org.elasticsearch.index.query.MoreLikeThisQueryBuilder 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
* "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.index.query;
import org.elasticsearch.ElasticsearchIllegalArgumentException;
import org.elasticsearch.common.xcontent.XContentBuilder;
import java.io.IOException;
/**
* A more like this query that finds documents that are "like" the provided {@link #likeText(String)}
* which is checked against the fields the query is constructed with.
*/
public class MoreLikeThisQueryBuilder extends BaseQueryBuilder implements BoostableQueryBuilder {
private final String[] fields;
private String likeText;
private float percentTermsToMatch = -1;
private int minTermFreq = -1;
private int maxQueryTerms = -1;
private String[] stopWords = null;
private int minDocFreq = -1;
private int maxDocFreq = -1;
private int minWordLength = -1;
private int maxWordLength = -1;
private float boostTerms = -1;
private float boost = -1;
private String analyzer;
private Boolean failOnUnsupportedField;
private String queryName;
/**
* Constructs a new more like this query which uses the "_all" field.
*/
public MoreLikeThisQueryBuilder() {
this.fields = null;
}
/**
* Sets the field names that will be used when generating the 'More Like This' query.
*
* @param fields the field names that will be used when generating the 'More Like This' query.
*/
public MoreLikeThisQueryBuilder(String... fields) {
this.fields = fields;
}
/**
* The text to use in order to find documents that are "like" this.
*/
public MoreLikeThisQueryBuilder likeText(String likeText) {
this.likeText = likeText;
return this;
}
/**
* The percentage of terms to match. Defaults to 0.3.
*/
public MoreLikeThisQueryBuilder percentTermsToMatch(float percentTermsToMatch) {
this.percentTermsToMatch = percentTermsToMatch;
return this;
}
/**
* The frequency below which terms will be ignored in the source doc. The default
* frequency is 2.
*/
public MoreLikeThisQueryBuilder minTermFreq(int minTermFreq) {
this.minTermFreq = minTermFreq;
return this;
}
/**
* Sets the maximum number of query terms that will be included in any generated query.
* Defaults to 25.
*/
public MoreLikeThisQueryBuilder maxQueryTerms(int maxQueryTerms) {
this.maxQueryTerms = maxQueryTerms;
return this;
}
/**
* Set the set of stopwords.
*
* Any word in this set is considered "uninteresting" and ignored. Even if your Analyzer allows stopwords, you
* might want to tell the MoreLikeThis code to ignore them, as for the purposes of document similarity it seems
* reasonable to assume that "a stop word is never interesting".
*/
public MoreLikeThisQueryBuilder stopWords(String... stopWords) {
this.stopWords = stopWords;
return this;
}
/**
* Sets the frequency at which words will be ignored which do not occur in at least this
* many docs. Defaults to 5.
*/
public MoreLikeThisQueryBuilder minDocFreq(int minDocFreq) {
this.minDocFreq = minDocFreq;
return this;
}
/**
* Set the maximum frequency in which words may still appear. Words that appear
* in more than this many docs will be ignored. Defaults to unbounded.
*/
public MoreLikeThisQueryBuilder maxDocFreq(int maxDocFreq) {
this.maxDocFreq = maxDocFreq;
return this;
}
/**
* Sets the minimum word length below which words will be ignored. Defaults
* to 0.
*/
public MoreLikeThisQueryBuilder minWordLength(int minWordLength) {
this.minWordLength = minWordLength;
return this;
}
/**
* Sets the maximum word length above which words will be ignored. Defaults to
* unbounded (0).
*/
public MoreLikeThisQueryBuilder maxWordLength(int maxWordLength) {
this.maxWordLength = maxWordLength;
return this;
}
/**
* Sets the boost factor to use when boosting terms. Defaults to 1.
*/
public MoreLikeThisQueryBuilder boostTerms(float boostTerms) {
this.boostTerms = boostTerms;
return this;
}
/**
* The analyzer that will be used to analyze the text. Defaults to the analyzer associated with the fied.
*/
public MoreLikeThisQueryBuilder analyzer(String analyzer) {
this.analyzer = analyzer;
return this;
}
public MoreLikeThisQueryBuilder boost(float boost) {
this.boost = boost;
return this;
}
/**
* Whether to fail or return no result when this query is run against a field which is not supported such as binary/numeric fields.
*/
public MoreLikeThisQueryBuilder failOnUnsupportedField(boolean fail) {
failOnUnsupportedField = fail;
return this;
}
/**
* Sets the query name for the filter that can be used when searching for matched_filters per hit.
*/
public MoreLikeThisQueryBuilder queryName(String queryName) {
this.queryName = queryName;
return this;
}
@Override
protected void doXContent(XContentBuilder builder, Params params) throws IOException {
builder.startObject(MoreLikeThisQueryParser.NAME);
if (fields != null) {
builder.startArray("fields");
for (String field : fields) {
builder.value(field);
}
builder.endArray();
}
if (likeText == null) {
throw new ElasticsearchIllegalArgumentException("moreLikeThis requires '"+
MoreLikeThisQueryParser.Fields.LIKE_TEXT.getPreferredName() +"' to be provided");
}
builder.field(MoreLikeThisQueryParser.Fields.LIKE_TEXT.getPreferredName(), likeText);
if (percentTermsToMatch != -1) {
builder.field(MoreLikeThisQueryParser.Fields.PERCENT_TERMS_TO_MATCH.getPreferredName(), percentTermsToMatch);
}
if (minTermFreq != -1) {
builder.field(MoreLikeThisQueryParser.Fields.MIN_TERM_FREQ.getPreferredName(), minTermFreq);
}
if (maxQueryTerms != -1) {
builder.field(MoreLikeThisQueryParser.Fields.MAX_QUERY_TERMS.getPreferredName(), maxQueryTerms);
}
if (stopWords != null && stopWords.length > 0) {
builder.startArray(MoreLikeThisQueryParser.Fields.STOP_WORDS.getPreferredName());
for (String stopWord : stopWords) {
builder.value(stopWord);
}
builder.endArray();
}
if (minDocFreq != -1) {
builder.field(MoreLikeThisQueryParser.Fields.MIN_DOC_FREQ.getPreferredName(), minDocFreq);
}
if (maxDocFreq != -1) {
builder.field(MoreLikeThisQueryParser.Fields.MAX_DOC_FREQ.getPreferredName(), maxDocFreq);
}
if (minWordLength != -1) {
builder.field(MoreLikeThisQueryParser.Fields.MIN_WORD_LENGTH.getPreferredName(), minWordLength);
}
if (maxWordLength != -1) {
builder.field(MoreLikeThisQueryParser.Fields.MAX_WORD_LENGTH.getPreferredName(), maxWordLength);
}
if (boostTerms != -1) {
builder.field(MoreLikeThisQueryParser.Fields.BOOST_TERMS.getPreferredName(), boostTerms);
}
if (boost != -1) {
builder.field("boost", boost);
}
if (analyzer != null) {
builder.field("analyzer", analyzer);
}
if (failOnUnsupportedField != null) {
builder.field(MoreLikeThisQueryParser.Fields.FAIL_ON_UNSUPPORTED_FIELD.getPreferredName(), failOnUnsupportedField);
}
if (queryName != null) {
builder.field("_name", queryName);
}
builder.endObject();
}
}