org.apache.solr.analysis.KeepWordFilter Maven / Gradle / Ivy
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/**
* 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.solr.analysis;
import org.apache.lucene.analysis.TokenFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.Token;
import org.apache.lucene.analysis.CharArraySet;
import org.apache.lucene.analysis.tokenattributes.TermAttribute;
import org.tartarus.snowball.SnowballProgram;
import java.io.IOException;
import java.util.Set;
/**
* A TokenFilter that only keeps tokens with text contained in the
* required words. This filter behaves like the inverse of StopFilter.
*
* @version $Id: KeepWordFilter.java 804726 2009-08-16 17:28:58Z yonik $
* @since solr 1.3
*/
public final class KeepWordFilter extends TokenFilter {
private final CharArraySet words;
private final TermAttribute termAtt;
public KeepWordFilter(TokenStream in, Set words, boolean ignoreCase ) {
super(in);
this.words = new CharArraySet(words, ignoreCase);
this.termAtt = (TermAttribute)addAttribute(TermAttribute.class);
}
@Override
public boolean incrementToken() throws IOException {
while (input.incrementToken()) {
if (words.contains(termAtt.termBuffer(), 0, termAtt.termLength())) return true;
}
return false;
}
}