/*
* 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.index.query;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.MultiTermQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.WildcardQuery;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.common.ParsingException;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.lucene.BytesRefs;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.mapper.MappedFieldType;
import org.elasticsearch.index.query.support.QueryParsers;
import java.io.IOException;
import java.util.Objects;
/**
* Implements the wildcard search query. Supported wildcards are <tt>*</tt>, which
* matches any character sequence (including the empty one), and <tt>?</tt>,
* which matches any single character. Note this query can be slow, as it
* needs to iterate over many terms. In order to prevent extremely slow WildcardQueries,
* a Wildcard term should not start with one of the wildcards <tt>*</tt> or
* <tt>?</tt>.
*/
public class WildcardQueryBuilder extends AbstractQueryBuilder<WildcardQueryBuilder> implements MultiTermQueryBuilder {
public static final String NAME = "wildcard";
private static final ParseField WILDCARD_FIELD = new ParseField("wildcard");
private static final ParseField VALUE_FIELD = new ParseField("value");
private static final ParseField REWRITE_FIELD = new ParseField("rewrite");
private final String fieldName;
private final String value;
private String rewrite;
/**
* Implements the wildcard search query. Supported wildcards are <tt>*</tt>, which
* matches any character sequence (including the empty one), and <tt>?</tt>,
* which matches any single character. Note this query can be slow, as it
* needs to iterate over many terms. In order to prevent extremely slow WildcardQueries,
* a Wildcard term should not start with one of the wildcards <tt>*</tt> or
* <tt>?</tt>.
*
* @param fieldName The field name
* @param value The wildcard query string
*/
public WildcardQueryBuilder(String fieldName, String value) {
if (Strings.isEmpty(fieldName)) {
throw new IllegalArgumentException("field name is null or empty");
}
if (value == null) {
throw new IllegalArgumentException("value cannot be null");
}
this.fieldName = fieldName;
this.value = value;
}
/**
* Read from a stream.
*/
public WildcardQueryBuilder(StreamInput in) throws IOException {
super(in);
fieldName = in.readString();
value = in.readString();
rewrite = in.readOptionalString();
}
@Override
protected void doWriteTo(StreamOutput out) throws IOException {
out.writeString(fieldName);
out.writeString(value);
out.writeOptionalString(rewrite);
}
public String fieldName() {
return fieldName;
}
public String value() {
return value;
}
public WildcardQueryBuilder rewrite(String rewrite) {
this.rewrite = rewrite;
return this;
}
public String rewrite() {
return this.rewrite;
}
@Override
public String getWriteableName() {
return NAME;
}
@Override
protected void doXContent(XContentBuilder builder, Params params) throws IOException {
builder.startObject(NAME);
builder.startObject(fieldName);
builder.field(WILDCARD_FIELD.getPreferredName(), value);
if (rewrite != null) {
builder.field(REWRITE_FIELD.getPreferredName(), rewrite);
}
printBoostAndQueryName(builder);
builder.endObject();
builder.endObject();
}
public static WildcardQueryBuilder fromXContent(QueryParseContext parseContext) throws IOException {
XContentParser parser = parseContext.parser();
String fieldName = null;
String rewrite = null;
String value = null;
float boost = AbstractQueryBuilder.DEFAULT_BOOST;
String queryName = null;
String currentFieldName = null;
XContentParser.Token token;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else if (parseContext.isDeprecatedSetting(currentFieldName)) {
// skip
} else if (token == XContentParser.Token.START_OBJECT) {
throwParsingExceptionOnMultipleFields(NAME, parser.getTokenLocation(), fieldName, currentFieldName);
fieldName = currentFieldName;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else {
if (WILDCARD_FIELD.match(currentFieldName)) {
value = parser.text();
} else if (VALUE_FIELD.match(currentFieldName)) {
value = parser.text();
} else if (AbstractQueryBuilder.BOOST_FIELD.match(currentFieldName)) {
boost = parser.floatValue();
} else if (REWRITE_FIELD.match(currentFieldName)) {
rewrite = parser.textOrNull();
} else if (AbstractQueryBuilder.NAME_FIELD.match(currentFieldName)) {
queryName = parser.text();
} else {
throw new ParsingException(parser.getTokenLocation(),
"[wildcard] query does not support [" + currentFieldName + "]");
}
}
}
} else {
throwParsingExceptionOnMultipleFields(NAME, parser.getTokenLocation(), fieldName, parser.currentName());
fieldName = parser.currentName();
value = parser.text();
}
}
return new WildcardQueryBuilder(fieldName, value)
.rewrite(rewrite)
.boost(boost)
.queryName(queryName);
}
@Override
protected Query doToQuery(QueryShardContext context) throws IOException {
MappedFieldType fieldType = context.fieldMapper(fieldName);
Term term;
if (fieldType == null) {
term = new Term(fieldName, BytesRefs.toBytesRef(value));
} else {
Query termQuery = fieldType.termQuery(value, context);
term = MappedFieldType.extractTerm(termQuery);
}
WildcardQuery query = new WildcardQuery(term);
MultiTermQuery.RewriteMethod rewriteMethod = QueryParsers.parseRewriteMethod(rewrite, null);
QueryParsers.setRewriteMethod(query, rewriteMethod);
return query;
}
@Override
protected int doHashCode() {
return Objects.hash(fieldName, value, rewrite);
}
@Override
protected boolean doEquals(WildcardQueryBuilder other) {
return Objects.equals(fieldName, other.fieldName) &&
Objects.equals(value, other.value) &&
Objects.equals(rewrite, other.rewrite);
}
}