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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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*/
package java.lang.reflect;
import java.security.AccessController;
import sun.reflect.ReflectionFactory;
import java.lang.annotation.Annotation;
/**
* 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.
*
* <p>Setting the {@code 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.
*
* @see Field
* @see Method
* @see Constructor
* @see ReflectPermission
*
* @since 1.2
*/
public class AccessibleObject implements AnnotatedElement {
/**
* The Permission object that is used to check whether a client
* has sufficient privilege to defeat Java language access
* control checks.
*/
static final private java.security.Permission ACCESS_PERMISSION =
new ReflectPermission("suppressAccessChecks");
/**
* Convenience method to set the {@code accessible} flag for an
* array of objects with a single security check (for efficiency).
*
* <p>First, if there is a security manager, its
* {@code checkPermission} method is called with a
* {@code ReflectPermission("suppressAccessChecks")} permission.
*
* <p>A {@code SecurityException} is raised if {@code flag} is
* {@code true} but accessibility of any of the elements of the input
* {@code array} may not be changed (for example, if the element
* object is a {@link Constructor} object for the class {@link
* java.lang.Class}). In the event of such a SecurityException, the
* accessibility of objects is set to {@code 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.
*
* @param array the array of AccessibleObjects
* @param flag the new value for the {@code accessible} flag
* in each object
* @throws SecurityException if the request is denied.
* @see SecurityManager#checkPermission
* @see java.lang.RuntimePermission
*/
public static void setAccessible(AccessibleObject[] array, boolean flag)
throws SecurityException {
SecurityManager sm = System.getSecurityManager();
if (sm != null) sm.checkPermission(ACCESS_PERMISSION);
for (int i = 0; i < array.length; i++) {
setAccessible0(array[i], flag);
}
}
/**
* Set the {@code accessible} flag for this object to
* the indicated boolean value. A value of {@code true} indicates that
* the reflected object should suppress Java language access
* checking when it is used. A value of {@code false} indicates
* that the reflected object should enforce Java language access checks.
*
* <p>First, if there is a security manager, its
* {@code checkPermission} method is called with a
* {@code ReflectPermission("suppressAccessChecks")} permission.
*
* <p>A {@code SecurityException} is raised if {@code flag} is
* {@code true} but accessibility of this object may not be changed
* (for example, if this element object is a {@link Constructor} object for
* the class {@link java.lang.Class}).
*
* <p>A {@code SecurityException} is raised if this object is a {@link
* java.lang.reflect.Constructor} object for the class
* {@code java.lang.Class}, and {@code flag} is true.
*
* @param flag the new value for the {@code accessible} flag
* @throws SecurityException if the request is denied.
* @see SecurityManager#checkPermission
* @see java.lang.RuntimePermission
*/
public void setAccessible(boolean flag) throws SecurityException {
SecurityManager sm = System.getSecurityManager();
if (sm != null) sm.checkPermission(ACCESS_PERMISSION);
setAccessible0(this, flag);
}
/* Check that you aren't exposing java.lang.Class.<init>. */
private static void setAccessible0(AccessibleObject obj, boolean flag)
throws SecurityException
{
if (obj instanceof Constructor && flag == true) {
Constructor c = (Constructor)obj;
if (c.getDeclaringClass() == Class.class) {
throw new SecurityException("Can not make a java.lang.Class" +
" constructor accessible");
}
}
obj.override = flag;
}
/**
* Get the value of the {@code accessible} flag for this object.
*
* @return the value of the object's {@code accessible} flag
*/
public boolean isAccessible() {
return override;
}
/**
* Constructor: only used by the Java Virtual Machine.
*/
protected AccessibleObject() {}
// Indicates whether language-level access checks are overridden
// by this object. Initializes to "false". This field is used by
// Field, Method, and Constructor.
//
// NOTE: for security purposes, this field must not be visible
// outside this package.
boolean override;
// Reflection factory used by subclasses for creating field,
// method, and constructor accessors. Note that this is called
// very early in the bootstrapping process.
static final ReflectionFactory reflectionFactory = (ReflectionFactory)
AccessController.doPrivileged
(new sun.reflect.ReflectionFactory.GetReflectionFactoryAction());
/**
* @throws NullPointerException {@inheritDoc}
* @since 1.5
*/
public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
throw new AssertionError("All subclasses should override this method");
}
/**
* @throws NullPointerException {@inheritDoc}
* @since 1.5
*/
public boolean isAnnotationPresent(
Class<? extends Annotation> annotationClass) {
return getAnnotation(annotationClass) != null;
}
/**
* @since 1.5
*/
public Annotation[] getAnnotations() {
return getDeclaredAnnotations();
}
/**
* @since 1.5
*/
public Annotation[] getDeclaredAnnotations() {
throw new AssertionError("All subclasses should override this method");
}
}