01: /*
02: * Copyright 2001-2004 The Apache Software Foundation.
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.apache.commons.codec;
18:
19: import java.util.Comparator;
20:
21: /**
22: * Strings are comparable, and this comparator allows
23: * you to configure it with an instance of a class
24: * which implements StringEncoder. This comparator
25: * is used to sort Strings by an encoding scheme such
26: * as Soundex, Metaphone, etc. This class can come in
27: * handy if one need to sort Strings by an encoded
28: * form of a name such as Soundex.
29: *
30: * @author Apache Software Foundation
31: * @version $Id: StringEncoderComparator.java,v 1.14 2004/06/21 23:24:17 ggregory Exp $
32: */
33: public class StringEncoderComparator implements Comparator {
34:
35: /**
36: * Internal encoder instance.
37: */
38: private StringEncoder stringEncoder;
39:
40: /**
41: * Constructs a new instance.
42: */
43: public StringEncoderComparator() {
44: // no init.
45: }
46:
47: /**
48: * Constructs a new instance with the given algorithm.
49: * @param stringEncoder the StringEncoder used for comparisons.
50: */
51: public StringEncoderComparator(StringEncoder stringEncoder) {
52: this .stringEncoder = stringEncoder;
53: }
54:
55: /**
56: * Compares two strings based not on the strings
57: * themselves, but on an encoding of the two
58: * strings using the StringEncoder this Comparator
59: * was created with.
60: *
61: * If an {@link EncoderException} is encountered, return <code>0</code>.
62: *
63: * @param o1 the object to compare
64: * @param o2 the object to compare to
65: * @return the Comparable.compareTo() return code or 0 if an encoding error was caught.
66: * @see Comparable
67: */
68: public int compare(Object o1, Object o2) {
69:
70: int compareCode = 0;
71:
72: try {
73: Comparable s1 = (Comparable) ((Encoder) this .stringEncoder)
74: .encode(o1);
75: Comparable s2 = (Comparable) ((Encoder) this .stringEncoder)
76: .encode(o2);
77: compareCode = s1.compareTo(s2);
78: } catch (EncoderException ee) {
79: compareCode = 0;
80: }
81: return compareCode;
82: }
83:
84: }
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