1 /*
2 * Copyright 2004-2009 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.springmodules.validation.util.condition.range;
17
18 import java.util.Comparator;
19
20 import org.springframework.util.Assert;
21
22
23 /**
24 * Comparator that adapts Comparables to the Comparator interface.
25 * Mainly for internal use in other Comparators, when supposed
26 * to work on Comparables.
27 *
28 * <p><strong>Note</strong>: Copied from Spring 2.5 to avoid redoing work using this.
29 *
30 * @author Keith Donald
31 * @since 1.2.2
32 * @see Comparable
33 */
34 public class ComparableComparator implements Comparator {
35
36 public int compare(Object o1, Object o2) {
37 Assert.isTrue(o1 instanceof Comparable, "The first object provided is not Comparable");
38 Assert.isTrue(o2 instanceof Comparable, "The second object provided is not Comparable");
39 return ((Comparable) o1).compareTo(o2);
40 }
41
42 }