org.elasticsearch.common.lucene.search.MoreLikeThisQuery Maven / Gradle / Ivy
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*
* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing,
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package org.elasticsearch.common.lucene.search;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.queries.mlt.MoreLikeThis;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.similarities.DefaultSimilarity;
import org.apache.lucene.search.similarities.Similarity;
import org.apache.lucene.search.similarities.TFIDFSimilarity;
import org.elasticsearch.common.io.FastStringReader;
import java.io.IOException;
import java.util.Set;
/**
*
*/
public class MoreLikeThisQuery extends Query {
public static final float DEFAULT_PERCENT_TERMS_TO_MATCH = 0.3f;
private TFIDFSimilarity similarity;
private String likeText;
private String[] moreLikeFields;
private Analyzer analyzer;
private float percentTermsToMatch = DEFAULT_PERCENT_TERMS_TO_MATCH;
private int minTermFrequency = MoreLikeThis.DEFAULT_MIN_TERM_FREQ;
private int maxQueryTerms = MoreLikeThis.DEFAULT_MAX_QUERY_TERMS;
private Set stopWords = MoreLikeThis.DEFAULT_STOP_WORDS;
private int minDocFreq = MoreLikeThis.DEFAULT_MIN_DOC_FREQ;
private int maxDocFreq = MoreLikeThis.DEFAULT_MAX_DOC_FREQ;
private int minWordLen = MoreLikeThis.DEFAULT_MIN_WORD_LENGTH;
private int maxWordLen = MoreLikeThis.DEFAULT_MAX_WORD_LENGTH;
private boolean boostTerms = MoreLikeThis.DEFAULT_BOOST;
private float boostTermsFactor = 1;
public MoreLikeThisQuery() {
}
public MoreLikeThisQuery(String likeText, String[] moreLikeFields, Analyzer analyzer) {
this.likeText = likeText;
this.moreLikeFields = moreLikeFields;
this.analyzer = analyzer;
}
@Override
public Query rewrite(IndexReader reader) throws IOException {
MoreLikeThis mlt = new MoreLikeThis(reader, similarity == null ? new DefaultSimilarity() : similarity);
mlt.setFieldNames(moreLikeFields);
mlt.setAnalyzer(analyzer);
mlt.setMinTermFreq(minTermFrequency);
mlt.setMinDocFreq(minDocFreq);
mlt.setMaxDocFreq(maxDocFreq);
mlt.setMaxQueryTerms(maxQueryTerms);
mlt.setMinWordLen(minWordLen);
mlt.setMaxWordLen(maxWordLen);
mlt.setStopWords(stopWords);
mlt.setBoost(boostTerms);
mlt.setBoostFactor(boostTermsFactor);
//LUCENE 4 UPGRADE this mapps the 3.6 behavior (only use the first field)
BooleanQuery bq = (BooleanQuery) mlt.like(new FastStringReader(likeText), moreLikeFields[0]);
BooleanClause[] clauses = bq.getClauses();
bq.setMinimumNumberShouldMatch((int) (clauses.length * percentTermsToMatch));
bq.setBoost(getBoost());
return bq;
}
@Override
public String toString(String field) {
return "like:" + likeText;
}
public String getLikeText() {
return likeText;
}
public void setLikeText(String likeText) {
this.likeText = likeText;
}
public String[] getMoreLikeFields() {
return moreLikeFields;
}
public void setMoreLikeFields(String[] moreLikeFields) {
this.moreLikeFields = moreLikeFields;
}
public Similarity getSimilarity() {
return similarity;
}
public void setSimilarity(Similarity similarity) {
if (similarity == null || similarity instanceof TFIDFSimilarity) {
//LUCENE 4 UPGRADE we need TFIDF similarity here so I only set it if it is an instance of it
this.similarity = (TFIDFSimilarity) similarity;
}
}
public Analyzer getAnalyzer() {
return analyzer;
}
public void setAnalyzer(Analyzer analyzer) {
this.analyzer = analyzer;
}
public float getPercentTermsToMatch() {
return percentTermsToMatch;
}
public void setPercentTermsToMatch(float percentTermsToMatch) {
this.percentTermsToMatch = percentTermsToMatch;
}
public int getMinTermFrequency() {
return minTermFrequency;
}
public void setMinTermFrequency(int minTermFrequency) {
this.minTermFrequency = minTermFrequency;
}
public int getMaxQueryTerms() {
return maxQueryTerms;
}
public void setMaxQueryTerms(int maxQueryTerms) {
this.maxQueryTerms = maxQueryTerms;
}
public Set getStopWords() {
return stopWords;
}
public void setStopWords(Set stopWords) {
this.stopWords = stopWords;
}
public int getMinDocFreq() {
return minDocFreq;
}
public void setMinDocFreq(int minDocFreq) {
this.minDocFreq = minDocFreq;
}
public int getMaxDocFreq() {
return maxDocFreq;
}
public void setMaxDocFreq(int maxDocFreq) {
this.maxDocFreq = maxDocFreq;
}
public int getMinWordLen() {
return minWordLen;
}
public void setMinWordLen(int minWordLen) {
this.minWordLen = minWordLen;
}
public int getMaxWordLen() {
return maxWordLen;
}
public void setMaxWordLen(int maxWordLen) {
this.maxWordLen = maxWordLen;
}
public boolean isBoostTerms() {
return boostTerms;
}
public void setBoostTerms(boolean boostTerms) {
this.boostTerms = boostTerms;
}
public float getBoostTermsFactor() {
return boostTermsFactor;
}
public void setBoostTermsFactor(float boostTermsFactor) {
this.boostTermsFactor = boostTermsFactor;
}
}