/**
* 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.shingle.ShingleFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.SolrException.ErrorCode;
import java.util.Map;
/**
* Factory for {@link ShingleFilter}.
* <pre class="prettyprint" >
* <fieldType name="text_shingle" class="solr.TextField" positionIncrementGap="100">
* <analyzer>
* <tokenizer class="solr.WhitespaceTokenizerFactory"/>
* <filter class="solr.ShingleFilterFactory" minShingleSize="2" maxShingleSize="2"
* outputUnigrams="true" outputUnigramsIfNoShingles="false" tokenSeparator=" "/>
* </analyzer>
* </fieldType></pre>
* @version $Id: ShingleFilterFactory.java 1074011 2011-02-24 01:49:49Z koji $
*/
public class ShingleFilterFactory extends BaseTokenFilterFactory {
private int minShingleSize;
private int maxShingleSize;
private boolean outputUnigrams;
private boolean outputUnigramsIfNoShingles;
private String tokenSeparator;
@Override
public void init(Map<String, String> args) {
super.init(args);
maxShingleSize = getInt("maxShingleSize",
ShingleFilter.DEFAULT_MAX_SHINGLE_SIZE);
if (maxShingleSize < 2) {
throw new SolrException(ErrorCode.SERVER_ERROR,
"Invalid maxShingleSize (" + maxShingleSize
+ ") - must be at least 2");
}
minShingleSize = getInt("minShingleSize",
ShingleFilter.DEFAULT_MIN_SHINGLE_SIZE);
if (minShingleSize < 2) {
throw new SolrException(ErrorCode.SERVER_ERROR,
"Invalid minShingleSize (" + minShingleSize
+ ") - must be at least 2");
}
if (minShingleSize > maxShingleSize) {
throw new SolrException(ErrorCode.SERVER_ERROR,
"Invalid minShingleSize (" + minShingleSize
+ ") - must be no greater than maxShingleSize ("
+ maxShingleSize + ")");
}
outputUnigrams = getBoolean("outputUnigrams", true);
outputUnigramsIfNoShingles = getBoolean("outputUnigramsIfNoShingles", false);
tokenSeparator = args.containsKey("tokenSeparator")
? args.get("tokenSeparator")
: ShingleFilter.TOKEN_SEPARATOR;
}
public ShingleFilter create(TokenStream input) {
ShingleFilter r = new ShingleFilter(input, minShingleSize, maxShingleSize);
r.setOutputUnigrams(outputUnigrams);
r.setOutputUnigramsIfNoShingles(outputUnigramsIfNoShingles);
r.setTokenSeparator(tokenSeparator);
return r;
}
}