org.apache.openjpa.meta.Order Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.openjpa.meta;
import java.io.Serializable;
import java.util.Comparator;
/**
* Order a field.
*
* @author Abe White
*/
public interface Order
extends Serializable {
/**
* Token denoting to order by the element value.
*/
public static final String ELEMENT = "#element";
/**
* Return the name of the orderable.
*/
public String getName();
/**
* Order direction.
*/
public boolean isAscending();
/**
* Return a comparator for ordering by this element, or null if
* the ordering is done in the datastore.
*/
public Comparator getComparator ();
}