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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
RFC 2891.
Author:
Vincent Ryan
See Also:
SortControl
Since:
1.5/**
 * 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.
Params:
attrID –  The non-null ID of the attribute to be used as a sort
         key./**
     * 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.
Params:
attrID –          The non-null ID of the attribute to be used as
                         a sort key.
ascendingOrder –  If true then entries are arranged in ascending
                         order. Otherwise there are arranged in
                         descending order.
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./**
     * 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.
Returns:
   The non-null Attribute ID of the sort key./**
     * 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.
Returns:
   true if the sort order is ascending, false if descending./**
     * 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.
Returns:
   The possibly null matching rule ID. If null then the
           ordering matching rule defined for the sort key attribute
           is used./**
     * 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;
    }
}