| /* |
| * Copyright 2001-2004 The Apache Software Foundation. |
| * |
| * Licensed 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.language; |
| |
| import org.apache.commons.codec.EncoderException; |
| import org.apache.commons.codec.StringEncoder; |
| |
| /** |
| * Utility methods for {@link Soundex} and {@link RefinedSoundex} classes. |
| * |
| * @author Apache Software Foundation |
| * @version $Id: SoundexUtils.java,v 1.5 2004/03/17 18:31:35 ggregory Exp $ |
| * @since 1.3 |
| */ |
| final class SoundexUtils { |
| |
| /** |
| * Cleans up the input string before Soundex processing by only returning |
| * upper case letters. |
| * |
| * @param str |
| * The String to clean. |
| * @return A clean String. |
| */ |
| static String clean(String str) { |
| if (str == null || str.length() == 0) { |
| return str; |
| } |
| int len = str.length(); |
| char[] chars = new char[len]; |
| int count = 0; |
| for (int i = 0; i < len; i++) { |
| if (Character.isLetter(str.charAt(i))) { |
| chars[count++] = str.charAt(i); |
| } |
| } |
| if (count == len) { |
| return str.toUpperCase(); |
| } |
| return new String(chars, 0, count).toUpperCase(); |
| } |
| |
| /** |
| * Encodes the Strings and returns the number of characters in the two |
| * encoded Strings that are the same. |
| * <ul> |
| * <li>For Soundex, this return value ranges from 0 through 4: 0 indicates |
| * little or no similarity, and 4 indicates strong similarity or identical |
| * values.</li> |
| * <li>For refined Soundex, the return value can be greater than 4.</li> |
| * </ul> |
| * |
| * @param encoder |
| * The encoder to use to encode the Strings. |
| * @param s1 |
| * A String that will be encoded and compared. |
| * @param s2 |
| * A String that will be encoded and compared. |
| * @return The number of characters in the two Soundex encoded Strings that |
| * are the same. |
| * |
| * @see #differenceEncoded(String,String) |
| * @see <a href="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_de-dz_8co5.asp"> |
| * MS T-SQL DIFFERENCE</a> |
| * |
| * @throws EncoderException |
| * if an error occurs encoding one of the strings |
| */ |
| static int difference(StringEncoder encoder, String s1, String s2) throws EncoderException { |
| return differenceEncoded(encoder.encode(s1), encoder.encode(s2)); |
| } |
| |
| /** |
| * Returns the number of characters in the two Soundex encoded Strings that |
| * are the same. |
| * <ul> |
| * <li>For Soundex, this return value ranges from 0 through 4: 0 indicates |
| * little or no similarity, and 4 indicates strong similarity or identical |
| * values.</li> |
| * <li>For refined Soundex, the return value can be greater than 4.</li> |
| * </ul> |
| * |
| * @param es1 |
| * An encoded String. |
| * @param es2 |
| * An encoded String. |
| * @return The number of characters in the two Soundex encoded Strings that |
| * are the same. |
| * |
| * @see <a href="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_de-dz_8co5.asp"> |
| * MS T-SQL DIFFERENCE</a> |
| */ |
| static int differenceEncoded(String es1, String es2) { |
| |
| if (es1 == null || es2 == null) { |
| return 0; |
| } |
| int lengthToMatch = Math.min(es1.length(), es2.length()); |
| int diff = 0; |
| for (int i = 0; i < lengthToMatch; i++) { |
| if (es1.charAt(i) == es2.charAt(i)) { |
| diff++; |
| } |
| } |
| return diff; |
| } |
| |
| } |