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Diffstat (limited to 'src/org/apache/commons/codec/language/SoundexUtils.java')
-rw-r--r-- | src/org/apache/commons/codec/language/SoundexUtils.java | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/src/org/apache/commons/codec/language/SoundexUtils.java b/src/org/apache/commons/codec/language/SoundexUtils.java new file mode 100644 index 0000000..48f2d87 --- /dev/null +++ b/src/org/apache/commons/codec/language/SoundexUtils.java @@ -0,0 +1,122 @@ +/* + * 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; + } + +} |