org.elasticsearch.index.query.MoreLikeThisQueryParser Maven / Gradle / Ivy
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* 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
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* specific language governing permissions and limitations
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package org.elasticsearch.index.query;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.queries.TermsFilter;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.ConstantScoreQuery;
import org.apache.lucene.search.Query;
import org.elasticsearch.ElasticsearchIllegalArgumentException;
import org.elasticsearch.action.get.MultiGetRequest;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.lucene.search.MoreLikeThisQuery;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.analysis.Analysis;
import org.elasticsearch.index.mapper.Uid;
import org.elasticsearch.index.mapper.internal.UidFieldMapper;
import org.elasticsearch.index.search.morelikethis.MoreLikeThisFetchService;
import java.io.IOException;
import java.util.*;
/**
*
*/
public class MoreLikeThisQueryParser implements QueryParser {
public static final String NAME = "mlt";
private MoreLikeThisFetchService fetchService = null;
public static class Fields {
public static final ParseField LIKE_TEXT = new ParseField("like_text");
public static final ParseField MIN_TERM_FREQ = new ParseField("min_term_freq");
public static final ParseField MAX_QUERY_TERMS = new ParseField("max_query_terms");
public static final ParseField MIN_WORD_LENGTH = new ParseField("min_word_length", "min_word_len");
public static final ParseField MAX_WORD_LENGTH = new ParseField("max_word_length", "max_word_len");
public static final ParseField MIN_DOC_FREQ = new ParseField("min_doc_freq");
public static final ParseField MAX_DOC_FREQ = new ParseField("max_doc_freq");
public static final ParseField BOOST_TERMS = new ParseField("boost_terms");
public static final ParseField PERCENT_TERMS_TO_MATCH = new ParseField("percent_terms_to_match");
public static final ParseField FAIL_ON_UNSUPPORTED_FIELD = new ParseField("fail_on_unsupported_field");
public static final ParseField STOP_WORDS = new ParseField("stop_words");
public static final ParseField DOCUMENT_IDS = new ParseField("ids");
public static final ParseField DOCUMENTS = new ParseField("docs");
public static final ParseField EXCLUDE = new ParseField("exclude");
}
public MoreLikeThisQueryParser() {
}
@Inject(optional = true)
public void setFetchService(@Nullable MoreLikeThisFetchService fetchService) {
this.fetchService = fetchService;
}
@Override
public String[] names() {
return new String[]{NAME, "more_like_this", "moreLikeThis"};
}
@Override
public Query parse(QueryParseContext parseContext) throws IOException, QueryParsingException {
XContentParser parser = parseContext.parser();
MoreLikeThisQuery mltQuery = new MoreLikeThisQuery();
mltQuery.setSimilarity(parseContext.searchSimilarity());
Analyzer analyzer = null;
List moreLikeFields = null;
boolean failOnUnsupportedField = true;
String queryName = null;
boolean exclude = true;
XContentParser.Token token;
String currentFieldName = null;
List items = new ArrayList();
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else if (token.isValue()) {
if (Fields.LIKE_TEXT.match(currentFieldName, parseContext.parseFlags())) {
mltQuery.setLikeText(parser.text());
} else if (Fields.MIN_TERM_FREQ.match(currentFieldName, parseContext.parseFlags())) {
mltQuery.setMinTermFrequency(parser.intValue());
} else if (Fields.MAX_QUERY_TERMS.match(currentFieldName, parseContext.parseFlags())) {
mltQuery.setMaxQueryTerms(parser.intValue());
} else if (Fields.MIN_DOC_FREQ.match(currentFieldName, parseContext.parseFlags())) {
mltQuery.setMinDocFreq(parser.intValue());
} else if (Fields.MAX_DOC_FREQ.match(currentFieldName, parseContext.parseFlags())) {
mltQuery.setMaxDocFreq(parser.intValue());
} else if (Fields.MIN_WORD_LENGTH.match(currentFieldName, parseContext.parseFlags())) {
mltQuery.setMinWordLen(parser.intValue());
} else if (Fields.MAX_WORD_LENGTH.match(currentFieldName, parseContext.parseFlags())) {
mltQuery.setMaxWordLen(parser.intValue());
} else if (Fields.BOOST_TERMS.match(currentFieldName, parseContext.parseFlags())) {
float boostFactor = parser.floatValue();
if (boostFactor != 0) {
mltQuery.setBoostTerms(true);
mltQuery.setBoostTermsFactor(boostFactor);
}
} else if (Fields.PERCENT_TERMS_TO_MATCH.match(currentFieldName, parseContext.parseFlags())) {
mltQuery.setPercentTermsToMatch(parser.floatValue());
} else if ("analyzer".equals(currentFieldName)) {
analyzer = parseContext.analysisService().analyzer(parser.text());
} else if ("boost".equals(currentFieldName)) {
mltQuery.setBoost(parser.floatValue());
} else if (Fields.FAIL_ON_UNSUPPORTED_FIELD.match(currentFieldName, parseContext.parseFlags())) {
failOnUnsupportedField = parser.booleanValue();
} else if ("_name".equals(currentFieldName)) {
queryName = parser.text();
} else if (Fields.EXCLUDE.match(currentFieldName, parseContext.parseFlags())) {
exclude = parser.booleanValue();
} else {
throw new QueryParsingException(parseContext.index(), "[mlt] query does not support [" + currentFieldName + "]");
}
} else if (token == XContentParser.Token.START_ARRAY) {
if (Fields.STOP_WORDS.match(currentFieldName, parseContext.parseFlags())) {
Set stopWords = Sets.newHashSet();
while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
stopWords.add(parser.text());
}
mltQuery.setStopWords(stopWords);
} else if ("fields".equals(currentFieldName)) {
moreLikeFields = Lists.newLinkedList();
while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
moreLikeFields.add(parseContext.indexName(parser.text()));
}
} else if (Fields.DOCUMENT_IDS.match(currentFieldName, parseContext.parseFlags())) {
MultiGetRequest.parseIds(parser, items);
} else if (Fields.DOCUMENTS.match(currentFieldName, parseContext.parseFlags())) {
MultiGetRequest.parseDocuments(parser, items);
} else {
throw new QueryParsingException(parseContext.index(), "[mlt] query does not support [" + currentFieldName + "]");
}
}
}
if ((mltQuery.getLikeText() == null && items.isEmpty()) || (mltQuery.getLikeText() != null && !items.isEmpty())) {
throw new QueryParsingException(parseContext.index(), "more_like_this requires either 'like_text' or 'ids/docs' to be specified");
}
if (analyzer == null) {
analyzer = parseContext.mapperService().searchAnalyzer();
}
mltQuery.setAnalyzer(analyzer);
if (moreLikeFields == null) {
moreLikeFields = Lists.newArrayList(parseContext.defaultField());
} else if (moreLikeFields.isEmpty()) {
throw new QueryParsingException(parseContext.index(), "more_like_this requires 'fields' to be non-empty");
}
removeUnsupportedFields(moreLikeFields, analyzer, failOnUnsupportedField);
if (moreLikeFields.isEmpty()) {
return null;
}
mltQuery.setMoreLikeFields(moreLikeFields.toArray(Strings.EMPTY_ARRAY));
if (queryName != null) {
parseContext.addNamedQuery(queryName, mltQuery);
}
if (!items.isEmpty()) {
// set default index, type and fields if not specified
for (MultiGetRequest.Item item : items) {
if (item.index() == null) {
item.index(parseContext.index().name());
}
if (item.type() == null) {
if (parseContext.queryTypes().size() > 1) {
throw new QueryParsingException(parseContext.index(),
"ambiguous type for item with id: " + item.id() + " and index: " + item.index());
} else {
item.type(parseContext.queryTypes().iterator().next());
}
}
if (item.fields() == null && item.fetchSourceContext() == null) {
item.fields(moreLikeFields.toArray(new String[moreLikeFields.size()]));
} else {
// TODO how about fields content fetched from _source?
removeUnsupportedFields(item, analyzer, failOnUnsupportedField);
}
}
// fetching the items with multi-get
List likeTexts = fetchService.fetch(items);
// right now we are just building a boolean query
BooleanQuery boolQuery = new BooleanQuery();
for (MoreLikeThisFetchService.LikeText likeText : likeTexts) {
addMoreLikeThis(boolQuery, mltQuery, likeText.field, likeText.text);
}
// exclude the items from the search
if (exclude) {
TermsFilter filter = new TermsFilter(UidFieldMapper.NAME, Uid.createUids(items));
ConstantScoreQuery query = new ConstantScoreQuery(filter);
boolQuery.add(query, BooleanClause.Occur.MUST_NOT);
}
return boolQuery;
}
return mltQuery;
}
private void addMoreLikeThis(BooleanQuery boolQuery, MoreLikeThisQuery mltQuery, String fieldName, String likeText) {
MoreLikeThisQuery mlt = new MoreLikeThisQuery();
mlt.setMoreLikeFields(new String[] {fieldName});
mlt.setLikeText(likeText);
mlt.setAnalyzer(mltQuery.getAnalyzer());
mlt.setPercentTermsToMatch(mltQuery.getPercentTermsToMatch());
mlt.setBoostTerms(mltQuery.isBoostTerms());
mlt.setBoostTermsFactor(mltQuery.getBoostTermsFactor());
mlt.setMinDocFreq(mltQuery.getMinDocFreq());
mlt.setMaxDocFreq(mltQuery.getMaxDocFreq());
mlt.setMinWordLen(mltQuery.getMinWordLen());
mlt.setMaxWordLen(mltQuery.getMaxWordLen());
mlt.setMinTermFrequency(mltQuery.getMinTermFrequency());
mlt.setMaxQueryTerms(mltQuery.getMaxQueryTerms());
mlt.setStopWords(mltQuery.getStopWords());
boolQuery.add(mlt, BooleanClause.Occur.SHOULD);
}
private List removeUnsupportedFields(List moreLikeFields, Analyzer analyzer, boolean failOnUnsupportedField) throws IOException {
for (Iterator it = moreLikeFields.iterator(); it.hasNext(); ) {
final String fieldName = it.next();
if (!Analysis.generatesCharacterTokenStream(analyzer, fieldName)) {
if (failOnUnsupportedField) {
throw new ElasticsearchIllegalArgumentException("more_like_this doesn't support binary/numeric fields: [" + fieldName + "]");
} else {
it.remove();
}
}
}
return moreLikeFields;
}
private void removeUnsupportedFields(MultiGetRequest.Item item, Analyzer analyzer, boolean failOnUnsupportedField) throws IOException {
item.fields((String[]) removeUnsupportedFields(Arrays.asList(item.fields()), analyzer, failOnUnsupportedField).toArray());
}
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