/*

 * Copyright (c) 2003, 2004, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package javax.naming.ldap;

/**

 * A sort key and its associated sort parameters.

 * This class implements a sort key which is used by the LDAPv3

 * Control for server-side sorting of search results as defined in

 * <a href="http://www.ietf.org/rfc/rfc2891.txt">RFC 2891</a>.

 *

 * @since 1.5

 * @see SortControl

 * @author Vincent Ryan

 */

public class SortKey {

    /*

     * The ID of the attribute to sort by.

     */

    private String attrID;

    /*

     * The sort order. Ascending order, by default.

     */

    private boolean reverseOrder = false;

    /*

     * The ID of the matching rule to use for ordering attribute values.

     */

    private String matchingRuleID = null;

    /**

     * Creates the default sort key for an attribute. Entries will be sorted

     * according to the specified attribute in ascending order using the

     * ordering matching rule defined for use with that attribute.

     *

     * @param   attrID  The non-null ID of the attribute to be used as a sort

     *          key.

     */

    public SortKey(String attrID) {

        this.attrID = attrID;

    }

    /**

     * Creates a sort key for an attribute. Entries will be sorted according to

     * the specified attribute in the specified sort order and using the

     * specified matching rule, if supplied.

     *

     * @param   attrID          The non-null ID of the attribute to be used as

     *                          a sort key.

     * @param   ascendingOrder  If true then entries are arranged in ascending

     *                          order. Otherwise there are arranged in

     *                          descending order.

     * @param   matchingRuleID  The possibly null ID of the matching rule to

     *                          use to order the attribute values. If not

     *                          specified then the ordering matching rule

     *                          defined for the sort key attribute is used.

     */

    public SortKey(String attrID, boolean ascendingOrder,

                    String matchingRuleID) {

        this.attrID = attrID;

        reverseOrder = (! ascendingOrder);

        this.matchingRuleID = matchingRuleID;

    }

    /**

     * Retrieves the attribute ID of the sort key.

     *

     * @return    The non-null Attribute ID of the sort key.

     */

    public String getAttributeID() {

        return attrID;

    }

    /**

     * Determines the sort order.

     *

     * @return    true if the sort order is ascending, false if descending.

     */

    public boolean isAscending() {

        return (! reverseOrder);

    }

    /**

     * Retrieves the matching rule ID used to order the attribute values.

     *

     * @return    The possibly null matching rule ID. If null then the

     *            ordering matching rule defined for the sort key attribute

     *            is used.

     */

    public String getMatchingRuleID() {

        return matchingRuleID;

    }

}