java.lang.reflect
Class AccessibleObject

java.lang.Object
  extended by java.lang.reflect.AccessibleObject
All Implemented Interfaces:
AnnotatedElement
Direct Known Subclasses:
Constructor, Field, Method

public class AccessibleObject
extends Object
implements AnnotatedElement

This class is the superclass of various reflection classes, and allows sufficiently trusted code to bypass normal restrictions to do necessary things like invoke private methods outside of the class during Serialization. If you don't have a good reason to mess with this, don't try. Fortunately, there are adequate security checks before you can set a reflection object as accessible.

Since:
1.2
See Also:
Field, Constructor, Method, ReflectPermission

Constructor Summary
protected AccessibleObject()
          Only the three reflection classes that extend this can create an accessible object.
 
Method Summary
<T extends Annotation>
T
getAnnotation(Class<T> annotationClass)
          Returns the element's annotation for the specified annotation type, or null if no such annotation exists.
 Annotation[] getAnnotations()
          Returns all annotations associated with the element.
 Annotation[] getDeclaredAnnotations()
          Returns all annotations directly defined by the element.
 boolean isAccessible()
          Return the accessibility status of this object.
 boolean isAnnotationPresent(Class<? extends Annotation> annotationClass)
          Returns true if an annotation for the specified type is associated with the element.
static void setAccessible(AccessibleObject[] array, boolean flag)
          Convenience method to set the flag on a number of objects with a single security check.
 void setAccessible(boolean flag)
          Sets the accessibility flag for this reflection object.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

AccessibleObject

protected AccessibleObject()
Only the three reflection classes that extend this can create an accessible object. This is not serializable for security reasons.

Method Detail

isAccessible

public boolean isAccessible()
Return the accessibility status of this object.

Returns:
true if this object bypasses security checks

setAccessible

public static void setAccessible(AccessibleObject[] array,
                                 boolean flag)
Convenience method to set the flag on a number of objects with a single security check. If a security manager exists, it is checked for ReflectPermission("suppressAccessChecks").

It is forbidden to set the accessibility flag to true on any constructor for java.lang.Class. This will result in a SecurityException. If the SecurityException is thrown for any of the passed AccessibleObjects, the accessibility flag will be set on AccessibleObjects in the array prior to the one which resulted in the exception.

Parameters:
array - the array of accessible objects
flag - the desired state of accessibility, true to bypass security
Throws:
NullPointerException - if array is null
SecurityException - if the request is denied
See Also:
SecurityManager.checkPermission(java.security.Permission), RuntimePermission

setAccessible

public void setAccessible(boolean flag)
Sets the accessibility flag for this reflection object. If a security manager exists, it is checked for ReflectPermission("suppressAccessChecks").

It is forbidden to set the accessibility flag to true on any constructor for java.lang.Class. This will result in a SecurityException.

Parameters:
flag - the desired state of accessibility, true to bypass security
Throws:
NullPointerException - if array is null
SecurityException - if the request is denied
See Also:
SecurityManager.checkPermission(java.security.Permission), RuntimePermission

getAnnotation

public <T extends Annotation> T getAnnotation(Class<T> annotationClass)
Description copied from interface: AnnotatedElement
Returns the element's annotation for the specified annotation type, or null if no such annotation exists.

Specified by:
getAnnotation in interface AnnotatedElement
Parameters:
annotationClass - the type of annotation to look for.
Returns:
this element's annotation for the specified type, or null if no such annotation exists.

getAnnotations

public Annotation[] getAnnotations()
Description copied from interface: AnnotatedElement
Returns all annotations associated with the element. If there are no annotations associated with the element, then a zero-length array will be returned. The returned array may be modified by the client code, but this will have no effect on the annotation content of the element, and hence no effect on the return value of this method for future callers.

Specified by:
getAnnotations in interface AnnotatedElement
Returns:
this element's annotations.

getDeclaredAnnotations

public Annotation[] getDeclaredAnnotations()
Description copied from interface: AnnotatedElement
Returns all annotations directly defined by the element. If there are no annotations directly associated with the element, then a zero-length array will be returned. The returned array may be modified by the client code, but this will have no effect on the annotation content of this class, and hence no effect on the return value of this method for future callers.

Specified by:
getDeclaredAnnotations in interface AnnotatedElement
Returns:
the annotations directly defined by the element.

isAnnotationPresent

public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass)
Description copied from interface: AnnotatedElement
Returns true if an annotation for the specified type is associated with the element. This is primarily a short-hand for using marker annotations.

Specified by:
isAnnotationPresent in interface AnnotatedElement
Parameters:
annotationClass - the type of annotation to look for.
Returns:
true if an annotation exists for the specified type.