and only if this field is a syntheticfield as defined by the Java Language Specification.

  Since:

  1.5

  See Also:

  • Javaprogramming language and JVM modeling in core reflection

• getType

  public Class<?> getType()

  Returns aClass object that identifies thedeclared type for the field represented by thisField object.

  Returns:

  aClass object identifying the declaredtype of the field represented by this object

• getGenericType

  public Type getGenericType()

  Returns aType object that represents the declared type forthe field represented by thisField object.

  If the declared type of the field is a parameterized type,theType object returned must accurately reflect theactual type arguments used in the source code.

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

  Returns:

  aType 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 inThe Java Virtual Machine Specification

  TypeNotPresentException - if the generic type signature of the underlying field refers to a non-existent class or interface 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 thisField against the specified object. Returnstrue if the objects are the same. TwoField objects are the same ifthey were declared by the same class and have the same nameand type.

  Overrides:

  equals in class Object

  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 thisField. This is computed as theexclusive-or of the hashcodes for the underlying field'sdeclaring class name and its name.

  Overrides:

  hashCode in class Object

  Returns:

  a hash code value for this object

  See Also:

  • Object.equals(java.lang.Object)
  • System.identityHashCode(Object)

• toString

  public String toString()

  Returns a string describing thisField. The format isthe access modifiers for the field, if any, followedby the field type, followed by a space, followed bythe 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 ispublic,protected orprivate first, and then othermodifiers in the following order:static,final,transient,volatile.

  Overrides:

  toString in class Object

  Returns:

  a string describing thisField

  SeeJava Language Specification:

  8.3.1 Field Modifiers
  

• toGenericString

  public String toGenericString()

  Returns a string describing thisField, includingits generic type. The format is the access modifiers for thefield, if any, followed by the generic field type, followed bya space, followed by the fully-qualified name of the classdeclaring the field, followed by a period, followed by the nameof the field.

  The modifiers are placed in canonical order as specified by"The Java Language Specification". This ispublic,protected orprivate first, and then othermodifiers in the following order:static,final,transient,volatile.

  Returns:

  a string describing thisField, includingits generic type

  SeeJava Language Specification:

  8.3.1 Field Modifiers
  

  Since:

  1.5

• get

  public Object get(Object obj) throwsIllegalArgumentException,IllegalAccessException

  Returns the value of the field represented by thisField, onthe specified object. The value is automatically wrapped in anobject if it has a primitive type.

  The underlying field's value is obtained as follows:

  If the underlying field is a static field, theobj argumentis ignored; it may be null.

  Otherwise, the underlying field is an instance field. If thespecifiedobj argument is null, the method throws aNullPointerException. If the specified object is not aninstance of the class or interface declaring the underlyingfield, the method throws anIllegalArgumentException.

  If thisField object is enforcing Java language access control, andthe underlying field is inaccessible, the method throws anIllegalAccessException.If the underlying field is static, the class that declared thefield is initialized if it has not already been initialized.

  Otherwise, the value is retrieved from the underlying instanceor static field. If the field has a primitive type, the valueis wrapped in an object before being returned, otherwise it isreturned as is.

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

  Parameters:

  obj - object from which the represented field's value isto be extracted

  Returns:

  the value of the represented field in objectobj; primitive values are wrapped in an appropriateobject 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) throwsIllegalArgumentException,IllegalAccessException

  Gets the value of a static or instanceboolean field.

  Parameters:

  obj - the object to extract theboolean valuefrom

  Returns:

  the value of theboolean 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(Object)

• getByte

  public byte getByte(Object obj) throwsIllegalArgumentException,IllegalAccessException

  Gets the value of a static or instancebyte field.

  Parameters:

  obj - the object to extract thebyte valuefrom

  Returns:

  the value of thebyte 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(Object)

• getChar

  public char getChar(Object obj) throwsIllegalArgumentException,IllegalAccessException

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

  Parameters:

  obj - the object to extract thechar valuefrom

  Returns:

  the value of the field converted to typechar

  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(Object)

• getShort

  public short getShort(Object obj) throwsIllegalArgumentException,IllegalAccessException

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

  Parameters:

  obj - the object to extract theshort valuefrom

  Returns:

  the value of the field converted to typeshort

  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(Object)

• getInt

  public int getInt(Object obj) throwsIllegalArgumentException,IllegalAccessException

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

  Parameters:

  obj - the object to extract theint valuefrom

  Returns:

  the value of the field converted to typeint

  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(Object)

• getLong

  public long getLong(Object obj) throwsIllegalArgumentException,IllegalAccessException

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

  Parameters:

  obj - the object to extract thelong valuefrom

  Returns:

  the value of the field converted to typelong

  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(Object)

• getFloat

  public float getFloat(Object obj) throwsIllegalArgumentException,IllegalAccessException

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

  Parameters:

  obj - the object to extract thefloat valuefrom

  Returns:

  the value of the field converted to typefloat

  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(Object)

• getDouble

  public double getDouble(Object obj) throwsIllegalArgumentException,IllegalAccessException

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

  Parameters:

  obj - the object to extract thedouble valuefrom

  Returns:

  the value of the field converted to typedouble

  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(Object)

• set

  public void set(Object obj,Object value) throwsIllegalArgumentException,IllegalAccessException

  Sets the field represented by thisField object on thespecified object argument to the specified new value. The newvalue is automatically unwrapped if the underlying field has aprimitive type.

  The operation proceeds as follows:

  If the underlying field is static, theobj argument isignored; it may be null.

  Otherwise the underlying field is an instance field. If thespecified object argument is null, the method throws aNullPointerException. If the specified object argument is notan instance of the class or interface declaring the underlyingfield, the method throws anIllegalArgumentException.

  If thisField object is enforcing Java language access control, andthe underlying field is inaccessible, the method throws anIllegalAccessException.

  If the underlying field is final, thisField object haswrite access if and only if the following conditions are met:

  • setAccessible(true) has succeeded for thisField object;
  • the field is non-static; and
  • the field's declaring class is not ahidden class; and
  • the field's declaring class is not arecord class.

  If any of the above checks is not met, this method throws anIllegalAccessException.

  Setting a final field in this wayis meaningful only during deserialization or reconstruction ofinstances of classes with blank final fields, before they aremade available for access by other parts of a program. Use inany other context may have unpredictable effects, including casesin which other parts of a program continue to use the originalvalue of this field.

  If the underlying field is of a primitive type, an unwrappingconversion is attempted to convert the new value to a value ofa primitive type. If this attempt fails, the method throws anIllegalArgumentException.

  If, after possible unwrapping, the new value cannot beconverted to the type of the underlying field by an identity orwidening conversion, the method throws anIllegalArgumentException.

  If the underlying field is static, the class that declared thefield 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 ofobj,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 ofobjbeing modified

  Throws:

  IllegalAccessException - if thisField object is enforcing Java language access control and the underlying field is inaccessible or final; or if thisField object has no write access.

  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) throwsIllegalArgumentException,IllegalAccessException

  Sets the value of a field as aboolean on the specified object.This method is equivalent toset(obj, zObj),wherezObj is aBoolean object andzObj.booleanValue() == z.

  Parameters:

  obj - the object whose field should be modified

  z - the new value for the field ofobjbeing modified

  Throws:

  IllegalAccessException - if thisField object is enforcing Java language access control and the underlying field is either inaccessible or final; or if thisField object has no write access.

  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(Object, Object)

• setByte

  public void setByte(Object obj, byte b) throwsIllegalArgumentException,IllegalAccessException

  Sets the value of a field as abyte on the specified object.This method is equivalent toset(obj, bObj),wherebObj is aByte object andbObj.byteValue() == b.

  Parameters:

  obj - the object whose field should be modified

  b - the new value for the field ofobjbeing modified

  Throws:

  IllegalAccessException - if thisField object is enforcing Java language access control and the underlying field is either inaccessible or final; or if thisField object has no write access.

  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(Object, Object)

• setChar

  public void setChar(Object obj, char c) throwsIllegalArgumentException,IllegalAccessException

  Sets the value of a field as achar on the specified object.This method is equivalent toset(obj, cObj),wherecObj is aCharacter object andcObj.charValue() == c.

  Parameters:

  obj - the object whose field should be modified

  c - the new value for the field ofobjbeing modified

  Throws:

  IllegalAccessException - if thisField object is enforcing Java language access control and the underlying field is either inaccessible or final; or if thisField object has no write access.

  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(Object, Object)

• setShort

  public void setShort(Object obj, short s) throwsIllegalArgumentException,IllegalAccessException

  Sets the value of a field as ashort on the specified object.This method is equivalent toset(obj, sObj),wheresObj is aShort object andsObj.shortValue() == s.

  Parameters:

  obj - the object whose field should be modified

  s - the new value for the field ofobjbeing modified

  Throws:

  IllegalAccessException - if thisField object is enforcing Java language access control and the underlying field is either inaccessible or final; or if thisField object has no write access.

  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(Object, Object)

• setInt

  public void setInt(Object obj, int i) throwsIllegalArgumentException,IllegalAccessException

  Sets the value of a field as anint on the specified object.This method is equivalent toset(obj, iObj),whereiObj is anInteger object andiObj.intValue() == i.

  Parameters:

  obj - the object whose field should be modified

  i - the new value for the field ofobjbeing modified

  Throws:

  IllegalAccessException - if thisField object is enforcing Java language access control and the underlying field is either inaccessible or final; or if thisField object has no write access.

  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(Object, Object)

• setLong

  public void setLong(Object obj, long l) throwsIllegalArgumentException,IllegalAccessException

  Sets the value of a field as along on the specified object.This method is equivalent toset(obj, lObj),wherelObj is aLong object andlObj.longValue() == l.

  Parameters:

  obj - the object whose field should be modified

  l - the new value for the field ofobjbeing modified

  Throws:

  IllegalAccessException - if thisField object is enforcing Java language access control and the underlying field is either inaccessible or final; or if thisField object has no write access.

  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(Object, Object)

• setFloat

  public void setFloat(Object obj, float f) throwsIllegalArgumentException,IllegalAccessException

  Sets the value of a field as afloat on the specified object.This method is equivalent toset(obj, fObj),wherefObj is aFloat object andfObj.floatValue() == f.

  Parameters:

  obj - the object whose field should be modified

  f - the new value for the field ofobjbeing modified

  Throws:

  IllegalAccessException - if thisField object is enforcing Java language access control and the underlying field is either inaccessible or final; or if thisField object has no write access.

  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(Object, Object)

• setDouble

  public void setDouble(Object obj, double d) throwsIllegalArgumentException,IllegalAccessException

  Sets the value of a field as adouble on the specified object.This method is equivalent toset(obj, dObj),wheredObj is aDouble object anddObj.doubleValue() == d.

  Parameters:

  obj - the object whose field should be modified

  d - the new value for the field ofobjbeing modified

  Throws:

  IllegalAccessException - if thisField object is enforcing Java language access control and the underlying field is either inaccessible or final; or if thisField object has no write access.

  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(Object, Object)

• getAnnotation

  public <T extendsAnnotation> T getAnnotation(Class<T> annotationClass)

  Returns this element's annotation for the specified type ifsuch an annotation ispresent, else null.

  Note that any annotation returned by this method is adeclaration annotation.

  Specified by:

  getAnnotation in interface AnnotatedElement

  Overrides:

  getAnnotation in class AccessibleObject

  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 extendsAnnotation> T[] getAnnotationsByType(Class<T> annotationClass)

  Returns annotations that areassociated with this element.If there are no annotationsassociated with this element, the returnvalue is an array of length 0.The difference between this method andAnnotatedElement.getAnnotation(Class)is that this method detects if its argument is arepeatableannotation type (JLS9.6), and if so, attempts to find one ormore annotations of that type by "looking through" a containerannotation.The caller of this method is free to modify the returned array; it willhave no effect on the arrays returned to other callers.

  Note that any annotations returned by this method aredeclaration annotations.

  Specified by:

  getAnnotationsByType in interface AnnotatedElement

  Overrides:

  getAnnotationsByType in class AccessibleObject

  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 specifythe declared type of the field represented by this Field.

  Returns:

  an object representing the declared type of the fieldrepresented by this Field

  Since:

  1.8