/*
 * Copyright 1997-1998 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun 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.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package java.security;

/**
 * <p> This interface represents a guard, which is an object that is used
 * to protect access to another object.
 *
 * <p>This interface contains a single method, <code>checkGuard</code>,
 * with a single <code>object</code> argument. <code>checkGuard</code> is
 * invoked (by the GuardedObject <code>getObject</code> method)
 * to determine whether or not to allow access to the object.
 *
 * @see GuardedObject
 *
 * @author Roland Schemers
 * @author Li Gong
 */

public interface Guard {

    /**
     * Determines whether or not to allow access to the guarded object
     * <code>object</code>. Returns silently if access is allowed.
     * Otherwise, throws a SecurityException.
     *
     * @param object the object being protected by the guard.
     *
     * @exception SecurityException if access is denied.
     *
     */
    void checkGuard(Object object) throws SecurityException;
}