001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     * 
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     * 
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    
018    package org.apache.commons.codec.language;
019    
020    import org.apache.commons.codec.EncoderException;
021    import org.apache.commons.codec.StringEncoder;
022    
023    /**
024     * Encodes a string into a Caverphone value.
025     * 
026     * This is an algorithm created the Caversham Project at the University of Otago. It implements the Caverphone 2.0
027     * algorithm:
028     * 
029     * @author Apache Software Foundation
030     * @version $Id: Caverphone.java 797690 2009-07-24 23:28:35Z ggregory $
031     * @see <a href="http://en.wikipedia.org/wiki/Caverphone">Wikipedia - Caverphone</a>
032     * @see <a href="http://caversham.otago.ac.nz/files/working/ctp150804.pdf">Caverphone 2.0 specification</a>
033     * @since 1.4
034     */
035    public class Caverphone implements StringEncoder {
036    
037        /**
038         * Creates an instance of the Caverphone encoder
039         */
040        public Caverphone() {
041            super();
042        }
043    
044        /**
045         * Find the caverphone value of a String. 
046         *
047         * @param txt String to find the caverphone code for
048         * @return A caverphone code corresponding to the String supplied
049         */
050        public String caverphone(String txt) {
051            // NOTE: Version 1.0 of Caverphone is easily derivable from this code 
052            // by commenting out the 2.0 lines and adding in the 1.0 lines
053    
054            if( txt == null || txt.length() == 0 ) {
055                return "1111111111";
056            }
057    
058            // 1. Convert to lowercase
059            txt = txt.toLowerCase(java.util.Locale.ENGLISH);
060    
061            // 2. Remove anything not A-Z
062            txt = txt.replaceAll("[^a-z]", "");
063    
064            // 2.5. Remove final e
065            txt = txt.replaceAll("e$", "");             // 2.0 only
066    
067            // 3. Handle various start options
068            txt = txt.replaceAll("^cough", "cou2f");
069            txt = txt.replaceAll("^rough", "rou2f");
070            txt = txt.replaceAll("^tough", "tou2f");
071            txt = txt.replaceAll("^enough", "enou2f");  // 2.0 only
072            txt = txt.replaceAll("^trough", "trou2f");  // 2.0 only - note the spec says ^enough here again, c+p error I assume
073            txt = txt.replaceAll("^gn", "2n");
074            txt = txt.replaceAll("^mb", "m2");
075    
076            // 4. Handle replacements
077            txt = txt.replaceAll("cq", "2q");
078            txt = txt.replaceAll("ci", "si");
079            txt = txt.replaceAll("ce", "se");
080            txt = txt.replaceAll("cy", "sy");
081            txt = txt.replaceAll("tch", "2ch");
082            txt = txt.replaceAll("c", "k");
083            txt = txt.replaceAll("q", "k");
084            txt = txt.replaceAll("x", "k");
085            txt = txt.replaceAll("v", "f");
086            txt = txt.replaceAll("dg", "2g");
087            txt = txt.replaceAll("tio", "sio");
088            txt = txt.replaceAll("tia", "sia");
089            txt = txt.replaceAll("d", "t");
090            txt = txt.replaceAll("ph", "fh");
091            txt = txt.replaceAll("b", "p");
092            txt = txt.replaceAll("sh", "s2");
093            txt = txt.replaceAll("z", "s");
094            txt = txt.replaceAll("^[aeiou]", "A");
095            txt = txt.replaceAll("[aeiou]", "3");
096            txt = txt.replaceAll("j", "y");        // 2.0 only
097            txt = txt.replaceAll("^y3", "Y3");     // 2.0 only
098            txt = txt.replaceAll("^y", "A");       // 2.0 only
099            txt = txt.replaceAll("y", "3");        // 2.0 only
100            txt = txt.replaceAll("3gh3", "3kh3");
101            txt = txt.replaceAll("gh", "22");
102            txt = txt.replaceAll("g", "k");
103            txt = txt.replaceAll("s+", "S");
104            txt = txt.replaceAll("t+", "T");
105            txt = txt.replaceAll("p+", "P");
106            txt = txt.replaceAll("k+", "K");
107            txt = txt.replaceAll("f+", "F");
108            txt = txt.replaceAll("m+", "M");
109            txt = txt.replaceAll("n+", "N");
110            txt = txt.replaceAll("w3", "W3");
111            //txt = txt.replaceAll("wy", "Wy");    // 1.0 only
112            txt = txt.replaceAll("wh3", "Wh3");
113            txt = txt.replaceAll("w$", "3");       // 2.0 only
114            //txt = txt.replaceAll("why", "Why");  // 1.0 only
115            txt = txt.replaceAll("w", "2");
116            txt = txt.replaceAll("^h", "A");
117            txt = txt.replaceAll("h", "2");
118            txt = txt.replaceAll("r3", "R3");
119            txt = txt.replaceAll("r$", "3");       // 2.0 only
120            //txt = txt.replaceAll("ry", "Ry");    // 1.0 only
121            txt = txt.replaceAll("r", "2");
122            txt = txt.replaceAll("l3", "L3");
123            txt = txt.replaceAll("l$", "3");       // 2.0 only
124            //txt = txt.replaceAll("ly", "Ly");    // 1.0 only
125            txt = txt.replaceAll("l", "2");
126            //txt = txt.replaceAll("j", "y");      // 1.0 only
127            //txt = txt.replaceAll("y3", "Y3");    // 1.0 only
128            //txt = txt.replaceAll("y", "2");      // 1.0 only
129    
130            // 5. Handle removals
131            txt = txt.replaceAll("2", "");
132            txt = txt.replaceAll("3$", "A");       // 2.0 only
133            txt = txt.replaceAll("3", "");
134    
135            // 6. put ten 1s on the end
136            txt = txt + "111111" + "1111";        // 1.0 only has 6 1s
137    
138            // 7. take the first six characters as the code
139            return txt.substring(0, 10);          // 1.0 truncates to 6
140        }
141    
142        /**
143         * Encodes an Object using the caverphone algorithm.  This method
144         * is provided in order to satisfy the requirements of the
145         * Encoder interface, and will throw an EncoderException if the
146         * supplied object is not of type java.lang.String.
147         *
148         * @param pObject Object to encode
149         * @return An object (or type java.lang.String) containing the 
150         *         caverphone code which corresponds to the String supplied.
151         * @throws EncoderException if the parameter supplied is not
152         *                          of type java.lang.String
153         */
154        public Object encode(Object pObject) throws EncoderException {
155            if (!(pObject instanceof String)) {
156                throw new EncoderException("Parameter supplied to Caverphone encode is not of type java.lang.String"); 
157            }
158            return caverphone((String) pObject);
159        }
160    
161        /**
162         * Encodes a String using the Caverphone algorithm. 
163         *
164         * @param pString String object to encode
165         * @return The caverphone code corresponding to the String supplied
166         */
167        public String encode(String pString) {
168            return caverphone(pString);   
169        }
170    
171        /**
172         * Tests if the caverphones of two strings are identical.
173         *
174         * @param str1 First of two strings to compare
175         * @param str2 Second of two strings to compare
176         * @return <code>true</code> if the caverphones of these strings are identical, 
177         *        <code>false</code> otherwise.
178         */
179        public boolean isCaverphoneEqual(String str1, String str2) {
180            return caverphone(str1).equals(caverphone(str2));
181        }
182    
183    }