01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one
03: * or more contributor license agreements. See the NOTICE file
04: * distributed with this work for additional information
05: * regarding copyright ownership. The ASF licenses this file
06: * to you under the Apache License, Version 2.0 (the
07: * "License"); you may not use this file except in compliance
08: * with the License. You may obtain a copy of the License at
09: *
10: * http://www.apache.org/licenses/LICENSE-2.0
11: *
12: * Unless required by applicable law or agreed to in writing,
13: * software distributed under the License is distributed on an
14: * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15: * KIND, either express or implied. See the License for the
16: * specific language governing permissions and limitations
17: * under the License.
18: */
19: package org.apache.openjpa.meta;
20:
21: import java.io.Serializable;
22: import java.util.Comparator;
23:
24: /**
25: * Order a field.
26: *
27: * @author Abe White
28: */
29: public interface Order extends Serializable {
30:
31: /**
32: * Token denoting to order by the element value.
33: */
34: public static final String ELEMENT = "#element";
35:
36: /**
37: * Return the name of the orderable.
38: */
39: public String getName();
40:
41: /**
42: * Order direction.
43: */
44: public boolean isAscending();
45:
46: /**
47: * Return a comparator for ordering by this element, or null if
48: * the ordering is done in the datastore.
49: */
50: public Comparator getComparator();
51: }
|