Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF 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.apache.solr.search; import java.util.ArrayList; import javax.servlet.http.HttpServletRequest; import org.apache.lucene.document.Document; import org.apache.lucene.queryParser.ParseException; import org.apache.lucene.search.BooleanQuery; import org.apache.lucene.search.Query; import org.apache.lucene.search.Sort; import org.apache.lucene.search.SortField; import org.apache.lucene.search.BooleanClause.Occur; import org.apache.lucene.spatial.geometry.LatLng; import org.apache.solr.common.params.CommonParams; import org.apache.solr.common.params.ModifiableSolrParams; import org.apache.solr.common.params.SolrParams; import org.apache.solr.common.params.SpatialParams; import org.apache.solr.request.SolrQueryRequest; import org.apache.solr.schema.FieldType; import org.apache.solr.schema.SchemaField; import org.apache.solr.util.GeotargetAdapter; /** * This class parses and executes a spatial query */ public class SpatialQParser extends QParser { private static final String NAME_FIELD = "asciiname"; private static final String STATE_FIELD = "admin1code"; private static final String COUNTRY_FIELD = "countrycode"; private static final String LOCATION_FIELD = "location"; private static final String POPULATION_FIELD = "population"; public static final String SEARCH_RADIUS = "20"; public static final String CITY = "ct"; public static final String STATE = "s"; public static final String COUNTRY = "c"; public static final String DISTANCE = "d"; private GeotargetAdapter geoTargeter; /** * Constructor * * @param qstr * the query string * @param localParams * solr localParams * @param params * other params * @param req * the query request object * @param geoTargeter * the adapter to use to geotarget client ip if no location is * provided */ public SpatialQParser(String qstr, SolrParams localParams, SolrParams params, SolrQueryRequest req, GeotargetAdapter geoTargeter) { super(qstr, localParams, params, req); this.geoTargeter = geoTargeter; } @Override public Query parse() throws ParseException { // this will combine the results that are found for each // administrative level BooleanQuery allQuery = new BooleanQuery(); // attempt to create a query on city (low level administrative division) String city = localParams.get(CITY); if (city != null) { city = city.toLowerCase(); SchemaField nameField = req.getSchema().getField(NAME_FIELD); FieldType nameFieldType = nameField.getType(); Query cityQuery = nameFieldType.getFieldQuery(this, nameField, city); allQuery.add(cityQuery, Occur.MUST); } // attempt to create a query on state (mid level administrative division) String state = localParams.get(STATE); if (state != null) { state = state.toLowerCase(); SchemaField stateField = req.getSchema().getField(STATE_FIELD); FieldType stateFieldType = stateField.getType(); Query stateQuery = stateFieldType.getFieldQuery(this, stateField, state); allQuery.add(stateQuery, Occur.MUST); } // attempt to create a query on city (high level administrative division) String country = localParams.get(COUNTRY); if (country != null) { country = country.toLowerCase(); SchemaField countryField = req.getSchema().getField(COUNTRY_FIELD); FieldType countryFieldType = countryField.getType(); Query countryQuery = countryFieldType.getFieldQuery(this, countryField, country); allQuery.add(countryQuery, Occur.MUST); } String latitude = null; String longitude = null; // no location provided, computer user's location via reverse-ip lookup if (allQuery.getClauses().length == 0) { HttpServletRequest httpreq = req.getHttpServletRequest(); String ip = httpreq.getRemoteAddr(); LatLng currLoc = geoTargeter.getCurrentLocation(ip); if (currLoc != null) { latitude = Double.toString(currLoc.getLat()); longitude = Double.toString(currLoc.getLng()); } } else { SolrIndexSearcher searcher = req.getSearcher(); Document geocodeDoc = null; try { Sort s = new Sort(new SortField(POPULATION_FIELD, SortField.LONG, true)); DocList docs = searcher.getDocList(allQuery, new ArrayList<Query>(), s, 0, 1, 0); if (docs == null) return query; DocIterator iter = docs.iterator(); int geocodeDocId = iter.nextDoc(); geocodeDoc = searcher.doc(geocodeDocId); } catch (Exception e) { e.printStackTrace(); return query; } latitude = geocodeDoc.get("latitude"); longitude = geocodeDoc.get("longitude"); } // combine the spatial and free-text queries BooleanQuery finalQuery = new BooleanQuery(); // if no location is provided and user's location cannot be determined, // do not search location if (latitude != null && longitude != null) { String distance = localParams.get(DISTANCE); try { Double.parseDouble(distance); } catch (Exception e) { distance = SEARCH_RADIUS; } SpatialFilterQParserPlugin spatialFilter = new SpatialFilterQParserPlugin(); ModifiableSolrParams spatialParams = new ModifiableSolrParams(); spatialParams.add(SpatialParams.POINT, latitude + "," + longitude); spatialParams.add(SpatialParams.DISTANCE, distance); spatialParams.add(CommonParams.FL, LOCATION_FIELD); Query spatialQuery = spatialFilter.createParser(qstr, spatialParams, spatialParams, req).parse(); finalQuery.add(spatialQuery, Occur.MUST); } // get results from default LuceneQParser Query defQuery = new LuceneQParserPlugin().createParser(qstr, localParams, params, req).parse(); finalQuery.add(defQuery, Occur.MUST); return finalQuery; } }