/*

 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. 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.  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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package com.sun.security.auth;

/**

 * An object that implements the {@code java.security.Principal}

 * interface typically also implements this interface to provide

 * a means for comparing that object to a specified {@code Subject}.

 *

 * <p> The comparison is achieved via the {@code implies} method.

 * The implementation of the {@code implies} method determines

 * whether this object "implies" the specified {@code Subject}.

 * One example application of this method may be for

 * a "group" object to imply a particular {@code Subject}

 * if that {@code Subject} belongs to the group.

 * Another example application of this method would be for

 * "role" object to imply a particular {@code Subject}

 * if that {@code Subject} is currently acting in that role.

 *

 * <p> Although classes that implement this interface typically

 * also implement the {@code java.security.Principal} interface,

 * it is not required.  In other words, classes may implement the

 * {@code java.security.Principal} interface by itself,

 * the {@code PrincipalComparator} interface by itself,

 * or both at the same time.

 *

 * @see java.security.Principal

 * @see javax.security.auth.Subject

 */

public interface PrincipalComparator {

    /**

     * Check if the specified {@code Subject} is implied by

     * this object.

     *

     * @return true if the specified {@code Subject} is implied by

     *          this object, or false otherwise.

     */

    boolean implies(javax.security.auth.Subject subject);

}