mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-02 18:53:22 +00:00
122 lines
4.0 KiB
Java
122 lines
4.0 KiB
Java
/* GuardedObject.java -- An object protected by a Guard
|
|
Copyright (C) 1998, 2002, 2004, 2005 Free Software Foundation, Inc.
|
|
|
|
This file is part of GNU Classpath.
|
|
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
GNU Classpath 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 for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
|
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
02110-1301 USA.
|
|
|
|
Linking this library statically or dynamically with other modules is
|
|
making a combined work based on this library. Thus, the terms and
|
|
conditions of the GNU General Public License cover the whole
|
|
combination.
|
|
|
|
As a special exception, the copyright holders of this library give you
|
|
permission to link this library with independent modules to produce an
|
|
executable, regardless of the license terms of these independent
|
|
modules, and to copy and distribute the resulting executable under
|
|
terms of your choice, provided that you also meet, for each linked
|
|
independent module, the terms and conditions of the license of that
|
|
module. An independent module is a module which is not derived from
|
|
or based on this library. If you modify this library, you may extend
|
|
this exception to your version of the library, but you are not
|
|
obligated to do so. If you do not wish to do so, delete this
|
|
exception statement from your version. */
|
|
|
|
|
|
package java.security;
|
|
|
|
import java.io.IOException;
|
|
import java.io.ObjectOutputStream;
|
|
import java.io.Serializable;
|
|
|
|
/**
|
|
* This class is an object that is guarded by a <code>Guard</code> object.
|
|
* The object that is being guarded is retrieved by a call to the only
|
|
* method in this class - <code>getObject</code>. That method returns the
|
|
* guarded <code>Object</code> after first checking with the
|
|
* <code>Guard</code>. If the <code>Guard</code> disallows access, an
|
|
* exception will be thrown.
|
|
*
|
|
* @author Aaron M. Renn (arenn@urbanophile.com)
|
|
* @since 1.1
|
|
* @status updated to 1.4
|
|
*/
|
|
public class GuardedObject implements Serializable
|
|
{
|
|
/**
|
|
* Compatible with JDK 1.1+.
|
|
*/
|
|
private static final long serialVersionUID = -5240450096227834308L;
|
|
|
|
/**
|
|
* This is the Guard that is protecting the object.
|
|
*
|
|
* @serial the guard
|
|
*/
|
|
private final Guard guard;
|
|
|
|
/**
|
|
* This is the object that is being guarded.
|
|
*
|
|
* @serial the protected object
|
|
*/
|
|
private final Object object;
|
|
|
|
/**
|
|
* This method initializes a new instance of <code>GuardedObject</code>
|
|
* that protects the specified <code>Object</code> using the specified
|
|
* <code>Guard</code>. A null guard means there are no restrictions on
|
|
* accessing the object.
|
|
*
|
|
* @param object the <code>Object</code> to guard
|
|
* @param guard the <code>Guard</code> that is protecting the object
|
|
*/
|
|
public GuardedObject(Object object, Guard guard)
|
|
{
|
|
this.object = object;
|
|
this.guard = guard;
|
|
}
|
|
|
|
/**
|
|
* This method first call the <code>checkGuard</code> method on the
|
|
* <code>Guard</code> object protecting the guarded object. If the
|
|
* <code>Guard</code> disallows access, an exception is thrown, otherwise
|
|
* the <code>Object</code> is returned.
|
|
*
|
|
* @return The object being guarded
|
|
* @throws SecurityException if access is denied
|
|
*/
|
|
public Object getObject()
|
|
{
|
|
if (guard != null)
|
|
guard.checkGuard(object);
|
|
return object;
|
|
}
|
|
|
|
/**
|
|
* Ensures that serialization is legal, by checking the guard.
|
|
*
|
|
* @param s the stream to write to
|
|
* @throws IOException if the underlying stream fails
|
|
*/
|
|
private void writeObject(ObjectOutputStream s) throws IOException
|
|
{
|
|
if (guard != null)
|
|
guard.checkGuard(object);
|
|
s.defaultWriteObject();
|
|
}
|
|
} // class GuardedObject
|