| /* |
| * 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.text.similarity; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| import org.apache.commons.lang3.StringUtils; |
| import org.apache.commons.lang3.Validate; |
| |
| /** |
| * A simple word tokenizer that utilizes regex to find words. It applies a regex |
| * {@code (\w)+} over the input text to extract words from a given character |
| * sequence. |
| * |
| * @since 1.0 |
| */ |
| class RegexTokenizer implements Tokenizer<CharSequence> { |
| /** The whitespace pattern. */ |
| private static final Pattern PATTERN = Pattern.compile("(\\w)+"); |
| |
| /** |
| * {@inheritDoc} |
| * |
| * @throws IllegalArgumentException if the input text is blank |
| */ |
| @Override |
| public CharSequence[] tokenize(final CharSequence text) { |
| Validate.isTrue(StringUtils.isNotBlank(text), "Invalid text"); |
| final Matcher matcher = PATTERN.matcher(text); |
| final List<String> tokens = new ArrayList<>(); |
| while (matcher.find()) { |
| tokens.add(matcher.group(0)); |
| } |
| return tokens.toArray(new String[0]); |
| } |
| |
| } |