package org.apache.lucene.analysis.miscellaneous;
/**
* 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.
*/
import java.io.IOException;
import java.util.Set;
import org.apache.lucene.analysis.TokenFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.KeywordAttribute;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.analysis.util.CharArraySet;
import org.apache.lucene.util.Version;
/**
* Marks terms as keywords via the {@link KeywordAttribute}. Each token
* contained in the provided is marked as a keyword by setting
* {@link KeywordAttribute#setKeyword(boolean)} to <code>true</code>.
*
* @see KeywordAttribute
*/
public final class KeywordMarkerFilter extends TokenFilter {
private final KeywordAttribute keywordAttr = addAttribute(KeywordAttribute.class);
private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
private final CharArraySet keywordSet;
/**
* Create a new KeywordMarkerFilter, that marks the current token as a
* keyword if the tokens term buffer is contained in the given set via the
* {@link KeywordAttribute}.
*
* @param in
* TokenStream to filter
* @param keywordSet
* the keywords set to lookup the current termbuffer
*/
public KeywordMarkerFilter(final TokenStream in,
final CharArraySet keywordSet) {
super(in);
this.keywordSet = keywordSet;
}
/**
* Create a new KeywordMarkerFilter, that marks the current token as a
* keyword if the tokens term buffer is contained in the given set via the
* {@link KeywordAttribute}.
*
* @param in
* TokenStream to filter
* @param keywordSet
* the keywords set to lookup the current termbuffer
*/
public KeywordMarkerFilter(final TokenStream in, final Set<?> keywordSet) {
this(in, keywordSet instanceof CharArraySet ? (CharArraySet) keywordSet
: CharArraySet.copy(Version.LUCENE_31, keywordSet));
}
@Override
public final boolean incrementToken() throws IOException {
if (input.incrementToken()) {
keywordAttr.setKeyword(keywordSet.contains(termAtt.buffer(), 0,
termAtt.length()));
return true;
} else
return false;
}
}