01: /*
02: * Copyright 2002-2005 the original author or authors.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
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:
17: package org.springframework.util.comparator;
18:
19: import java.util.Comparator;
20:
21: import org.springframework.util.Assert;
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: * @author Keith Donald
29: * @since 1.2.2
30: * @see Comparable
31: */
32: public class ComparableComparator implements Comparator {
33:
34: public int compare(Object o1, Object o2) {
35: Assert.isTrue(o1 instanceof Comparable,
36: "The first object provided is not Comparable");
37: Assert.isTrue(o2 instanceof Comparable,
38: "The second object provided is not Comparable");
39: return ((Comparable) o1).compareTo(o2);
40: }
41:
42: }
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