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
17package org.apache.commons.codec.language;
18
19import org.apache.commons.codec.EncoderException;
20import org.apache.commons.codec.StringEncoder;
21
22/**
23 * Encodes a string into a Refined Soundex value. A refined soundex code is
24 * optimized for spell checking words. Soundex method originally developed by
25 * <CITE>Margaret Odell</CITE> and <CITE>Robert Russell</CITE>.
26 *
27 * @author Apache Software Foundation
28 * @version $Id: RefinedSoundex.java,v 1.21 2004/06/05 18:32:04 ggregory Exp $
29 *
30 * @deprecated Please use {@link java.net.URL#openConnection} instead.
31 *     Please visit <a href="http://android-developers.blogspot.com/2011/09/androids-http-clients.html">this webpage</a>
32 *     for further details.
33 */
34@Deprecated
35public class RefinedSoundex implements StringEncoder {
36
37    /**
38     * This static variable contains an instance of the RefinedSoundex using
39     * the US_ENGLISH mapping.
40     */
41    public static final RefinedSoundex US_ENGLISH = new RefinedSoundex();
42
43    /**
44     * RefinedSoundex is *refined* for a number of reasons one being that the
45     * mappings have been altered. This implementation contains default
46     * mappings for US English.
47     */
48    public static final char[] US_ENGLISH_MAPPING = "01360240043788015936020505".toCharArray();
49
50    /**
51     * Every letter of the alphabet is "mapped" to a numerical value. This char
52     * array holds the values to which each letter is mapped. This
53     * implementation contains a default map for US_ENGLISH
54     */
55    private char[] soundexMapping;
56
57    /**
58     * Creates an instance of the RefinedSoundex object using the default US
59     * English mapping.
60     */
61    public RefinedSoundex() {
62        this(US_ENGLISH_MAPPING);
63    }
64
65    /**
66     * Creates a refined soundex instance using a custom mapping. This
67     * constructor can be used to customize the mapping, and/or possibly
68     * provide an internationalized mapping for a non-Western character set.
69     *
70     * @param mapping
71     *                  Mapping array to use when finding the corresponding code for
72     *                  a given character
73     */
74    public RefinedSoundex(char[] mapping) {
75        this.soundexMapping = mapping;
76    }
77
78    // BEGIN android-note
79    // Removed @see reference to SoundexUtils below, since the class isn't
80    // public.
81    // END android-note
82    /**
83     * Returns the number of characters in the two encoded Strings that are the
84     * same. This return value ranges from 0 to the length of the shortest
85     * encoded String: 0 indicates little or no similarity, and 4 out of 4 (for
86     * example) indicates strong similarity or identical values. For refined
87     * Soundex, the return value can be greater than 4.
88     *
89     * @param s1
90     *                  A String that will be encoded and compared.
91     * @param s2
92     *                  A String that will be encoded and compared.
93     * @return The number of characters in the two encoded Strings that are the
94     *             same from 0 to to the length of the shortest encoded String.
95     *
96     * @see <a href="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_de-dz_8co5.asp">
97     *          MS T-SQL DIFFERENCE</a>
98     *
99     * @throws EncoderException
100     *                  if an error occurs encoding one of the strings
101     * @since 1.3
102     */
103    public int difference(String s1, String s2) throws EncoderException {
104        return SoundexUtils.difference(this, s1, s2);
105    }
106
107    /**
108     * Encodes an Object using the refined soundex algorithm. This method is
109     * provided in order to satisfy the requirements of the Encoder interface,
110     * and will throw an EncoderException if the supplied object is not of type
111     * java.lang.String.
112     *
113     * @param pObject
114     *                  Object to encode
115     * @return An object (or type java.lang.String) containing the refined
116     *             soundex code which corresponds to the String supplied.
117     * @throws EncoderException
118     *                  if the parameter supplied is not of type java.lang.String
119     */
120    public Object encode(Object pObject) throws EncoderException {
121        if (!(pObject instanceof java.lang.String)) {
122            throw new EncoderException("Parameter supplied to RefinedSoundex encode is not of type java.lang.String");
123        }
124        return soundex((String) pObject);
125    }
126
127    /**
128     * Encodes a String using the refined soundex algorithm.
129     *
130     * @param pString
131     *                  A String object to encode
132     * @return A Soundex code corresponding to the String supplied
133     */
134    public String encode(String pString) {
135        return soundex(pString);
136    }
137
138    /**
139     * Returns the mapping code for a given character. The mapping codes are
140     * maintained in an internal char array named soundexMapping, and the
141     * default values of these mappings are US English.
142     *
143     * @param c
144     *                  char to get mapping for
145     * @return A character (really a numeral) to return for the given char
146     */
147    char getMappingCode(char c) {
148        if (!Character.isLetter(c)) {
149            return 0;
150        }
151        return this.soundexMapping[Character.toUpperCase(c) - 'A'];
152    }
153
154    /**
155     * Retreives the Refined Soundex code for a given String object.
156     *
157     * @param str
158     *                  String to encode using the Refined Soundex algorithm
159     * @return A soundex code for the String supplied
160     */
161    public String soundex(String str) {
162        if (str == null) {
163            return null;
164        }
165        str = SoundexUtils.clean(str);
166        if (str.length() == 0) {
167            return str;
168        }
169
170        StringBuffer sBuf = new StringBuffer();
171        sBuf.append(str.charAt(0));
172
173        char last, current;
174        last = '*';
175
176        for (int i = 0; i < str.length(); i++) {
177
178            current = getMappingCode(str.charAt(i));
179            if (current == last) {
180                continue;
181            } else if (current != 0) {
182                sBuf.append(current);
183            }
184
185            last = current;
186
187        }
188
189        return sBuf.toString();
190    }
191}
192