/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.codec;
import java.util.Comparator;
/**
* Strings are comparable, and this comparator allows
* you to configure it with an instance of a class
* which implements StringEncoder. This comparator
* is used to sort Strings by an encoding scheme such
* as Soundex, Metaphone, etc. This class can come in
* handy if one need to sort Strings by an encoded
* form of a name such as Soundex.
*
* @author Apache Software Foundation
* @version $Id: StringEncoderComparator.java 793391 2009-07-12 18:38:08Z ggregory $
*/
public class StringEncoderComparator implements Comparator {
/**
* Internal encoder instance.
*/
private final StringEncoder stringEncoder;
/**
* Constructs a new instance.
* @deprecated as creating without a StringEncoder will lead to a
* broken NullPointerException creating comparator.
*/
public StringEncoderComparator() {
this.stringEncoder = null; // Trying to use this will cause things to break
}
/**
* Constructs a new instance with the given algorithm.
* @param stringEncoder the StringEncoder used for comparisons.
*/
public StringEncoderComparator(StringEncoder stringEncoder) {
this.stringEncoder = stringEncoder;
}
/**
* Compares two strings based not on the strings
* themselves, but on an encoding of the two
* strings using the StringEncoder this Comparator
* was created with.
*
* If an {@link EncoderException} is encountered, return <code>0</code>.
*
* @param o1 the object to compare
* @param o2 the object to compare to
* @return the Comparable.compareTo() return code or 0 if an encoding error was caught.
* @see Comparable
*/
public int compare(Object o1, Object o2) {
int compareCode = 0;
try {
Comparable s1 = (Comparable) this.stringEncoder.encode(o1);
Comparable s2 = (Comparable) this.stringEncoder.encode(o2);
compareCode = s1.compareTo(s2);
}
catch (EncoderException ee) {
compareCode = 0;
}
return compareCode;
}
}