AccessibleObject (Java Platform SE 7 ) (original) (raw)

• java.lang.Object

• • java.lang.reflect.AccessibleObject

• All Implemented Interfaces:
  AnnotatedElement
  Direct Known Subclasses:
  Constructor, Field, Method

public class AccessibleObject
extends Object
implements AnnotatedElement
The AccessibleObject class is the base class for Field, Method and Constructor objects. It provides the ability to flag a reflected object as suppressing default Java language access control checks when it is used. The access checks--for public, default (package) access, protected, and private members--are performed when Fields, Methods or Constructors are used to set or get fields, to invoke methods, or to create and initialize new instances of classes, respectively.
Setting the accessible flag in a reflected object permits sophisticated applications with sufficient privilege, such as Java Object Serialization or other persistence mechanisms, to manipulate objects in a manner that would normally be prohibited.
By default, a reflected object is not accessible.
Since:
1.2
See Also:
Field, Method, Constructor, ReflectPermission

• • Constructor Summary

  Constructors

  Modifier	Constructor and Description
  protected	AccessibleObject() Constructor: only used by the Java Virtual Machine.

  • Method Summary

  Methods

  Modifier and Type	Method and Description
  <T extends Annotation> T	getAnnotation(Class annotationClass) Returns this element's annotation for the specified type if such an annotation is present, else null.
  Annotation[]	getAnnotations() Returns all annotations present on this element.
  Annotation[]	getDeclaredAnnotations() Returns all annotations that are directly present on this element.
  boolean	isAccessible() Get the value of the accessible flag for this object.
  boolean	isAnnotationPresent(Class<? extends Annotation> annotationClass) Returns true if an annotation for the specified type is present on this element, else false.
  static void	setAccessible(AccessibleObject[] array, boolean flag) Convenience method to set the accessible flag for an array of objects with a single security check (for efficiency).
  void	setAccessible(boolean flag) Set the accessible flag for this object to the indicated boolean value.

     * ### Methods inherited from class java.lang.[Object](../../../java/lang/Object.html "class in java.lang")  
     `[clone](../../../java/lang/Object.html#clone%28%29), [equals](../../../java/lang/Object.html#equals%28java.lang.Object%29), [finalize](../../../java/lang/Object.html#finalize%28%29), [getClass](../../../java/lang/Object.html#getClass%28%29), [hashCode](../../../java/lang/Object.html#hashCode%28%29), [notify](../../../java/lang/Object.html#notify%28%29), [notifyAll](../../../java/lang/Object.html#notifyAll%28%29), [toString](../../../java/lang/Object.html#toString%28%29), [wait](../../../java/lang/Object.html#wait%28%29), [wait](../../../java/lang/Object.html#wait%28long%29), [wait](../../../java/lang/Object.html#wait%28long,%20int%29)`

• • Constructor Detail

     * #### AccessibleObject  
     protected AccessibleObject()  
     Constructor: only used by the Java Virtual Machine.  

  • Method Detail

    * #### setAccessible  
    public static void setAccessible([AccessibleObject](../../../java/lang/reflect/AccessibleObject.html "class in java.lang.reflect")[] array,  
                     boolean flag)  
                              throws [SecurityException](../../../java/lang/SecurityException.html "class in java.lang")  
    Convenience method to set the `accessible` flag for an array of objects with a single security check (for efficiency).  
    First, if there is a security manager, its`checkPermission` method is called with a`ReflectPermission("suppressAccessChecks")` permission.  
    A `SecurityException` is raised if `flag` is`true` but accessibility of any of the elements of the input`array` may not be changed (for example, if the element object is a [Constructor](../../../java/lang/reflect/Constructor.html "class in java.lang.reflect") object for the class [Class](../../../java/lang/Class.html "class in java.lang")). In the event of such a SecurityException, the accessibility of objects is set to `flag` for array elements upto (and excluding) the element for which the exception occurred; the accessibility of elements beyond (and including) the element for which the exception occurred is unchanged.  
    Parameters:  
    `array` \- the array of AccessibleObjects  
    `flag` \- the new value for the `accessible` flag in each object  
    Throws:  
    `[SecurityException](../../../java/lang/SecurityException.html "class in java.lang")` \- if the request is denied.  
    See Also:  
    [SecurityManager.checkPermission(java.security.Permission)](../../../java/lang/SecurityManager.html#checkPermission%28java.security.Permission%29), [RuntimePermission](../../../java/lang/RuntimePermission.html "class in java.lang")  
    * #### setAccessible  
    public void setAccessible(boolean flag)  
                       throws [SecurityException](../../../java/lang/SecurityException.html "class in java.lang")  
    Set the `accessible` flag for this object to the indicated boolean value. A value of `true` indicates that the reflected object should suppress Java language access checking when it is used. A value of `false` indicates that the reflected object should enforce Java language access checks.  
    First, if there is a security manager, its`checkPermission` method is called with a`ReflectPermission("suppressAccessChecks")` permission.  
    A `SecurityException` is raised if `flag` is`true` but accessibility of this object may not be changed (for example, if this element object is a [Constructor](../../../java/lang/reflect/Constructor.html "class in java.lang.reflect") object for the class [Class](../../../java/lang/Class.html "class in java.lang")).  
    A `SecurityException` is raised if this object is a [Constructor](../../../java/lang/reflect/Constructor.html "class in java.lang.reflect") object for the class`java.lang.Class`, and `flag` is true.  
    Parameters:  
    `flag` \- the new value for the `accessible` flag  
    Throws:  
    `[SecurityException](../../../java/lang/SecurityException.html "class in java.lang")` \- if the request is denied.  
    See Also:  
    [SecurityManager.checkPermission(java.security.Permission)](../../../java/lang/SecurityManager.html#checkPermission%28java.security.Permission%29), [RuntimePermission](../../../java/lang/RuntimePermission.html "class in java.lang")  
    * #### isAccessible  
    public boolean isAccessible()  
    Get the value of the `accessible` flag for this object.  
    Returns:  
    the value of the object's `accessible` flag  
    * #### getAnnotation  
    public <T extends [Annotation](../../../java/lang/annotation/Annotation.html "interface in java.lang.annotation")> T getAnnotation([Class](../../../java/lang/Class.html "class in java.lang")<T> annotationClass)  
    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")`  
    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](../../../java/lang/NullPointerException.html "class in java.lang")` \- if the given annotation class is null  
    Since:  
    1.5  
    * #### isAnnotationPresent  
    public boolean isAnnotationPresent([Class](../../../java/lang/Class.html "class in java.lang")<? extends [Annotation](../../../java/lang/annotation/Annotation.html "interface in java.lang.annotation")> annotationClass)  
    Returns true if an annotation for the specified type is present on this element, else false. This method is designed primarily for convenient access to marker annotations.  
    **Specified by:**  
    `[isAnnotationPresent](../../../java/lang/reflect/AnnotatedElement.html#isAnnotationPresent%28java.lang.Class%29)` in interface `[AnnotatedElement](../../../java/lang/reflect/AnnotatedElement.html "interface in java.lang.reflect")`  
    Parameters:  
    `annotationClass` \- the Class object corresponding to the annotation type  
    Returns:  
    true if an annotation for the specified annotation type is present on this element, else false  
    Throws:  
    `[NullPointerException](../../../java/lang/NullPointerException.html "class in java.lang")` \- if the given annotation class is null  
    Since:  
    1.5  
    * #### getAnnotations  
    public [Annotation](../../../java/lang/annotation/Annotation.html "interface in java.lang.annotation")[] getAnnotations()  
    Returns all annotations present on this element. (Returns an array of length zero if this element has no annotations.) 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:**  
    `[getAnnotations](../../../java/lang/reflect/AnnotatedElement.html#getAnnotations%28%29)` in interface `[AnnotatedElement](../../../java/lang/reflect/AnnotatedElement.html "interface in java.lang.reflect")`  
    Returns:  
    all annotations present on this element  
    Since:  
    1.5  
    * #### getDeclaredAnnotations  
    public [Annotation](../../../java/lang/annotation/Annotation.html "interface in java.lang.annotation")[] getDeclaredAnnotations()  
    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")`  
    Returns:  
    All annotations directly present on this element  
    Since:  
    1.5

Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2020, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.