org.pageseeder.flint.lucene.query.PredicateSearchQuery Maven / Gradle / Ivy
/*
* Copyright 2015 Allette Systems (Australia)
* http://www.allette.com.au
*
* Licensed 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.pageseeder.flint.lucene.query;
import java.io.IOException;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.queryparser.classic.ParseException;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.SortField.Type;
import org.pageseeder.xmlwriter.XMLWriter;
/**
* A search query to submit a predicate directly to the index.
*
* This query uses the Lucene {@link QueryParser} to create a valid query instance from the
* supplied predicate.
*
* @author Christophe Lauret (Weborganic)
* @author Jean-Baptiste Reure (Weborganic)
*
* @version 2 August 2010
*/
public final class PredicateSearchQuery implements SearchQuery {
/**
* Bypasses all the other query parameters.
*/
private final String _predicate;
/**
* The analyser used in this query.
*/
private final Analyzer _analyser;
/**
* The sort order.
*/
private final Sort _sort;
/**
* The default field.
*/
private final String _defaultfield;
/**
* A flag to specify if wildcard ('*' or '?') is allowed as the first character of the predicate.
*/
private boolean _allowLeadingWildcard = false;
/**
* Creates new predicate search query.
*
* @param predicate The predicate for this query.
* @param sortField The field name to use to order the results.
*
* @throws IllegalArgumentException If the predicate is null.
*/
public PredicateSearchQuery(String predicate, String sortField) throws IllegalArgumentException {
this(predicate, sortField == null ? Sort.INDEXORDER : new Sort(new SortField(sortField, Type.STRING)));
}
/**
* Creates new predicate search query.
*
* @param predicate The predicate for this query.
* @param analyzer The analyzer to use for the query, should be the same as the one used to write the Index.
* @param sortField The field name to use to order the results.
*
* @throws IllegalArgumentException If the predicate is null.
*/
public PredicateSearchQuery(String predicate, Analyzer analyzer, String sortField) throws IllegalArgumentException {
this(predicate, analyzer, sortField == null ? Sort.INDEXORDER : new Sort(new SortField(sortField, Type.STRING)));
}
/**
* Creates new predicate search query.
*
* @param predicate The predicate for this query.
*
* @throws IllegalArgumentException If the predicate is null.
*/
public PredicateSearchQuery(String predicate) throws IllegalArgumentException {
this(predicate, Sort.INDEXORDER);
}
/**
* Creates new predicate search query.
*
* @param predicate The predicate for this query.
* @param analyzer The analyzer to use for the query, should be the same as the one used to write the Index.
*
* @throws IllegalArgumentException If the predicate is null.
*/
public PredicateSearchQuery(String predicate, Analyzer analyzer) throws IllegalArgumentException {
this(predicate, analyzer, Sort.INDEXORDER);
}
/**
* Creates new predicate search query.
*
* @param predicate The predicate for this query.
* @param sort The sort order for the results.
*
* @throws IllegalArgumentException If the predicate is null.
*/
public PredicateSearchQuery(String predicate, Sort sort) throws IllegalArgumentException {
this(predicate, new StandardAnalyzer(), sort);
}
/**
* Creates new predicate search query.
*
* @param predicate The predicate for this query.
* @param analyzer The analyzer to use for the query, should be the same as the one used to write the Index.
* @param sort The sort order for the results.
*
* @throws IllegalArgumentException If the predicate is null.
*/
public PredicateSearchQuery(String predicate, Analyzer analyzer, Sort sort) throws IllegalArgumentException {
this(predicate, analyzer, null, sort);
}
/**
* Creates new predicate search query.
*
* @param predicate The predicate for this query.
* @param analyzer The analyzer to use for the query, should be the same as the one used to write the Index.
* @param defaultfield The default field
* @param sort The sort order for the results.
*
* @throws IllegalArgumentException If the predicate is null.
*/
public PredicateSearchQuery(String predicate, Analyzer analyzer, String defaultfield, Sort sort) throws IllegalArgumentException {
if (predicate == null) throw new IllegalArgumentException("predicate is null");
this._predicate = predicate;
this._analyser = analyzer;
this._defaultfield = defaultfield;
this._sort = sort;
}
// getters and setters
// --------------------------------------------------------------------------------------------
/**
* Whether a wildcard ('*' or '?') is allowed as the first character of the predicate.
*
* @param allowWildCardStart true if wildcard should be allowed, false otherwise
*/
public void setAllowWildCardStart(boolean allowWildCardStart) {
this._allowLeadingWildcard = allowWildCardStart;
}
/**
* Returns the Lucene query instance corresponding to this object.
*
*
* This method uses a query parser to parse the predicate.
*
* @return The Lucene query instance or null if the predicate was null.
*/
@Override
public Query toQuery() {
if (this._predicate == null)
return null;
try {
QueryParser parser = new QueryParser(this._defaultfield, this._analyser);
parser.setAllowLeadingWildcard(this._allowLeadingWildcard);
return parser.parse(this._predicate);
} catch (ParseException ex) {
return null;
}
}
/**
* Returns true if the predicate has not been set.
*
* @return true if the predicate has not been set; false otherwise.
*/
@Override
public boolean isEmpty() {
return this._predicate == null;
}
/**
* Serialises the search query as XML.
*
*
{@code
*
* [predicate]
*
* }
*
* @param xml The XML writer.
*
* @throws IOException Should there be any I/O exception while writing the XML.
*/
@Override
public void toXML(XMLWriter xml) throws IOException {
xml.openElement("search-query", true);
xml.element("predicate", this._predicate);
xml.closeElement();
}
/**
* Returns the sort order.
*
* @return the sorting rules for the search results
*/
@Override
public Sort getSort() {
return this._sort;
}
@Override
public String toString() {
return this._predicate;
}
}