org.apache.lucene.analysis.miscellaneous.LimitTokenCountAnalyzer Maven / Gradle / Ivy
/*
* 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 org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.AnalyzerWrapper;
/**
* This Analyzer limits the number of tokens while indexing. It is
* a replacement for the maximum field length setting inside {@link org.apache.lucene.index.IndexWriter}.
* @see LimitTokenCountFilter
*
* @since 3.1
*/
public final class LimitTokenCountAnalyzer extends AnalyzerWrapper {
private final Analyzer delegate;
private final int maxTokenCount;
private final boolean consumeAllTokens;
/**
* Build an analyzer that limits the maximum number of tokens per field.
* This analyzer will not consume any tokens beyond the maxTokenCount limit
*
* @see #LimitTokenCountAnalyzer(Analyzer,int,boolean)
*/
public LimitTokenCountAnalyzer(Analyzer delegate, int maxTokenCount) {
this(delegate, maxTokenCount, false);
}
/**
* Build an analyzer that limits the maximum number of tokens per field.
* @param delegate the analyzer to wrap
* @param maxTokenCount max number of tokens to produce
* @param consumeAllTokens whether all tokens from the delegate should be consumed even if maxTokenCount is reached.
*/
public LimitTokenCountAnalyzer(Analyzer delegate, int maxTokenCount, boolean consumeAllTokens) {
super(delegate.getReuseStrategy());
this.delegate = delegate;
this.maxTokenCount = maxTokenCount;
this.consumeAllTokens = consumeAllTokens;
}
@Override
protected Analyzer getWrappedAnalyzer(String fieldName) {
return delegate;
}
@Override
protected TokenStreamComponents wrapComponents(String fieldName, TokenStreamComponents components) {
return new TokenStreamComponents(components.getSource(),
new LimitTokenCountFilter(components.getTokenStream(), maxTokenCount, consumeAllTokens));
}
@Override
public String toString() {
return "LimitTokenCountAnalyzer(" + delegate.toString() + ", maxTokenCount=" + maxTokenCount + ", consumeAllTokens=" + consumeAllTokens + ")";
}
}