/*
* 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.lucene.analysis.miscellaneous;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.analysis.tokenattributes.KeywordAttribute;
/**
* Marks terms as keywords via the {@link KeywordAttribute}. Each token
* that matches the provided pattern is marked as a keyword by setting
* {@link KeywordAttribute#setKeyword(boolean)} to <code>true</code>.
*/
public final class PatternKeywordMarkerFilter extends KeywordMarkerFilter {
private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
private final Matcher matcher;
/**
* Create a new {@link PatternKeywordMarkerFilter}, that marks the current
* token as a keyword if the tokens term buffer matches the provided
* {@link Pattern} via the {@link KeywordAttribute}.
*
* @param in
* TokenStream to filter
* @param pattern
* the pattern to apply to the incoming term buffer
**/
public PatternKeywordMarkerFilter(TokenStream in, Pattern pattern) {
super(in);
this.matcher = pattern.matcher("");
}
@Override
protected boolean isKeyword() {
matcher.reset(termAtt);
return matcher.matches();
}
}