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/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.common.lucene.search;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.index.Fields;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.similarities.ClassicSimilarity;
import org.apache.lucene.search.similarities.Similarity;
import org.apache.lucene.search.similarities.TFIDFSimilarity;
import org.apache.lucene.util.BytesRef;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.io.FastStringReader;
import java.io.IOException;
import java.io.Reader;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Objects;
import java.util.Set;
/**
*
*/
public class MoreLikeThisQuery extends Query {
public static final String DEFAULT_MINIMUM_SHOULD_MATCH = "30%";
private TFIDFSimilarity similarity;
private String[] likeText;
private Fields[] likeFields;
private String[] unlikeText;
private Fields[] unlikeFields;
private String[] moreLikeFields;
private Analyzer analyzer;
private String minimumShouldMatch = DEFAULT_MINIMUM_SHOULD_MATCH;
private int minTermFrequency = XMoreLikeThis.DEFAULT_MIN_TERM_FREQ;
private int maxQueryTerms = XMoreLikeThis.DEFAULT_MAX_QUERY_TERMS;
private Set stopWords = XMoreLikeThis.DEFAULT_STOP_WORDS;
private int minDocFreq = XMoreLikeThis.DEFAULT_MIN_DOC_FREQ;
private int maxDocFreq = XMoreLikeThis.DEFAULT_MAX_DOC_FREQ;
private int minWordLen = XMoreLikeThis.DEFAULT_MIN_WORD_LENGTH;
private int maxWordLen = XMoreLikeThis.DEFAULT_MAX_WORD_LENGTH;
private boolean boostTerms = XMoreLikeThis.DEFAULT_BOOST;
private float boostTermsFactor = 1;
public MoreLikeThisQuery() {
}
public MoreLikeThisQuery(String likeText, String[] moreLikeFields, Analyzer analyzer) {
this.likeText = new String[]{likeText};
this.moreLikeFields = moreLikeFields;
this.analyzer = analyzer;
}
@Override
public int hashCode() {
return Objects.hash(classHash(), boostTerms, boostTermsFactor, Arrays.hashCode(likeText),
maxDocFreq, maxQueryTerms, maxWordLen, minDocFreq, minTermFrequency, minWordLen,
Arrays.hashCode(moreLikeFields), minimumShouldMatch, stopWords);
}
@Override
public boolean equals(Object obj) {
if (sameClassAs(obj) == false) {
return false;
}
MoreLikeThisQuery other = (MoreLikeThisQuery) obj;
if (!analyzer.equals(other.analyzer))
return false;
if (boostTerms != other.boostTerms)
return false;
if (boostTermsFactor != other.boostTermsFactor)
return false;
if (!(Arrays.equals(likeText, other.likeText)))
return false;
if (maxDocFreq != other.maxDocFreq)
return false;
if (maxQueryTerms != other.maxQueryTerms)
return false;
if (maxWordLen != other.maxWordLen)
return false;
if (minDocFreq != other.minDocFreq)
return false;
if (minTermFrequency != other.minTermFrequency)
return false;
if (minWordLen != other.minWordLen)
return false;
if (!Arrays.equals(moreLikeFields, other.moreLikeFields))
return false;
if (!minimumShouldMatch.equals(other.minimumShouldMatch))
return false;
if (similarity == null) {
if (other.similarity != null)
return false;
} else if (!similarity.equals(other.similarity))
return false;
if (stopWords == null) {
if (other.stopWords != null)
return false;
} else if (!stopWords.equals(other.stopWords))
return false;
return true;
}
@Override
public Query rewrite(IndexReader reader) throws IOException {
Query rewritten = super.rewrite(reader);
if (rewritten != this) {
return rewritten;
}
XMoreLikeThis mlt = new XMoreLikeThis(reader, similarity == null ? new ClassicSimilarity() : 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);
if (this.unlikeText != null || this.unlikeFields != null) {
handleUnlike(mlt, this.unlikeText, this.unlikeFields);
}
return createQuery(mlt);
}
private Query createQuery(XMoreLikeThis mlt) throws IOException {
BooleanQuery.Builder bqBuilder = new BooleanQuery.Builder();
if (this.likeFields != null) {
Query mltQuery = mlt.like(this.likeFields);
mltQuery = Queries.applyMinimumShouldMatch((BooleanQuery) mltQuery, minimumShouldMatch);
bqBuilder.add(mltQuery, BooleanClause.Occur.SHOULD);
}
if (this.likeText != null) {
Reader[] readers = new Reader[likeText.length];
for (int i = 0; i < readers.length; i++) {
readers[i] = new FastStringReader(likeText[i]);
}
//LUCENE 4 UPGRADE this mapps the 3.6 behavior (only use the first field)
Query mltQuery = mlt.like(moreLikeFields[0], readers);
mltQuery = Queries.applyMinimumShouldMatch((BooleanQuery) mltQuery, minimumShouldMatch);
bqBuilder.add(mltQuery, BooleanClause.Occur.SHOULD);
}
return bqBuilder.build();
}
private void handleUnlike(XMoreLikeThis mlt, String[] unlikeText, Fields[] unlikeFields) throws IOException {
Set skipTerms = new HashSet<>();
// handle like text
if (unlikeText != null) {
for (String text : unlikeText) {
// only use the first field to be consistent
String fieldName = moreLikeFields[0];
try (TokenStream ts = analyzer.tokenStream(fieldName, text)) {
CharTermAttribute termAtt = ts.addAttribute(CharTermAttribute.class);
ts.reset();
while (ts.incrementToken()) {
skipTerms.add(new Term(fieldName, termAtt.toString()));
}
ts.end();
}
}
}
// handle like fields
if (unlikeFields != null) {
for (Fields fields : unlikeFields) {
for (String fieldName : fields) {
Terms terms = fields.terms(fieldName);
final TermsEnum termsEnum = terms.iterator();
BytesRef text;
while ((text = termsEnum.next()) != null) {
skipTerms.add(new Term(fieldName, text.utf8ToString()));
}
}
}
}
if (!skipTerms.isEmpty()) {
mlt.setSkipTerms(skipTerms);
}
}
@Override
public String toString(String field) {
return "like:" + Arrays.toString(likeText);
}
public String getLikeText() {
return (likeText == null ? null : likeText[0]);
}
public String[] getLikeTexts() {
return likeText;
}
public void setLikeText(String likeText) {
setLikeText(new String[]{likeText});
}
public void setLikeText(String... likeText) {
this.likeText = likeText;
}
public Fields[] getLikeFields() {
return likeFields;
}
public void setLikeText(Fields... likeFields) {
this.likeFields = likeFields;
}
public void setLikeText(List likeText) {
setLikeText(likeText.toArray(Strings.EMPTY_ARRAY));
}
public void setUnlikeText(Fields... unlikeFields) {
this.unlikeFields = unlikeFields;
}
public void setUnlikeText(String[] unlikeText) {
this.unlikeText = unlikeText;
}
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;
}
/**
* Number of terms that must match the generated query expressed in the
* common syntax for minimum should match.
*
* @see org.elasticsearch.common.lucene.search.Queries#calculateMinShouldMatch(int, String)
*/
public String getMinimumShouldMatch() {
return minimumShouldMatch;
}
/**
* Number of terms that must match the generated query expressed in the
* common syntax for minimum should match. Defaults to 30%.
*
* @see org.elasticsearch.common.lucene.search.Queries#calculateMinShouldMatch(int, String)
*/
public void setMinimumShouldMatch(String minimumShouldMatch) {
this.minimumShouldMatch = minimumShouldMatch;
}
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;
}
}