1 /* 2 * Copyright 2001-2004 The Apache Software Foundation. 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 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 */ StringEncoderComparator()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 */ StringEncoderComparator(StringEncoder stringEncoder)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 */ compare(Object o1, Object o2)68 public int compare(Object o1, Object o2) { 69 70 int compareCode = 0; 71 72 try { 73 Comparable s1 = (Comparable) ((Encoder) this.stringEncoder).encode(o1); 74 Comparable s2 = (Comparable) ((Encoder) this.stringEncoder).encode(o2); 75 compareCode = s1.compareTo(s2); 76 } 77 catch (EncoderException ee) { 78 compareCode = 0; 79 } 80 return compareCode; 81 } 82 83 } 84